Light-emitting device

Abstract

To provide a liquid crystal display device and a light-emitting device that can be produced with a small number of masks and are highly reliable.SOLUTION: A light-emitting device includes: a gate electrode; a gate insulation film that is positioned on the gate electrode; a semiconductor film that is positioned on the game insulation film and overlaps with the gate electrode; an island-shaped first insulation film that is positioned on the semiconductor film and overlaps with the gate electrode; a first conductive film that is positioned on the semiconductor film; a pair of second conductive films that sandwich the first insulation film therebetween and are positioned on the semiconductor film; a second insulation film that is positioned on the first insulation film, the first conductive film, and the pair of second conductive films; and a pixel electrode that is positioned on the second insulation film, and is connected to one of the pair of second conductive films via a first opening provided in the second insulation film. A second opening positioned between the first conductive film and one or the other of the pair of second conductive films is provided in the second insulation film and the semiconductor film.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a liquid crystal display device having a transistor in each pixel, and a method for manufacturing the same. The present invention relates to a light-emitting device having a transistor in each pixel, and a method for manufacturing the same. [Background technology]

[0002] High mobility obtained from crystalline silicon and obtained from amorphous silicon As a new semiconductor material that combines uniform device characteristics, a semiconductor called an oxide semiconductor is being developed. Metal oxides exhibiting conductive properties are attracting attention. Metal oxides are used in a variety of applications. For example, indium oxide, a well-known metal oxide, is used in liquid crystal displays and other applications. It is used in photosensitive pixel electrodes. Examples of metal oxides that exhibit semiconductor properties include, for example, Examples of semiconductors include tungsten oxide, tin oxide, indium oxide, and zinc oxide. Transistors that use metal oxides exhibiting specific properties in the channel formation region are already known. Patent Documents 1 and 2). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2007-123861 [Patent Document 2] Japanese Patent Publication No. 2007-96055 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] By the way, the transistors used in liquid crystal display devices have electrical characteristics (threshold) that deteriorate over time. Small changes in voltage, mobility, S value, etc., and electrical characteristics that arise due to deterioration over time. It is desirable that the variation is small. Transistors with small changes in electrical characteristics due to deterioration over time are desirable. Furthermore, transistors with small variations in electrical characteristics due to degradation over time are used. This can improve the reliability of liquid crystal display devices and enhance the quality of the displayed images. can.

[0005] Furthermore, the exposure masks used in photolithography are generally expensive, and In photolithography, for each mask, the process involves film deposition of photoresist, exposure, and current A series of processes such as imaging, etching, and stripping are required. Therefore, it is necessary for the manufacture of liquid crystal display devices. As the number of masks required increases, the number of manufacturing steps also increases, and the time spent on manufacturing also increases. Costs tend to be high.

[0006] Against the technical background described above, the present invention aims to provide a highly reliable liquid crystal display device. This invention is one such invention. Furthermore, the present invention can be manufactured with a small number of masks and is highly reliable. One of the challenges is to provide liquid crystal display devices.

[0007] Alternatively, the present invention can provide a highly reliable liquid crystal display device using a small number of masks. One of the objectives is to provide a method for manufacturing liquid crystal display devices.

[0008] Also, OLED (Organic Light Emitting Diode) In an active-matrix light-emitting device using light-emitting elements, a trace is provided at each pixel. The inverter exhibits minimal changes in electrical characteristics due to aging, and also generates... It is desirable that there be little variation in electrical characteristics. By using a transistor with small variations in electrical characteristics caused by deterioration over time, the reliability of the light-emitting device can be improved, and the quality of the displayed image can be enhanced.

[0009] In addition, the exposure mask used in the photolithography method is generally expensive, and moreover, in the photolithography method, a series of processes such as film formation of photoresist, exposure, imaging, etching, and peeling are required for each mask. Therefore, when the number of masks required for manufacturing the light-emitting device increases, the number of manufacturing processes increases accordingly, and the cost spent on manufacturing tends to be high.

[0010] Under the technical background as described above, an object of the present invention is to provide a highly reliable light-emitting device. Another object of the present invention is to provide a light-emitting device that can be manufactured with a small number of masks and has high reliability.

[0011] Alternatively, an object of the present invention is to provide a method for manufacturing a light-emitting device that can obtain a highly reliable light-emitting device using a small number of masks.

Means for Solving the Problems

[0012] In one aspect of the present invention, in the step of forming an opening portion for connecting a pixel electrode to a source electrode or a drain electrode in an insulating film on the source electrode and the drain electrode, not only the shape of the insulating film but also the shape of the semiconductor film is processed. Specifically, in the method for manufacturing a liquid crystal display device according to one aspect of the present invention, a step of forming a gate electrode, a step of forming an insulating film (hereinafter also referred to as a channel protection film) having a function of protecting a channel formation region of a semiconductor film, and a step of forming a source electrode and a drain electrode are included. ​ A step of forming a source electrode or drain electrode, and an insulating film on the source electrode and drain electrode. A process of forming an opening and processing the shape of the semiconductor film, and a process of forming a pixel electrode. In this process, a photolithography method using a mask is employed. Therefore, the shape of the semiconductor film is determined. In one aspect of the present invention, a process using photolithography solely for the purpose of processing is described below. This can be omitted.

[0013] Furthermore, specifically, in a method for manufacturing a light-emitting device according to one aspect of the present invention, the gate electrode is formed The process involves forming an insulating film that has the function of protecting the channel formation region of the semiconductor film. The process involves forming a source electrode or a drain electrode, and the source electrode and drain electrode The process involves forming an opening in the insulating film and processing the shape of the semiconductor film, and forming a pixel electrode. The process involves the steps of: creating an opening in the insulating film on the pixel electrode to form a partition wall, and odor Therefore, a photolithography method using a mask is employed. Thus, the shape of the semiconductor film can be determined independently. In one aspect of the present invention, a process using photolithography solely for processing purposes is omitted. It is possible.

[0014] Furthermore, the source electrode and drain electrode are formed in the same layer as the source electrode and drain electrode. The conductive film exists between the insulating film on the source and drain electrodes and the semiconductor film. Therefore, the shape of the insulating film on the source electrode and drain electrode and the shape of the semiconductor film, as described above, When using a manufacturing method that processes the shape with the same mask, the lower part of the semiconductor film is The area in question is difficult to process in terms of its shape. Furthermore, multiple conductive films interact with the semiconductor film. When they overlap, the electric field applied from the pixel electrode to the semiconductor film causes a semiconductor between the conductive films. Channels (hereinafter referred to as parasitic channels) may form in the body membrane. Once formed, conductive films that should be electrically separated are electrically connected via a semiconductor film. This can lead to a decrease in the displayed image quality.

[0015] Therefore, in a liquid crystal display device or light-emitting device according to one aspect of the present invention, between a plurality of conductive films Multiple insulating films on the conductive film have openings, and the semiconductor film in the region overlapping with the openings The configuration is removed. Therefore, the semiconductor film is provided at a position that overlaps with each of the multiple conductive films. The elements are separated at the opening. With the above configuration, the parasitic channels This suppresses the formation of conductive films and prevents them from being electrically connected to each other.

[0016] Furthermore, the process involves forming a channel protective film, or forming a source electrode or drain electrode. In the etching process, impurities are found on the surface of the semiconductor film or channel protection film exposed by etching. When material adheres to the transistor, it can increase the transistor's off-current or degrade its electrical characteristics. This easily leads to the formation of parasitic channels in the semiconductor film, which can lead to electrical isolation. Conductive films that should be connected to each other become more easily electrically connected via the semiconductor film. Specifically, The impurities mentioned include elements constituting the source or drain electrode, and the etching process. Elements present in the room, or the etching gas and etching solution used for etching, constitute the components. It contains elements such as [this element]. Therefore, a liquid crystal display device or light-emitting device according to one aspect of the present invention In the fabrication method, after etching to form the channel protective film is completed, or, After etching for forming the drain electrode or drain electrode is completed, the semiconductor film or The process also includes a step to remove any impurities that may have adhered to the surface of the channel protective film.

[0017] Specifically, a liquid crystal display device according to one aspect of the present invention includes a gate electrode and a component located on the gate electrode. A gate insulating film, a semiconductor film located on the gate insulating film and overlapping the gate electrode, and a semiconductor film An island-shaped first insulating film located above and overlapping the gate electrode, and a first conductive film located on the semiconductor film. And, sandwiching between the island-shaped first insulating film, a pair of second conductive films located on the semiconductor film, A semiconductor film, an island-shaped first insulating film, a first conductive film, and a second insulating film located on a pair of second conductive films. A film and a pair of second films located on the second insulating film, with a first opening provided in the second insulating film. The second insulating film and the semiconductor film have a pixel electrode connected to either one of the conductive films, A second opening located between the first conductive film and either one or the other of the pair of second conductive films It is provided.

[0018] Specifically, a method for manufacturing a liquid crystal display device according to one aspect of the present invention involves a gate insulating film on the gate A process of forming a semiconductor film so as to overlap the gate electrode, and on the semiconductor film, overlapping the gate electrode The process involves forming an island-shaped first insulating film by photolithography, and the first conductive The film and a pair of second conductive films sandwiching an island-shaped first insulating film are separated by photolithography. The process involves forming a semiconductor film and a second insulating film on a semiconductor film, an island-shaped first insulating film, and a first conductive film. , and the steps of forming on a pair of second conductive films, and partially exposing one of the pair of second conductive films The first opening, the second insulating film and the semiconductor film, and the first conductive film and the pair of second conductive films A second opening located between one or the other is formed by photolithography. The process involves a pixel on the second insulating film that is connected to one of a pair of second conductive films via a first aperture. The process includes a step of forming electrodes by photolithography.

[0019] Specifically, a light-emitting device according to one aspect of the present invention includes a gate electrode and a gate located on the gate electrode. A gate insulating film, a semiconductor film located on the gate insulating film and overlapping the gate electrode, and on the semiconductor film A first insulating film in the shape of an island, located and overlapping with the gate electrode, and a first conductive film located on the semiconductor film, A pair of second conductive films are located on a semiconductor film, with an island-shaped first insulating film sandwiched in between, and a semiconductor A body film, an island-shaped first insulating film, a first conductive film, and a second insulating film located on a pair of second conductive films. , located on the second insulating film, and through the first opening provided in the second insulating film, a pair of second conductive It has a pixel electrode connected to either side of the film, and a third insulating film on the pixel electrode, and a second insulating film The edge film and semiconductor film have a first conductive film and a gap between either one or the other of the pair of second conductive films. A second aperture is provided located at the third insulating film, and the pixel electrode is partially exposed. A third opening is provided.

[0020] Specifically, a method for manufacturing a light-emitting device according to one aspect of the present invention involves a gate insulating film on a gate A process of forming a semiconductor film so as to overlap with the electrode, and on the semiconductor film, overlapping with the gate electrode The process involves forming an island-shaped first insulating film by photolithography, and the first conductive film and A pair of second conductive films, with an island-shaped first insulating film sandwiched in between, are separated by photolithography. The process of forming on a body film, and the second insulating film, a semiconductor film, an island-shaped first insulating film, a first conductive film, and The process involves forming a pair of second conductive films on a surface, and partially exposing one of the pair of second conductive films. The first opening and the second insulating film and semiconductor film, one of the first conductive film and the pair of second conductive films A process of forming a second opening located between one or the other by photolithography. And, on the second insulating film, a pixel electrode connected to one of the pair of second conductive films via the first aperture. The process involves forming the pixel electrode using photolithography, and placing the pixel electrode at a position that overlaps with the pixel electrode. The process includes a step of forming a third insulating film having an opening by photolithography. . [Effects of the Invention]

[0021] In one aspect of the present invention, a highly reliable liquid crystal display device can be provided. In one embodiment, a highly reliable liquid crystal display device can be provided with a small number of masks. ru.

[0022] Furthermore, in the method for manufacturing a liquid crystal display device according to one aspect of the present invention, a small number of masks are used, and reliable High-performance liquid crystal display devices can be manufactured.

[0023] In one aspect of the present invention, a highly reliable light-emitting device can be provided. In this embodiment, a highly reliable light-emitting device can be provided with a small number of masks.

[0024] Furthermore, in a method for manufacturing a light-emitting device according to one aspect of the present invention, a reliable method can be achieved with a small number of masks. High-performance light-emitting devices can be manufactured. [Brief explanation of the drawing]

[0025] [Figure 1] A diagram showing the structure of a liquid crystal display device. [Figure 2] A diagram showing the structure of a liquid crystal display device. [Figure 3] A diagram showing the structure of a liquid crystal display device. [Figure 4] A diagram showing the structure of a liquid crystal display device. [Figure 5] Top view of the pixels of a liquid crystal display device. [Figure 6] Cross-sectional view of a pixel in a liquid crystal display device. [Figure 7] A diagram showing the structure of a liquid crystal display device. [Figure 8] Structure of the pixel section of a liquid crystal display device and a circuit diagram of the pixel. [Figure 9] A diagram illustrating the method for manufacturing a liquid crystal display device. [Figure 10] A diagram illustrating the method for manufacturing a liquid crystal display device. [Figure 11] A diagram illustrating the method for manufacturing a liquid crystal display device. [Figure 12] A diagram illustrating the method for manufacturing a liquid crystal display device. [Figure 13] A diagram illustrating the method for manufacturing a liquid crystal display device. [Figure 14] A diagram showing the structure of the panel. [Figure 15] Perspective view of a liquid crystal display device. [Figure 16] A diagram of an electronic device. [Figure 17] A diagram showing the structure of a light-emitting device. [Figure 18] A diagram showing the structure of a light-emitting device. [Figure 19] A diagram showing the structure of a light-emitting device. [Figure 20] A diagram showing the structure of a light-emitting device. [Figure 21] Top view of the pixels of the light-emitting device. [Figure 22] Cross-sectional view of a pixel in a light-emitting device. [Figure 23] Cross-sectional view of a pixel in a light-emitting device. [Figure 24] Structure of the pixel section of the light-emitting device and a circuit diagram of the pixel. [Figure 25] A diagram showing the structure of a light-emitting device. [Figure 26] A diagram showing the method for manufacturing a light-emitting device. [Figure 27] A diagram showing the method for manufacturing a light-emitting device. [Figure 28] A diagram showing the method for manufacturing a light-emitting device. [Figure 29] A diagram showing the method for manufacturing a light-emitting device. [Figure 30] A diagram showing the method for manufacturing a light-emitting device. [Figure 31] Cross-sectional view of a pixel. [Figure 32] A diagram showing the structure of the panel. [Figure 33] Perspective view of the light-emitting device. [Modes for carrying out the invention]

[0026] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is... Not limited to the following description, the present invention may have forms and characteristics that do not depart from the spirit and scope of the invention. Those skilled in the art will readily understand that the details can be modified in various ways. Therefore, the present invention This shall not be interpreted as being limited to the contents of the embodiments described below.

[0027] In this specification, a liquid crystal display device is defined as a panel in which liquid crystal elements are formed in each pixel, and A module in which an IC or other component including a dynamic circuit or controller is mounted on the panel. This includes the above. Furthermore, a liquid crystal display device according to one aspect of the present invention is said liquid crystal display device In the process of manufacturing liquid crystal elements, the element substrate, which is a form of the element before the liquid crystal element is completed, falls under that category. The element substrate includes a transistor and a pixel to which voltage is supplied via the transistor. Each of the multiple pixels is equipped with an electrode.

[0028] Furthermore, in this specification, a light-emitting device is defined as a panel in which light-emitting elements are formed on each pixel, and a drive circuit A module in which an IC including a circuit or controller is mounted on the panel, It is included in that category. Furthermore, a light-emitting device according to one aspect of the present invention is a process for manufacturing the light-emitting device. This category includes a device substrate that corresponds to one form of the light-emitting element before it is completed, and The element substrate consists of a transistor and a pixel electrode to which voltage is supplied via the transistor, Each pixel of the number is equipped with it.

[0029] (Embodiment 1) Figure 1 illustrates the structure of a liquid crystal display device according to one aspect of the present invention. Figure 1(A) shows a structure with pixels This is an example of a cross-sectional view of transistor 100 in the channel length direction.

[0030] Figure 1(A) shows the gate electrode 101 on the insulating surface and the gate electrode located on the gate electrode 101. A gate insulating film 102 and a semiconductor film located on the gate insulating film 102 and overlapping the gate electrode 101 103 and an island-shaped insulating film 104 located on the semiconductor film 103 and overlapping with the gate electrode 101 A conductive film 105 located on the semiconductor film 103 and an insulating film 104 are sandwiched in between, and the semiconductor Conductive films 106a and 106b located on the body film 103, semiconductor film 103, insulating film 104, conductive film 105, conductive film 106a and conductive film 106b, insulating film 107 located on the conductive film 106b , located on the insulating film 107, and through the opening 108 provided in the insulating film 107, the conductive film 10 Pixel electrode 109 connected to 6b, and aperture provided in insulating film 107 and semiconductor film 103 Part 110 is shown in the diagram.

[0031] Then, in Figure 1(A), the gate electrode 101, gate insulating film 102, semiconductor film 103, and The insulating film 104, conductive film 106a, and conductive film 106b function as channel protective films. It constitutes ZISTA 100. And conductive film 106a and conductive film 106b are either One side functions as the source electrode, and the other as the drain electrode.

[0032] A method for manufacturing a liquid crystal display device according to one aspect of the present invention includes the step of forming a gate electrode 101 and , a step of forming an insulating film 104, conductive film 105, conductive film 106a, and conductive film 106b The process involves forming an opening 108 in the insulating film 107, and also forming an opening 108 in the insulating film 107 and the semi-insulating film 107 and The process involves forming an opening 110 in the conductive film 103, forming a pixel electrode 109, and odor Therefore, a photolithography method using a mask is employed. That is, in one aspect of the present invention, In the process of forming an opening 110 in the edge film 107, the shape of the semiconductor film 103 is processed. Therefore, a photolithography method is used solely for the purpose of processing the shape of the semiconductor film 103. The process described above can be omitted. Therefore, in a liquid crystal display device according to one aspect of the present invention, Photolithography involves the deposition, exposure, development, etching, and stripping of photoresists. Some steps in the process, such as separation, can be omitted. Furthermore, the number of expensive exposure masks can be reduced. This can reduce the cost of manufacturing liquid crystal displays. ru.

[0033] Furthermore, conductive films 105, 106a, and 106b are made of insulating film 107 and semiconductor It exists between the films 103. Therefore, in the process of forming the opening 108 in the insulating film 107 When a manufacturing method is used that also processes the shape of the semiconductor film 103, the conductive film 105, conductive film 10 It is difficult to process the shape of the semiconductor film 103 located beneath 6a and the conductive film 106b. And, conductive film 105, conductive film 106a, and conductive film 106b overlap with semiconductor film 103. When this is the case, the electric field applied from the pixel electrode 109 to the semiconductor film 103 causes the semiconductor film 10 Parasitic channels may form in 3. When parasitic channels are formed, they are electrically separated. The conductive film 105 to be treated and the conductive film 106a or conductive film 106b are connected to the semiconductor film 103 Because it is electrically connected via this, it causes a decrease in the displayed image quality.

[0034] Therefore, in a liquid crystal display device according to one aspect of the present invention, the position of the opening 110 is set to the conductive film 105 This is set between the conductive film 106a or the conductive film 106b, thereby dividing the semiconductor film 103. The configuration is designed to remove the material in stages. Note that in Figure 1(A), the semiconductor film 10 at the opening 110 As an example, let's consider the case where not only 3 and the insulating film 107, but also the gate insulating film 102 has been removed. In one aspect of the present invention, the gate insulating film 102 is not necessarily removed at the opening 110. It is not necessary, and the gate insulating film 102 may remain in the opening 110.

[0035] Figure 1(B) shows an example of a top view of a liquid crystal display device having the cross-sectional structure shown in Figure 1(A). However, in Figure 1(B), in order to clarify the layout of the liquid crystal display device, gate isolation is used. The top view is shown with the edge film 102 and insulating film 107 omitted. Also, the dashed line A1 in Figure 1(B) -The cross-sectional view in A2 corresponds to Figure 1(A).

[0036] As shown in Figures 1(A) and 1(B), in one aspect of the present invention, the semiconductor film 103 and the insulating film are used. Film 107 has an open film located between the conductive film 105 and the conductive film 106a or the conductive film 106b. An opening 110 is provided.

[0037] In one aspect of the present invention, the opening 110 allows for the guidance of the guide, as shown in Figures 1(A) and 1(B). The semiconductor film 103 located beneath the electrical film 106a or the conductive film 106b, and beneath the conductive film 105 The semiconductor film 103 located at the right is in a separated state. Therefore, in one aspect of the present invention, Even when an electric field is applied to the semiconductor film 103 from the elementary electrode 109, the opening 110 remains connected to the conductive film 10 5 is present between conductive film 106a or conductive film 106b, thereby contributing to the semiconductor film 103. The formation of live channels can be suppressed. And the formation of parasitic channels is suppressed. As a result, the conductive film 105 and the conductive film 106a or conductive film 106b unintentionally become electrically charged This prevents unwanted connections and prevents a decrease in image quality displayed on the LCD screen.

[0038] Note that in Figure 1(B), semiconductor film 1 is located beneath conductive film 106a or conductive film 106b. This example illustrates a case where 03 and the semiconductor film 103 located beneath the conductive film 105 are completely separated. However, in one aspect of the present invention, the semiconductor film 103 is not necessarily completely separated. It is not necessary, and between the conductive film 105 and the conductive film 106a or conductive film 106b, The body membrane 103 may be partially separated.

[0039] Figure 2 shows an example of a top view of a liquid crystal display device having the cross-sectional structure shown in Figure 1(A). Furthermore, in Figure 2, in order to clarify the layout of the liquid crystal display device, the gate insulating film 102 and A top view is shown with the insulating film 107 omitted.

[0040] In the liquid crystal display device shown in Figure 2, the shape of the aperture 110 is different from that in Figure 1(B). The opening 110 is, as in the case of Figure 1(B), a conductive film 105 and a conductive film 106a or It is located between the conductive films 106b, but is located beneath the conductive films 106a or 106b. The semiconductor film 103 and the semiconductor film 103 located beneath the conductive film 105 are separated by an opening 110. They are connected in the outer region. That is, in Figure 2, conductive film 105 and conductive film 106a or The semiconductor film 103 is partially separated from the conductive film 106b. Even when 103 is partially separated, the generation of parasitic channels is suppressed. You can obtain this.

[0041] Furthermore, a portion of the region where the opening 110 is formed is a conductive film 106a or conductive film 106b They may overlap. Alternatively, the conductive film 105 may be located in part of the region where the opening 110 is formed. It is acceptable for the formed area to overlap with the area being formed.

[0042] Figure 3(A) shows a cross-sectional view of a transistor 100 in the channel length direction of a pixel. An example is shown. Also, Figure 3(B) shows a liquid crystal display device having the cross-sectional structure shown in Figure 3(A). An example of a top view is shown. However, Figure 3(B) clarifies the layout of the liquid crystal display device. Therefore, a top view is shown in which the gate insulating film 102 and insulating film 107 are omitted. Also, Figure 3(B The cross-sectional view along the dashed line B1-B2 corresponds to Figure 3(A).

[0043] In the liquid crystal display device shown in Figures 3(A) and 3(B), the region where the aperture 110 is formed is shown in Figure This differs from the cases shown in Figures 1(A) and 1(B). In Figures 3(A) and 3(B), the opening 110 A portion of the region where the conductive film 106b is formed overlaps with the region where the conductive film 106b is formed. The semiconductor film 103 located beneath 06b is not removed during the formation of the opening 110. Therefore, within the region where the opening 110 is formed, the semiconductor film 103 remains partially intact. In this state, the edge of the semiconductor film 103 and the edge of the insulating film 107 at the opening 110 This does not match.

