Indication device

Abstract

To provide a display device including transistors in a pixel region and a driving circuit region, in which the variation in electric characteristics is suppressed and the reliability is improved.SOLUTION: A display device includes a first substrate 102 including a driving circuit region 140, which is externally adjacent to a pixel region 142, including at least one second transistor 103 that supplies a signal to a first transistor 101 included in each pixel of the pixel region, a second substrate 152 provided so as to face the first substrate, a liquid crystal layer 162 held between the first and second substrates, a first interlayer insulating film 114 formed of an inorganic insulating material on the first transistor and the second transistor, a second interlayer insulating film 116 formed of an organic insulating material on the first interlayer insulating film, and a third interlayer insulating film 120 formed of an inorganic insulating material on the second interlayer insulating film. The third interlayer insulating film is provided on a part of the pixel region, and an end part of the third interlayer insulating film is formed on the inside relative to the driving circuit region.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This relates to a display device using a liquid crystal panel, or a display device using an organic EL panel. The present invention relates to electronic equipment having said display device. [Background technology]

[0002] In recent years, there has been a surge in the development of display devices using liquid crystal panels and organic EL panels. Yes, this display device contains, broadly speaking, only transistors for pixel control (pixel transistors). One method involves forming the image on a substrate and using peripheral ICs for the scanning circuit (driving circuit), while the other method involves using pixel transistors and Both are classified as devices that form scanning circuits on the same substrate.

[0003] To reduce the bezel size of the display device or the cost of peripheral ICs, a display device with an integrated drive circuit is being developed. This is advantageous. However, as for the transistors used in the driving circuit, pixel transistors are The electrical characteristics used in the zista (e.g., field-effect mobility (μFE) or threshold value) Furthermore, high electrical characteristics are required.

[0004] Silicon-based semiconductor materials are widely known as semiconductor thin films applicable to transistors. However, oxide semiconductors are attracting attention as another material. For example, they are used in transistors. As a semiconductor thin film, the electron carrier concentration is 10 18 / cm 3 Indium (In) is less than A transistor using an amorphous oxide containing gallium (Ga) and zinc (Zn) is disclosed. This has been done (see, for example, Patent Document 1).

[0005] Transistors that use oxide semiconductors as semiconductor layers use amorphous silicon-based semiconductor materials. Since the field-effect mobility is higher than that of a transistor using silicon for the semiconductor layer, the operating speed is high, making it suitable for a display device with an integrated drive circuit. Moreover, the manufacturing process is easier than that of a transistor using polycrystalline silicon for the semiconductor layer.

[0006] However, in a transistor using an oxide semiconductor for the semiconductor layer, there is a problem that carriers are formed when impurities such as hydrogen and moisture enter the oxide semiconductor, and the electrical characteristics of the transistor change.

[0007] To solve the above problems, a transistor with improved reliability is disclosed by setting the concentration of hydrogen atoms in the oxide semiconductor film used as the channel formation region of the transistor to less than 1 × 10 cm 16 -3 (For example, Patent Document 2).

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0009] As described in Patent Document 2, in a transistor using an oxide semiconductor film for the semiconductor layer, in order to sufficiently maintain its electrical characteristics, it is important to extremely exclude hydrogen, moisture, etc. from the oxide semiconductor film. [[ID= 56]]

[0010] In addition, when transistors are used in both the pixel region and the drive circuit region of a display device, the drive​​​​​​ Depending on the method, the transistors used in the driving circuit region are more electrically efficient than those used in the pixel region. Due to the heavy load, the electrical characteristics of the transistors used in the drive circuit region become crucial.

[0011] In particular, transistors using oxide semiconductor films as semiconductor layers are used in the pixel region and the drive circuit region. In the display device used in the region, in reliability testing under high temperature and high humidity conditions, the drive circuit region is used Transistor degradation is becoming a problem. The cause of this transistor degradation is... Moisture and other substances can penetrate from the organic insulating film formed on the slab into the oxide semiconductor film used as the semiconductor layer. This is because the carrier density of the oxide semiconductor film increases.

[0012] Therefore, one aspect of the present invention is a display device having transistors in the pixel region and the drive circuit region. In this setup, one of the challenges is to suppress fluctuations in electrical characteristics and improve reliability. In particular, in display devices that use an oxide semiconductor film in the channel formation region of a transistor... This suppresses the intrusion of hydrogen and moisture into the oxide semiconductor film, thereby suppressing fluctuations in electrical properties. Together, we aim to improve reliability as one of our challenges. [Means for solving the problem]

[0013] In view of the above-mentioned problems, in one aspect of the present invention, transistors used in the pixel region and the driving circuit region In a display device having a transistor, it is possible to suppress fluctuations in the electrical characteristics of the transistor. The structure provides an oxide semiconductor film in the channel formation region of the transistor. Using this, the structure of the planarized film formed by the organic insulating material provided on the transistor The oxide semiconductor film, in particular, is characterized by hydrogen and water, and is used in the drive circuit region. The structure should be designed to make it difficult to penetrate. More specifically, this is as follows:

[0014] One aspect of the present invention provides a pixel electrode and at least one element electrically connected to the pixel electrode. A pixel region in which multiple pixels containing transistor 1 are arranged, and adjacent to the outside of the pixel region. and supply a signal to at least one first transistor included in each pixel of the pixel region. A drive circuit region including a second transistor, a first substrate on which the second transistor is formed, and the first substrate A second substrate is provided opposite to the first substrate, and a liquid crystal layer is sandwiched between the first and second substrates. The first transistor and the second transistor are formed of an inorganic insulating material. A first interlayer insulating film and a second interlayer insulating film formed of an organic insulating material on the first interlayer insulating film. The third interlayer insulating film is formed of an inorganic insulating material on the second interlayer insulating film, and The interlayer insulating film is provided on a portion of the pixel region, and the end of the third interlayer insulating film is in the drive circuit region. This is a display device characterized by being formed inside the specified area.

[0015] In the above configuration, a first alignment film is provided on the pixel electrode, and a first alignment film is formed on the first alignment film. A liquid crystal layer, a second alignment layer provided on the liquid crystal layer, and opposing layers provided on the second alignment layer An electrode, an organic protective insulating film provided on the counter electrode, and a colored material provided on the organic protective insulating film. The device may include a film and a light-shielding film, and a second substrate provided on the colored film and the light-shielding film.