[0044] In one aspect of the present invention, as shown in Figures 3(A) and 3(B), an opening 110 is formed Even if a portion of the region overlaps with the region where the conductive film 106b is formed, the conductive film 106b The semiconductor film 103 located below and the semiconductor film 103 located below the conductive film 105 are separated. This can be achieved by suppressing the production of parasitic channels. It is possible.

[0045] Furthermore, a portion of the region where the opening 110 is formed overlaps with the region where the conductive film 106a is formed. Even in such cases, the effect of suppressing the generation of parasitic channels can be obtained. Alternatively, a portion of the region where the opening 110 is formed may overlap with the region where the conductive film 105 is formed. Even in such cases, the effect of suppressing the generation of parasitic channels can be obtained.

[0046] Furthermore, the region where the opening 110 is formed is partially separated from the region where the conductive film 106b is formed. If they overlap, an opening 108 is provided to connect the conductive film 106b and the pixel electrode 109. There is no need to do so. Therefore, there is no need to secure an area for forming the opening 108. This enables high resolution of the pixel area.

[0047] Furthermore, Figure 4(A) shows a cross-section of the transistor 100 of the pixel in the channel length direction. An example of the figure is shown. Also, Figure 4(B) shows a liquid crystal display device having the cross-sectional structure shown in Figure 4(A). An example of a top view of the installation is shown. However, in Figure 4(B), the layout of the liquid crystal display device is clearly shown. To achieve this, a top view is shown with the gate insulating film 102 and insulating film 107 omitted. The cross-sectional view along the dashed line C1-C2 in 4(B) corresponds to Figure 4(A).

[0048] The liquid crystal display device shown in Figures 4(A) and 4(B) has a conductive film 1 in the same layer as the gate electrode 101. In terms of the presence of 11, the structure differs from that of the liquid crystal display device shown in Figures 1(A) and 1(B). However, they are different. Specifically, in Figures 4(A) and 4(B), the conductive film 111 is located on the insulating surface. The gate insulating film 102 and the semiconductor film 103 are stacked sequentially on the conductive film 111. A conductive film 105 is provided on the semiconductor film 103 at a position overlapping with the conductive film 111. It's being kicked.

[0049] In Figures 4(A) and 4(B), the region where the opening 110 is formed and the conductive film 11 The region where 1 is formed partially overlaps, and at the opening 110, one of the conductive films 111 The part is exposed. And, since the conductive film 111 is located beneath the semiconductor film 103, At the opening 110, the semiconductor film 103 is partially removed. Therefore, Figure 4( Even in cases A) and Figure 4(B), the semicircular film located beneath conductive film 106a or conductive film 106b The conductive film 103 and the semiconductor film 103 located beneath the conductive film 105 are in a separated state. Therefore, the effect of suppressing the production of parasitic channels can be obtained.

[0050] In addition, in a liquid crystal display device according to one aspect of the present invention, the semiconductor film 1 of the transistor 100 03 includes wide-bandgap semiconductors such as oxide semiconductors.

[0051] The oxide semiconductor must contain at least indium (In) or zinc (Zn). This is preferable. Furthermore, it reduces variations in the electrical characteristics of transistors using the oxide semiconductor. It is preferable to have gallium (Ga) in addition to them as a stabilizer for this purpose. Furthermore, it is preferable to have tin (Sn) as a stabilizer. It is preferable to have hafnium (Hf) as the stabilizer. Also, as It is preferable to have aluminum (Al). Also, zirconium as a stabilizer. It is preferable that it contains mu (Zr).

[0052] Also, other stabilizers include lanthanides such as lanthanum (La) and cerium ( Ce, praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), hol Mium (Ho), Erbium (Er), Thulium (Tm), Ytterbium (Yb), Lu It may contain one or more types of tecium (Lu).

[0053] For example, oxide semiconductors include indium oxide, tin oxide, zinc oxide, and the oxide of binary metals. These are In-Zn oxides, Sn-Zn oxides, Al-Zn oxides, and Zn-Mg oxides. Oxides, Sn-Mg oxides, In-Mg oxides, In-Ga oxides, ternary metals In-Ga-Zn oxides (also written as IGZO), In-Al-Zn oxides Oxides, In-Sn-Zn oxides, Sn-Ga-Zn oxides, Al-Ga-Zn acids oxides, Sn-Al-Zn oxides, In-Hf-Zn oxides, In-La-Zn oxides Materials, In-Pr-Zn oxides, In-Nd-Zn oxides, In-Sm-Zn oxides In-Eu-Zn oxides, In-Gd-Zn oxides, In-Tb-Zn oxides, In-Dy-Zn oxides, In-Ho-Zn oxides, In-Er-Zn oxides, I n-Tm-Zn oxide, In-Yb-Zn oxide, In-Lu-Zn ​​oxide, quaternary In-Sn-Ga-Zn oxides and In-Hf-Ga-Zn oxides are oxides of metal systems. In-Al-Ga-Zn oxides, In-Sn-Al-Zn oxides, In-Sn- Hf-Zn oxides and In-Hf-Al-Zn oxides are used in the semiconductor film 103. It is possible.

[0054] For example, an In-Ga-Zn oxide is an oxide containing In, Ga, and Zn. This is about taste, and the ratio of In, Ga, and Zn is not important. Also, metal elements other than In, Ga, and Zn are not considered. It may contain. In-Ga-Zn oxides have sufficiently high resistance in the absence of an electric field and are off-electric. It is possible to significantly reduce the flow rate, and it also has high mobility.

[0055] For example, In:Ga:Zn = 1:1:1 (= 1 / 3:1 / 3:1 / 3) or In:G In-Ga-Zn system oxidation with atomic ratio a:Zn=2:2:1 (=2 / 5:2 / 5:1 / 5) Oxides with a similar composition to the substance can be used. Alternatively, In:Sn:Zn=1: 1:1(=1 / 3:1 / 3:1 / 3), In:Sn:Zn=2:1:3(=1 / 3:1 / 6:1 / 2) or In:Sn:Zn=2:1:5 (=1 / 4:1 / 8:5 / 8) It is advisable to use In-Sn-Zn oxides with a specific ratio or oxides with a similar composition.

[0056] For example, high mobility can be obtained relatively easily with In-Sn-Zn oxides. However, Furthermore, even with In-Ga-Zn oxides, mobility can be increased by reducing the bulk defect density. It is possible to do so.

[0057] Furthermore, impurities such as water or hydrogen, which act as electron donors, are reduced, and acid Purified oxide semiconductors (purified Oxi) are achieved by reducing elemental defects. A de Semiconductor is an i-type (intrinsic semiconductor) or very close to an i-type. Therefore, transistors using the above-mentioned oxide semiconductor have the characteristic of having a remarkably low off-current. It has the following characteristics. Furthermore, the band gap of the oxide semiconductor is 2 eV or more, preferably 2.5 eV. More preferably, the voltage is 3 eV or higher. The concentration of impurities such as water or hydrogen is sufficiently reduced. Furthermore, by reducing oxygen deficiency, a highly purified oxide semiconductor film is used. This allows the transistor's off-current to be reduced.

[0058] Specifically, transistors using highly purified oxide semiconductors as semiconductor films have a low off-current. This can be proven through various experiments. For example, if the channel width is 1 × 10⁻⁶ 6 micrometers Even with an element with a channel length of 10 μm, the voltage between the source terminal and the drain terminal (drain voltage) When the voltage is in the range of 1V to 10V, the off-current is measured by a semiconductor parameter analyzer. Below the limit, i.e., 1 × 10⁻⁶ -13 It is possible to obtain the characteristic of being A or less. In this case, The off-current, which corresponds to the value obtained by dividing the f-current by the transistor's channel width, is 100 Hz / μF. It can be seen that it is less than or equal to m. Also, by connecting the capacitive element and the transistor, the current flows through the capacitive element. A circuit is used to control the charge flowing out from an input or capacitive element using the transistor, and the off-power Current measurements were performed. In these measurements, a highly purified oxide semiconductor film was applied to the transistor. Used in the channel formation region, the transition of the charge amount per unit time of the capacitive element is used to determine the transient. The off-current of the transistor was measured. As a result, the voltage between the source and drain terminals of the transistor was measured. It was found that an even lower off-current of several tens of yA / μm can be obtained when the voltage is 3V. Therefore, transistors that use a highly purified oxide semiconductor film in the channel formation region are The off-current is significantly lower compared to transistors using crystalline silicon.

[0059] Unless otherwise specified, in this specification, off-current refers to the off-current of an n-channel transistor. In this state, with the drain terminal at a higher potential than the source terminal and gate electrode, When the potential of the gate electrode is 0 or less with respect to the potential of the source terminal, the source terminal and This refers to the current flowing between the drain terminals. Alternatively, in this specification, off-current means p In channel transistors, the drain terminal is lower than the source terminal and gate terminal. In a state where the potential is such that the potential of the gate electrode is 0 or less when the potential of the source terminal is used as a reference. This refers to the current flowing between the source and drain terminals when the voltage is at its highest.

[0060] Furthermore, the source terminal of a transistor is the source region, which is part of the active layer, or the active layer. It refers to the connected source electrode. Similarly, the drain terminal of a transistor refers to the active layer This refers to a drain region, or a drain electrode connected to the active layer.

[0061] Furthermore, oxide semiconductor films can be single crystals, polycrystalline (also called polycrystals), or amorphous. Which state should it take? Preferably, the oxide semiconductor film is CAAC-OS(C Axis Al Ignished Crystalline Oxide Semiconductor film and do.

[0062] CAAC-OS films are neither perfectly single crystals nor perfectly amorphous. This is an oxide semiconductor film having a crystalline-amorphous multiphase structure with crystalline and amorphous parts in the amorphous phase. Yes, it exists. Furthermore, the crystalline portion must be small enough to fit within a cube with sides less than 100 nm long. There are many. Also, transmission electron microscopes (TEM) In the image observed using a microscope, the amorphous region contained in the CAAC-OS film and The boundary with the crystalline portion is not clear. Also, TEM revealed grain boundaries in the CAAC-OS film. Also called inboundary. ) cannot be confirmed. Therefore, the CAAC-OS film has grain boundaries. The resulting decrease in electron mobility is suppressed.

[0063] The crystalline portion contained in the CAAC-OS film has a c-axis that is the normal vector to the surface on which the CAAC-OS film is formed. Aligned in a direction parallel to the normal vector of the plane or surface, and triangular when viewed from a direction perpendicular to the ab plane. Having a shape or hexagonal atomic arrangement, the metal atoms are layered or when viewed from a direction perpendicular to the c-axis. Metal atoms and oxygen atoms are arranged in layers. Furthermore, between different crystalline regions, the a-axis is... The orientation of the b-axis may be different. In this specification, when simply referred to as vertical, 8 The range of 5° to 95° is also included. Furthermore, when simply describing something as parallel, -5 This will include the range of 5° to 5°.

[0064] Furthermore, the distribution of crystalline regions in the CAAC-OS film does not need to be uniform. For example, CAA In the formation process of a C-OS film, when crystal growth is performed from the surface side of the oxide semiconductor film, the shape The proportion of crystalline material may be higher near the surface compared to near the surface of the material. Also, CA By adding impurities to the AC-OS film, the crystalline region in the impurity-added area becomes amorphous. It can also become qualitative.

[0065] The c-axis of the crystalline portion contained in the CAAC-OS film is the normal vector to the surface on which the CAAC-OS film is formed. Because it aligns in a direction parallel to the normal vector of the surface or the material, the shape of the CAAC-OS film (formed Depending on the cross-sectional shape of the surface or face, they may face in different directions. Oh, the direction of the c-axis of the crystalline portion is the normal vector to the surface on which the CAAC-OS film was formed. The direction is parallel to the normal vector of the crystalline or surface. The crystalline portion is formed by deposition, and It is formed by performing crystallization treatments such as heat treatment after film formation.

[0066] Transistors using CAAC-OS film exhibit changes in electrical characteristics due to irradiation with visible light or ultraviolet light. The dynamics are small. Therefore, this transistor is highly reliable.

[0067] CAAC-OS films are used, for example, for polycrystalline oxide semiconductor sputtering targets. The film is deposited using a sputtering method. Ions are directed onto the sputtering target. Upon collision, the crystalline region contained in the sputtering target cleaves from the ab plane, and a -The sputtering particles are exfoliated as flat or pellet-shaped sputtering particles having a surface parallel to the -b surface. In this case, the flat sputtering particles maintain their crystalline state and form a base By reaching the plate, the CAAC-OS film can be deposited.

[0068] Furthermore, it is preferable to apply the following conditions for forming the CAAC-OS film.

[0069] By reducing the inclusion of impurities during film formation, it is possible to suppress the disruption of the crystalline state due to impurities. For example, the concentration of impurities (hydrogen, water, carbon dioxide, and nitrogen, etc.) present in the deposition chamber. It would be good to reduce it. Also, it would be good to reduce the impurity concentration in the film formation gas. Specifically, the dew point is A film-forming gas with a temperature of -80°C or lower, preferably -100°C or lower, is used.

[0070] Furthermore, by increasing the substrate heating temperature during film deposition, the sputtering particles can be prevented from migrating after reaching the substrate. A reaction occurs. Specifically, the substrate heating temperature is preferably between 100°C and 740°C. The film is deposited at a temperature between 200°C and 500°C. By increasing the substrate heating temperature during film deposition, the flat When plate-shaped sputtering particles reach the substrate, migration occurs on the substrate. The flat side of the sputtered particles adheres to the substrate.

[0071] Furthermore, by increasing the oxygen content in the deposition gas and optimizing the power, plasma damage during film deposition can be reduced. It is preferable to reduce this. The oxygen content in the film-forming gas is 30% by volume or more, preferably 100% by volume. Let the product be %.

[0072] As an example of a target for sputtering, an In-Ga-Zn oxide target is used. The following is shown.

[0073] InO X powder, GaO Y Powder and ZnO Z The powders are mixed in a predetermined molar ratio and then subjected to pressure treatment. Furthermore, by heat treatment at a temperature between 1000°C and 1500°C, polycrystalline In-G is produced. The target is an α-Zn oxide. X, Y, and Z are arbitrary positive numbers. The given molar ratio is, for example, InO X powder, GaO YPowder and ZnO Z The powder is 2 The ratios are 2:1, 8:4:3, 3:1:1, 1:1:1, 4:2:3, or 3:1:2. The type of powder and the molar ratio in which they are mixed will be determined by the sputtering target being prepared. You can adjust it as needed depending on the situation.

[0074] (Embodiment 2) Next, an example of the specific configuration of the pixel portion of a liquid crystal display device according to one aspect of the present invention will be presented. I will list and explain.

[0075] Figure 8(A) shows an example of the configuration of the pixel unit 10. In Figure 8(A), the pixel unit 10 includes a scan line drive Y scan lines GL (GL1 to GLy) whose potential is controlled by a circuit, and signal line drive circuits x signal lines SL (SL1 to SLx) whose potential is controlled by the path are provided. .

[0076] The scan line GL is connected to each of the multiple pixels 11. Specifically, each scan line GL is an x ​​element located in any row of a plurality of pixels 11 arranged in a matrix. It is connected to individual pixels 11.

[0077] Furthermore, the signal line SL is one of the multiple pixels 11 provided in the x column and y row of the pixel section 10, It is connected to y pixels 11 located in any of the columns.

[0078] In this specification, "connection" means an electrical connection, and current, voltage, or potential is... This corresponds to a state where it can be supplied or transmitted. Therefore, a connected state is a state where it is directly connected. It does not necessarily refer to a state in which current, voltage, or potential is available or To enable transmission, circuit elements such as wiring, resistors, diodes, and transistors are used. This category also includes situations where the connection is indirect.

[0079] Even if components that appear independent in the circuit diagram are connected to each other, in reality For example, when a part of the wiring also functions as an electrode, one conductive film can function as multiple components. It may also have the functions of a single conductive device. In this specification, connection means such a single conductive device. This category also includes cases where a membrane possesses the functions of multiple components.

[0080] Figure 8(B) shows an example of the circuit diagram of pixel 11. Pixel 11 shown in Figure 8(B) is a switch. A transistor 12 that functions as a linking element, and an image given via transistor 12. It has a liquid crystal element 13 whose transmittance is controlled according to the potential of the signal, and a capacitive element 14. .

[0081] The liquid crystal element 13 comprises a pixel electrode, a common electrode, and a liquid to which a voltage is applied between the pixel electrode and the common electrode. It has a liquid crystal layer containing crystals. The capacitive element 14 has pixels of the liquid crystal element 13. It has the function of maintaining the voltage between the electrode and the common electrode.

[0082] The liquid crystal layer includes, for example, liquid crystals classified as thermotropic liquid crystals or lyotropic liquid crystals. Materials can be used. Alternatively, the liquid crystal layer can be, for example, nematic liquid crystal, smectic Using liquid crystal materials classified as chlorocrystalline, cholesteric, or discotic liquid crystals Alternatively, the liquid crystal layer may contain, for example, a ferroelectric liquid crystal or an antiferroelectric liquid crystal. Classified liquid crystal materials can be used. Alternatively, the liquid crystal layer may be, for example, a main-chain polymer. Polymer liquid crystals such as liquid crystals, side-chain polymer liquid crystals, or composite polymer liquid crystals, or low molecular weight liquids Liquid crystal materials classified as crystals can be used. Alternatively, the liquid crystal layer may contain, for example, polymer components. Liquid crystal materials classified as diffused liquid crystals (PDLCs) can be used.

[0083] Alternatively, a liquid crystal exhibiting a blue phase without an alignment layer may be used as the liquid crystal layer. The blue phase is the liquid crystal phase. One such example is when a cholesteric liquid crystal is heated, and it transitions from the cholesteric phase to the isotropic phase. This phase appears just before transfer. The blue phase only appears within a narrow temperature range, so Kaira The temperature range is improved by adding a curing agent or UV-curing resin. The liquid crystal exhibits a blue phase and a chiral agent. A liquid crystal composition containing these elements has a short response time of 1 msec or less and is optically isotropic, therefore orientation It is preferable because it requires no processing and has low dependence on the viewing angle.

[0084] Furthermore, the driving methods for the LCD include TN (Twisted Nematic) mode and STN (Super Twisted Nematic) mode, VA (Vertical A) lignment) mode, MVA (Multi-domain Vertical A) Ignition mode, IPS (In-Plane Switching) mode, OCB(Optically Compensated Birefringence) Mode, FFS (Fringe Field Switching) mode, Blue phase mode Code, TBA (Transverse Bend Alignment) mode, VA- IPS mode, ECB (Electrically Controlled Birefringence) ringence) mode, FLC (Ferroelectric Liquid Cr ystal) mode, AFLC(AntiFerroelectric Liquid Crystal mode, PDLC (Polymer Dispersed Liquid) d Crystal) mode, PNLC (Polymer Network Liquid) It is possible to apply modes such as Crystal mode and guest host mode.

[0085] Pixel 11 may contain transistors, diodes, resistors, capacitives, and inductors as needed. It may also have other circuit elements such as a t.

[0086] Specifically, in Figure 8(B), the gate electrode of transistor 12 is connected to scan line GL. Transistor 12 has either its source terminal or drain terminal connected to the signal line SL. The other end is connected to the pixel electrode of the liquid crystal element 13. The capacitive element 14 has one electrode that It is connected to the pixel electrode of the liquid crystal element 13, and the other electrode is given a specific potential. It is connected to the node. Furthermore, a specific potential is applied to the common electrode of the liquid crystal element 13. The potential applied to the common electrode is then applied to the other electrode of the capacitive element 14. The potential obtained may be the same as the potential obtained.

[0087] In Figure 8(B), in pixel 11, one transistor 12 is used as a switching element. The present invention is shown in the case where it is used in this way, but the present invention is not limited to this configuration. Multiple transistors may be used to function as switching elements. When a transistor functions as a single switching element, the above multiple transistors are connected in parallel. They can be connected in series, or in a combination of series and parallel. It's okay if it's included.

[0088] In this specification, a state in which transistors are connected in series means, for example, a first transistor Only one of the transistor's source terminals, either the source terminal or the drain terminal, is connected to the source terminal of the second transistor. This refers to a state where only one of the terminals, either the sub-terminal or the drain terminal, is connected. The state in which they are connected in parallel is when the source terminal or drain terminal of the first transistor is connected. One end is connected to either the source terminal or the drain terminal of the second transistor, and the first The source terminal or drain terminal of one transistor is the other of the source terminal of the second transistor. Alternatively, it means that the other terminal of the drain is connected.

[0089] By including an oxide semiconductor in the channel formation region of transistor 12, the off-current is extremely small. Furthermore, it is possible to realize a transistor 12 that is also highly resistant to voltage. By using a transistor 12 having the properties as a switching element, ordinary silicon and Compared to using transistors made of semiconductor materials such as germanium, liquid crystal elements This prevents the leakage of charge accumulated in child 13.

[0090] By using a transistor 12 with an extremely small off-current, the power supplied to the liquid crystal element 13 is reduced. This allows for a longer period of pressure retention. Therefore, like a still image, continuous Over several frame periods, an image signal containing the same image information is written to the pixel unit 10. In cases such as this, the drive frequency is lowered, or in other words, the drive frequency of the pixel unit 10 within a certain period of time. The image display can be maintained even if the number of times the image signal is written is reduced. By using a transistor 12 that uses a highly purified oxide semiconductor as the active layer, the image The interval for writing signals should be 10 seconds or more, preferably 30 seconds or more, and more preferably 1 minute or more. This can be done. And the longer the interval at which the image signal is written, the more power is consumed. Power consumption can be reduced further.

[0091] Furthermore, because the potential of the image signal can be maintained for a longer period of time, the potential of the image signal In order to maintain the position, even without connecting the capacitive element 14 to the liquid crystal element 13, the displayed image quality is This prevents a decrease. Therefore, by not providing the capacitive element 14, or By reducing the size of the capacitive element 14, the aperture ratio can be increased, thus the liquid This can reduce the power consumption of the crystal display device.

[0092] Furthermore, an inversion drive is performed to reverse the polarity of the image signal's potential, using the potential of the common electrode as a reference. This prevents the deterioration of the liquid crystal material known as burn-in. However, when performing reverse drive When the polarity of the image signal changes, the change in potential applied to the signal line SL becomes larger. Therefore, the power supply between the source terminal and drain terminal of transistor 12, which functions as a switching element, The positional difference becomes larger. Therefore, transistor 12 experiences characteristic degradation such as a shift in the threshold voltage. This is prone to occurring. Also, in order to maintain the voltage held in the liquid crystal element 13, the source terminal Even if the potential difference between the transistor and the drain terminal is large, a low off-current is required. 12. It has a larger band gap than silicon or germanium, and intrinsic carrier density By using semiconductors such as oxide semiconductors with low voltage, the breakdown voltage of transistor 12 can be increased. The current can be significantly reduced. Therefore, ordinary silicon and germanium Compared to using a transistor made of semiconductor material, the degradation of transistor 12 is This prevents the voltage held in the liquid crystal element 13 from being maintained.

[0093] Next, the layout of pixel 11 shown in Figure 8(B) will be explained using Figures 5 and 6. Figure 5 is an example of a top view of pixel 11. Figure 6(A) is a top view of the same pixel as shown in Figure 5. This corresponds to an example of a cross-sectional view along the dashed line D1-D2. Figure 6(B) is the upper part shown in Figure 5. This corresponds to an example of a cross-sectional view along the dashed line D3-D4 in the plan view. However, in Figure 5, pixels To clearly show the layout of 11, various insulating films are omitted, and a top view of pixel 11 is shown. Furthermore, Figure 5 clearly shows the layout of the various semiconductor elements in pixel 11. The liquid crystal layer and common electrode of the liquid crystal element 13 are omitted, and a top view of the pixel 11 is shown.

[0094] In the pixel 11 shown in Figures 5 and 6, the transistor 12 is located on a substrate 20 having an insulating surface. On 2, a conductive film 203 that functions as a gate electrode, and a gate insulating film 20 on the conductive film 203 4 and the semiconductor film 20 located on the gate insulating film 204 at a position overlapping with the conductive film 203 5 is located on the semiconductor film 205 at a position overlapping with the conductive film 203, and is a channel protective film. An insulating film 206 that functions as a source terminal or drain terminal, and a semiconductor film 2 It has conductive films 207 and 208 located on 05.