[0016] Another aspect of the present invention relates to a pixel electrode and at least one that is electrically connected to the pixel electrode. A pixel region in which multiple pixels containing another first transistor are arranged, and A small number of transistors adjacent to the outside and containing signals to the first transistors included in each pixel of the pixel region. A first substrate on which a drive circuit region including at least one second transistor is formed, and A second substrate is provided so as to face the first substrate, and a sandwiched between the first substrate and the second substrate. The device has a light-emitting layer, and an inorganic insulating material is placed on the first transistor and the second transistor. A first interlayer insulating film is formed, and a second organic insulating material is formed on the first interlayer insulating film. An interlayer insulating film, and a third interlayer insulating film formed of an inorganic insulating material on the second interlayer insulating film, The third interlayer insulating film is provided on a portion of the pixel region, and the end of the third interlayer insulating film is This display device is characterized by being formed inside the drive circuit region.

[0017] In the above configuration, a light-emitting layer is provided on the pixel electrode, and an electrode is provided on the light-emitting layer, It may have.

[0018] Furthermore, in each of the above configurations, the third interlayer insulating film is a silicon nitride film, silicon nitride oxide It is preferable that the film is one of the following selected from the aluminum oxide film.

[0019] Furthermore, in each of the above configurations, the first transistor and the second transistor are channel It is preferable that the semiconductor material forming the formation region is an oxide semiconductor. Also, the first transient The first and second transistors consist of a gate electrode and an oxide semiconductor formed on the gate electrode. A semiconductor layer comprising a source electrode and a drain electrode formed on the semiconductor layer. It is preferable that it be structured in this way.

[0020] Furthermore, one aspect of the present invention also includes electronic devices having the above-described display devices. That is the case. [Effects of the Invention]

[0021] In a display device having transistors in the pixel region and the driving circuit region, variation in electrical characteristics This can suppress the transistor channel and improve reliability. In a display device using an oxide semiconductor film in the formation region, hydrogen and moisture are introduced into the oxide semiconductor film. This suppresses the intrusion of certain elements, thereby reducing fluctuations in electrical characteristics and improving reliability. ru. [Brief explanation of the drawing]

[0022] [Figure 1] A diagram illustrating the top view of one type of display device. [Figure 2] A diagram illustrating a cross-section of one type of display device. [Figure 3] A diagram illustrating the top view of one type of display device. [Figure 4] A diagram illustrating a cross-section of one type of display device. [Figure 5] A circuit diagram and a cross-sectional view showing an example of a display device with an image sensor according to one aspect of the present invention. [Figure 6] A diagram showing an example of a tablet terminal according to one aspect of the present invention. [Figure 7] A figure showing an example of an electronic device according to one aspect of the present invention. [Figure 8] A diagram showing the ionic strength of the released gas at various mass-to-charge ratios. [Figure 9] A diagram showing the ionic intensity of each mass-to-charge ratio as a function of the substrate surface temperature. [Figure 10] Cross-sectional view of the sample. [Figure 11] A diagram showing the electrical characteristics of each sample. [Modes for carrying out the invention]

[0023] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention This is not limited to the description below, and its form and details can be changed in various ways, as is the case for those skilled in the art. This will be easily understood. Furthermore, the present invention shall be interpreted as being limited to the contents of the embodiments described below. It is not something that should be done.

[0024] In the embodiments described below, reference numerals that refer to the same thing are used in common across different drawings. It is. Furthermore, the components shown in the drawing, namely the thickness and width of layers and regions, and their relative positions. The details, etc., are exaggerated for clarity in the description of the embodiments.

[0025] Furthermore, in this specification, the terms "electrode" and "wiring" refer to these components functionally. It is not limited to this. For example, "electrode" can be used as part of "wiring". And the reverse is also true. Furthermore, the terms "electrode" and "wiring" can refer to multiple "electrodes" and This includes cases where the wiring is formed as an integrated unit.

[0026] Furthermore, in this specification, a silicon nitride film is defined as a film containing nitrogen, oxygen, silicon, It is a membrane that contains as a component and has a nitrogen content greater than the oxygen content. A silicon nitride film contains oxygen, nitrogen, and silicon as its components, and also contains oxygen This is a membrane in which the content of [substance] is greater than the content of nitrogen.

[0027] Furthermore, the "source" and "drain" functions are used when employing transistors with different polarities. For example, the direction of the current may change during circuit operation. Therefore, in this specification, the terms "source" and "drain" may be used interchangeably. It is assumed that this is possible.

[0028] (Embodiment 1) In this embodiment, a display device using a liquid crystal panel is shown as one form of the display device. This will be explained using Figure 1 and Figure 2.

[0029] Figures 1(A), (B), and (C) show a top view of a display device as one form of the display device. Figure 1(A) shows the entire display device, and Figure 1(B) shows a part of the drive circuit section of the display device. Figure 1(C) shows a top view of a portion of the pixel region. Figure 2 is a top view of Figure 1(A). This corresponds to a cross-sectional view of X1-Y1.

[0030] In the display device shown in Figure 1(A), a pixel region 142 is provided on the first substrate 102. And, in the drive circuit region adjacent to the outside of the pixel region 142 and supplying signals to the pixel region 142 A gate driver circuit section 140 and a source driver circuit section 144 are surrounded by a A material 166 is provided and is sealed by a second substrate 152. Also, pixel region 1 42 and the first gate driver circuit section 140 and source driver circuit section 144 are provided A second substrate 152 is provided so as to face the substrate 102. Therefore, the pixel region 14 2, the gate driver circuit section 140, and the source driver circuit section 144 are located on the first substrate 1 The display element is sealed together with 02, the sealing material 166, and the second substrate 152.

[0031] Furthermore, in Figure 1(A), the sealing material 166 on the first substrate 102 is surrounded In a region different from the area where it is located, there is a pixel region 142, a gate driver circuit section 140, and a source driver. The FPC terminal section 146 (FPC: Flexible Circuit Section 144) is electrically connected to the IBA circuit section 144. A printed circuit is provided, and the FPC terminal section 146 is, FPC148 is connected, and the pixel area 142, gate driver circuit section 140, and sourced The various signals and potentials supplied to the driver circuit section 144 are provided by the FPC 148. Yes, they are.

[0032] Furthermore, in Figure 1(A), the gate driver circuit section 140 and the source driver circuit section This example shows that 144 is formed on the same first substrate 102 as pixel region 142, The configuration is not limited to this. For example, only the gate driver circuit section 140 can be mounted on the first substrate 102. A substrate (for example, a single-crystal semiconductor film) on which a separately prepared source driver circuit is formed. A configuration in which a drive circuit substrate (formed from a polycrystalline semiconductor film) is mounted on the first substrate 102. That's good too.