[0095] The conductive film 203 also functions as a scan line that applies potential to the gate electrode of transistor 12. Furthermore, the conductive film 207 also functions as a signal line that supplies the potential of the image signal to the pixel 11.

[0096] The capacitive element 14 is made of a conductive film 210 on a substrate 202 having an insulating surface, and on the conductive film 210 The gate insulating film 204 and the semiconductor film 205 overlap with the conductive film 210 at a position where they meet. It has a border film 204 and a conductive film 211 located on the semiconductor film 205.

[0097] Furthermore, an insulating film 212 is provided on the conductive film 207, conductive film 208, and conductive film 211. And the insulating film 212, the semiconductor film 205, and the gate insulating film 204 have openings 2 13 and an opening 214 are provided.

[0098] The opening 213 is provided between the conductive film 207 or conductive film 208 and the conductive film 211. Furthermore, a conductive film 208 is formed in a portion of the region where the opening 213 is formed. A portion of the region overlaps with a portion of the region where the conductive film 210 is formed. In 13, the insulating film 212 on the conductive film 208 and the insulating film 212 on the conductive film 210, semiconducting Body film 205 and gate insulating film 204 have been removed, and conductive film 208 and conductive film 21 0 is electrically connected by conductive film 208 and conductive film 215 on conductive film 210.

[0099] Furthermore, at the opening 214, the insulating film 212 on the conductive film 210, the semiconductor film 205, and The insulating film 204 has been removed, and the conductive film 210 is a conductive film that functions as a pixel electrode. It is connected to 16. Note that the conductive film 216 is on the conductive film 210 at the opening 214. Furthermore, it is also provided on the insulating film 212.

[0100] Furthermore, at the opening 214, the insulating film 212 on the conductive film 203, the semiconductor film 205, and The gate insulating film 204 is also removed. With the above configuration, the conductive film 203 and gate insulating film 20 4. The parasitic capacitance formed in the region where the semiconductor film 205 and the semiconductor film 205 overlap can be reduced. .

[0101] Furthermore, an insulating film 212 is placed in a position that overlaps with the conductive film 211, which functions as a spacer. A border film 217 is provided.

[0102] In Figures 5 and 6, a portion of the region where the opening 213 is formed is covered by the conductive film 208. A portion of the formed region and a portion of the region where the conductive film 210 is formed overlap. This illustrates a case where conductive film 208 and conductive film 215 are connected, and conductive film 21 The connection between 0 and the conductive film 215 will both be made at the opening 213. In one aspect of the present invention, the connection between conductive film 208 and conductive film 215, and conductive film 210 and conductive The connections of the membrane 215 may be made at different openings.

[0103] Figure 7 shows the connection points between conductive film 208 and conductive film 210 and conductive film 215, and pixel 11 An example of a cross-sectional view is shown. In Figure 7, the opening 213a provided in the insulating film 212 is conductive Film 208 and conductive film 215 are connected. Also, insulating film 212, semiconductor film 205, and In the opening 213b provided in the gate insulating film 204, the conductive film 210 and the conductive film 215 are in contact. It continues.

[0104] However, as shown in Figures 5 and 6, the connection between conductive film 208 and conductive film 215 and conductive film 210 When both the connection of the conductive film 215 and the connection of the conductive film 215 are made at the opening 213, multiple openings Since there is no need to secure an area for formation, it is possible to achieve high resolution of the pixel portion 10. can.

[0105] In FIGS. 5 and 6, the layout of pixel 11 is shown when a liquid crystal layer and a common electrode are sequentially provided on the conductive film 216 that functions as a pixel electrode. However, the liquid crystal display device according to one aspect of the present invention is not limited to this configuration. Pixel 11 may have a structure in which a liquid crystal layer is provided on the pixel electrode and the common electrode, such as an IPS-type liquid crystal element or a liquid crystal element using a blue phase.

[0106] This embodiment can be implemented in appropriate combination with other embodiments.

[0107] (Embodiment 3) In this embodiment, a method for manufacturing a liquid crystal display device according to one aspect of the present invention will be described by taking pixel 11 shown in FIGS. 5 and 6 as an example.

[0108] First, as shown in FIG. 9(A), a conductive film 203 that functions as a gate electrode and a conductive film 210 that functions as an electrode of the capacitive element 14 are formed on a substrate 202 having an insulating surface.

[0109] There is no major limitation on the substrate that can be used as the substrate 202 having an insulating surface, but at least it needs to have heat resistance enough to withstand subsequent heat treatment. For example, a glass substrate manufactured by the fusion method or the float method can be used. When the temperature of the subsequent heat treatment is high, a glass substrate having a strain point of 730° C. or higher is preferably used. In addition, for the glass substrate, for example, glass materials such as aluminosilicate glass, aluminoborosilicate glass, and barium borosilicate glass are used.

[0110] Note that instead of the above glass substrate, an insulating substrate such as a ceramic substrate, a quartz substrate, or a sapphire substrate can be used. A substrate made of edge material may also be used. Other materials such as crystallized glass can also be used. A substrate in which an insulating film is provided on the surface of a metal substrate such as a stainless steel alloy may also be used. However, liquid crystal If the display device is transmissive or semi-transmissive, a light-transmitting substrate is used for the substrate 202. .

[0111] The materials for conductive film 203 and conductive film 210 are molybdenum, titanium, chromium, tantalum, and tungsten. Metal materials such as stainless steel, aluminum, copper, neodymium, scandium, niobium, and these metals A conductive film using an alloy material with the material as the main component, or nitrides of these metals, in a single layer or It can be used in lamination. Furthermore, it can withstand the heat treatment temperatures performed in subsequent processes. Therefore, aluminum and copper can also be used as the above-mentioned metal materials. Alternatively, copper is used in combination with high-melting-point metal materials to avoid problems with heat resistance and corrosion. It would be good to have them. High melting point metal materials include molybdenum, titanium, chromium, tantalum, and tungsten. Stainless steel, neodymium, scandium, etc., can be used.

[0112] For example, a conductive film 203 and conductive film 210 having a two-layer structure, wherein a copper film is deposited on a titanium film. Layered two-layer structure, two-layer structure with a molybdenum film laminated on an aluminum film, copper film A two-layer structure with a molybdenum film laminated on top, and a titanium nitride film or tantalum nitride film on top of a copper film. The structure consists of two stacked layers, or two stacked layers consisting of a titanium nitride film and a molybdenum film. It is preferable that the conductive film 203 and conductive film 210 having a three-layer structure are, for example, It is preferable to have a three-layer structure consisting of a titanium nitride film, a copper film, and a tungsten film stacked together. .

[0113] Furthermore, conductive films 203 and 210 contain indium oxide, indium oxide-tin oxide, and oxide Indium-zinc oxide, zinc oxide, aluminum zinc oxide, aluminum zinc oxynitride, Alternatively, translucent metal oxides such as zinc gallium oxide can be used.

[0114] The thickness of conductive film 203 and conductive film 210 is 10 nm to 400 nm, preferably 100 nm to The thickness is set to 200 nm. In this embodiment, tungsten is coated with a film thickness of 200 nm by sputtering. After forming the film, the tungsten film is etched using photolithography. By processing (patterning) the film into the desired shape, conductive films 203 and 210 are formed. Furthermore, if the ends of the formed conductive film 203 and conductive film 210 are tapered, then This is preferable because it improves the coverage of the stacked gate insulating film 204. It may also be formed by an inkjet method. When the resist mask is formed by an inkjet method, Since no photomasks are used, manufacturing costs can be reduced.

[0115] In this embodiment, the conductive film 203 and conductive film 210 are formed directly on the substrate 202. The example given is to first form an insulating film on the substrate 202 that functions as an underlayer, and then... Conductive films 203 and 210 may be formed on the aforementioned substrate. For example, the substrate may be: Silicon oxide film, silicon oxide nitride film, silicon nitride film, silicon nitride oxide film, aluminum nitride film, and This involves using one of the aluminum nitride oxide films as a single layer or by stacking multiple layers. This is possible. In particular, a highly barrier insulating film, such as a silicon nitride film or silicon oxide nitride film, can be used as the underlayer. Using aluminum nitride film, aluminum oxide film, or aluminum nitride oxide film, etc. By doing so, it is possible to prevent impurities in the atmosphere such as moisture or hydrogen, or impurities such as alkali metals or heavy metals contained in the substrate 202, from entering into the semiconductor film 205 to be formed later, the gate insulating film 2 04, or the interface between the semiconductor film 205 and other insulating films and the vicinity thereof. This can be achieved.

[0116] Note that in this specification, an oxynitride is a substance having a higher oxygen content than nitrogen in its composition, and a nitroxide is a substance having a higher nitrogen content than oxygen in its composition. This means a substance.

[0117] Note that FIG. 11 is a top view of the liquid crystal display device at the time when the above-described process is completed. The cross-sectional view taken along the dashed-dotted line A1 - A2 in FIG. 11 corresponds to FIG. 9(A).

[0118] Next, as shown in FIG. 9(B), a gate insulating film 2 04 is formed on the conductive film 203 and the conductive film 210. The gate insulating film 204 can be formed by using the plasma CVD method, the sputtering method, or the like, to form a single layer or a laminate of a silicon oxide film, a silicon nitride film, an oxynitride film, a nitroxide film, an aluminum oxide film, an aluminum nitride film, an aluminum oxynitride film, an aluminum nitroxide film, a hafnium oxide film, a yttrium oxide film, a gallium oxide film, a lanthanum oxide film, or a tantalum oxide film. It is desirable that the gate insulating film 204 contains as few impurities such as moisture and hydrogen as possible.

[0119] The gate insulating film 204 may be composed of a single insulating film, or may be composed of a plurality of insulating films laminated together. In any case, the gate insulating film 204 is formed so that an insulating film containing an amount of oxygen exceeding the stoichiometric composition is in contact with the semiconductor film 205 to be formed later. ​ It is desirable to achieve this. With the above configuration, oxygen is transferred from the gate insulating film 204 to the semiconductor film 205. Since it can supply [the necessary power], it is possible to obtain a transistor 12 with good electrical characteristics. can.

[0120] Furthermore, a gate insulating film having a structure in which a highly barrier insulating film and an oxygen-containing insulating film are stacked is also available. When forming the edge film 204, the highly barrier insulating film is an insulating film containing oxygen and a conductive film 20 It is preferable to provide a barrier insulating film between 3 and the conductive film 210. Therefore, impurities in the atmosphere such as moisture or hydrogen, or alkali gold contained in the substrate 202, Impurities such as genus and heavy metals may be present in the semiconductor film 205, the gate insulating film 204, or the semiconductor It can prevent penetration into the interface between film 205 and other insulating films, and its vicinity. High barrier properties Examples of insulating films include silicon nitride films, silicon oxide nitride films, aluminum nitride films, and aluminum oxide films. Examples include a nium film or an aluminum nitride oxide film.

[0121] The thickness of the gate insulating film 204 can be set appropriately according to the characteristics required of the transistor. For example, the wavelength is 1 nm to 800 nm, preferably 200 nm to 500 nm. By forming a thicker gate insulating film 204, the breakdown voltage of the transistor 12 is improved. This can be achieved. In this embodiment, a 100 nm thick oxidized nitride film formed by plasma CVD is produced. A silicon film is used as the gate insulating film 204.

[0122] Next, as shown in Figure 9(B), a film thickness of 2 nm to 200 nm is applied to the gate insulating film 204. Preferably, the film thickness is 3 nm to 50 nm, and more preferably 3 nm to 20 nm. The following semiconductor film 205 is formed. The semiconductor film 205 targets an oxide semiconductor. It is formed by sputtering using a noble gas (e.g., argon). Under an atmosphere, under an oxygen atmosphere, or under a mixed atmosphere of a noble gas (e.g., argon) and oxygen. It can be formed by sputtering.

[0123] Furthermore, before forming the oxide semiconductor film by sputtering, argon gas is introduced to form plasma Reverse sputtering is performed to generate sputtering, and dust adhering to the surface of the gate insulating film 204 is removed. It is preferable to do so. Reverse sputtering is a method in which voltage is not applied to the target side, and an argon atmosphere is used. Under atmospheric pressure, a voltage is applied to the substrate side using an RF power supply to form plasma near the substrate and modify the surface. This is a testing method. Note that nitrogen, helium, or other elements may be used instead of an argon atmosphere. Alternatively, the procedure may be carried out in an atmosphere where oxygen, nitrous oxide, etc., are added to an argon atmosphere. The procedure may also be carried out in an atmosphere containing chlorine, carbon tetrafluoride, etc., in addition to a argon atmosphere.

[0124] As the oxide semiconductor used in semiconductor film 205, as mentioned above, indium oxide, sodium oxide Zinc oxide, an oxide of a binary metal, such as In-Zn oxides, Sn-Zn oxides, and A l-Zn oxides, Zn-Mg oxides, Sn-Mg oxides, In-Mg oxides, I n-Ga oxides, and in-Ga-Zn oxides (also known as IGZO), which are oxides of ternary metals. (To be written as), In-Al-Zn oxides, In-Sn-Zn oxides, Sn-Ga-Zn Al-Ga-Zn oxides, Sn-Al-Zn oxides, In-Hf-Zn oxides Oxides, In-La-Zn oxides, In-Pr-Zn oxides, In-Nd-Zn acids In-Sm-Zn oxides, In-Eu-Zn oxides, In-Gd-Zn oxides Materials, In-Tb-Zn oxides, In-Dy-Zn oxides, In-Ho-Zn oxides In-Er-Zn oxides, In-Tm-Zn oxides, In-Yb-Zn oxides, In-Lu-Zn ​​oxides, and In-Sn-Ga-Zn oxides, which are oxides of quaternary metals. In-Hf-Ga-Zn oxides, In-Al-Ga-Zn oxides, In-Sn-A l-Zn oxides, In-Sn-Hf-Zn oxides, In-Hf-Al-Zn oxides These are some examples.

[0125] For example, the semiconductor film 205 is made of In (indium), Ga (gallium), and Zn ( It can be formed by sputtering using a target containing zinc. When forming a Zn-based semiconductor film 205 by sputtering, preferably, the atomic ratio is I n:Ga:Zn=1:1:1, 4:2:3, 3:1:2, 1:1:2, 2:1:3, also This uses an In-Ga-Zn oxide target represented by a 3:1:4 ratio. By forming an oxide semiconductor film using an In-Ga-Zn-based oxide target having a specific ratio, This facilitates the formation of polycrystalline or CAAC. Also contains In, Ga, and Zn. The target filling rate is 90% or more and 100% or less, preferably 95% or more and less than 100%. By using a target with a high packing density, the formed oxide semiconductor film is a dense film. Yes.

[0126] Furthermore, when using an In-Zn-based oxide as the oxide semiconductor, the composition of the target used is In terms of atomic ratio, In:Zn = 50:1 to 1:2 (converted to a mole ratio of In2O3:Zn) O=25:1~1:4), preferably In:Zn=20:1~1:1 (convert to mole ratio) Then In2O3:ZnO=10:1~1:2), more preferably In:Zn=1.5: The ratio is 1 to 15:1 (which translates to In2O3:ZnO = 3:4 to 15:2 in terms of mole ratio). For example, the target used to form the semiconductor film 205, which is an In-Zn oxide, has a number of atoms. When the ratio is In:Zn:O=X:Y:Z, assume Z>1.5X+Y. The ratio of Zn is within the above range. By enclosing them in an enclosure, mobility can be improved.

[0127] Furthermore, when using In-Sn-Zn oxide materials as oxide semiconductors, the target used The composition of the net is based on the atomic ratio of In:Sn:Zn, which can be 1:2:2, 2:1:3, or 1:1:1. Alternatively, you could use 20:45:35.

[0128] In this embodiment, the substrate is held in a processing chamber that is maintained under reduced pressure, and residual moisture in the processing chamber is removed. Sputtered gas from which hydrogen and water have been removed while removing the above target is introduced, and the above target is used An oxide semiconductor film is formed on the substrate 202. In order to remove residual moisture in the processing chamber, an absorbent is used. It is preferable to use a vacuum pump of the type that attaches to the surface. For example, a cryopump, an ion pump, or a chrysalis. It is preferable to use a tank sublimation pump. Furthermore, as an exhaust means, a turbocharger is preferable. A cold trap may be added to the pump. A cryopump can be used in the processing chamber. When exhausting, for example, hydrogen atoms, water (H2O) and other compounds containing hydrogen atoms (preferably... Because compounds containing carbon atoms are exhausted, oxide semiconductors formed in the processing chamber are affected. The concentration of impurities in the membrane can be reduced.

[0129] Three methods can be used to form the semiconductor film 205 composed of CAAC-OS. First, the semiconductor film 205 is formed at a film deposition temperature of 200°C to 450°C. The first method involves forming a thin semiconductor film 205, and then heating it at a temperature of 200°C to 700°C. The following is a method of heat treatment. The third is to first form a thin first layer of oxide semiconductor film, A heat treatment is performed at a temperature between 200°C and 700°C, followed by the formation of a second oxide semiconductor film. This is a method for forming a semiconductor film 205.

[0130] In this embodiment, the distance between the substrate 202 and the target is 100 mm, the pressure is 0.4 Pa, and the current is DC. (DC) Power supply 0.5kW, board temperature 250℃, argon and oxygen flow rates 30 Under an atmosphere of sccm and 15 sccm, an In-Ga-Zn oxide semiconductor is used. A semiconductor film 205 with a thickness of 25 nm is formed.

[0131] Furthermore, in order to minimize the presence of hydrogen, hydroxyl groups, and water in the semiconductor film 205, As a pretreatment before formation, the gate insulating film 204 is formed in the preheating chamber of the sputtering apparatus. The prepared substrate 202 is preheated to remove impurities such as moisture or hydrogen adsorbed on the substrate 202. It is preferable to exhaust the gases separately. The preheating temperature should be between 100°C and 400°C. The temperature range is between 150°C and 300°C.

[0132] Furthermore, the semiconductor film 205 formed by sputtering, etc., contains water or hydrogen as an impurity (water It may contain a large amount of acidic groups. Water or hydrogen readily forms donor levels. Therefore, it is an impurity for oxide semiconductors. In one aspect of the present invention, the semiconductor film After forming 205, the impurities such as water or hydrogen in the semiconductor film 205 are reduced (dehydration or To dehydrogenate the semiconductor film 205, nitrogen and noble gases are used under a reduced pressure atmosphere. The material is subjected to heat treatment under an inert gas atmosphere.

[0133] By subjecting the semiconductor film 205 to heat treatment, water or hydrogen is removed from the semiconductor film 205. This is possible. Specifically, the substrate can be heated to a temperature of 250°C to 750°C, preferably 400°C or higher. Heat treatment should be performed at a temperature below the strain point. If the RTA method is used for heat treatment, desaturation can be achieved in a short time. Because hydration or dehydrogenation can be performed, processing can be carried out even at temperatures exceeding the strain point of the glass substrate. In this embodiment, the material is heat-treated at 450°C for about 1 hour in an ultra-dry air atmosphere. To do so.

[0134] Furthermore, the heating apparatus is not limited to electric furnaces, but also includes heat conduction or heat radiation from heat-generating elements such as resistance heating elements. The device may include an apparatus for heating the object to be processed by injection. For example, GRTA(Gas Rapid Thermal Anneal) equipment, LRTA (Lamp Rapid RTA (Rapid Thermal Anneal) for Thermal Anneal devices, etc. A device can be used. The LRTA device uses halogen lamps and metal halide lamps. Lamps, xenon arc lamps, carbon arc lamps, high-pressure sodium lamps, high-pressure water A device that heats an object to be processed by radiating light (electromagnetic waves) from a lamp such as a silver lamp. Yes, there is. The GRTA device is a device that performs heat treatment using high-temperature gas. The gas contains aluminum. Noble gases such as gon, or inert gases such as nitrogen that do not react with the material being treated by heat treatment. The body is used.

[0135] In the heat treatment, nitrogen, or a noble gas such as helium, neon, or argon is used, along with water or water It is preferable that it does not contain elements such as nitrogen or helium. Alternatively, nitrogen or helium introduced into the heat treatment device. The purity of noble gases such as neon and argon is 6N (99.9999%) or higher, preferably 7 N(99.99999%) or higher (i.e., impurity concentration of 1 ppm or less, preferably 0.1 ppm), It is preferable to use a value of 0.5 (pm or less).

[0136] Through the above process, the concentration of water or hydrogen in the semiconductor film 205 can be reduced. Oh, in the semiconductor film 205, moisture or hydrogen is removed by the above heat treatment, as well as oxygen There is a risk that oxygen deficiency due to desorption is increasing. Therefore, after the above heat treatment, the semiconductor film It is desirable to supply oxygen to 205 to reduce oxygen deficiency.

[0137] High-purity semiconductors are produced by reducing the concentration of water or hydrogen, and by reducing oxygen deficiency. By using the conductive film 205, transistor 12 has high breakdown voltage and extremely low off-current. It is possible to produce this.

[0138] For example, by performing a heat treatment in an oxygen-containing gas atmosphere, oxygen is introduced into the semiconductor film 205. It can supply oxygen. Heat treatment for supplying oxygen is the same as above, for moisture or hydrogen The same conditions as those used for heat treatment to reduce the concentration should be applied. However, to supply oxygen... The heat treatment is performed using oxygen gas or ultra-dry air (CRDS (cavity ring down laser)). When measured using a spectroscopic dew point meter, the moisture content was 20 ppm (equivalent to a dew point of -55°C). ) Preferably 1 ppm or less, preferably 10 ppb or less, in an atmosphere such as air It will be done at [location].

[0139] The above oxygen-containing gas preferably has low concentrations of water, hydrogen, etc. Specifically, oxygen The concentration of impurities contained in the gas containing the specified substance is set to 1 ppm or less, preferably 0.1 ppm or less. It is preferable to do so.

[0140] Alternatively, ion implantation, ion doping, plasma immersion ion implantation Oxygen can be supplied to the semiconductor film 205 using methods such as oxygenation and plasma treatment. After supplying oxygen to the semiconductor film 205 using the above method, the crystals contained in the semiconductor film 205 If the part is damaged, heat treatment is performed to repair the damaged crystalline part. good.

[0141] A resist mask for forming the semiconductor film 205 may be formed by an inkjet method. When a resist mask is formed using an inkjet method, a photomask is not used, so the manufacturing process It can reduce stress.

[0142] Next, as shown in Figure 9(C), an insulating film is formed on the semiconductor film 205, and then photolithography is performed. By etching using the Graph method, the channel protective film is processed into the desired shape. An island-shaped insulating film 206 that functions is formed on the semiconductor film 205. It is placed in a position that overlaps with the conductive film 203.

[0143] The film thickness of the insulating film 206 is 50 nm or more and 600 nm or less, preferably 100 nm or more and 400 nm or less. The size should be less than or equal to nm. Furthermore, the insulating film 206 uses the same structure and material as the gate insulating film 204. It can be formed by water. And the insulating film 206, like the gate insulating film 204, It is desirable that the product contains as few impurities as possible, such as hydrogen, and that its composition exceeds stoichiometric limits. It is desirable to include a certain amount of oxygen. With the above configuration, moisture in the semiconductor film 205, water The concentration of impurities such as elemental compounds is kept low, and oxygen is supplied from the insulating film 206 to the semiconductor film 205. Since it can be supplied, a transistor 12 with good electrical characteristics can be obtained. ru.

[0144] In this embodiment, a silicon oxide nitride film with a thickness of 300 nm formed by plasma CVD is used. It is used as insulating film 206.

[0145] Furthermore, the insulating film 206 is a metal oxide containing at least one of In or Zn. Furthermore, by including Ti, Zr, Hf, Ge, Ce, etc., it provides better insulation than semiconductor film 205. Metal oxides with improved properties may also be used.

[0146] For example, an In-M1-M2-Zn oxide may be used for the insulating film 206. However, the original Element M1 is a trivalent element belonging to groups 3A, 3B, and 4A. M2 is a tetravalent element belonging to groups 4A and 4B. Specifically, element M When Ga is used in 1, in In-M1-M2-Zn oxides, a portion of the trivalent Ga It will be replaced by a tetravalent element. Tetravalent elements have one more bond than trivalent elements. Since there are many, by replacing some of the trivalent elements with tetravalent elements, In-M1-M2-Zn This can increase the bonding strength between the metal element (M1 or M2) that makes up the oxide system and oxygen. Therefore, by using an In-M1-M2-Zn oxide as the insulating film 206, The insulating properties can be improved. Specifically, as element M2, Ti, Zr, Hf, Ge, Examples include Ce.

[0147] For example, using a target of In:Zr:Ga:Zn = 3:0.05:0.95:2, an insulating film 206 made of an In-M1-M2-Zn based oxide can be formed by sputtering. That's all.

[0148] Also, for example, an In-M-Zn based oxide represented by the chemical formula InMZnO x can be used for the insulating film 206. As the element M, an element is applied such that the insulating property of the In-M-Zn based oxide is higher than the insulating property of the metal oxide constituting the semiconductor film 205. For example, as the element M, tetravalent elements such as Ti, Zr, Hf, Ge, and Ce can be applied. Since tetravalent elements have more single bonds than trivalent elements, the In-M-Zn based oxide using these tetravalent elements as the element M has a high binding force between the element M and oxygen. Therefore, by using the In-M-Zn based oxide for the insulating film 206, the insulating property of the insulating film 206 can be enhanced. For example, the energy gap of the In-Zr-Zn based oxide using Zr as the element M is larger than the energy gap (about 3.2 eV) of the In-Ga-Zn based oxide. That is, it can be said that the In-Zr-Zn based oxide has higher insulating property than the In-Ga-Zn based oxide. Also, the electronegativity of yttrium is smaller than that of Ga. Therefore, in the In-M1-M2-Zn based oxide, when the element M2 is yttrium, the difference in electronegativity between oxygen and the element M2 can be increased, and the ionic bond with oxygen in the metal oxide can be made stronger. Therefore, even when the element M2 is yttrium, in the In-M1-M2-Zn system oxide, the insulating property can be enhanced.

[0149] For example, the energy gap of the In-Zr-Zn based oxide using Zr as the element M is larger than the energy gap (about 3.2 eV) of the In-Ga-Zn based oxide. That is, it can be said that the In-Zr-Zn based oxide has higher insulating property than the In-Ga-Zn based oxide. That is, it can be said that the In-Zr-Zn based oxide has higher insulating property than the In-Ga-Zn based oxide. That's all.

[0150] Also, the electronegativity of yttrium is smaller than that of Ga. Therefore, in the In-M1-M2-Zn system oxide, when the element M2 is yttrium, the difference in electronegativity between oxygen and the element M2 can be increased, and the ionic bond with oxygen in the metal oxide can be made stronger. Therefore, even when the element M2 is yttrium, in the In-M1-M2-Zn system oxide, the insulating property can be enhanced. Therefore, even when the element M2 is yttrium, in the In-M1-M2-Zn The insulating properties of insulating film 206 using an In-M-Zn system can be improved. In oxides, if element M is yttrium, the difference in electronegativity between oxygen and element M is large. This can be done to strengthen the ionic bond with oxygen in the metal oxide. Therefore, even if element M is yttrium, an In-M-Zn oxide can be used for insulation. The insulating properties of the border film 206 can be improved.

[0151] In this specification, the term "energy gap" is used interchangeably with "band gap" and It is used with the same meaning as "band gap." Also, the band gap value is the width of the single film of the material. The values ​​obtained by measuring with a liposcope are used.

[0152] Furthermore, the element M content in In-M-Zn oxides should be at least 0.3 times the In content. It is less than 3 times. Also, the amount of element M in In-M-Zn oxides is less than the amount of Zn. The ratio is between 0.3 and 1.3. The relative number of In or Zn elements to element M is small. To that extent, a more insulating insulating film 206 can be obtained.

[0153] Specifically, when forming a metal oxide material containing element M by sputtering, Or, the atomic ratios are In:M:Zn=1:1:1, 3:1:3, 3:2:4, 2:1:3, Use a metal oxide target with a ratio of 4:5:4 or 4:2:3.

[0154] In-M-Zn oxides and In-M1-M2-Zn oxides are used as insulating film 206. This allows the interface between the insulating film 206 and the semiconductor film 205 to be kept in good condition, and the transient The electrical characteristics of TA12 can be improved.

[0155] Furthermore, on the surface of the semiconductor film 205 exposed by etching to form the insulating film 206 This material is prone to the adhesion of impurities. The above impurities include etching gas used for etching or Elements that make up the etching solution, or elements present in the etching chamber, etc. It contains. Specifically, the impurities mentioned above include boron, chlorine, fluorine, carbon, and aluminum. These are some examples.

[0156] When the above impurities adhere to the surface of the semiconductor film 205, the off-current of the transistor increases, or This can easily lead to a degradation of the transistor's electrical characteristics. Furthermore, parasitic cells can form on the semiconductor film 205. Channels are more likely to occur, and the conductive film that should be electrically isolated is electrically separated through the semiconductor film 205. Therefore, it becomes easier to connect to the target. In one aspect of the present invention, for forming the insulating film 206 After etching is complete, any residues that may have adhered to the surfaces of the semiconductor film 205 and the insulating film 206 may have been present. A washing process is performed to remove pure substances.

[0157] The cleaning process involves using an alkaline solution such as TMAH (tetramethylammonium hydroxide) solution. This can be done using water or dilute hydrofluoric acid. Specifically, dilute hydrofluoric acid can be used in the washing process. If using, dilute 50% by weight hydrofluoric acid with water to 1 / 10 2 ~1 / 10 5 Dilute with water and perform the washing process. It is desirable to use it in the following cases: that is, when the concentration is 0.5% by weight or 5 × 10 -4 Weight % of It is preferable to use acid in the cleaning process. The cleaning process removes the semiconductor film 205 and the insulating film. The above impurities adhering to the surface of 206 can be removed. In addition, a dilute fluoride can be used in the cleaning process. Using acid removes impurities attached to the semiconductor film 205 along with a portion of the semiconductor film 205. It is possible.

[0158] Next, a conductive film is formed on the semiconductor film 205 by sputtering or vacuum deposition, and then photo By patterning the conductive film using etching with lithography, Figure 9( As shown in D), an insulating film 206 is provided on the semiconductor film 205 with an insulating film 206 sandwiched in between. The gate insulating film 20 overlaps with conductive films 207 and 208 and conductive film 210. 4 and the conductive film 211 provided on the semiconductor film 205 are formed, respectively. Conductive film 20 7 and the conductive film 208 function as the source electrode or drain electrode of the transistor 12. Furthermore, the conductive film 211 functions as an electrode for the capacitive element 14.

[0159] Conductive films 207, 208, and 211 are the same as conductive films 203 and 210. Various structures and materials can be used. Conductive film 207, conductive film 208, and conductive film 211 If heat treatment is performed after the formation, the conductive film must have heat resistance to withstand this heat treatment. This is preferable. In this embodiment, conductive film 207, conductive film 208, and conductive film 211 are used. Therefore, a tungsten film with a thickness of 150 nm is used.

[0160] Furthermore, during etching to form conductive films 207, 208, and 211 Therefore, the materials and etching conditions are adjusted to minimize the removal of the semiconductor film 205. Adjust as needed. Depending on the etching conditions, some exposed parts of the semiconductor film 205 may be etched. This process can sometimes create grooves (recesses).

[0161] In this embodiment, dry etching by the ICP etching method is used to remove the conductive film 207 , conductive film 208 and conductive film 211 are formed. Specifically, hexafluoride, which is an etching gas, is used. Sulfur dioxide flow rate: 50 sccm, reaction pressure: 1.5 Pa, lower electrode temperature: 70°C, coil type. The RF (13.56MHz) power applied to the electrode is 500W, and the lower electrode (bias side) After setting the power input to 50W, the flow rate of the etching gas, boron trichloride, was set to 60 scc. m, chlorine flow rate 20 sccm, reaction pressure 1.9 Pa, lower electrode temperature 21°C, coil type RF (13.56MHz) power of 450W is applied to the electrode, and is applied to the lower electrode (bias side). Dry etching is performed by changing the conditions midway through the process so that the power consumption is 100W.

[0162] Furthermore, in order to reduce the number of masks and steps used in photolithography, the transmitted light is Etching is performed using a resist mask formed by a multi-level mask that provides multiple levels of intensity. A polishing process may be performed. The resist mask formed using a multi-gradation mask has multiple film thicknesses. It takes on a certain shape, and by etching, the shape can be further deformed, thus different It can be used in multiple etching processes to process into a pattern. A resist mask that supports at least two different patterns using a grayscale mask. This allows for the formation of a [specific type of mask]. Therefore, the number of exposure masks can be reduced, and the process can be simplified. It becomes Noh.

[0163] Furthermore, etching to form conductive films 207, 208, and 211 On the exposed semiconductor film 205 and insulating film 206 surfaces, boron, chlorine, fluorine, carbon, Impurities such as aluminum tend to adhere to it. Furthermore, the above impurities include conductive film 207, conductive The elements constituting the electrical film 208 and the conductive film 211 may also be included.

[0164] When the above impurities adhere to the surface of the semiconductor film 205, the transistor turns off as described above. This can easily lead to an increase in current or a deterioration of the transistor's electrical characteristics. Parasitic channels are more likely to form in film 205, and the conductive film that should be electrically isolated becomes semiconductor film 2 It becomes easier to connect electrically via 05. Therefore, in one aspect of the present invention, the conductive film 207 After etching for forming conductive film 208 and conductive film 211 is completed, the semiconductor film A cleaning process is performed to remove any impurities that may have adhered to the surfaces of 205 and the insulating film 206. cormorant.

[0165] The washing process is carried out using an alkaline solution such as TMAH solution, water, or dilute hydrofluoric acid. It is possible to do so. Specifically, when using dilute hydrofluoric acid in a cleaning treatment, 50% by weight hydrofluoric acid is used in water. 1 / 10 2 ~1 / 10 5 It is preferable to dilute it and use it in the washing process. That is, Concentration of 0.5% by weight to 5 × 10 -4 It is desirable to use a dilute hydrofluoric acid solution of weight percent in the cleaning process. The cleaning process removes the impurities adhering to the surfaces of the semiconductor film 205 and the insulating film 206. It can be removed. Also, if dilute hydrofluoric acid is used in the cleaning process, it adheres to the semiconductor film 205. The impurities can be removed along with a portion of the semiconductor film 205.

[0166] In this embodiment, the cleaning process for removing impurities after etching is performed using an absolute method. Twice, once after the formation of the edge film 206, and again after the formation of the conductive films 207, 208, and 211. Although the cases in which the procedure is performed have been described, in one aspect of the present invention, the above cleaning treatment is performed only once. You can.

[0167] Figure 12 is a top view of the liquid crystal display device at the end of the process described above. The cross-sectional view along the dashed line A1-A2 corresponds to Figure 9(D).

[0168] Next, as shown in Figure 10(A), the semiconductor film 205, the insulating film 206, and the conductive film 207 And an insulating film 212 is formed so as to cover the conductive film 208 and the conductive film 211. 12 is preferably free of impurities such as water and hydrogen, and is a single-layer insulating film. It may be a single layer, or it may be composed of multiple stacked insulating films. The insulating film 212 contains hydrogen. When hydrogen is present, it penetrates the semiconductor film 205, or the hydrogen draws oxygen from the semiconductor film 205. As a result, the area near the surface of the semiconductor film 205 becomes less resistive (n-type). Parasitic channels are easily formed near the surface of the semiconductor film 205, and by the parasitic channels There is a risk that conductive film 208 and conductive film 211 may become electrically connected. Therefore, insulating film 212 To create a film that contains as little hydrogen as possible, it is important to avoid using hydrogen in the film deposition method. ru.

[0169] Even if the above cleaning process is performed, the substrate 202 is exposed to the atmosphere before the insulating film 212 is formed. When exposed, impurities such as carbon contained in the atmosphere affect the surface of the semiconductor film 205 and the insulating film 206. It may adhere to the surface. Therefore, in one aspect of the present invention, for forming the insulating film 212 In the processing chamber, before forming the insulating film 212, the surface of the semiconductor film 205 and the insulating film 206 Impurities such as carbon adhering to the surface are removed with oxygen, nitrous oxide, or noble gases (typically A The cleaning is performed using plasma treatment with a substance such as argon to remove impurities such as carbon. It is also acceptable to do so. Then, after removing impurities by plasma treatment, the substrate 202 is exposed to the atmosphere. Without causing any damage, the insulating film 212 is formed, thereby insulating the semiconductor film 205 and the insulating film 206. This prevents impurities from entering near the interface of film 212, thereby increasing the transistor's off-current, or This can prevent the degradation of the transistor's electrical characteristics.

[0170] Furthermore, it is desirable to use a material with high barrier properties for the insulating film 212. For example, burr As insulating films with high thermal properties, silicon nitride film, silicon oxide nitride film, aluminum nitride film, aluminum oxide film Aluminum film or aluminum nitride oxide film can be used. Multiple layers are stacked. When using an insulating film, an insulating film such as an oxygen-containing silicon oxide film or silicon oxide nitride film is used as described above. It is formed closer to the semiconductor film 205 than to the highly transparent insulating film. And, an oxygen-containing insulating film A highly barrier insulating film is formed with a border film in between, overlapping with the semiconductor film 205. By using an insulating film with high barrier properties, within the semiconductor film 205, within the gate insulating film 204, or This occurs when impurities such as water or hydrogen enter the interface between the semiconductor film 205 and other insulating films, or in the vicinity thereof. It can prevent it from getting inside.

[0171] Furthermore, when multiple stacked insulating films are used as the insulating film 212, the insulating films other than the first layer and For example, acrylic resin, polyimide resin, benzocyclobutene resin, polyamide Heat-resistant organic materials such as resins and epoxy resins can be used. In addition to the materials, siloxane resins, silicon dioxide, silicon nitride, silicon oxide nitride, silicon dioxide, and Lumina and other materials can be used. Siloxane resins are composed of silicon (Si) and oxygen (O) It is a material whose skeletal structure is formed by the bonds of these atoms. In addition to hydrogen, fluorine and fluoropolymers can be used as substituents. It has at least one of the following: a group, an organic group (e.g., an alkyl group, an aromatic hydrocarbon) That is also good. And for forming the insulating film 212, depending on the material, CVD method, sputtering method, Spin coating, dipping, spray coating, droplet ejection (inkjet method), printing method ( Formed using methods such as clean printing and offset printing. Also, a doctor's knife and a rhinoceros knife are used. It may also be formed using equipment such as a coater, curtain coater, or knife coater. The acid is fabricated by chemical vapor deposition using an organosilane as the insulating film layer other than the first layer. Silicon film can also be used. Examples of organosilanes include ethyl silicate (TEOS:Si(O)). C2H5)4), trimethylsilane (TMS:(CH3)3SiH), tetramethylsilane Tetrasiloxane (TMCTS), Octamethylcyclotetrasiloxane (OMCTS) ), hexamethyldisilazane (HMDS), triethoxysilane (SiH(OC2H5) 3) Trisdimethylaminosilane (SiH(N(CH3)2)3), etc. can be used. Cut.

[0172] In this embodiment, a silicon oxide film with a thickness of 300 nm formed by sputtering is used as the insulating film 212 It is used as follows. The substrate temperature during film formation should be between room temperature and 300°C, according to this embodiment. Let's set it to 100°C.

[0173] Next, as shown in Figure 10(B), the gate insulating film 204, the semiconductor film 205, and the insulating film are arranged. By processing 212 into the desired shape using photolithography etching, , openings 213 and 214 are formed.

[0174] In this embodiment, dry etching by the ICP etching method is used to create the gate insulating film. Patterning is performed on 204, the semiconductor film 205, and the insulating film 212. Specifically, etching The flow rates for the gases trifluoromethane, helium, and methane were set to 22.5 sccm each. , 127.5 sccm, 5 sccm, reaction pressure 3.5 Pa, lower electrode temperature 21°C, The RF (13.56MHz) power applied to the till-type electrode is 475W, and the lower electrode (bias) Dry etching is performed with a power supply of 300W applied to the side.

[0175] The region where the opening 213 is formed is a part of the region where the conductive film 208 is formed, and is conductive Because it overlaps with a portion of the region where film 210 is formed, the conductive film at the opening 213 208 and the conductive film 210 are partially exposed. Also, the region in which the opening 214 is formed is Because it overlaps with a portion of the area where the conductive film 210 is formed, the opening 214 is conductive The film 210 is partially exposed.

[0176] Figure 13 is a top view of the liquid crystal display device at the end of the process described above. The cross-sectional view along the dashed line A1-A2 corresponds to Figure 10(B).

[0177] Next, as shown in Figure 10(C), conductive film 208 and conductive film 21 A conductive film 215 that is in contact with 0, and a conductive film 216 that is in contact with the conductive film 210 at the opening 214. The conductive film 216 functions as a pixel electrode, and a portion of it is also provided on the insulating film 212. It is being done.

[0178] In the case of a transmissive liquid crystal display device, conductive films 215 and 216 are conductive films that are light-transmitting. It is preferable to form them with materials. Furthermore, conductive films 215 and 216 are reflective liquid crystals. In the case of display devices, it is desirable to form them from a conductive material that reflects light.

[0179] Specifically, conductive films 215 and 216 are indium oxide, indium oxide-oxide Contains tin (ITO: Indium Tin Oxide), silicon, or silicon oxide. Indium oxide-tin oxide, Indium oxide-zinc oxide Indium oxide containing tungsten oxide and zinc oxide, and nitrogen-containing A l-Zn oxide semiconductor, nitrogen-containing Zn oxide semiconductor, nitrogen-containing Sn-Z n-based oxide semiconductors, gold (Au), platinum (Pt), nickel (Ni), tungsten (W) Chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), In addition to palladium (Pd) and titanium (Ti), other elements belonging to Group 1 or Group 2 of the periodic table Elements, namely alkali metals such as lithium (Li) and cesium (Cs), and magnesium Alkaline earth metals such as magnesium (Mg), calcium (Ca), strontium (Sr), and and alloys containing these (MgAg, AlLi), europium (Eu), ytterbium ( Rare earth metals such as Yb and alloys containing them can be used. 215 and the conductive film 216 are, for example, deposited by sputtering or evaporation (including vacuum evaporation). After forming a conductive film using the above materials, etching is performed using photolithography. The conductive film can then be formed by processing it into a desired shape.

[0180] After the above process, an insulating film that functions as a spacer is formed on the insulating film 212, and is used as a pixel electrode. A conductive film 216 that functions and a separately prepared counter electrode are placed facing each other with a liquid crystal layer in between. By doing so, a liquid crystal display device can be manufactured.

[0181] In this embodiment, the case in which transistor 12 has a single-gate structure is illustrated as an example. However, if necessary, it has multiple electrically connected conductive films 203, It is also possible to form multi-gate transistors that have multiple gate formation regions.

[0182] This embodiment can be implemented in appropriate combination with other embodiments.

[0183] (Embodiment 4) Next, the appearance of the panel of a liquid crystal display device according to one aspect of the present invention will be described using Figure 14. To clarify, Figure 14(A) shows that substrate 4001 and opposing substrate 4006 are sealed by a sealing material 4005. Figure 14(B) is a top view of the bonded panel, and is shown in Figure 14(A) along the dashed line E1-E This corresponds to the cross-sectional view in section 2.

[0184] The pixel section 4002 and the scanning line driving circuit 4004 are located on the substrate 4001. A sealing material 4005 is provided. Also, a pixel section 4002 and a scanning line driving circuit 4004 A counter substrate 4006 is provided on top of it. Therefore, the pixel section 4002 and the scanning line driving circuit 4 004 is formed by the substrate 4001, the sealing material 4005 and the opposing substrate 4006, and the liquid crystal layer 40 It is sealed together with 07.

[0185] Furthermore, in a region different from the region surrounded by the sealing material 4005 on the substrate 4001, A circuit board 4021 on which the signal line drive circuit 4003 is formed is mounted. In Figure 14, The transistor 4009 included in the line drive circuit 4003 is shown as an example. In this configuration, the scan line driving circuit 4004 is formed on the substrate 4001 together with the pixel section 4002. The example shows a case where the scan line drive circuit 4004 is formed on a separate substrate, but the substrate 400 It may also be implemented in 1. In this embodiment, the signal lines formed on the substrate 4021 The example shows the case where the drive circuit 4003 is mounted on the board 4001, but the signal line drive cycle The path 4003 may be formed on the substrate 4001 together with the pixel section 4002. Alternatively, A part of the scan line drive circuit 4003, or a part of the scan line drive circuit 4004, controls the pixel section 4002 They may also be formed on the substrate 4001.

[0186] Furthermore, the pixel section 4002 and the scanning line driving circuit 4004 provided on the substrate 4001 are transistors It has multiple transistors. In Figure 14(B), transistor 4 is included in the pixel section 4002. 010 is shown in the diagram. The pixel electrode 4030 of the liquid crystal element 4011 is connected to transistor 4 It is connected to 010. And the counter electrode 4031 of the liquid crystal element 4011 is on the counter substrate 4 It is formed in 006. The pixel electrode 4030, the counter electrode 4031, and the liquid crystal layer 4007 overlap. The part that looks like this corresponds to the liquid crystal element 4011.

[0187] Furthermore, the shielding film 4040 formed on the opposing substrate 4006 is shaped by the transistor 4010 It overlaps with the area where it is being done. Also, the opposing substrate 4006 has a color filter. A functional colored layer 4041 is formed that preferentially transmits only visible light in a specific wavelength range. Furthermore, the colored layer 4041 overlaps with the region where the liquid crystal element 4011 is formed.

[0188] Colored layers 4041 that preferentially transmit light in wavelength regions corresponding to red, blue, and green, respectively. By providing a white element for each pixel, a full-color image can be displayed. In this case, the white element Using a backlight that provides sufficient light is desirable for improving the color purity of the image. As a backlight that produces white light, for example, a combination of red, blue, and green light sources can be used. A combination of light sources, a combination of yellow or orange light sources and blue light sources, and a single white light source. This configuration, which combines a cyan light source, a magenta light source, and a yellow light source, is used. It is possible.

[0189] Alternatively, the backlight can sequentially output light in the wavelength ranges corresponding to red, blue, and green. It is also possible to display a full-color image without using a color filter. This allows for an increase in the luminous efficiency of liquid crystal display devices.

[0190] In addition, light sources used for backlighting include not only cold cathode fluorescent lamps but also light-emitting elements such as LEDs and OLEDs. A child can be used. However, the wavelength of light obtained differs depending on the light source, so if necessary It is best to select a light source that is appropriate for the color you want to capture.

[0191] In Figure 14, the shielding film 4040 and the colored layer 4041 are provided on the opposing substrate 4006 side. Although this is an example, the shielding film 4040 or the colored layer 4041 is provided on the substrate 4001 side. It is also acceptable. The direction of light incidence onto the liquid crystal element 4011 and the emission of light that has passed through the liquid crystal element 4011 Depending on the direction, the positions of the shielding film 4040 and the colored layer 4041 can be appropriately determined. can.

[0192] Furthermore, the spacer 4035 is the distance (serg) between the pixel electrode 4030 and the counter electrode 4031. It is provided to control the cap. Note that in Figure 14(B), spacer 4035 However, the example given is that it is formed by patterning an insulating film, but spherical space It is also acceptable to use "sa".

[0193] Furthermore, the signal line drive circuit 4003, the scan line drive circuit 4004, and the pixel unit 4002 are supplied Various signals and potentials are transmitted via wiring 4014 and 4015 to connection terminal 4016. It is supplied from. The connection terminal 4016 is connected to the terminals of FPC4018 and an anisotropic conductive film 4 It is electrically connected via 019.