[0033] Furthermore, in Figure 1(A), the gate driver circuit section 140 is located on both sides of the pixel region 142. The example shows a configuration with two elements, but it is not limited to this configuration. For example, pixel area Alternatively, the gate driver circuit section 140 may be placed on only one side of 142.

[0034] Furthermore, the method of connecting the separately formed drive circuit board is not particularly limited, COG (Chip On Glass) method, wire bonding method, or TAB (Tap Methods such as Automated Bonding can be used. The device comprises a panel in which the display elements are sealed, and an IC including a controller within the panel. This includes modules that have implemented features such as the above.

[0035] In this way, part or all of the drive circuit including the transistor is the same as pixel region 142. It can be integrally formed on the first substrate 102 to form a system-on-panel.

[0036] Furthermore, in Figure 1(C), the pixel region 142 contains the first transistor 101 and a capacitance element. A sub-transistor 107 is formed. The first transistor 101 is connected to the semiconductor layer 108. The drain electrode 104, source electrode 110, and drain electrode 112 are electrically connected to each other. It is done. Also, in the plan view shown in Figure 1(C), although not shown, the first transition On the sta 101, there is a first interlayer insulating film formed of an inorganic insulating material, and on the first interlayer insulating film A second interlayer insulating film formed of an organic insulating material, and an inorganic insulating material on the second interlayer insulating film. A third interlayer insulating film is formed. Also, the capacitive element 107 has a capacitive electrode 11 8, a third interlayer insulating film formed on the capacitive electrode 118, and formed on the third interlayer insulating film It is composed of the pixel electrodes 122.

[0037] Furthermore, in Figure 1(B), the gate driver circuit section 140, which is the drive circuit region, A second transistor 103 and a third transistor 105 are formed. Each transistor in the driver circuit section 140 has a gate electrode 10 connected to the semiconductor layer 108. 4. The source electrode 110 and the drain electrode 112 are electrically connected to each other. Furthermore, in the gate driver circuit section 140, the gate wires including the gate electrode 104 are on the left and right sides. The source wire, including the source electrode 110, extends in the vertical direction, and the drain electrode 11 The drain wire, including point 2, extends vertically, spaced apart from the source electrode.

[0038] Gate driver circuit including second transistor 103 and third transistor 105 The unit 140 supplies signals to the first transistor 101 included in each pixel of the pixel region 142. It is possible.

[0039] Furthermore, the second transistor 103 and the third transistor in the gate driver circuit section 140 The Rangitta 105 requires relatively high voltages for controlling various signals and boosting them. This means that a voltage of approximately 10V to 30V is required. On the other hand, in pixel region 142 The first transistor 101 is used solely for pixel switching. It can be driven with a voltage of several volts to about 20 volts. Therefore, the gate driver circuit section 1 The second transistor 103 and the third transistor 105 in 40 are in the pixel region 1 Compared to the first transistor 101 in 42, the structure that is subjected to a much larger stress It will come to fruition.

[0040] To explain the configuration of the display device shown in Figures 1(A), (B), and (C) in more detail, Figure 1 Using Figure 2, which corresponds to the cross-sectional view of X1-Y1 in (A), (B), and (C), gated The configuration of the driver circuit section 140 and the pixel area 142 will be described below.

[0041] In the pixel region 142, the first substrate 102 and a game formed on the first substrate 102 A gate electrode 104, a gate insulating film 106 formed on the gate electrode 104, and the gate insulating film A semiconductor layer 108 is provided in a position that is in contact with 106 and overlaps with the gate electrode 104, and the gate Source electrode 110 and drain electrode 1 formed on insulating film 106 and semiconductor layer 108 12 and form the first transistor 101.

[0042] Furthermore, in the pixel region 142, on the first transistor 101, more specifically, the gate is isolated Inorganic insulating film is placed on the edge film 106, semiconductor layer 108, source electrode 110, and drain electrode 112. A first interlayer insulating film 114 formed of a material, and an organic insulating material on the first interlayer insulating film 114. A second interlayer insulating film 116 formed by and a capacitive electric field formed on the second interlayer insulating film 116 The electrode 118 and the second interlayer insulating film 116 and the capacitive electrode 118 are formed of an inorganic insulating material. A third interlayer insulating film 120, and a pixel electrode 122 formed on the third interlayer insulating film 120, It has.

[0043] Furthermore, the capacitance is determined by the capacitive electrode 118, the third interlayer insulating film 120, and the pixel electrode 122. Element 107 is formed. Capacitive electrode 118, third interlayer insulating film 120, and pixel electrode Each of the 122 is formed from a material that is transparent in visible light, This method is preferable because it allows for securing a large volume without compromising the aperture ratio of the region.

[0044] Furthermore, a first alignment layer 124 is provided on the pixel electrode 122, and a first alignment layer 124 is provided on the first alignment layer 124. A liquid crystal layer 162, a second alignment film 164 provided on the liquid crystal layer 162, and the second alignment film A counter electrode 158 provided on 164, and an organic protective insulating film provided on the counter electrode 158. 156, a colored film 153 and a light-shielding film 154 provided on the organic protective insulating film 156, and color It comprises a film 153 and a second substrate 152 provided on the light-shielding film 154.

[0045] Furthermore, the pixel electrode 122, the first alignment layer 124, the liquid crystal layer 162, and the second alignment layer 16 A liquid crystal element 150, which is a display element, is formed by 4 and the opposing electrode 158.

[0046] In the gate driver circuit section 140, the first substrate 102 and a shape formed on the first substrate 102 The formed gate electrode 104 and the gate insulating film 106 formed on the gate electrode 104, A semiconductor layer 10 is provided in a position that is in contact with the gate insulating film 106 and overlaps with the gate electrode 104. 8, the gate insulating film 106, and the source electrode 110 and the semiconductor layer 108 formed on the semiconductor layer 108. The rain electrode 112, and the second transistor 103 and the third transistor 10 A 5 is formed.

[0047] Furthermore, in the gate driver circuit section 140, the second transistor 103 and the third transistor On the transistor 105, more specifically the gate insulating film 106, and the semiconductor layer 108, and the source electric A first interlayer insulating film 114 formed on the electrode 110 and the drain electrode 112, and the first layer A second interlayer insulating film 116 is formed on the interlayer insulating film 114.

[0048] In other words, the third interlayer insulating film 120 is provided on a part of the pixel region 142, and the third layer The end of the inter-insulating film 120 is shaped to be inward from the gate driver circuit section 140, which is the drive circuit area. It will be accomplished.