[0194] This embodiment can be implemented in appropriate combination with other embodiments.

[0195] (Embodiment 5) Figure 15 is an example of a perspective view showing the structure of a liquid crystal display device. The liquid crystal display device shown in Figure 15. It comprises a panel 1601 in which a pixel portion is formed between a pair of substrates, a first diffuser plate 1602, and A rhythm sheet 1603, a second diffuser plate 1604, a light guide plate 1605, and multiple light sources 16 A backlight 1620 having 07, a reflector 1606, a circuit board 1608, and a signal line It has a substrate 1611 on which a drive circuit is formed.

[0196] Panel 1601, first diffuser plate 1602, prism sheet 1603, second diffuser plate 1604, the light guide plate 1605, and the reflector plate 1606 are stacked in that order. To 1620 is positioned at the end of the light guide plate 1605. Diffused inside the light guide plate 1605 Light from the light source 1607 is directed to the first diffuser plate 1602, the prism sheet 1603, and the second diffuser plate. The diffuser plate 1604 irradiates the panel 1601 uniformly.

[0197] In this embodiment, a first diffuser plate 1602 and a second diffuser plate 1604 are used. However, the number of diffusers is not limited to this; it can be one or three or more. The diffuser plate only needs to be placed between the light guide plate 1605 and the panel 1601. Therefore, prism The diffuser plate may be provided only on the side closer to panel 1601 than sheet 1603. Even if the diffuser plate is provided only on the side closer to the light guide plate 1605 than the prism sheet 1603, good.

[0198] Furthermore, the prism sheet 1603 is not limited to having a sawtooth cross-section as shown in Figure 15, and the light guide It is sufficient if the shape is such that it can concentrate the light from plate 1605 towards panel 1601.

[0199] Circuit board 1608 contains circuits that generate various signals input to panel 1601, or Circuits for processing these signals are provided. And in Figure 15, the circuit board 160 8 and panel 1601 are connected via COF tape 1609. Also, signal lines The substrate 1611 on which the drive circuit is formed is subjected to the COF (Chip On Film) method It is connected to COF tape 1609.

[0200] In Figure 15, the control system circuit that controls the driving of the backlight 1620 is located on circuit board 1608. The control system circuit and the backlight 1620 are connected via the FPC 1610. An example of a continuation is shown. However, the control system circuit described above is formed on panel 1601. It is also acceptable for the panel 1601 and the backlight 1620 to be connected by an FPC or the like. Ensure it continues.

[0201] Note that in Figure 15, an edge-lit backlight 1 is located at the edge of panel 1601. Although the example shows the use of 620, the present invention is not limited to this configuration. In one embodiment, a direct-type backlight positioned directly below the panel 1601 may be used. Alternatively, in one aspect of the present invention, a front light may be used.

[0202] This embodiment can be implemented in appropriate combination with other embodiments.

[0203] (Embodiment 6) Figure 17 illustrates the structure of a light-emitting device according to one aspect of the present invention. Figure 17(A) shows a device with pixels. This is an example of a cross-sectional view of transistor 300 in the channel length direction.

[0204] Figure 17(A) shows the gate electrode 301 on the insulating surface and the gate located on the gate electrode 301. A semiconductor comprising a gate insulating film 302 and a gate electrode 301 located on the gate insulating film 302. The film 303 and the island-shaped insulating film 304 located on the semiconductor film 303 and overlapping with the gate electrode 301. And, a conductive film 305 located on the semiconductor film 303 and an insulating film 304 are sandwiched in between, and also semi Conductive films 306a and 306b located on the conductive film 303, semiconductor film 303, insulating Insulating film 307 located on film 304, conductive film 305, conductive film 306a, and conductive film 306b And, located on the insulating film 307, a conductive film 3 is transmitted through an opening 308 provided in the insulating film 307. The pixel electrode 309 connected to 06a, and the opening provided in the insulating film 307 and the semiconductor film 303 The mouth portion 310, the insulating film 320 located on the pixel electrode 309, and the insulating film 320 At the opening 321, the EL layer 322 and the counter electrode 32 are sequentially stacked on the pixel electrode 309. Figure 3 is shown.

[0205] Then, in Figure 17(A), the gate electrode 301, gate insulating film 302, semiconductor film 303, The insulating film 304, conductive film 306a, and conductive film 306b, which function as channel protective films, It constitutes the radiator 300. And the conductive film 306a and conductive film 306b are either One electrode functions as the source electrode, and the other as the drain electrode.

[0206] Furthermore, in Figure 17(A), the pixel electrode 309, EL layer 322 and opposite are shown in the aperture 321. The portion where the electrodes 323 are stacked corresponds to the light-emitting element 324.

[0207] A method for manufacturing a light-emitting device according to one aspect of the present invention comprises the steps of forming a gate electrode 301 and The process involves forming the edge film 304 and forming the conductive film 305, conductive film 306a, and conductive film 306b. The process involves forming an opening 308 in the insulating film 307, and also forming the insulating film 307 and the semiconductor A step of forming an opening 310 in the film 303, a step of forming a pixel electrode 309, and an insulating film 3 A step of forming an opening 321 in 20, and a photolithography method using a mask The present invention uses the following steps: In other words, in one aspect of the present invention, the step of forming an opening 310 in the insulating film 307. In this process, the shape of the semiconductor film 303 is processed, so the shape of the semiconductor film 303 is processed independently. The process using photolithography, which is solely for the purpose of processing, can be omitted. In a light-emitting device according to one aspect of the present invention, a photoresist performed by photolithography is used. This allows for the partial omission of a series of processes, including film formation, exposure, development, etching, and stripping. Furthermore, it reduces the number of expensive exposure masks needed, thus simplifying the fabrication of the light-emitting device. It can reduce the costs incurred.

[0208] Furthermore, conductive films 305, 306a, and 306b are made of insulating film 307 and semiconductor It exists between the films 303. Therefore, in the process of forming the opening 308 in the insulating film 307 When a manufacturing method is used that also processes the shape of the semiconductor film 303, the conductive film 305, conductive film 30 It is difficult to process the shape of the semiconductor film 303 located beneath 6a and the conductive film 306b. And, conductive film 305, conductive film 306a, and conductive film 306b overlap with semiconductor film 303. When this is the case, the electric field applied from the pixel electrode 309 to the semiconductor film 303 causes the semiconductor film 30 Parasitic channels may form in 3. When parasitic channels are formed, they are electrically separated. The conductive film 305 and the conductive film 306a or conductive film 306b are semiconductor film 303 Because it is electrically connected via this, it causes a decrease in the displayed image quality.

[0209] Therefore, in a light-emitting device according to one aspect of the present invention, the position of the opening 310 is such that the conductive film 305 is... A conductive film 306a or conductive film 306b is defined between them, thereby partially forming the semiconductor film 303. The configuration is such that it is removed. Note that in Figure 17(A), the semiconductor film 303 in the opening 310 The example also illustrates the case where not only the insulating film 307 but also the gate insulating film 302 has been removed. In one aspect of the present invention, the gate insulating film 302 is not necessarily removed at the opening 310. It is not necessary, and the gate insulating film 302 may remain in the opening 310.

[0210] Figure 17(B) shows an example of a top view of a light-emitting device having the cross-sectional structure shown in Figure 17(A). However, in Figure 17(B), in order to clarify the layout of the light-emitting device, gate insulation is used. The film 302, insulating film 307, insulating film 320, EL layer 322, and counter electrode 323 were omitted. A top view is shown. Also, the cross-sectional view along the dashed line A1-A2 in Figure 17(B) is shown in Figure 17(A). This corresponds to ).

[0211] As shown in Figures 17(A) and 17(B), in one aspect of the present invention, the semiconductor film 303 and The insulating film 307 is located between the conductive film 305 and the conductive film 306a or the conductive film 306b. An opening 310 is provided.

[0212] As shown in Figures 17(A) and 17(B), the opening 310 allows for the opening to be used in one aspect of the present invention. , a semiconductor film 303 located beneath conductive film 306a or conductive film 306b, and conductive film 305 The semiconductor film 303 located below it is in a separated state. Therefore, in one aspect of the present invention Even when an electric field is applied to the semiconductor film 303 from the pixel electrode 309, etc., the opening 310 is a conductive film By being present between 305 and the conductive film 306a or conductive film 306b, the semiconductor film 303 The formation of parasitic channels can be suppressed. By being suppressed, the conductive film 305 and the conductive film 306a or conductive film 306b will not be subjected to unintended action. This prevents electrical connection and thus prevents a decrease in image quality displayed on the light-emitting device.

[0213] Note that in Figure 17(B), the semiconductor film located beneath conductive film 306a or conductive film 306b For example, consider the case where 303 and the semiconductor film 303 located beneath the conductive film 305 are completely separated. This indicates that, however, in one aspect of the present invention, the semiconductor film 303 is not necessarily completely separated. It is not necessary to do so, and between the conductive film 305 and the conductive film 306a or conductive film 306b, The conductive film 303 may be partially separated.

[0214] Figure 18 shows an example of a top view of a light-emitting device having the cross-sectional structure shown in Figure 17(A). Furthermore, in Figure 18, in order to clarify the layout of the light-emitting device, the gate insulating film 302, The top view shows the edge film 307, insulating film 320, EL layer 322, and counter electrode 323 omitted. .

[0215] In the light-emitting device shown in Figure 18, the shape of the opening 310 is different from that in Figure 17(B). Figure 18 Then, the opening 310 is connected to the conductive film 305 and the conductive film 306a, as in the case of Figure 17(B). Or it is located between conductive films 306b, but under conductive film 306a or conductive film 306b The semiconductor film 303 located above the conductive film 305 and the semiconductor film 303 located below the conductive film 305 are at the opening 31 They are connected in regions other than 0. That is, in Figure 18, conductive film 305 and conductive film 306a Alternatively, the semiconductor film 303 is partially separated from the conductive film 306b. Even when the conductive film 303 is partially separated, the formation of parasitic channels is suppressed. This effect can be obtained.

[0216] Furthermore, a portion of the region where the opening 310 is formed is a conductive film 306a or conductive film 306b They may overlap. Alternatively, the conductive film 305 may be located in part of the region where the opening 310 is formed. It is acceptable for the formed area to overlap with the area being formed.

[0217] Figure 19(A) shows a cross-sectional view of the transistor 300 of the pixel in the channel length direction. An example is shown. Figure 19(B) also shows a light-emitting device having the cross-sectional structure shown in Figure 19(A). An example of a top view is shown. However, in Figure 19(B), the layout of the light-emitting device is made clearer. Therefore, the gate insulating film 302, insulating film 307, insulating film 320, EL layer 322, and counter-electric A top view is shown with pole 323 omitted. Also, the cross section at the dashed line B1-B2 in Figure 19(B) is shown. The top view corresponds to Figure 19(A).

[0218] In the light-emitting device shown in Figures 19(A) and 19(B), the region where the opening 310 is formed is shown in Figure This differs from the cases shown in Figures 17(A) and 17(B). In Figures 19(A) and 19(B), the opening A portion of the region where part 310 is formed overlaps with the region where the conductive film 306a is formed. The semiconductor film 303 located beneath the conductive film 306a is removed during the formation of the opening 310. No. Therefore, within the region where the opening 310 is formed, the semiconductor film 303 is partially It remains in a state where the edge of the semiconductor film 303 at the opening 310 and the insulating film 30 It does not coincide with the end of 7.

[0219] In one aspect of the present invention, an opening 310 is formed as shown in Figures 19(A) and 19(B). Even if a portion of the area to be formed overlaps with the area where the conductive film 306a is formed, the conductive film 306 The semiconductor film 303 located below a and the semiconductor film 303 located below the conductive film 305 are, This allows for a separation of the parasitic channels. Therefore, the production of parasitic channels is suppressed. You can obtain this.

[0220] Furthermore, a portion of the region where the opening 310 is formed overlaps with the region where the conductive film 306b is formed. Even in such cases, the effect of suppressing the generation of parasitic channels can be obtained. Alternatively, a portion of the region where the opening 310 is formed may overlap with the region where the conductive film 305 is formed. Even in such cases, the effect of suppressing the generation of parasitic channels can be obtained.

[0221] Furthermore, the region where the opening 310 is formed is partially separated from the region where the conductive film 306a is formed. If they overlap, an opening 308 is provided to connect the conductive film 306a and the pixel electrode 309. There is no need to do so. Therefore, there is no need to secure an area for forming the opening 308. This enables high resolution of the pixel area.

[0222] Furthermore, Figure 20(A) shows the cross-section of the transistor 300 of the pixel in the channel length direction. An example of a surface view is shown. Also, Figure 20(B) shows a light-emitting device having the cross-sectional structure shown in Figure 20(A). An example of a top view of the device is shown. However, in Figure 20(B), the layout of the light-emitting device is clearly shown. To achieve this, the gate insulating film 302, insulating film 307, insulating film 320, EL layer 322, and A top view is shown with the counter electrode 323 omitted. Also, the dashed line C1-C2 in Figure 20(B) The cross-sectional view shown corresponds to Figure 20(A).

[0223] The light-emitting device shown in Figures 20(A) and 20(B) has a conductive film 3 in the same layer as the gate electrode 301. In terms of the provision of 11, the light-emitting device and structure shown in Figures 17(A) and 17(B) The differences are as follows. Specifically, in Figures 20(A) and 20(B), the conductive film 311 is on the insulating surface. The gate insulating film 302 and the semiconductor film 303 are positioned so that they are sequentially stacked on the conductive film 311. It is provided therein, and a conductive film 305 is located on the semiconductor film 303 at a position that overlaps with the conductive film 311. A system is in place.

[0224] In Figures 20(A) and 20(B), the region where the opening 310 is formed and the conductive film are shown. The region where 311 is formed partially overlaps with the region where the conductive film 311 is formed at the opening 310. A portion of it is exposed. And the conductive film 311 is located beneath the semiconductor film 303. Therefore, the semiconductor film 303 is partially removed at the opening 310. Thus, Figure In the cases of 20(A) and 20(B), a position beneath the conductive film 306a or conductive film 306b The semiconductor film 303 placed below the conductive film 305 and the semiconductor film 303 located beneath the conductive film 305 are separated. Because it is in a certain state, the effect of suppressing the generation of parasitic channels can be obtained.

[0225] In addition, in a light-emitting device according to one aspect of the present invention, the semiconductor film 303 of the transistor 300 However, it includes wide-bandgap semiconductors such as oxide semiconductors as described above.

[0226] (Embodiment 7) Next, an example of the specific configuration of the pixel portion of a light-emitting device according to one aspect of the present invention will be given. I will explain.

[0227] Figure 24(A) shows an example of the configuration of the pixel unit 510. In Figure 24(A), the pixel unit 510 is configured with Y scan lines GL (GL1 to GLy) whose potential is controlled by a scan line drive circuit, and a signal x signal lines SL (SL1 to SLx) whose potential is controlled by a line drive circuit, and pixel electricity x power lines VL (VL1 to VLx) are provided to supply potential to the poles.

[0228] Furthermore, the scan line GL is connected to each of the multiple pixels 511. Specifically, each scan Line GL is provided in any row of the multiple pixels 511 arranged in a matrix. It is connected to x pixels 511.

[0229] Furthermore, the signal line SL is connected to a plurality of pixels 511 provided in the x column and y row of the pixel section 510. The power line VL is connected to y pixels 511 located in any of the rows. In 10, among the multiple pixels 511 provided in column x and row y, one of the columns provided It is connected to y pixels 511.

[0230] In this embodiment, pixel 511 is connected to scan line GL, signal line SL, and power line VL respectively. The example shows the case where connections are made, but the type and number of wires connected to each pixel 511 are not specified. This can be appropriately determined by the configuration, number, and arrangement of the pixels 511.

[0231] Figure 24(B) shows an example of the circuit diagram of pixel 511. Pixel 511 is the image to pixel 511. A transistor 512 controls the signal input, and there are a pixel electrode, a counter electrode, and a pixel electrode opposite to it. A light-emitting element 515 having an EL layer provided between electrodes, and a light-emitting element 51 that reacts according to the image signal 5 has a transistor 513 that controls the potential of the pixel electrodes and a transistor that holds the potential of the image signal. It has a capacitive element 514 for this purpose.

[0232] Note that Figure 24(B) illustrates the case where pixel 511 has a capacitive element 514, For example, if the gate capacitance formed between the gate electrode and the active layer of transistor 513 is sufficiently large In cases where the potential of the image signal can be sufficiently maintained by other capacitances, such as when capacitance is not necessary, the capacitance element is not necessarily required. It is not necessary to provide child 514 in pixel 511.

[0233] The light-emitting element 515 includes elements whose brightness is controlled by current or voltage. For example, an OLED element can be used as the light-emitting element 515. The element has at least an EL layer, an anode, and a cathode. The anode and cathode are either one or the other. One side functions as the pixel electrode, and the other side functions as the counter electrode. The EL layer is between the anode and cathode. It is provided and consists of one or more layers. Inorganic compounds are placed within these layers. It may also contain. Luminescence in the EL layer ranges from singlet excited states to ground states. The emission (fluorescence) when returning to the state and the emission (phosphorescence) when returning from the triplet excited state to the ground state are It is included.

[0234] The potential of the pixel electrodes of the light-emitting element 515 is controlled according to the image signal input to the pixel 511. Furthermore, the brightness of the light-emitting element 515 is determined by the potential difference between the pixel electrode and the counter electrode. And in each of the multiple pixels 511 of the pixel section 510, the light-emitting element 51 The brightness of 5 is adjusted according to the image signal, so that an image is displayed in the pixel unit 510.

[0235] Pixel 511 may contain transistors, diodes, resistors, capacitive elements, and industrial components as needed. It may also have other circuit elements such as kuta.

[0236] Next, the pixel 511 has transistor 512, transistor 513, and capacitive element 51 4. The connection configuration of the light-emitting element 515 will be explained.

[0237] Transistor 512 has either its source terminal or drain terminal connected to the signal line SL. The other terminal, either the source or drain terminal, is connected to the gate electrode of transistor 513. ru. Transistor 513 has either its source or drain terminal connected to the power line VL. The other terminal, either the source terminal or the drain terminal, is connected to the light-emitting element 515. 5 has a pixel electrode, a counter electrode, and an EL layer between the pixel electrode and the counter electrode, specifically Specifically, the source terminal or drain terminal of transistor 513 is connected to the light-emitting element 515. It is connected to the pixel electrode. A potential (common potential) is applied to the counter electrode of the light-emitting element 515.

[0238] The power supply potential and the common potential are the same when transistor 513 is ON, and are the same as the pixel electrodes of light-emitting element 515. A forward bias voltage large enough to cause the light-emitting element 515 to emit light is applied between the and the counter electrode. It is a potential difference that would result in this.

[0239] Furthermore, transistors 512 and 513 have gates that are present only on one side of the active layer. It is sufficient to have at least electrodes, but the pair of gate electrodes that exist with the active layer in between It may have. Also, transistors 512 and 513 have a single gate voltage. It may be a single-gate structure having poles and a single channel-forming region, or electrically connected Having multiple connected gate electrodes, it has multiple channel-forming regions, a multi-gate It may also be a T-structure.

[0240] Next, the driving method of the light-emitting device shown in Figures 24(A) and 24(B) will be explained.

[0241] Scan lines GL1 through GLy are selected in order. For example, scan line GLj (where j is between 1 and y). When a natural number (of the sequence) is selected, transistor 5 has its gate electrode connected to scan line GLj. 12 turns on. Then, the potential of the image signal input to signal line SL1 or signal line SLx is turned on. However, when transistor 512 is turned on, it is applied to the gate electrode of transistor 513. Then, when the selection of scan line GLj is complete, transistor 512 turns off, and the image The potential of the image signal is held at the gate electrode of transistor 513.

[0242] Then, if transistor 513 is turned on according to the potential of the image signal, the light-emitting element 515 The light-emitting element 515 lights up when current is supplied to it. The value of the current flowing through the light-emitting element 515 Since this is determined by the drain current of transistor 513, the brightness of light-emitting element 515 is It is determined according to the potential of the image signal. Conversely, according to the potential of the image signal, transistor 513 When it is turned off, no current is supplied to the light-emitting element 515, and the light-emitting element 515 turns off. Light it.

[0243] The above steps allow the image to be displayed.

[0244] Note that in Figure 24(B), transistor 512 is used as a switching element. Although this example illustrates a case, the present invention is not limited to this configuration. One switching element and Multiple transistors that function together may be used in pixel 511. When a transistor functions as a single switching element, the above multiple transistors are connected in parallel. They can be connected in series, or in a combination of series and parallel. It's okay if it's included.

[0245] By including an oxide semiconductor in the channel formation region of transistor 512, the off-current is extremely low. This makes it possible to create a small yet high-voltage transistor 512. By using transistor 512 having the above configuration as a switching element, a normal series Compared to using transistors made of semiconductor materials such as condensate or germanium, This prevents the leakage of charge accumulated in the gate electrode of transistor 513.

[0246] By using transistor 512, which has an extremely low off-current, the gateway of transistor 513 This allows for a longer period during which the potential of the electrode is maintained. Therefore, like a still image... , over several consecutive frame periods, the pixel unit 510 receives an image message containing the same image information. When a number is written, the drive frequency is lowered, or in other words, within a certain period of time Even if the number of times the image signal is written to the pixel unit 510 is reduced, the display of the image can be maintained. Yes, it is possible. For example, using transistor 512 which uses a highly purified oxide semiconductor as the active layer. By doing so, the interval between writing the image signal can be set to 10 seconds or more, preferably 30 seconds or more, and even more preferably It can be made to be more than one minute. And by lengthening the interval at which the image signal is written... The more you do this, the more you can reduce power consumption.

[0247] Furthermore, because the potential of the image signal can be maintained for a longer period of time, the potential of the image signal In order to maintain the position, the capacitive element 514 is not connected to the gate electrode of transistor 513. This also prevents a decrease in the displayed image quality. Therefore, by not providing the capacitive element 514... By doing so, or by reducing the size of the capacitive element 514, the aperture ratio can be increased. This allows for a reduction in the power consumption of the light-emitting device.

[0248] Next, regarding the layout of pixel 511 shown in Figure 24(B), using Figures 21 to 23... Let me explain. Figure 21 is an example of a top view of pixel 511. Also, Figure 22 is a comparison of Figure 21. This corresponds to an example of a cross-sectional view along the dashed-dotted lines D1-D2 and D3-D4 in the top view shown. Figure 23 is an example of a cross-sectional view along the dashed line D5-D6 of the top view shown in Figure 21. This applies. However, in Figure 21, in order to clearly show the layout of pixel 511, various insulating elements are used. The film is omitted, and a top view of pixel 511 is shown. Also, in Figure 21, various aspects of pixel 511 are shown. To clearly show the layout of the semiconductor element, the EL layer and counter element of the light-emitting element 515 are shown. The poles are omitted, and a top view of pixel 511 is shown.

[0249] In the pixel 511 shown in Figures 21 to 23, the transistor 512 has an insulating surface. A conductive film 401 that functions as a gate electrode is placed on the substrate 400, and a gate insulating film on the conductive film 401 is placed on the substrate 400. Semiconductor film located on the gate insulating film 402 at a position where it overlaps with the edge film 402 and the conductive film 401 A channel is located on the semiconductor film 403 at a position where it overlaps with the body film 403 and the conductive film 401. An insulating film 404 that functions as a protective film, and a semiconductor that functions as a source terminal or drain terminal. It has conductive films 405 and 406 located on the conductive film 403.

[0250] The conductive film 401 also functions as a scan line GL that provides potential to the gate electrode of transistor 512. Furthermore, the conductive film 405 also serves as a signal line SL that supplies the potential of the image signal to the pixel 511. It works.

[0251] Furthermore, transistor 513 functions as a gate electrode on the substrate 400 which has an insulating surface. A conductive film 407, a gate insulating film 402 on the conductive film 407, and a portion that overlaps with the conductive film 407. In this position, the semiconductor film 403 located on the gate insulating film 402 and the conductive film 407 overlap In this configuration, an insulating film 408 is located on the semiconductor film 403 and functions as a channel protective film, A conductive film 409 located on the semiconductor film 403 functions as either a source terminal or a drain terminal. and a conductive film 410.

[0252] The capacitive element 514 has a conductive film 407 on a substrate 400 having an insulating surface, and on the conductive film 407 The gate insulating film 402 and semiconductor film 403 overlap with the conductive film 407 at the gate It has an insulating film 402 and a conductive film 410 located on the semiconductor film 403.

[0253] Furthermore, insulating film 4 is present on conductive film 405, conductive film 406, conductive film 409, and conductive film 410. 11 is provided. And an insulating film 411, a semiconductor film 403, and a gate insulating film 40 Part 2 is provided with openings 412, 413, and 414.

[0254] The opening 412 is provided between the conductive film 406 and the conductive film 409. A portion of the region where 12 is formed is a portion of the region where the conductive film 406 is formed, and It overlaps with a portion of the region where film 407 is formed. At the opening 412, conductive The insulating film 411 on film 406, the insulating film 411 on conductive film 407, semiconductor film 403, and The insulating film 402 has been removed, and conductive films 406 and 407 are the conductive film 406 They are electrically connected by the conductive film 415 on the conductive film 407.

[0255] The opening 413 is provided between the conductive film 410 and the conductive films 405 and 406. Furthermore, a conductive film 409 is formed in a portion of the region where the opening 413 is formed. It overlaps with a part of the region. At the opening 413, the insulating film 411 on the conductive film 409 The conductive film 409 has been removed, and the conductive film 409 and insulating film 411 are used as pixel electrodes. It is connected to a functional conductive film 416.

[0256] The opening 414 is provided between the conductive film 410 and the conductive film 405, between adjacent pixels 511. In the opening 414, the insulating film 411, the semiconductor film 403, and the gate insulating film 40 Number 2 has been removed.

[0257] In Figures 21 to 23, a portion of the region where the opening 412 is formed is the conductive film 40 A portion of the region where 6 is formed overlaps with a portion of the region where the conductive film 407 is formed. This illustrates a case where the conductive film 406 and conductive film 415 are connected, and the conductive film The connection between 407 and the conductive film 415 will both be made at the opening 412. However, in one aspect of the present invention, the connection of conductive film 406 and conductive film 415, and conductive film 407 and The connections of the conductive film 415 may be made at different openings.

[0258] Figure 25 shows the connection point between conductive film 406 and conductive film 407 and conductive film 415, pixel 5 An example of a cross-sectional view of 11 is shown. In Figure 25, at the opening 412a provided in the insulating film 411 The conductive film 406 and the conductive film 415 are connected. Also, the insulating film 411 and the semiconductor film 403 , and in the opening 412b provided in the gate insulating film 402, conductive film 407 and conductive film 41 5 is connected.

[0259] However, as shown in Figures 21 to 23, the connection between conductive film 406 and conductive film 415 and conductive film 4 When the connection between 07 and the conductive film 415 is made at the opening 412, multiple openings Since there is no need to secure an area to form the part, the pixel part 510 can be made high-resolution. It is possible.

[0260] Furthermore, an insulating film 417 is provided on the insulating film 411 so as to partially cover the conductive film 416. The opening 418 in the insulating film 417 overlaps with a part of the conductive film 416, and the opening 4 In 18, an EL layer 419 and a conductive film 420 that functions as a counter electrode are placed on the conductive film 416. These are stacked in order. Conductive film 416, EL layer 419, and conductive film 420 are stacked. The part that is attached functions as a light-emitting element 515.

[0261] This embodiment can be implemented in appropriate combination with other embodiments.

[0262] (Embodiment 8) In this embodiment, pixel 511 shown in Figures 21 to 23 is used as an example to illustrate one aspect of the present invention. This document describes the method for manufacturing a light-emitting device related to this.

[0263] First, as shown in Figure 26(A), on the substrate 400 having an insulating surface, as a gate electrode A functional conductive film 407 is formed.

[0264] There are no major restrictions on the type of substrate that can be used as the substrate 400 having an insulating surface, however At the very least, it must have sufficient heat resistance to withstand subsequent heat treatments. Glass substrates produced by fusion or float methods can be used. For the plates, if the subsequent heat treatment temperature is high, use plates with a strain point of 730°C or higher. This is good. Also, for the glass substrate, for example, aluminosilicate glass, aluminosilicate glass, etc. Glass materials such as acidic glass and barium borosilicate glass are used.

[0265] In addition, ceramic substrates, quartz substrates, sapphire substrates, etc. can be used instead of the glass substrates mentioned above. A substrate made of edge material may also be used. Other materials such as crystallized glass can also be used. A substrate with an insulating film on the surface of a metal substrate such as a stainless steel alloy may also be used. However, light emission The device has a bottom emission structure in which light from the light-emitting element 515 is directed toward the substrate 400. In this case, a light-transmitting substrate is used for the substrate 400.

[0266] The materials for conductive film 407 are molybdenum, titanium, chromium, tantalum, tungsten, and aluminum. Metallic materials such as nium, copper, neodymium, scandium, and niobium, and these metallic materials as the main components Conductive films using alloy materials, or nitrides of these metals, can be used in single layers or in multilayer configurations. This can be done. Furthermore, if it can withstand the temperature of the heat treatment performed in a later process, Aluminum and copper can also be used as the metal material. Aluminum or copper is resistant To avoid thermal and corrosive problems, it is best to use it in combination with high-melting-point metal materials. Examples of melting point metal materials include molybdenum, titanium, chromium, tantalum, tungsten, and neodymium. Materials such as um and scandium can be used.

[0267] For example, a conductive film 407 having a two-layer structure, such as a copper film laminated on a titanium film. Structure: A two-layer structure with a molybdenum film laminated on an aluminum film, and a molybdenum film on a copper film. A two-layer structure with a copper film and a titanium nitride film or tantalum nitride film stacked on top of it. The structure, or a two-layer structure consisting of a titanium nitride film and a molybdenum film stacked on top of each other, is preferable. i. The conductive film 407 having a three-layer structure may be, for example, a titanium nitride film, a copper film, and tan. It is preferable to have a three-layer structure in which a gusten film is laminated.

[0268] Furthermore, conductive film 407 contains indium oxide, indium oxide-tin oxide, and indium oxide-acid oxide. Zinc oxide, zinc oxide, aluminum zinc oxide, aluminum zinc oxynitride, or zinc oxide Translucent metal oxides such as lium can also be used.

[0269] The thickness of the conductive film 407 is 10 nm to 400 nm, preferably 100 nm to 200 nm. In this embodiment, a tungsten film with a thickness of 200 nm is formed by sputtering. The tungsten film is then etched into a desired shape using photolithography. A conductive film 407 is formed by patterning. If the end of 7 is tapered, the coverage of the gate insulating film 402 stacked on top is improved. Therefore, it is preferable. The resist mask may also be formed by an inkjet method. Forming screens using an inkjet method eliminates the need for photomasks, thus reducing manufacturing costs. can.

[0270] In this embodiment, the case in which the conductive film 407 is directly formed on the substrate 400 is illustrated. However, an insulating film that functions as an underlayer is formed on the substrate 400, and then a conductive film is applied to the underlayer. A film 407 may be formed. For example, a silicon oxide film, a silicon oxide nitride film, or a nitride film may be used as the underlayer. Silicon film, silicon nitride / oxide film, aluminum nitride film, or aluminum nitride / oxide film It can be used as a single layer or by layering multiple layers. In particular, a barrier film can be used as a base film. Highly insulating films, such as silicon nitride films, silicon oxide nitride films, aluminum nitride films, and aluminum oxide films. By using a nium film or an aluminum nitride film, moisture or hydrogen can be removed. Impurities in the atmosphere, or impurities such as alkali metals and heavy metals contained within the substrate 400 later formed semiconductor film 403, gate insulating film 402, or semiconductor film 403 This prevents the substance from penetrating the interface of other insulating films and its vicinity.

[0271] In this specification, an oxidized nitride is defined as a compound in which the oxygen content is higher than the nitrogen content. It is a substance, and nitride oxides have a higher nitrogen content than oxygen in their composition. It means substance.

[0272] Figure 28 is a top view of the light-emitting device at the time the above process is completed. The cross-sectional view along the dashed line D5-D6 corresponds to Figure 26(A).

[0273] Next, as shown in Figure 26(B), a gate insulating film 402 is formed on the conductive film 407. The gate insulating film 402 is made of silicon oxide using plasma CVD or sputtering. Film, silicon nitride film, silicon oxide nitride film, silicon oxide nitride film, aluminum oxide film, aluminum nitride Aluminum film, aluminum oxide nitride film, aluminum oxide nitride film, hafnium oxide film, aluminum oxide film A gallium oxide film, lanthanum oxide film, or tantalum oxide film can be applied as a single layer or in multiple layers. It can be formed by layering. The gate insulating film 402 contains as few impurities as possible, such as water and hydrogen. It is preferable not to include it.

[0274] The gate insulating film 402 may consist of a single insulating film or multiple insulating films stacked together. It may also be composed of such a quantity of oxygen as the stoichiometric composition. The gate insulating film 402 is formed such that the insulating film containing it is in contact with the semiconductor film 403 that is formed later. It is desirable to achieve this. With the above configuration, oxygen is transferred from the gate insulating film 402 to the semiconductor film 403. Since it can supply [the necessary power], a transistor 513 with good electrical characteristics can be obtained. It is possible.

[0275] Furthermore, a gate insulating film having a structure in which a highly barrier insulating film and an oxygen-containing insulating film are stacked is also available. When forming the edge film 402, the highly barrier insulating film is an insulating film containing oxygen and a conductive film 40 It is desirable to provide it between 7. By using a highly barrier insulating film, moisture or water Impurities in the atmosphere such as elements, or alkali metals, heavy metals, etc. contained within the substrate 400 Impurities may be present within the semiconductor film 403, within the gate insulating film 402, or between the semiconductor film 403 and other insulating films. It can prevent penetration into the interface of the edge film and its vicinity. As a highly barrier insulating film, For example, silicon nitride film, silicon oxide nitride film, aluminum nitride film, aluminum oxide film, or Examples include aluminum nitride oxide films.

[0276] The thickness of the gate insulating film 402 is set appropriately according to the characteristics required of the transistor 513. It is sufficient if the wavelength is between 1 nm and 800 nm, preferably between 200 nm and 500 nm. This is achieved by forming a thicker gate insulating film 402, thereby improving the breakdown voltage of the transistor 513. This can be done. In this embodiment, a film thickness of 100 nm formed by plasma CVD is A silicon oxide nitride film is used as the gate insulating film 402.

[0277] Next, as shown in Figure 26(B), a film thickness of 2 nm to 200 nm is applied to the gate insulating film 402. Preferably, the film thickness is 3 nm to 50 nm, and more preferably 3 nm to 20 nm. A semiconductor film 403 of m or less is formed. The semiconductor film 403 targets an oxide semiconductor. It is used and formed by sputtering. The semiconductor film 403 is formed using a noble gas (for example, argon). ) under an atmosphere, under an oxygen atmosphere, or under a mixed atmosphere of a noble gas (e.g., argon) and oxygen It can be formed by sputtering.

[0278] Furthermore, before forming the oxide semiconductor film by sputtering, argon gas is introduced to form plasma Reverse sputtering is performed to generate sputtering, and dust adhering to the surface of the gate insulating film 402 is removed. It is preferable to do so. Reverse sputtering is a method in which voltage is not applied to the target side, and an argon atmosphere is used. Under atmospheric pressure, a voltage is applied to the substrate side using an RF power supply to form plasma near the substrate and modify the surface. This is a testing method. Note that nitrogen, helium, or other elements may be used instead of an argon atmosphere. Alternatively, the procedure may be carried out in an atmosphere where oxygen, nitrous oxide, etc., are added to an argon atmosphere. The procedure may also be carried out in an atmosphere containing chlorine, carbon tetrafluoride, etc., in addition to a argon atmosphere.

[0279] As the oxide semiconductor used in semiconductor film 403, as mentioned above, indium oxide, sodium oxide Zinc oxide, an oxide of a binary metal, such as In-Zn oxides, Sn-Zn oxides, and A l-Zn oxides, Zn-Mg oxides, Sn-Mg oxides, In-Mg oxides, I n-Ga oxides, and in-Ga-Zn oxides (also known as IGZO), which are oxides of ternary metals. (To be written as), In-Al-Zn oxides, In-Sn-Zn oxides, Sn-Ga-Zn Al-Ga-Zn oxides, Sn-Al-Zn oxides, In-Hf-Zn oxides Oxides, In-La-Zn oxides, In-Pr-Zn oxides, In-Nd-Zn acids In-Sm-Zn oxides, In-Eu-Zn oxides, In-Gd-Zn oxides Materials, In-Tb-Zn oxides, In-Dy-Zn oxides, In-Ho-Zn oxides In-Er-Zn oxides, In-Tm-Zn oxides, In-Yb-Zn oxides, In-Lu-Zn ​​oxides, and In-Sn-Ga-Zn oxides, which are oxides of quaternary metals. In-Hf-Ga-Zn oxides, In-Al-Ga-Zn oxides, In-Sn-A l-Zn oxides, In-Sn-Hf-Zn oxides, In-Hf-Al-Zn oxides These are some examples.

[0280] For example, the semiconductor film 403 is made of In (indium), Ga (gallium), and Zn ( It can be formed by sputtering using a target containing zinc. When forming a Zn-based semiconductor film 403 by sputtering, preferably, the atomic ratio is I n:Ga:Zn=1:1:1, 4:2:3, 3:1:2, 1:1:2, 2:1:3, also This uses an In-Ga-Zn oxide target represented by a 3:1:4 ratio. By forming an oxide semiconductor film using an In-Ga-Zn-based oxide target having a specific ratio, This facilitates the formation of polycrystalline or CAAC. Also contains In, Ga, and Zn. The target filling rate is 90% or more and 100% or less, preferably 95% or more and less than 100%. By using a target with a high packing density, the formed oxide semiconductor film is a dense film. Yes.

[0281] Furthermore, when using an In-Zn-based oxide as the oxide semiconductor, the composition of the target used is In terms of atomic ratio, In:Zn = 50:1 to 1:2 (converted to a mole ratio of In2O3:Zn) O=25:1~1:4), preferably In:Zn=20:1~1:1 (convert to mole ratio) Then In2O3:ZnO=10:1~1:2), more preferably In:Zn=1.5: The ratio is 1 to 15:1 (which translates to In2O3:ZnO = 3:4 to 15:2 in terms of mole ratio). For example, the target used to form the semiconductor film 403, which is an In-Zn oxide, has a number of atoms. When the ratio is In:Zn:O=X:Y:Z, assume Z>1.5X+Y. The ratio of Zn is within the above range. By enclosing them in an enclosure, mobility can be improved.

[0282] Furthermore, when using In-Sn-Zn oxide materials as oxide semiconductors, the target used The composition of the net is based on the atomic ratio of In:Sn:Zn, which can be 1:2:2, 2:1:3, or 1:1:1. Alternatively, you could use 20:45:35.

[0283] In this embodiment, the substrate is held in a processing chamber that is maintained under reduced pressure, and residual moisture in the processing chamber is removed. Sputtered gas from which hydrogen and water have been removed while removing the above target is introduced, and the above target is used An oxide semiconductor film is formed on the substrate 400. In order to remove residual moisture in the processing chamber, an absorbent is used. It is preferable to use a vacuum pump of the type that attaches to the surface. For example, a cryopump, an ion pump, or a chrysalis. It is preferable to use a tank sublimation pump. Furthermore, as an exhaust means, a turbocharger is preferable. A cold trap may be added to the pump. A cryopump can be used in the processing chamber. When exhausting, for example, hydrogen atoms, water (H2O) and other compounds containing hydrogen atoms (preferably... Because compounds containing carbon atoms are exhausted, oxide semiconductors formed in the processing chamber are affected. The concentration of impurities in the membrane can be reduced.

[0284] Three methods can be used to form the semiconductor film 403 composed of CAAC-OS. First, the semiconductor film 403 is formed at a film deposition temperature of 200°C to 450°C. The first method involves forming a thin semiconductor film 403, and then heating it at a temperature of 200°C to 700°C. The following is a method of heat treatment. The third is to first form a thin first layer of oxide semiconductor film, A heat treatment is performed at a temperature between 200°C and 700°C, followed by the formation of a second oxide semiconductor film. This is a method for forming a semiconductor film 403.

[0285] In this embodiment, the distance between the substrate 400 and the target is 100 mm, the pressure is 0.4 Pa, and the current is DC. (DC) Power supply 0.5kW, board temperature 250℃, argon and oxygen flow rates 30 Under an atmosphere of sccm and 15 sccm, an In-Ga-Zn oxide semiconductor is used. A semiconductor film 403 with a thickness of 25 nm is formed.

[0286] Furthermore, in order to minimize the presence of hydrogen, hydroxyl groups, and water in the semiconductor film 403, As a pretreatment before formation, the gate insulating film 402 is formed in the preheating chamber of the sputtering apparatus. The prepared substrate 400 is preheated to remove impurities such as moisture or hydrogen adsorbed on the substrate 400. It is preferable to exhaust the gases separately. The preheating temperature should be between 100°C and 400°C. The temperature range is between 150°C and 300°C.

[0287] Furthermore, the semiconductor film 403 formed by sputtering, etc., contains water or hydrogen as an impurity (water It may contain a large amount of acidic groups. Water or hydrogen readily forms donor levels. Therefore, it is an impurity for oxide semiconductors. In one aspect of the present invention, the semiconductor film After forming 403, the impurities such as water or hydrogen in the semiconductor film 403 are reduced (dehydration or To dehydrogenate the semiconductor film 403, nitrogen and noble gases are used under a reduced pressure atmosphere. The material is subjected to heat treatment under an inert gas atmosphere.

[0288] By subjecting the semiconductor film 403 to heat treatment, water or hydrogen is removed from the semiconductor film 403. This is possible. Specifically, the substrate can be heated to a temperature of 250°C to 750°C, preferably 400°C or higher. Heat treatment should be performed at a temperature below the strain point. If the RTA method is used for heat treatment, desaturation can be achieved in a short time. Because hydration or dehydrogenation can be performed, processing can be carried out even at temperatures exceeding the strain point of the glass substrate. In this embodiment, the material is heat-treated at 450°C for about 1 hour in an ultra-dry air atmosphere. To do so.

[0289] Furthermore, the heating apparatus is not limited to electric furnaces, but also includes heat conduction or heat radiation from heat-generating elements such as resistance heating elements. The device may include an apparatus for heating the object to be processed by injection. For example, GRTA(Gas Rapid Thermal Anneal) equipment, LRTA (Lamp Rapid RTA (Rapid Thermal Anneal) for Thermal Anneal devices, etc. A device can be used. The LRTA device uses halogen lamps and metal halide lamps. Lamps, xenon arc lamps, carbon arc lamps, high-pressure sodium lamps, high-pressure water A device that heats an object to be processed by radiating light (electromagnetic waves) from a lamp such as a silver lamp. Yes, there is. The GRTA device is a device that performs heat treatment using high-temperature gas. The gas contains aluminum. Noble gases such as gon, or inert gases such as nitrogen that do not react with the material being treated by heat treatment. The body is used.

[0290] In the heat treatment, nitrogen, or a noble gas such as helium, neon, or argon is used, along with water or water It is preferable that it does not contain elements such as nitrogen or helium. Alternatively, nitrogen or helium introduced into the heat treatment device. The purity of noble gases such as neon and argon is 6N (99.9999%) or higher, preferably 7 N(99.99999%) or higher (i.e., impurity concentration of 1 ppm or less, preferably 0.1 ppm), It is preferable to use a value of 0.5 (pm or less).

[0291] Through the above process, the concentration of water or hydrogen in the semiconductor film 403 can be reduced. Oh, in the semiconductor film 403, moisture or hydrogen is removed by the above heat treatment, as well as oxygen There is a risk that oxygen deficiency due to desorption is increasing. Therefore, after the above heat treatment, the semiconductor film It is desirable to supply oxygen to unit 403 to reduce oxygen deficiency.

[0292] High-purity semiconductors are produced by reducing the concentration of water or hydrogen, and by reducing oxygen deficiency. By using the conductive film 403, transistor 51 has high breakdown voltage and extremely low off-current. It is possible to create 3.

[0293] For example, by performing a heat treatment in an oxygen-containing gas atmosphere, oxygen is introduced into the semiconductor film 403. It can supply oxygen. Heat treatment for supplying oxygen is the same as above, for moisture or hydrogen The same conditions as those used for heat treatment to reduce the concentration should be applied. However, to supply oxygen... The heat treatment is performed using oxygen gas or ultra-dry air (CRDS (cavity ring down laser)). When measured using a spectroscopic dew point meter, the moisture content was 20 ppm (equivalent to a dew point of -55°C). ) Preferably 1 ppm or less, preferably 10 ppb or less, under an atmosphere such as air Do it.

[0294] The above oxygen-containing gas preferably has low concentrations of water, hydrogen, etc. Specifically, oxygen The concentration of impurities contained in the gas containing the specified substance is set to 1 ppm or less, preferably 0.1 ppm or less. It is preferable to do so.

[0295] Alternatively, ion implantation, ion doping, plasma immersion ion implantation Oxygen can be supplied to the semiconductor film 403 using methods such as oxygenation and plasma treatment. After supplying oxygen to the semiconductor film 403 using the above method, the crystals contained in the semiconductor film 403 If the part is damaged, heat treatment is performed to repair the damaged crystalline part. good.

[0296] A resist mask for forming the semiconductor film 403 may be formed by an inkjet method. When a resist mask is formed using an inkjet method, a photomask is not used, so the manufacturing process It can reduce stress.

[0297] Next, as shown in Figure 26(C), an insulating film is formed on the semiconductor film 403, and then photolithography is performed. By etching using the sography method, the channel protective film and It forms an island-shaped insulating film 408 that functions as such. The insulating film 408 is on the semiconductor film 403. It is placed in a position that overlaps with the conductive film 407.

[0298] The film thickness of the insulating film 408 is 50 nm or more and 600 nm or less, preferably 100 nm or more and 400 nm or less. The size should be less than or equal to nm. Furthermore, the insulating film 408 uses the same structure and material as the gate insulating film 402. It can be formed by doing so. And the insulating film 408, like the gate insulating film 402, is water It is desirable that the product contains as few impurities as possible, such as hydrogen, and that its composition exceeds stoichiometric limits. It is desirable to include a certain amount of oxygen. With the above configuration, moisture in the semiconductor film 403, water The concentration of impurities such as elemental compounds is kept low, and oxygen is supplied from the insulating film 408 to the semiconductor film 403. Since it can be supplied, a transistor 513 with good electrical characteristics can be obtained. Cut.

[0299] In this embodiment, a silicon oxide nitride film with a thickness of 300 nm formed by plasma CVD is used. It is used as insulating film 408.

[0300] Furthermore, the insulating film 408 is a metal oxide containing at least one of In or Zn. Furthermore, by including Ti, Zr, Hf, Ge, Ce, etc., it provides better insulation than semiconductor film 403. Metal oxides with improved properties may also be used.

[0301] For example, an In-M1-M2-Zn oxide may be used as the insulating film 408. However, the original Element M1 is a trivalent element belonging to groups 3A, 3B, and 4A. M2 is a tetravalent element belonging to groups 4A and 4B. Specifically, element M When Ga is used in 1, in In-M1-M2-Zn oxides, a portion of the trivalent Ga It will be replaced by a tetravalent element. Tetravalent elements have one more bond than trivalent elements. Since there are many, by replacing some of the trivalent elements with tetravalent elements, In-M1-M2-Zn This can increase the bonding strength between the metal element (M1 or M2) that makes up the oxide system and oxygen. Therefore, by using an In-M1-M2-Zn oxide as the insulating film 408, The insulating properties can be improved. Specifically, as element M2, Ti, Zr, Hf, Ge, Examples include Ce.