[0049] This configuration allows moisture to be taken in from the outside, or inside the display device. The resulting moisture, hydrogen, and other gases are then removed from the second interlayer insulating film 116 of the gate driver circuit section 140. Therefore, the first transistor 101 and the second transistor Moisture, hydrogen, and other gases are introduced into transistor 103 and the third transistor 105. This can be suppressed.

[0050] Furthermore, the second interlayer insulating film 116, formed from an organic insulating material, constitutes the display device. To reduce irregularities in transistors, highly flat organic insulating materials are required. This improves the image quality of the display device by reducing irregularities such as bumps and ridges in the transistors. This is because it is possible. However, the organic insulating material may absorb hydrogen, moisture, or It releases organic components as gas.

[0051] However, if the semiconductor layer 108 is, for example, a silicon film which is a silicon-based semiconductor material In transistors, the aforementioned hydrogen, moisture, or organic gases pose a significant problem. The possibility is low. However, in one embodiment of the present invention, an oxide semiconductor film is applied to the semiconductor layer 108. To use this, gas from the second interlayer insulating film 116 formed of organic insulating material is released to the outside. It is necessary to release it appropriately. Note that the edge of the third interlayer insulating film 120 is in the drive circuit region. The configuration formed inside the gate driver circuit section 140 is such that the semiconductor layer 108 is made of oxide When formed with a semiconductor film, it exhibits excellent effects. However, the semiconductor layer 108 Materials other than oxide semiconductors (for example, amorphous silicon, which is a silicon-based semiconductor material, crystalline silicon) Similar effects can be obtained in transistors formed from materials such as silicon.

[0052] Furthermore, an inorganic insulating material is formed on the second interlayer insulating film 116 made of an organic insulating material. In this embodiment, the third interlayer insulating film 120 formed by the capacitive element 107 induces It is used as an electrical element. Also, the third interlayer insulating film 120, which is made of an inorganic insulating material, is externally... This makes it possible to suppress hydrogen, moisture, etc., from entering the second interlayer insulating film 116.

[0053] However, the second method uses the third interlayer insulating film 120 in the gate driver circuit section 140. Formed on the second interlayer insulating film 116 on transistors 103 and 3 transistors 105 Then, the gas released from the organic insulating material used in the second interlayer insulating film 116 is diffused to the outside. Unable to do so, the second transistor 103 and the third transistor 105 enter the interior. Insert.

[0054] The gas released from the aforementioned organic insulating material is used in the semiconductor layer 108 of the transistor. When it enters the oxide semiconductor, it is incorporated as an impurity in the oxide semiconductor film, and the semiconductor layer 1 The characteristics of the transistor using 08 will fluctuate.

[0055] However, as shown in Figure 2, the second transistor used in the gate driver circuit section 140 The configuration in which the third interlayer insulating film 120 on transistors 103 and 105 is open, In other words, the third interlayer insulating film 120 is provided in a part of the pixel region 142, and the third interlayer insulating The end of the film 120 is formed to be inside the gate driver circuit section 140. Therefore, the structure is designed to allow the gas emitted from the second interlayer insulating film 116 to diffuse to the outside. It is possible.

[0056] Furthermore, as shown in Figure 2, in the first transistor 101 used in the pixel region 142 Furthermore, a third interlayer insulating film 120 is formed of an inorganic insulating material at the position where the semiconductor layer 108 overlaps. A configuration in which the organic insulating material is removed is preferred. The gas released from the second interlayer insulating film 116 enters the first transistor 101. It can be suppressed.

[0057] Here, we will provide a detailed explanation of the other components of the display device shown in Figures 1 and 2. .

[0058] The first substrate 102 and the second substrate 152 are made of aluminosilicate glass and aluminum. Glass materials such as noborosilicate glass and barium borosilicate glass are used. So, the first substrate 102 and the second substrate 152 are the 8th generation (2160mm x 2460mm) m), 9th generation (2400mm x 2800mm, or 2450mm x 3050mm), It is preferable to use a mother glass of the 10th generation (2950mm x 3400mm), etc. Mother glass shrinks significantly when the processing temperature is high and the processing time is long, therefore mother glass When mass production is carried out using this method, the heat treatment in the manufacturing process is preferably 600°C or lower, and more preferably It is desirable that the temperature be 450°C or lower, and more preferably 350°C or lower.

[0059] Furthermore, an underlayer insulating film may be provided between the first substrate 102 and the gate electrode 104. Examples of insulating films include silicon oxide film, silicon oxide nitride film, silicon nitride film, silicon oxide nitride film Cone film, gallium oxide film, hafnium oxide film, yttrium oxide film, aluminum oxide film Examples include aluminum oxide nitride film. Furthermore, silicon nitride film and aluminum oxide film can be used as the underlying insulating film. Using a ttrium film, hafnium oxide film, yttrium oxide film, aluminum oxide film, etc. Then, impurities, typically alkali metals, water, hydrogen, etc., are transferred from the first substrate 102 to the semiconductor layer 10 This can prevent entry into 8.

[0060] The gate electrode 104 can be made of aluminum, chromium, copper, tantalum, titanium, or molybdenum. N, a metal element selected from tungsten, or an alloy containing the aforementioned metal elements, It can be formed using alloys or the like that combining the aforementioned metal elements. Also, manganese A metallic element selected from one or more of the following, including zirconium, may also be used. The gate electrode 104 may have a single-layer structure or a stacked structure of two or more layers. For example, silicone A single-layer structure of an aluminum film containing , a double-layer structure in which a titanium film is laminated on an aluminum film, A two-layer structure in which a titanium film is laminated on top of a titanium nitride film, and a tungsten film is laminated on top of a titanium nitride film. A two-layer structure, where a tungsten film is laminated on top of a tantalum nitride film or a tungsten nitride film. A two-layer structure, consisting of a titanium film and an aluminum film laminated on top of that titanium film, and then another titanium film on top of that. There are also three-layer structures that form a film. In addition, aluminum is combined with titanium, tantalum, and tungsten. A film of elements selected from tene, molybdenum, chromium, neodymium, and scandium, or multiple such films. A combined alloy film or nitride film may also be used.

[0061] Furthermore, the electrode 104 is indium containing indium tin oxide and tungsten oxide. Indium zinc oxide containing oxides, tungsten oxide, and indium acid containing titanium oxide Indium tin oxide containing titanium oxide, indium zinc oxide, and silicon oxide are added. It is also possible to apply conductive materials with light-transmitting properties, such as indium tin oxide. Alternatively, a laminated structure of the above-mentioned light-transmitting conductive material and the above-mentioned metal element can be used.