[0302] For example, using a target with In:Zr:Ga:Zn=3:0.05:0.95:2, An insulating film 408 using an In-M1-M2-Zn oxide was formed by sputtering. You should do that.

[0303] Also, for example, the chemical formula InMZnO x In-M-Zn oxide represented by insulating film 408 It may also be used. As element M, the insulating properties of the In-M-Zn oxide are such that the semiconductor film 403 An element is applied that has a higher insulating property than the constituent metal oxide. For example, let element M Therefore, tetravalent elements such as Ti, Zr, Hf, Ge, and Ce can be applied. Since tetravalent elements have one more bond than trivalent elements, I use these tetravalent elements as element M. nM-Zn oxides have a strong bond between element M and oxygen. Therefore, In-M-Zn oxides... By using a material in the insulating film 408, the insulating properties of the insulating film 408 can be improved.

[0304] For example, the energy gap of an In-Zr-Zn oxide using Zr as the element M is: The energy gap becomes larger than that of In-Ga-Zn oxides (approximately 3.2 eV). In other words, In-Zr-Zn oxides have higher insulating properties than In-Ga-Zn oxides. El.

[0305] Furthermore, yttrium has lower electronegativity than ga. Therefore, In-M1-M2-Z In n-based oxides, if element M2 is yttrium, the electronegativity of oxygen and element M2 This can increase the difference and strengthen the ionic bond with oxygen in the metal oxide. Therefore, even if element M2 is yttrium, In-M1-M2-Zn The insulating properties of insulating film 408 using an In-M-Zn system can be improved. In oxides, if element M is yttrium, the difference in electronegativity between oxygen and element M is large. This can be done to strengthen the ionic bond with oxygen in the metal oxide. Therefore, even if element M is yttrium, an In-M-Zn oxide can be used for insulation. The insulating properties of the border film 408 can be improved.

[0306] Furthermore, the element M content in In-M-Zn oxides should be at least 0.3 times the In content. It is less than 3 times. Also, the amount of element M in In-M-Zn oxides is less than the amount of Zn. The ratio is between 0.3 and 1.3. The relative number of In or Zn elements to element M is small. To that extent, a more insulating insulating film 408 can be obtained.

[0307] Specifically, when forming a metal oxide material containing element M by sputtering, Or, the atomic ratios are In:M:Zn=1:1:1, 3:1:3, 3:2:4, 2:1:3, Use a metal oxide target with a ratio of 4:5:4 or 4:2:3.

[0308] In-M-Zn oxides and In-M1-M2-Zn oxides are used in insulating film 408. This allows the interface between the insulating film 408 and the semiconductor film 403 to be kept in good condition, and the transient The electrical characteristics of the TA513 can be improved.

[0309] Furthermore, on the surface of the semiconductor film 403 exposed by etching to form the insulating film 408 This material is prone to the adhesion of impurities. The above impurities include etching gas used for etching or Elements that make up the etching solution, or elements present in the etching chamber, etc. It contains. Specifically, the impurities mentioned above include boron, chlorine, fluorine, carbon, and aluminum. These are some examples.

[0310] When the above impurities adhere to the surface of the semiconductor film 403, the off-current of the transistor increases, or This can easily lead to a degradation of the transistor's electrical characteristics. Furthermore, parasitic cells can form on the semiconductor film 403. Channels are more likely to occur, and the conductive film that should be electrically isolated is electrically separated through the semiconductor film 403. Therefore, it becomes easier to connect to the target. In one aspect of the present invention, for forming the insulating film 408 After etching is complete, any residues that may have adhered to the surfaces of the semiconductor film 403 and the insulating film 408 may have been present. A washing process is performed to remove pure substances.

[0311] The cleaning process involves using an alkaline solution such as TMAH (tetramethylammonium hydroxide) solution. This can be done using water or dilute hydrofluoric acid. Specifically, dilute hydrofluoric acid can be used in the washing process. If using, dilute 50% by weight hydrofluoric acid with water to 1 / 10 2 ~1 / 10 5 Dilute with water and perform the washing process. It is desirable to use it in the following cases: that is, when the concentration is 0.5% by weight or 5 × 10 -4 Weight % of It is preferable to use acid in the cleaning process. The cleaning process removes the semiconductor film 403 and the insulating film. The above impurities adhering to the surface of 408 can be removed. In addition, a dilute fluoride can be used in the cleaning process. Using acid removes impurities attached to the semiconductor film 403 along with a portion of the semiconductor film 403. It is possible.

[0312] Next, a conductive film is formed on the semiconductor film 403 by sputtering or vacuum deposition, and then photo By patterning the conductive film using etching with lithography, Figure 26 As shown in (D), an insulating film 408 is provided on the semiconductor film 403 with the insulating film 408 sandwiched in between. Conductive films 409 and 410 are formed. Conductive films 409 and 410 are made of translucent material. It functions as either the source or drain electrode of the ZISTA 513.

[0313] The conductive films 409 and 410 can use the same structure and materials as the conductive film 407. If heat treatment is performed after the formation of conductive films 409 and 410, this heat treatment It is preferable that the conductive films 409 and 410 have sufficient heat resistance. Therefore, a tungsten film with a thickness of 150 nm is used as conductive film 409 and conductive film 410. .

[0314] Furthermore, during etching to form conductive films 409 and 410, the semiconductor film 40 Adjust the materials and etching conditions as appropriate to minimize the removal of step 3. Depending on the etching conditions, a portion of the exposed area of ​​the semiconductor film 403 may be etched. In some cases, grooves (recesses) may be formed.

[0315] In this embodiment, dry etching by the ICP etching method is used to remove the conductive film 409 and a conductive film 410 is formed. Specifically, the flow rate of sulfur hexafluoride, which is an etching gas, is The reaction pressure is 1.5 Pa, the temperature of the lower electrode is 70°C, and the mixture is introduced into a coil-type electrode. RF (13.56MHz) power is 500W, and the power applied to the lower electrode (bias side) is 5 After setting the wattage to 0W, the flow rate of the etching gas, boron trichloride, was set to 60 sccm, and the flow rate of chlorine was set to 2. 0 sccm, reaction pressure 1.9 Pa, lower electrode temperature 21°C, R introduced into coil-type electrode F (13.56MHz) power 450W, power applied to the lower electrode (bias side) 100W To achieve this, the conditions are changed midway through the process, and dry etching is performed.

[0316] Furthermore, in order to reduce the number of masks and steps used in photolithography, the transmitted light is Etching is performed using a resist mask formed by a multi-level mask that provides multiple levels of intensity. A polishing process may be performed. The resist mask formed using a multi-gradation mask has multiple film thicknesses. It takes on a certain shape, and by etching, the shape can be further deformed, thus different It can be used in multiple etching processes to process into a pattern. A resist mask that supports at least two different patterns using a grayscale mask. This allows for the formation of a [specific type of mask]. Therefore, the number of exposure masks can be reduced, and the process can be simplified. It becomes Noh.

[0317] Furthermore, the semiconductor exposed by etching to form conductive films 409 and 410 The surfaces of film 403 and insulating film 408 contain boron, chlorine, fluorine, carbon, aluminum, etc. Impurities tend to adhere to it. Furthermore, the conductive films 409 and 410 are composed of the above impurities. It may also contain elements that make up the mixture.

[0318] When the above impurities adhere to the surface of the semiconductor film 403, the transistor turns off as described above. This can easily lead to an increase in current or a deterioration of the transistor's electrical characteristics. Parasitic channels are more likely to form in film 403, and the conductive film that should be electrically isolated becomes the semiconductor film 4 It becomes easier to connect electrically via 03. Therefore, in one aspect of the present invention, conductive film 409 And after etching for forming the conductive film 410 is completed, the semiconductor film 403 and the insulating film are formed. A cleaning process is performed to remove any impurities that may have adhered to the surface of the 408.

[0319] The washing process is carried out using an alkaline solution such as TMAH solution, water, or dilute hydrofluoric acid. It is possible to do so. Specifically, when using dilute hydrofluoric acid in a cleaning treatment, 50% by weight hydrofluoric acid is used in water. 1 / 10 2~1 / 10 5 It is preferable to dilute it and use it in the washing process. That is, Concentration of 0.5% by weight to 5 × 10 -4 It is desirable to use a dilute hydrofluoric acid solution of weight percent in the cleaning process. The cleaning process removes the impurities adhering to the surfaces of the semiconductor film 403 and the insulating film 408. It can be removed. Also, if dilute hydrofluoric acid is used in the cleaning process, it adheres to the semiconductor film 403. The impurities can be removed along with a portion of the semiconductor film 403.

[0320] In this embodiment, the cleaning process for removing impurities after etching is performed using an absolute method. Regarding the case where the process is performed twice, once after the formation of the edge film 408 and again after the formation of the conductive films 409 and 410: As explained, in one aspect of the present invention, the above cleaning process may be performed only once.

[0321] Figure 29 is a top view of the light-emitting device at the time the above process is completed. The cross-sectional view along the dashed line D5-D6 corresponds to Figure 26(D).

[0322] Next, as shown in Figure 27(A), the semiconductor film 403, the insulating film 408, and the conductive film 409 And an insulating film 411 is formed to cover the conductive film 410. The insulating film 411 is resistant to moisture and water It is desirable to contain as few impurities as possible, and it may be a single-layer insulating film or a multilayer film. It may be composed of multiple insulating films. If the insulating film 411 contains hydrogen, that hydrogen Hydrogen penetrates into the semiconductor film 403, or hydrogen extracts oxygen from the semiconductor film 403, causing the semiconductor film 4 The area near the surface of 03 becomes less resistive (n-type). And the semiconductor film 403 becomes less resistive. Parasitic channels are easily formed near the surface, and these parasitic channels cause the conductive film 409 or There is a risk that the conductive film 410 and other conductive films on the semiconductor film 403 may become electrically connected. Therefore, the insulating film 411 is made to contain as little hydrogen as possible, and hydrogen is used in the film deposition method. It's important that it's not there.

[0323] Even if the above cleaning process is performed, the substrate 400 is exposed to the atmosphere before the insulating film 411 is formed. When exposed, impurities such as carbon contained in the atmosphere affect the surface of the semiconductor film 403 and the insulating film 408. It may adhere to the surface. Therefore, in one aspect of the present invention, for forming the insulating film 411 In the processing chamber, before forming the insulating film 411, the surface of the semiconductor film 403 and the insulating film 408 Impurities such as carbon adhering to the surface are removed with oxygen, nitrous oxide, or noble gases (typically A The cleaning is performed using plasma treatment with a substance such as argon to remove impurities such as carbon. It is also acceptable to do so. Then, after removing impurities by plasma treatment, the substrate 400 is exposed to the atmosphere. Without causing any damage, the insulating film 411 is formed, thereby insulating the semiconductor film 403 and the insulating film 408. This prevents impurities from entering near the interface of film 411, thereby increasing the transistor's off-current, or This can prevent the degradation of the transistor's electrical characteristics.

[0324] Furthermore, it is desirable to use a material with high barrier properties for the insulating film 411. For example, burr As insulating films with high thermal properties, silicon nitride film, silicon oxide nitride film, aluminum nitride film, aluminum oxide film Aluminum film or aluminum nitride oxide film can be used. Multiple layers are stacked. When using an insulating film, an insulating film such as an oxygen-containing silicon oxide film or silicon oxide nitride film is used as described above. It is formed closer to the semiconductor film 403 than to the highly transparent insulating film. And, an oxygen-containing insulating film A highly barrier insulating film is formed with a border film in between, overlapping with the semiconductor film 403. By using an insulating film with high barrier properties, within the semiconductor film 403, within the gate insulating film 402, or This occurs when impurities such as water or hydrogen enter the interface between the semiconductor film 403 and other insulating films, or in the vicinity thereof. It can prevent it from getting inside.

[0325] Furthermore, when multiple stacked insulating films are used as insulating film 411, the insulating films other than the first layer and For example, acrylic resin, polyimide resin, benzocyclobutene resin, polyamide Heat-resistant organic materials such as resins and epoxy resins can be used. In addition to the materials, siloxane resins, silicon dioxide, silicon nitride, silicon oxide nitride, silicon dioxide, and Lumina and other materials can be used. Siloxane resins are composed of silicon (Si) and oxygen (O) It is a material whose skeletal structure is formed by the bonds of these atoms. In addition to hydrogen, fluorine and fluoropolymers can be used as substituents. It has at least one of the following: a group, an organic group (e.g., an alkyl group, an aromatic hydrocarbon) That is also good. And for forming the insulating film 411, depending on the material, CVD method, sputtering method, Spin coating, dipping, spray coating, droplet ejection (inkjet method), printing method ( Formed using methods such as clean printing and offset printing. Also, a doctor's knife and a rhinoceros knife are used. It may also be formed using equipment such as a coater, curtain coater, or knife coater. The acid is fabricated by chemical vapor deposition using an organosilane as the insulating film layer other than the first layer. Silicon film can also be used. Examples of organosilanes include ethyl silicate (TEOS:Si(O)). C2H5)4), trimethylsilane (TMS:(CH3)3SiH), tetramethylsilane Tetrasiloxane (TMCTS), Octamethylcyclotetrasiloxane (OMCTS) ), hexamethyldisilazane (HMDS), triethoxysilane (SiH(OC2H5) 3) Trisdimethylaminosilane (SiH(N(CH3)2)3), etc. can be used. Cut.

[0326] In this embodiment, a silicon oxide film with a thickness of 300 nm formed by sputtering is used as the insulating film 411 It is used as follows. The substrate temperature during film formation should be between room temperature and 300°C, according to this embodiment. Let's set it to 100°C.

[0327] Next, as shown in Figure 27(B), the gate insulating film 402, the semiconductor film 403, and the insulating film are arranged. By processing 411 into the desired shape using photolithography etching, , openings 412 to 414 are formed.

[0328] In this embodiment, dry etching by the ICP etching method is used to create the gate insulating film. Patterning is performed on 402, the semiconductor film 403, and the insulating film 411. Specifically, etching The flow rates for the gases trifluoromethane, helium, and methane were set to 22.5 sccm each. , 127.5 sccm, 5 sccm, reaction pressure 3.5 Pa, lower electrode temperature 21°C, The RF (13.56MHz) power applied to the till-type electrode is 475W, and the lower electrode (bias) Dry etching is performed with a power supply of 300W applied to the side.

[0329] The region in which the opening 413 is formed overlaps with a portion of the region in which the conductive film 409 is formed. Therefore, the conductive film 409 is partially exposed at the opening 413.

[0330] Figure 30 is a top view of the light-emitting device at the time the above process is completed. The cross-sectional view along the dashed line D5-D6 corresponds to Figure 27(B).

[0331] Next, as shown in Figure 27(B), the conductive film in contact with the conductive film 409 at the opening 413 A 416 is formed. The conductive film 416 functions as a pixel electrode, and a portion of it is on the insulating film 411. They are also provided.

[0332] Next, as shown in Figure 27(C), on the conductive film 416, covering a portion of the conductive film 416 An insulating film 417 having an opening 418 is formed in the insulating film 417. The conductive film 416 is partially exposed. The insulating film 417 is an organic resin film, an inorganic insulating film, Alternatively, it can be formed using a siloxane-based insulating film. If it is an organic resin film, for example, acrylic For inorganic insulating films such as polyyl resin, polyimide resin, and polyamide resin, silicon oxide and nitriding are used. Silicon and the like can be used. In particular, a photosensitive organic resin film is used as the insulating film 417, and a conductive film An opening 418 is formed on 416, and the side walls of the opening 418 are formed with a continuous curvature. By forming it so that it becomes an inclined surface, the conductive film 416 and the conductive film 42 that will be formed later This prevents connection with 0. A mask for forming the opening 418, droplet discharge. It can be formed by ejection or printing. The insulating film 417 itself can also be formed by droplet ejection or It can also be formed by printing.

[0333] Next, the EL layer 419 and the conductive film 420 are sequentially deposited on the conductive film 416 and the insulating film 417. Formed in layers. Through the above process, a conductive film 4 is formed at the opening 418 of the insulating film 417. 16. A light-emitting element 515 is formed by sequentially stacking an EL layer 419 and a conductive film 420. can.

[0334] Furthermore, the light-emitting element 515 is directed towards the substrate 400. Even in a mission structure, the light from the light-emitting element 515 is directed away from the substrate 400. It may also be a bottom emission structure. Alternatively, the light from the light-emitting element 515 may be on the substrate 40 Even with a dual emission structure that directs both the 0 direction and the direction opposite to the substrate 400 Good. Of the three structures above, conductive film 416 and conductive film 420 are used according to the desired structure. Select the appropriate materials and film thicknesses accordingly.

[0335] Specifically, conductive film 416 or conductive film 420 may be indium oxide, indium oxide-acid Contains tin oxide (ITO: Indium Tin Oxide), silicon, or silicon oxide. Indium oxide-tin oxide, indium oxide-zinc oxide (Indium Zinc O) (xide), indium oxide containing tungsten oxide and zinc oxide, nitrogen-containing Al-Zn oxide semiconductor, nitrogen-containing Zn oxide semiconductor, nitrogen-containing Sn- Zn-based oxide semiconductors, gold (Au), platinum (Pt), nickel (Ni), tungsten (W) ), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu) In addition to palladium (Pd) and titanium (Ti), other elements belonging to Group 1 or Group 2 of the periodic table. Elements, namely alkali metals such as lithium (Li) and cesium (Cs), and magnesium Alkaline earth metals such as magnesium (Mg), calcium (Ca), and strontium (Sr), and alloys containing these (MgAg, AlLi), europium (Eu), ytterbium Rare earth metals such as (Yb) and alloys containing them can be used. The film 416 is made from the above material by, for example, sputtering or deposition (including vacuum deposition). After forming a conductive film using the method, the conductive film is etched using photolithography. It can be formed by processing it into the desired shape.

[0336] Furthermore, once the light-emitting element 515 is formed, the light-emitting element should not be exposed to the outside air. It is preferable to enclose the child 515 between the substrate 400 and the cover material.

[0337] In this embodiment, the case in which transistor 513 has a single-gate structure is illustrated. However, if necessary, by having multiple electrically connected conductive films 407, It is also possible to form multi-gate transistors that have multiple Nell-forming regions.

[0338] This embodiment can be implemented in appropriate combination with other embodiments.

[0339] (Embodiment 9) In one aspect of the present invention, a light-emitting device comprises a light-emitting element that emits monochromatic light such as white, and a color-emitting element. It employs a color filter method that displays full-color images by combining filters. This can be done. Alternatively, by using multiple light-emitting elements that emit light of different hues, A method for displaying multicolor images can also be adopted. This method utilizes the light-emitting element The EL layer provided between a pair of electrodes is painted with different colors according to the corresponding color, and the painting method is I was called.

[0340] In the case of the paint separation method, the EL layer is usually painted using a mask such as a metal mask. This is done using a vapor deposition method. Therefore, the size of the pixels depends on the precision of the EL layer coating achieved by the vapor deposition method. On the other hand, in the case of the color filter method, unlike the paint separation method, the paint separation of the EL layer is It is not necessary to do so. Therefore, it is easier to reduce the pixel size than with the color-coding method. This enables the realization of high-resolution pixels.

[0341] Furthermore, the light-emitting device emits light from the light-emitting element from the substrate on which the transistor is formed, the so-called element substrate side. A bottom emission structure extracts light from the light-emitting element from the side opposite the element substrate. There is a top emission structure. In the case of a top emission structure, the light emitted from the light-emitting element... The light is not obstructed by various elements such as wiring, transistors, and capacitive elements. Therefore, compared to a bottom emission structure, it is possible to improve the efficiency of light extraction from the pixels. Therefore, the top emission structure allows for low current supply to the light-emitting element. Because high brightness can be obtained, it is advantageous for extending the lifespan of light-emitting elements.

[0342] Furthermore, in a light-emitting device according to one aspect of the present invention, the light emitted from the EL layer is resonated within the light-emitting element. It may have a microcavity (micro-optical resonator) structure. The T-structure allows for increased extraction efficiency from light-emitting elements for specific wavelengths. Therefore, it is possible to improve the brightness and color purity of the pixel area.

[0343] Figure 31 shows an example of a cross-sectional view of a pixel. Note that in Figure 31, the cross-section of the pixel corresponding to red is shown. The image shows a portion of the surface, a portion of the cross-section of a pixel corresponding to blue, and a portion of the cross-section of a pixel corresponding to green. Yes, they are.

[0344] Specifically, in Figure 31, there is pixel 340r corresponding to red, pixel 340g corresponding to green, and blue The corresponding pixel 340b is shown. Pixel 340r, pixel 340g, pixel 340b Each has anode 715r, anode 715g, and anode 715b, respectively. The above anode 715r, Anode 715g and Anode 715b correspond to pixel 340r, pixel 340g, and pixel 340b, respectively. In this configuration, it is provided on top of the insulating film 750 formed on the substrate 740.

[0345] Furthermore, a partition wall 73 having an insulating film is placed on anode 715r, anode 715g, and anode 715b. 0 is provided. Partition wall 730 has an opening, and in the opening, anode 715r, Anode 715g and anode 715b are partially exposed. To cover the area, an EL layer 731 and a transparent material for visible light are placed on the partition wall 730. The cathode 732 and the other elements are stacked in sequence.

[0346] The area where the anode 715r, the EL layer 731, and the cathode 732 overlap is the light-emitting element corresponding to red. This corresponds to 741r. The area where the anode 715g, the EL layer 731, and the cathode 732 overlap is This corresponds to the light-emitting element 741g which is green. Anode 715b, EL layer 731, cathode 73 The overlapping portion with 2 corresponds to the light-emitting element 741b, which is blue.

[0347] Furthermore, the substrate 742 is positioned between the light-emitting element 741r, the light-emitting element 741g, and the light-emitting element 741b. It is positioned between the substrate 740 and the substrate 742. On substrate 742, there is a corresponding to pixel 340r. Coloring layer 743r, corresponding to pixel 340g; Coloring layer 743g, corresponding to pixel 340b. A layer 743b is provided. The colored layer 743r has a transmittance of light in the wavelength region corresponding to red. The colored layer 743g has a higher transmittance of light in other wavelength regions, and the colored layer 743g has a higher transmittance of light in the wavelength region corresponding to green. The light transmittance in this region is higher than that of light in other wavelength regions, and the colored layer 743b is blue. This layer has a higher transmittance of light in the corresponding wavelength range than the transmittance of light in other wavelength ranges.

[0348] Furthermore, the substrate 742 is covered with a colored layer 743r, a colored layer 743g, and a colored layer 743b. An overcoat 744 is provided. The overcoat 744 is a colored layer 743 r, a transparent material to visible light for protecting the colored layer 743g and colored layer 743b. It is preferable to use a resin material that is a layer and has high flatness. Colored layer 743r, colored layer 743 g, and the colored layer 743b, along with the overcoat 744, are considered together as a color filter. Alternatively, you can color each of the colored layers 743r, 743g, and 743b. It can be considered a filter.

[0349] Then, in Figure 31, the anode 715r has a conductive film 745r with high visible light reflectivity, and visible light A conductive film 746r, whose transmittance is higher than that of the conductive film 745r, is used in sequence by laminating it. Furthermore, the anode 715g is coated with a conductive film 745g with high visible light reflectivity, and the transmittance of visible light is as described above. A conductive film with a higher conductivity of 746g is used by sequentially laminating it with a conductive film with a conductivity of 745g. The thickness shall be less than the thickness of the conductive film 746r. Also, visible light shall be applied to the anode 715b. A conductive film 745b with high reflectivity is used.

[0350] Therefore, in the light-emitting device shown in Figure 31, the light-emitting element 741r emits light from the EL layer 731. The optical path length of the emitted light can be adjusted by the distance between the conductive film 745r and the cathode 732. Furthermore, in the light-emitting element 741g, the optical path length of the light emitted from the EL layer 731 is the conductive film 7 The distance between 45g and cathode 732 can be adjusted. Also, the light-emitting element 741b The optical path length of the light emitted from the EL layer 731 depends on the distance between the conductive film 745b and the cathode 732. It can be adjusted.

[0351] In one aspect of the present invention, a light-emitting element 741r, a light-emitting element 741g, and a light-emitting element 741b are provided together. By adjusting the optical path length according to the corresponding wavelength of light, the EL layer 731 emits This can also be used as a microcavity structure that causes the emitted light to resonate within each of the above-mentioned light-emitting elements. stomach.

[0352] By employing the above microcavity structure in a light-emitting device according to one aspect of the present invention, In the light emitted from element 741r, the intensity of the light having a wavelength corresponding to red is at resonance. This increases the color purity and brightness of the red light obtained through the colored layer 743r. Furthermore, in the light emitted from the light-emitting element 741g, the intensity of light having a wavelength corresponding to green The degree increases due to resonance. Therefore, the color purity of the green light obtained through the colored layer 743g and Brightness increases. Also, in the light emitted from the light-emitting element 741b, the wavelength corresponding to blue is The intensity of the light it possesses increases due to resonance. Therefore, the blue light obtained through the colored layer 743b The color purity and brightness are enhanced.

[0353] Note that Figure 31 shows a configuration using pixels corresponding to three colors: red, green, and blue. In one aspect of the invention, the configuration is not limited to that. The color combination used in one aspect of the invention is For example, using four colors: red, green, blue, and yellow, or three colors: cyan, magenta, and yellow. It is acceptable to include them. Alternatively, the above color combinations include light red, green, and blue, as well as dark red. You may also use six colors: green, blue, and red. Alternatively, the above color combinations may include red, green, blue, and blue. You may also use six colors: um, magenta, yellow, and red.

[0354] For example, the colors that can be represented using red, green, and blue pixels are represented by the respective pixels on the chromaticity diagram. It is limited to the colors shown inside the triangle formed by the three points corresponding to the light color. Therefore, red, green, blue, When a yellow pixel is used, the emitted color of a light-emitting element exists outside the triangle on the chromaticity diagram. By adding this separately, the color gamut that can be expressed by the light-emitting device is expanded, enriching color reproduction. It is possible.

[0355] Furthermore, in Figure 31, among the light-emitting element 741r, light-emitting element 741g, and light-emitting element 741b, In the light-emitting element 741b with the shortest wavelength λ, the conductive film 745b with high reflectivity of visible light is used. When used as an anode, the film thickness of the other light-emitting elements 741r and 741g differs from that of the other elements. The optical path length is adjusted by using conductive films 746r and 746g. In one aspect of the invention, even in the light-emitting element 741b with the shortest wavelength λ, the reflectivity of visible light is high. On the conductive film 745b, a highly permeable conductive film such as conductive film 746r and conductive film 746g is applied. A film may be provided. However, as shown in Figure 31, the light-emitting element 741 has the shortest wavelength λ. In b, when the anode is made of a conductive film 745b with high visible light reflectivity, all light-emitting elements In this case, the anode fabrication process is simplified compared to when a highly permeable conductive film is used for the anode. Therefore, it is preferable.

[0356] Furthermore, conductive film 745b, which has a high reflectivity of visible light, and conductive film 746r, which has a high transmittance of visible light. Compared to conductive film 746g, the work function is often smaller. Therefore, the wavelength of light λ is shortest. In the light-emitting element 741b, compared to the light-emitting elements 741r and 741g, the anode 715b Because hole injection into the EL layer 731 is difficult, the luminous efficiency tends to be low. In one aspect of the present invention, in the light-emitting element 741b with the shortest wavelength λ of light, the EL layer 731 Among these, in the layer in contact with the conductive film 745b, which has a high reflectivity of visible light, a material with high hole transport properties. The substance contains a material that exhibits acceptor properties (electron-accepting properties) for the material with high hole transport capabilities. It is preferable to use a composite material having the properties described above. The composite material is formed in contact with the anode 715b. This facilitates hole injection from the anode 715b to the EL layer 731, resulting in light emission. This can increase the luminous efficiency of element 741b.

[0357] Substances that exhibit acceptor properties include 7,7,8,8-tetracyano-2,3,5,6- Examples include tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, etc. It is possible. Furthermore, transition metal oxides can be cited. Also, in the periodic table, Group 4 elements Examples include oxides of metals belonging to Group 8. Specifically, vanadium oxide, acid Niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide Rhenium oxide is preferred because of its high acceptability. In particular, molybdenum oxide is It is preferable because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle.

[0358] Examples of highly hole-transporting materials used in composite materials include aromatic amine compounds and carbazole derivatives. Conductors, aromatic hydrocarbons, polymer compounds (oligomers, dendrimers, polymers, etc.), Various compounds can be used. Note that the organic compounds used in the composite material include holes. It is preferable that the organic compound has high transportability. Specifically, 10 -6 cm 2 / Vs or more It is preferable that the material has a hole mobility of . However, it is preferable that the material has a higher hole transport capability than electron transport. Other materials may also be used.

[0359] Furthermore, conductive films 745r, 745g, and 745b, which have high reflectivity of visible light, are also considered. For example, aluminum, silver, or alloys containing these metallic materials, etc., in a single layer, or It can be formed by lamination. Also, conductive film 745r, conductive film 745g, The conductive film 745b consists of a highly reflective conductive film and a thin conductive film (preferably 20 nm or less). More preferably, it may be formed by stacking (10 nm or less) and a high reflectivity. The conductive film 745b is formed by laminating thin titanium films and molybdenum films onto a conductive film. A conductive film with higher reflectivity (aluminum, aluminum-containing alloys, or silver, etc.) This prevents the formation of an oxide film on the surface.

[0360] Furthermore, conductive films 746r and 746g, which have high visible light transmittance, contain, for example, 100% nitrile oxide. The following are used: zinc, tin oxide, zinc oxide, indium tin oxide, indium zinc oxide, etc. It is possible.

[0361] Furthermore, the cathode 732 is, for example, a thin conductive film that transmits light (preferably 20 nm or less). More preferably, a conductive film composed of a conductive metal oxide is laminated with a film of 10 nm or less. This can be formed by [doing something]. A thin conductive film that transmits light can be made of silver, magnesium or alloys containing these metallic materials can be formed in a single layer or in layers. Examples of conductive metal oxides include indium oxide, tin oxide, zinc oxide, and indium tin oxide. Oxides, indium zinc oxide, or these metal oxide materials containing silicon oxide You can use the one that you have.

[0362] This embodiment can be implemented in appropriate combination with other embodiments.

[0363] (Embodiment 10) Next, the appearance of the panel of a light-emitting device according to one aspect of the present invention will be described with reference to Figure 32. Figure 32(A) shows substrate 6001 and substrate 6006 bonded together by sealing material 6005. This is a top view of the panel, and Figure 32(B) is located along the dashed line E1-E2 in Figure 32(A). This corresponds to a cross-sectional view.

[0364] The pixel section 6002 and the scan line driving circuit 6004 are surrounded on the substrate 6001. A sealing material 6005 is provided. Also, a pixel section 6002 and a scan line driving circuit 6004 are provided. A substrate 6006 is provided on top of it. Therefore, the pixel section 6002 and the scanning line driving circuit 600 4 is formed by substrate 6001, sealing material 6005 and substrate 6006 together with filler material 6007 It is sealed.

[0365] In addition to inert gases such as nitrogen and argon, fillers 6007 can also include UV-curing resins. Thermosetting resins can be used. The sealing material 6005 can contain resin (ultraviolet curing resin, Thermosetting resins, or glass frit, can be used.

[0366] Furthermore, in a region different from the region surrounded by the sealing material 6005 on the substrate 6001, A circuit board 6021 on which the signal line drive circuit 6003 is formed is mounted. In Figure 32, The transistor 6009 included in the line drive circuit 6003 is shown as an example. In this configuration, the scan line driving circuit 6004 is formed on the substrate 6001 together with the pixel unit 6002. The example shows a case where the scan line drive circuit 6004 is formed on a separate substrate, but the substrate 600 It may also be implemented in 1. In this embodiment, the signal lines formed on the substrate 6021 The example shows the case where the drive circuit 6003 is mounted on the board 6001, but the signal line drive cycle The path 6003 may be formed on the substrate 6001 together with the pixel portion 6002. Alternatively, A part of the scan line drive circuit 6003, or a part of the scan line drive circuit 6004, controls the pixel section 6002 They may also be formed on the substrate 6001.

[0367] Furthermore, the pixel section 6002 and the scanning line driving circuit 6004 provided on the substrate 6001 are transistors It has multiple transistors. In Figure 32(B), transistor 6 is included in the pixel section 6002. 008 and transistor 6010 are shown. Pixel electrode 6 of light-emitting element 6011 030 is connected to transistor 6010. Pixel electrode 6030 and counter electrode 603 The portion where 1 and the EL layer 6029 overlap corresponds to the light-emitting element 6011.

[0368] Furthermore, the shielding film 6040 formed on the substrate 6006 protects the transistor 6008 and the transistor 6008. It overlaps with the area where the converter 6010 is formed. Also, substrate 6006 has a color - A colored layer 60 that functions as a filter, preferentially transmitting only visible light in a specific wavelength range. 41 is formed, and the colored layer 6041 overlaps with the region where the light-emitting element 6011 is formed. It is.

[0369] Colored layers 6041 that preferentially transmit light in wavelength regions corresponding to red, blue, and green, respectively. By providing a light-emitting element 6011 that emits white light for each pixel, a full-color image can be created. An image can be displayed. Alternatively, a light-emitting element 6011 that emits red light and a corresponding red light By combining the colored layer 6041, a light-emitting element 6011 that emits blue light and a colored layer corresponding to blue are formed. By combining 6041, and also by the light-emitting element 6011 which can produce green light and the corresponding green light By combining color layers 6041, it is possible to display full-color images with high color purity. Alternatively, multiple emitters can be used to obtain red, blue, and green light without providing the colored layer 6041. By providing the optical element 6011 in the pixel section 6002, a full-color image can be displayed. Cut.

[0370] Note that in Figure 32, the case where the shielding film 6040 and the colored layer 6041 are provided on the substrate 6006 side. Although this is an example, even if the shielding film 6040 or the colored layer 6041 is provided on the substrate 6001 side Good. The direction of light incidence onto the light-emitting element 6011 and the direction of light emission after passing through the light-emitting element 6011. Accordingly, the positions of the shielding film 6040 and the colored layer 6041 can be determined as appropriate. ru.

[0371] Furthermore, the signal line drive circuit 6003, the scan line drive circuit 6004, and the pixel unit 6002 are supplied with Various signals and potentials are transmitted via wiring 6014 and 6015 to connection terminal 6016. It is supplied from there. The connection terminal 6016 is the terminal and anisotropic conductive film of FPC6018. It is electrically connected via 6019.

[0372] This embodiment can be implemented in appropriate combination with other embodiments.

[0373] (Embodiment 11) Figure 33 is an example of a perspective view of a light-emitting device according to one aspect of the present invention.

[0374] The light-emitting device shown in Figure 33 consists of a panel 2601, a circuit board 2602, and a COF tape 260 It has 3 and a chip 2604 on which a signal line driving circuit is formed. The chip 2604 was processed using the COF (Chip On Film) method to create a COF tape. It is connected to 2603. Circuit board 2602 receives various signals input to panel 2601. A circuit for generating signals, or a circuit for processing these signals, is provided. Various signals and potentials are transmitted from circuit board 2602 via COF tape 2603 to panel 26 It is entered into 01.

[0375] Panel 2601 includes a pixel section 2605 with multiple pixels, and a scan line driving circuit 2606. The scan line drive circuit 2606 drives the multiple pixels of the pixel unit 2605 row by row. Select. The signal line drive circuit provided on chip 2604 is controlled by the scan line drive circuit 2606. This controls the input of the image signal to the pixels within the selected row.

[0376] Note that instead of COF tape 2603, FPC (Flexible Printed Tape) The circuit board 2602 and the panel 2601 are electrically connected using a circuit board (or similar device). It is also possible.

[0377] Furthermore, when using COF tape 2603, some circuits within circuit board 2602 must be prepared separately. The chip is formed and then connected to the COF tape 2603 using the COF method. It is also acceptable to leave it as is. In addition, some or all of the scan line drive circuit 2606, or the signal line drive A portion of the circuit is formed on a chip, and the chip is attached to the COF tape 2603 using the COF method. You can continue doing it.

[0378] This embodiment can be implemented in appropriate combination with other embodiments.

[0379] (Embodiment 12) A liquid crystal display device according to one aspect of the present invention comprises a display device, a personal computer, and a recording medium. Equipped with an image playback device (typically DVD: Digital Versatile Disc) (Used in a device that has a display capable of playing back recording media such as c and displaying the images thereof) This can be done. In addition, a liquid crystal display device or light-emitting device according to one aspect of the present invention can be used. Electronic devices capable of doing so include mobile phones, game consoles (including portable ones), personal digital assistants, e-books, Video cameras, digital still cameras, goggle-type displays (head-mounted displays) Playback), navigation system, sound playback device (car audio, digital audio) (Optical players, etc.), photocopiers, fax machines, printers, multifunction printers, ATMs Examples include ATMs and vending machines. Figure 1 shows specific examples of these electronic devices. This is shown in 6.

[0380] Figure 16(A) shows a portable game console, comprising a casing 5001, casing 5002, display unit 5003, Display unit 5004, microphone 5005, speaker 5006, operation keys 5007, stand It has illustration 5008, etc. Display unit 5003 or display unit 5004 has according to one aspect of the present invention. By using such liquid crystal display or light-emitting device, a highly reliable portable game console can be provided. This is possible. Note that the portable game console shown in Figure 16(A) has two display units 5003 It has a display unit 5004, but the number of display units that a portable game console has is not limited to this. It will not be done.

[0381] Figure 16(B) shows a display device, which includes a housing 5201, a display unit 5202, a support base 5203, etc. The display unit 5202 uses a liquid crystal display device or light-emitting device according to one aspect of the present invention. This allows us to provide highly reliable display devices. Furthermore, the display devices include personal co This includes all information display devices, such as those for computers, TV broadcast reception, and advertising. .

[0382] Figure 16(C) shows a notebook personal computer, consisting of a casing 5401 and a display unit 5402. It has a keyboard 5403, a pointing device 5404, etc. Display unit 5402 By using a liquid crystal display device or light-emitting device according to one aspect of the present invention, a highly reliable notebook We can provide a personal computer of a certain type.

[0383] Figure 16(D) shows a portable information terminal, consisting of a first housing 5601, a second housing 5602, and a first display unit. It includes 5603, a second display unit 5604, a connection unit 5605, an operation key 5606, etc. Table 1 The display unit 5603 is provided in the first housing 5601, and the second display unit 5604 is provided in the second housing 56 It is located at 02. And the first housing 5601 and the second housing 5602 are connected at the connection part 56 They are connected by 05, and the angle between the first housing 5601 and the second housing 5602 is the connection part This can be changed by 5605. The video switching in the first display unit 5603 , according to the angle between the first housing 5601 and the second housing 5602 at the connection part 5605, A configuration that allows switching between displays is also acceptable. Furthermore, the number of first display units 5603 and second display units 5604 is small. However, one of the devices may be a liquid crystal display or light-emitting device that has been added the function of a position input device. It is acceptable to have it there. Furthermore, the function as a position input device is provided by a liquid crystal display or light-emitting device. It can be added by installing a touch panel in the location. Alternatively, as a position input device. The function involves a photoelectric conversion element, also called a photosensor, being used in the pixel section of a liquid crystal display or light-emitting device. It can also be added by providing it in the first display unit 5603 or the second display unit 560 4. By using a liquid crystal display device or light-emitting device according to one aspect of the present invention, a highly reliable portable We can provide a mobile information terminal.

[0384] Figure 16(E) shows a video camera, consisting of a first housing 5801, a second housing 5802, and a display unit 58 03, it has an operation key 5804, a lens 5805, a connector 5806, etc. Operation key 580 4 and lens 5805 are provided in the first housing 5801, and the display unit 5803 is in the second housing It is located in 5802. And the first housing 5801 and the second housing 5802 are connected by a connection part. They are connected by 5806, and the angle between the first housing 5801 and the second housing 5802 is, The change can be made by the extension unit 5806. The video switching in the display unit 5803 , according to the angle between the first housing 5801 and the second housing 5802 at the connection part 5806 The configuration may also be as follows: Display unit 5803 may display a liquid crystal display device or light-emitting device according to one aspect of the present invention. By using this method, we can provide a highly reliable video camera.

[0385] This embodiment can be implemented in appropriate combination with other embodiments. [Explanation of symbols]

[0386] 10 pixel section 11 pixels 12 transistors 13 Liquid crystal elements 14 Capacitive elements 100 transistors 101 Guard Station 102 Gate Insulator 103 Semiconductor film 104 Insulating film 105 Conductive film 106a Conductive film 106b Conductive film 107 Insulating Film 108 Opening 109 Pixel Electrodes 110 Opening 111 Conductive film 202 circuit boards 203 Conductive film 204 Gate Insulator 205 Semiconductor film 206 Insulating film 207 Conductive film 208 Conductive film 210 Conductive film 211 Conductive film 212 Insulating film 213 Opening 213a opening 213b opening 214 Opening 215 Conductive film 216 Conductive film 217 Insulating film 300 transistors 301 gate 302 Gate Insulator 303 Semiconductor film 304 Insulating Film 305 Conductive film 306a Conductive film 306b Conductive film 307 Insulating film 308 Opening 309 Pixel Electrodes 310 Opening 311 Conductive film 320 insulating film 321 Opening 322 EL layer 323 Counter electrode 324 Light-emitting element 340b pixels 340g pixels 340r pixels 400 circuit boards 401 Conductive film 402 Gate Insulator 403 Semiconductor film 404 Insulating film 405 Conductive film 406 Conductive film 407 Conductive film 408 Insulating film 409 Conductive film 410 Conductive film 411 Insulating film 412 Opening 412a opening 412b opening 413 Opening 414 Opening 415 Conductive film 416 Conductive film 417 Insulating Film 418 Opening 419 EL layer 420 Conductive film 510 pixel section 511 pixels 512 transistors 513 Transistors 514 Capacitive element 515 Light-emitting element 715b Anode 715g anode 715r anode 730 Bulkhead 731 EL layer 732 Cathode 740 circuit boards 741b Light-emitting element 741g light-emitting element 741r light-emitting element 742 circuit boards 743b Colored layer 743g colored layer 743r colored layer 744 Overcoat 745b Conductive film 745g conductive film 745r conductive film 746g conductive film 746r conductive film 750 insulating film 1601 Panel 1602 Diffuser 1603 Prism Sheet 1604 Diffuser 1605 Light guide plate 1606 Reflector 1607 Light source 1608 Circuit board 1609 COF Tape 1610 FPC 1611 circuit board 1620 Backlight 2601 Panel 2602 Circuit board 2603 COF Tape 2604 chips 2605 pixel section 2606 Scan Line Drive Circuit 4001 circuit board 4002 pixel section 4003 Signal Line Drive Circuit 4004 Scan Line Drive Circuit 4005 Sealant 4006 Opposing substrate 4007 Liquid Crystal Layer 4009 Transistor 4010 Transistor 4011 Liquid crystal element 4014 Wiring 4016 Connection terminal 4018 FPC 4019 Anisotropic conductive film 4021 circuit board 4030 Pixel Electrode 4031 Counter electrode 4035 Spacer 4040 Shielding membrane 4041 Colored layer 5001 enclosure 5002 enclosure 5003 Display section 5004 Display section 5005 Microphone 5006 Speaker 5007 Operation Keys 5008 Stylus 5201 enclosure 5202 Display section 5203 Support stand 5401 enclosure 5402 Display section 5403 Keyboard 5404 Pointing device 5601 enclosure 5602 enclosure 5603 Display section 5604 Display section 5605 Connection part 5606 Operation Keys 5801 enclosure 5802 enclosure 5803 Display section 5804 Operation Keys 5805 Lens 5806 Connection part 6001 circuit board 6002 pixel section 6003 Signal Line Drive Circuit 6004 Scan Line Drive Circuit 6005 Sealant 6006 circuit board 6007 Filling material 6008 Transistor 6009 Transistor 6010 transistor 6011 Light-emitting element 6014 Wiring 6016 Connection terminal 6018 FPC 6019 Anisotropic conductive film 6021 circuit board 6029 EL layer 6030 Pixel Electrode 6031 Counter electrode 6040 Shielding membrane 6041 shader layer

Claims

1. It has a first pixel and a second pixel that share a single semiconductor film and are arranged adjacent to each other, Each of the first and second pixels has a first transistor, a second transistor, and a light-emitting element. In each of the first and second pixels, either the source or drain of the first transistor is always in contact with the gate of the second transistor. In each of the first and second pixels, the second transistor has the function of controlling the current flowing to the light-emitting element according to the potential corresponding to the image signal. The channel formation region of the second transistor having the first pixel and the channel formation region of the second transistor having the second pixel are arranged on the one semiconductor film. The aforementioned semiconductor film has a first region, a second region and a third region, Each of the first region and the third region has an overlap with a conductive film that functions as a scanning line and is always in contact with the gate of the first transistor of the first pixel. The second region does not overlap with the conductive film. The first region and the third region are arranged to be connected by the second region in between. Light-emitting device.

2. It has a first pixel and a second pixel that share a single semiconductor film and are arranged adjacent to each other, Each of the first and second pixels has a first transistor, a second transistor, and a light-emitting element. In each of the first and second pixels, either the source or drain of the first transistor is always in contact with the gate of the second transistor. In each of the first and second pixels, the second transistor has the function of controlling the current flowing to the light-emitting element according to the potential corresponding to the image signal. The channel formation region of the second transistor having the first pixel and the channel formation region of the second transistor having the second pixel are arranged on the one semiconductor film. The aforementioned semiconductor film has a first region, a second region and a third region, Each of the first region and the third region has an overlap with a conductive film that functions as a scanning line and is always in contact with the gate of the first transistor of the first pixel. The second region does not overlap with the conductive film. The first region and the third region are arranged to be connected by the second region in between. In a plan view, there is a region between the first region and the third region where the first semiconductor film is not located. Light-emitting device.

3. It has a first pixel and a second pixel that share a single semiconductor film and are arranged adjacent to each other, Each of the first and second pixels has a first transistor, a second transistor, and a light-emitting element. In each of the first and second pixels, either the source or drain of the first transistor is always in contact with the gate of the second transistor. In each of the first and second pixels, the second transistor has the function of controlling the current flowing to the light-emitting element according to the potential corresponding to the image signal. The channel formation region of the second transistor having the first pixel and the channel formation region of the second transistor having the second pixel are arranged on the one semiconductor film. The aforementioned semiconductor film has a first region, a second region and a third region, Each of the first region and the third region has an overlap with a conductive film having the function of a scanning line that is always in contact with the gate of the first transistor of the second pixel. The second region does not overlap with the conductive film. The first region and the third region are arranged to be connected by the second region in between. Light-emitting device.

4. It has a first pixel and a second pixel that share a single semiconductor film and are arranged adjacent to each other, Each of the first and second pixels has a first transistor, a second transistor, and a light-emitting element. In each of the first and second pixels, either the source or drain of the first transistor is always in contact with the gate of the second transistor. In each of the first and second pixels, the second transistor has the function of controlling the current flowing to the light-emitting element according to the potential corresponding to the image signal. The channel formation region of the second transistor having the first pixel and the channel formation region of the second transistor having the second pixel are arranged on the one semiconductor film. The aforementioned semiconductor film has a first region, a second region and a third region, Each of the first region and the third region has an overlap with a conductive film having the function of a scanning line that is always in contact with the gate of the first transistor of the second pixel. The second region does not overlap with the conductive film. The first region and the third region are arranged to be connected by the second region in between. In a plan view, there is a region between the first region and the third region where the first semiconductor film is not located. Light-emitting device.

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