[0062] Furthermore, between the gate electrode 104 and the gate insulating film 106, an In-Ga-Zn oxynitride is placed. Semiconductor films, In-Sn oxynitride semiconductor films, In-Ga oxynitride semiconductor films, In-Zn Sn-based oxynitride semiconductor films, Sn-based oxynitride semiconductor films, In-based oxynitride semiconductor films, metal nitride films ( These films may be provided with InN, ZnN, etc. The film thickness should be 5 eV or higher, preferably 5.5 eV. It has the above work function, and since it is greater than the electron affinity of oxide semiconductors, The threshold voltage of a transistor using a conductor can be shifted to a positive value, which is known as normalization. This enables the realization of switching elements with re-off characteristics. For example, In-Ga-Zn oxynitride semiconductors When using a conductive film, the nitrogen concentration should be at least higher than that of the semiconductor layer 108, specifically 7 atomic percent. The above-mentioned In-Ga-Zn oxynitride semiconductor film is used.

[0063] Examples of gate insulating film 106 include silicon oxide film, silicon oxide nitride film, and silicon oxide nitride film. Silicon film, silicon nitride film, aluminum oxide film, hafnium oxide film, gallium oxide film Alternatively, a Ga-Zn-based metal oxide film may be used, and it can be provided in a laminated or single layer configuration. In order to improve the interface characteristics with the semiconductor layer 108, at least the gate insulating film 106 It is preferable that the region in contact with the semiconductor layer 108 be formed of an oxide insulating film.

[0064] Furthermore, the gate insulating film 106 is coated with an insulating film having a blocking effect such as oxygen, hydrogen, and water. By providing this, oxygen can diffuse from the semiconductor layer 108 to the outside and from the outside to the semiconductor layer 108. It can prevent hydrogen, water, etc. from entering. It has a blocking effect on oxygen, hydrogen, water, etc. Examples of insulating films include aluminum oxide, aluminum oxide nitride, gallium oxide, and nitrile oxide. Gallium oxide, yttrium oxide, yttrium oxide and nitride, hafnium oxide, hafnium oxide and nitride It includes things like nium.

[0065] Furthermore, the gate insulating film 106 is made into a layered structure, and the first silicon nitride film has fewer defects. A silicon nitride film is formed, and on the first silicon nitride film, a second silicon nitride film is formed, hydrogen A silicon nitride film with low emission and ammonia emission is provided, and on the second silicon nitride film By providing an oxide insulating film, the gate insulating film 106 has fewer defects and contains hydrogen and a A gate insulating film 106 with low emission of monoxide can be formed. As a result, This suppresses the migration of hydrogen and nitrogen contained in the insulating film 106 to the semiconductor layer 108. This is possible.

[0066] Furthermore, by using a silicon nitride film for the gate insulating film 106, the following effects can be obtained. Yes, it is possible. Silicon nitride films have a higher dielectric constant and equivalent capacitance compared to silicon oxide films. Because a large film thickness is required to obtain the desired result, the gate insulating film can be made physically thicker. Therefore, the first transistor 101, the second transistor 103, and the third transistor This technology suppresses the decrease in dielectric strength of Ta105 and further improves its dielectric strength, making it suitable for use in display devices. This can suppress electrostatic discharge breakdown of the transistor.

[0067] Furthermore, copper is used as the gate electrode 104, and the gate insulating film 10 is in contact with the gate electrode 104. When using a silicon nitride film in step 6, in order to suppress the reaction between copper and ammonia molecules The silicon nitride film is designed to minimize the amount of ammonia molecules released by heating. It seems so.

[0068] In a transistor using an oxide semiconductor film as the semiconductor layer 108, the oxide semiconductor film and If there are trapping levels (also called interface levels) at the interface of the gate insulating film or within the gate insulating film, The threshold voltage fluctuation of a transistor, typically a negative shift in the threshold voltage, and The gate voltage required for the drain current to change by an order of magnitude when the transistor turns on is This causes an increase in the subthreshold coefficient (S value) shown. As a result, there is a problem that the electrical characteristics vary for each transistor. Therefore, by using a silicon nitride film with few defects as the gate insulating film, a negative shift in the threshold voltage and variations in the electrical characteristics of the transistor can be reduced.

[0069] Also, as the gate insulating film 106, hafnium silicate (HfSiO x ), hafnium silicate (HfSi with nitrogen added x O y N z ), hafnium aluminate (HfAl with nitrogen added x O y N z ), high-k materials such as hafnium oxide and yttrium oxide can be used to reduce the gate leakage of the transistor.

[0070] The thickness of the gate insulating film 106 is preferably 5 nm or more and 400 nm or less, more preferably 10 nm or more and 300 nm or less, and even more preferably 50 nm or more and 250 nm or less. <管理编号:

[0071] The semiconductor layer 108 preferably uses an oxide semiconductor and contains at least indium (In) or zinc (Zn). Or it preferably contains both In and Zn. Also, in order to reduce variations in the electrical characteristics of the transistor using the oxide semiconductor, it preferably has one or more stabilizers in combination with them.

[0072] Examples of the stabilizer include gallium (Ga), tin (Sn), hafnium (Hf), aluminum (Al), or zirconium (Zr). Also, other stabilizers Examples include lanthanides, such as lanthanum (La), cerium (Ce), and praseodymium. Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), Elvi These include um (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), etc. ru.

[0073] For example, oxide semiconductors include indium oxide, tin oxide, zinc oxide, and in-Zn gold. metal oxides, Sn-Zn metal oxides, Al-Zn metal oxides, Zn-Mg metal oxides Sn-Mg metal oxides, In-Mg metal oxides, In-Ga metal oxides, In- W-type metal oxides, In-Ga-Zn-type metal oxides (also written as IGZO), In-Al -Zn-based metal oxides, In-Sn-Zn-based metal oxides, Sn-Ga-Zn-based metal oxides, Al-Ga-Zn metal oxide, Sn-Al-Zn metal oxide, In-Hf-Zn metal oxide In-La-Zn metal oxides, In-Ce-Zn metal oxides, In-Pr -Zn-based metal oxides, In-Nd-Zn-based metal oxides, In-Sm-Zn-based metal oxides, In-Eu-Zn metal oxide, In-Gd-Zn metal oxide, In-Tb-Zn gold In-Dy-Zn metal oxides, In-Ho-Zn metal oxides, In-Er -Zn-based metal oxides, In-Tm-Zn-based metal oxides, In-Yb-Zn-based metal oxides, In-Lu-Zn ​​metal oxides, In-Sn-Ga-Zn metal oxides, In-Hf-G α-Zn metal oxides, In-Al-Ga-Zn metal oxides, In-Sn-Al-Zn metal oxides, In-Sn-Hf-Zn metal oxides, In-Hf-Al-Zn metal acids Monsters can be used.

[0074] For example, in-Ga-Zn metal oxides are mainly composed of In, Ga, and Zn. This refers to oxides present as a component, and the ratio of In, Ga, and Zn is irrelevant. It may contain metal elements other than n, Ga, and Zn.

[0075] In addition, as an oxide semiconductor, InMO3(ZnO) m (m>0, and m is not an integer) Materials represented by ) may also be used. M is selected from Ga, Fe, Mn, and Co. It represents one or more metallic elements. Also, as an oxide semiconductor, In2SnO 5(ZnO) n Materials expressed as (n>0 and n is an integer) may also be used.

[0076] For example, In:Ga:Zn=1:1:1 (=1 / 3:1 / 3:1 / 3), In:Ga: Zn=2:2:1 (=2 / 5:2 / 5:1 / 5), or In:Ga:Zn=3:1: In-Ga-Zn metal oxides with an atomic ratio of 2 (=1 / 2:1 / 6:1 / 3) and their composition Oxides in the vicinity 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) Alternatively, the atomic ratio of In:Sn:Zn = 2:1:5 (= 1 / 4:1 / 8:5 / 8) -Sn-Zn metal oxides are preferable. Note that the atomic ratio of the metal oxides should be considered as an error. This includes a variation of plus or minus 20% in the atomic ratio mentioned above.

[0077] However, this is not limited to these, and may include any other semiconductor characteristics and electrical characteristics (field effect mobility, etc.) required. A suitable composition should be used depending on the key voltage, variation, etc. To obtain semiconductor properties, the carrier density, impurity concentration, defect density, and the atoms of metal elements and oxygen are all considered. It is preferable to use appropriate numerical ratios, interatomic distances, densities, etc.

[0078] For example, high mobility can be obtained relatively easily with In-Sn-Zn metal oxides. However, Furthermore, even with In-Ga-Zn metal oxides, by lowering the bulk defect density... This can increase the field effect mobility.

[0079] Furthermore, the oxide semiconductor film that can be used as the semiconductor layer 108 is, The gap is 2 eV or more, preferably 2.5 eV or more, and more preferably 3 eV or more. Thus, by using oxide semiconductor films with a wide energy gap, transistors can be manufactured. The off-current can be reduced.

[0080] Next, we will explain the structure of an oxide semiconductor film that can be used as semiconductor layer 108. do.

[0081] Oxide semiconductor films are broadly classified into non-single-crystal oxide semiconductor films and single-crystal oxide semiconductor films. Non-single-crystal oxide semiconductor films are CAAC-OS (C Axis Aligned Crystal Sturtine Oxide Semiconductor film, polycrystalline oxide semiconductor This refers to films, microcrystalline oxide semiconductor films, amorphous oxide semiconductor films, etc.

[0082] This section describes the CAAC-OS membrane.

[0083] CAAC-OS film is one of the oxide semiconductor films having multiple crystalline regions, and most The crystalline portion is small enough to fit within a cube with sides less than 100 nm. Therefore, CAAC- The crystalline portion contained in the OS film is a cube with sides of less than 10 nm, less than 5 nm, or less than 3 nm. This also includes cases where the item fits inside.

[0084] CAAC-OS film is examined using a transmission electron microscope (TEM). When observed with a tron ​​microscope, a clear boundary between crystalline regions is observed, i.e. The grain boundaries (also called crystal grain boundaries) cannot be identified. Therefore, C AAC-OS films are less susceptible to the decrease in electron mobility caused by grain boundaries.

[0085] The CAAC-OS film was observed by TEM from a direction roughly parallel to the sample surface (cross-sectional TEM view). (Inference) It can be confirmed that in the crystalline part, metal atoms are arranged in layers. Each of these layers has a concave surface on the surface (also called the surface to be formed) or upper surface that forms the CAAC-OS film. The shape reflects a convexity and is arranged parallel to the surface or top surface of the CAAC-OS film to be formed.

[0086] On the other hand, the CAAC-OS film was observed by TEM from a direction roughly perpendicular to the sample surface (plane T). EM observation reveals that in the crystalline region, metal atoms are arranged in a triangular or hexagonal shape. This can be confirmed. However, no regularity is observed in the arrangement of metal atoms between different crystalline regions. do not have.

[0087] In this specification, "parallel" means that two lines are at an angle of -10° or more and 10° or less. This refers to a state in which the positions are arranged. Therefore, it also includes cases where the angle is between -5° and 5°. Also, "Perpendicular" refers to a state where two straight lines are positioned at an angle between 80° and 100°. Therefore, this also includes cases where the angle is between 85° and 95°.

[0088] Cross-sectional TEM observation and planar TEM observation revealed that the crystalline portion of the CAAC-OS film exhibits orientation. It can be seen that this is the case.

[0089] X-ray diffraction (XRD) of CAAC-OS film When structural analysis is performed using the instrument, for example, CAAC-OS having InGaZnO4 crystals is found. Out-of-plane analysis of the film showed a peak at a diffraction angle (2θ) of around 31°. This peak may appear. This peak is attributed to the (009) plane of the InGaZnO4 crystal. Therefore, the crystals of the CAAC-OS film have c-axis orientation, and the c-axis is on the surface to be formed or on the upper surface. It can be confirmed that it is oriented in a roughly vertical direction.

[0090] On the other hand, in the CAAC-OS film, X-rays are incident from a direction approximately perpendicular to the c-axis in an in-p In analysis using the lane method, a peak may appear when 2θ is around 56°. This is attributed to the (110) plane of the InGaZnO4 crystal. For a crystalline semiconductor film, fix 2θ to approximately 56° and use the normal vector of the sample surface as the axis (φ axis). When the analysis (φ scan) is performed while rotating the sample, a crystal plane equivalent to the (110) plane is found. Six peaks attributable to this are observed. In contrast, in the case of the CAAC-OS film, 2θ Even when fixed at approximately 56° and scanned using the φ scan function, no clear peak appears.

[0091] From the above, it can be concluded that in CAAC-OS films, the orientation of the a-axis and b-axis between different crystalline regions is Although irregular, it has c-axis orientation, and the c-axis is parallel to the normal vector of the formed surface or the upper surface. It can be seen that it is oriented in a specific direction. Therefore, the layered structure confirmed by the aforementioned cross-sectional TEM observation is Each layer of arranged metal atoms is a plane parallel to the ab-plane of the crystal.

[0092] Furthermore, the crystalline portion is formed when the CAAC-OS film is deposited, or during crystallization treatments such as heat treatment. It is formed when the process is carried out. As mentioned above, the c-axis of the crystal is aligned with the surface on which the CAAC-OS film is formed. Or it is oriented in a direction parallel to the normal vector of the upper surface. Therefore, for example, the CAAC-OS film When the shape is altered by etching or other means, the c-axis of the crystal becomes the target area for CAAC-OS film formation. The normal vector may not be parallel to the normal vector of the face or top surface.

[0093] Furthermore, the degree of crystallinity in the CAAC-OS film does not need to be uniform. For example, CAAC-OS When the crystalline portion of the film is formed by crystal growth from near the upper surface of the CAAC-OS film, The region near the surface may have a higher degree of crystallinity than the region near the surface being formed. Also, CA When impurities are added to an AC-OS film, the degree of crystallinity in the region where the impurities are added changes, and Regions with varying degrees of crystallinity may also be formed.

[0094] Furthermore, the out-of-plane CAAC-OS film having InGaZnO4 crystals Analysis using this method revealed that in addition to the peak near 2θ = 31°, there is also a peak near 2θ = 36°. In some cases, this occurs. Peaks near 2θ of 36° are found on the (311) plane of the ZnGa2O4 crystal. Since it is attributed to this, a portion of the CAAC-OS film containing InGaZnO4 crystals contains Z This indicates the presence of nGa2O4 crystals. The CAAC-OS film has a 2θ of nearly 31°. It is preferable that the peak is shown to the side and that the peak does not appear near 36° for 2θ.

[0095] CAAC-OS films are oxide semiconductor films with low impurity concentrations. The impurities include hydrogen and carbon. These are elements other than the main components of oxide semiconductor films, such as silicon and transition metal elements. In particular, silicon Elements such as condensate, which have a stronger bonding force with oxygen than the metal elements that make up oxide semiconductor films, are acidic. By removing oxygen from the oxide semiconductor film, the atomic arrangement of the oxide semiconductor film is disrupted, reducing its crystallinity. This is a contributing factor. Also, heavy metals such as iron and nickel, argon, and carbon dioxide have a high atomic ratio. Because of its large diameter (or molecular radius), when it is contained within an oxide semiconductor film, the oxide semiconductor film This disrupts the atomic arrangement and reduces crystallinity. Pure substances can act as carrier traps or carrier sources.

[0096] Furthermore, CAAC-OS films are oxide semiconductor films with a low defect level density. For example, oxidation Oxygen vacancies in semiconductor films can act as carrier traps or capture hydrogen. This can sometimes become a source of carrier transmission.

[0097] A low impurity concentration and low defect level density (few oxygen vacancies) are referred to as high-purity intrinsic or This is essentially called high-purity intrinsic. Oxide semiconductors that are high-purity intrinsic or substantially high-purity intrinsic. Because the membrane has fewer carrier sources, the carrier density can be lowered. Therefore, A transistor using this oxide semiconductor film exhibits electrical characteristics such as a negative threshold voltage ( - Also called Marieion.) It rarely becomes high purity genuine or substantially high purity. Intrinsic oxide semiconductor films have few carrier traps. Therefore, the oxide semiconductor... Transistors using film have small variations in electrical characteristics and are highly reliable. Furthermore, the charge trapped in the carrier trap of the oxide semiconductor film requires time to be released. It can last for a long time and behave as if it were a fixed charge. Therefore, when the impurity concentration is high... Furthermore, transistors using oxide semiconductor films with a high defect level density exhibit unstable electrical properties. There are cases where this occurs.

[0098] Furthermore, transistors using CAAC-OS films exhibit electrical properties when irradiated with visible light or ultraviolet light. Sexual variation is small.

[0099] Furthermore, CAAC-OS films are used, for example, for sputtering polycrystalline oxide semiconductors. Using a GET, the film is deposited by sputtering. When ions collide, the crystalline region contained in the sputtering target is cleaved from the ab plane. As flat or pellet-shaped sputtering particles having an open surface parallel to the ab-plane Delamination may occur. In this case, the flat sputtered particles maintain their crystalline state. By reaching the substrate in this state, the CAAC-OS film can be deposited.

[0100] Furthermore, it is preferable to apply the following conditions for forming the CAAC-OS film.

[0101] 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 present in the deposition chamber (such as hydrogen, water, carbon dioxide, and nitrogen). It should be reduced. Also, the concentration of impurities in the film-forming gas should be reduced. Specifically, the dew point A film-forming gas with a temperature of -80°C or lower, preferably -100°C or lower, is used.

[0102] Furthermore, by increasing the substrate heating temperature during film deposition, the sputtering particles can be removed after reaching the substrate. Grazing occurs. Specifically, the substrate heating temperature is preferably between 100°C and 740°C. The film is deposited at a temperature of 150°C to 500°C. By increasing the substrate heating temperature during film deposition, When flat sputtering particles reach the substrate, migration occurs on the substrate. The flat surface of the sputtered particles adheres to the substrate.

[0103] 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 the amount of oxygen. The oxygen content in the film-forming gas is 30% by volume or more, preferably 100%. This is expressed as a percentage by volume.

[0104] Furthermore, the oxide semiconductor film used as the semiconductor layer 108 is made up of multiple oxide semiconductor films stacked on top of each other. A structure like this is also acceptable. For example, an oxide semiconductor film can be made into a first oxide semiconductor film and a second oxide semiconductor film. As a conductive film lamination, a first oxide semiconductor film and a second oxide semiconductor film are layered with gold of different compositions. A group oxide may also be used. For example, a binary metal oxide to a quaternary metal oxide may be used as the first oxide semiconductor film. Using one metal oxide, a different binary metal is used in the second oxide semiconductor film compared to the first oxide semiconductor film. A quaternary metal oxide may also be used.

[0105] Furthermore, the constituent elements of the first oxide semiconductor film and the second oxide semiconductor film are the same, and the combination of the two The composition may be different. For example, the atomic ratio of the first oxide semiconductor film may be In:Ga:Zn = Assuming a 1:1:1 ratio, the atomic ratio of the second oxide semiconductor film is In:Ga:Zn=3:1:2. Alternatively, the atomic ratio of the first oxide semiconductor film may be set to In:Ga:Zn=1:3:2. The atomic ratio of the second oxide semiconductor film may be set to In:Ga:Zn = 2:1:3. The atomic ratio of each oxide semiconductor film is within a tolerance of plus or minus 20% of the above atomic ratio. Includes fluctuations.

[0106] At this time, of the first oxide semiconductor film and the second oxide semiconductor film, the side closer to the terminal electrode ( It is preferable to set the content of In and Ga in the oxide semiconductor film on the channel side to In > Ga. The In and Ga content of the oxide semiconductor film on the side furthest from the electrode (back channel side) is determined by the ratio of In to Ga. It is best to set Ga ≤ Ga.

[0107] Furthermore, the oxide semiconductor film has a three-layer structure, consisting of the first oxide semiconductor film to the third oxide semiconductor film. The constituent elements may be the same, but their respective compositions may be different. For example, the first oxide The atomic ratio of the semiconductor film is set to In:Ga:Zn=1:3:2, and the atoms of the second oxide semiconductor film The atomic ratio is set to In:Ga:Zn = 3:1:2, and the atomic ratio of the third oxide semiconductor film is set to In:G a:Zn = 1:1:1 is also acceptable.

[0108] Oxide semiconductor films in which the atomic ratio of In is smaller than that of Ga and Zn, typically those with a lower atomic ratio of In. The first oxide semiconductor film with Ga:Zn=1:3:2 has more In atoms than Ga and Zn. Oxide semiconductor films with a large numerical ratio, typically the second oxide semiconductor film, and Ga, Zn, and Compared to oxide semiconductor films with the same atomic ratio of In, typically a third oxide semiconductor film, Because oxygen deficiency is less likely to occur, the increase in carrier density can be suppressed. The first oxide semiconductor film, with an atomic ratio of In:Ga:Zn=1:3:2, has an amorphous structure. If present, the second oxide semiconductor film is more likely to become a CAAC-OS film.

[0109] Furthermore, since the constituent elements of the first oxide semiconductor film to the third oxide semiconductor film are the same, The oxide semiconductor film 1 has fewer trap levels at its interface with the second oxide semiconductor film. Therefore, by using the above structure for the oxide semiconductor film, the aging and photodegradation of the transistor can be reduced. This can reduce the amount of fluctuation in the threshold voltage.

[0110] In oxide semiconductors, the s orbitals of heavy metals primarily contribute to carrier conduction, and the presence of In By increasing the ratio, more s orbitals overlap, resulting in an oxidation composition where In > Ga. The material exhibits high carrier mobility compared to oxides with a composition of In ≤ Ga. Compared to In, the energy required to form an oxygen vacancy is higher, making oxygen vacancies less likely to occur, therefore In ≤ Oxides with a Ga composition possess more stable properties compared to oxides with an In > Ga composition. ru.

[0111] An oxide semiconductor with an In > Ga composition is applied to the channel side, and In is applied to the back channel side. By applying an oxide semiconductor with a composition of ≤Ga, the field-effect mobility of the transistor and This will allow for even greater reliability.

[0112] Furthermore, the first to third oxide semiconductor films are made of oxide semiconductors with different crystalline properties. The material may be applied. That is, single-crystal oxide semiconductors, polycrystalline oxide semiconductors, microcrystalline oxides Even in configurations that appropriately combine material semiconductors, amorphous oxide semiconductors, or CAAC-OS. Good. Also, amorphous oxidation is applied to either the first oxide semiconductor film or the second oxide semiconductor film. Applying a semiconductor material relieves internal and external stresses in oxide semiconductor films, and transients This reduces variations in transistor characteristics and further enhances the reliability of the transistors. This is the result.

[0113] The thickness of the oxide semiconductor film is 1 nm or more and 100 nm or less, more preferably 1 nm or more and 30 nm or less. less than or equal to nm, more preferably 1 nm to 50 nm, and even more preferably 3 nm to 20 nm The following is preferable.

[0114] In the oxide semiconductor film used for semiconductor layer 108, secondary ion mass spectrometry (SIMS) is used. The results obtained by Secondary Ion Mass Spectrometry The concentration of potassium metal or alkaline earth metal is 1 × 10⁻⁶ 18 atoms / cm 3 The following, More preferably 2 × 10 16 atoms / cm 3 The following is preferable: Alkali gold Alkaline earth metals and other metals may generate carriers when they combine with oxide semiconductors. This is because it causes an increase in the transistor's off-current.

[0115] Furthermore, in the oxide semiconductor film used for the semiconductor layer 108, secondary ion mass spectrometry is used The hydrogen concentration obtained is 5 × 10 18 atoms / cm 3 Less than 1 × 10 18 a toms / cm 3 The following is more preferable: 5 x 10 17 atoms / cm 3 Below, further better Mashiku is 1 x 10 16 atoms / cm 3 The following is preferable.

[0116] The hydrogen contained in the oxide semiconductor film reacts with the oxygen bonded to the metal atoms to form water. As a result, defects are formed in the lattice where oxygen has been removed (or in the areas where oxygen has been removed). Furthermore, when some of the hydrogen combines with oxygen, electrons, which act as carriers, are produced. Therefore, in the film deposition process of oxide semiconductor films, by drastically reducing hydrogen-containing impurities, Therefore, it is possible to reduce the hydrogen concentration in oxide semiconductor films. By using the removed oxide semiconductor film as the channel region, the negative threshold voltage This can suppress vibrations and reduce variations in electrical characteristics. Typically, the leakage current in the source and drain of a transistor is reduced by lowering the off-current. It is possible to reduce it.

[0117] Furthermore, the nitrogen concentration of the oxide semiconductor film used in semiconductor layer 108 is set to 5 × 10⁻⁶. 18 atom / cm 3 The following measures suppress the negative shift in the transistor threshold voltage. This allows for the reduction of variations in electrical characteristics.

[0118] Furthermore, by removing as much hydrogen as possible, the highly purified oxide semiconductor film is used in the channel region. The low off-current of the transistor used can be proven through various experiments. For example If the channel width is 1 x 10 6 Even with a transistor with a channel length of 10 μm in μm, When the voltage between the drain electrode and the drain electrode (drain voltage) is in the range of 1V to 10V, The current is below the measurement limit of the semiconductor parameter analyzer, i.e., 1 × 10⁻⁶. -13 Below A This characteristic can be obtained. In this case, the off-current is divided by the channel width of the transistor. The off-current corresponding to the value is found to be 100 Hz / μm or less. Also, the capacitance element The child and the transistor are connected, and the charge flowing into or out of the capacitive element is... Using a circuit controlled by a transistor, the off-current was measured. In this measurement, an oxide semiconductor film with high purity was used for the channel region of the above-mentioned transistor, and the off-current of the transistor was measured from the change in the charge amount per unit time of the capacitor element. As a result, when the voltage between the source electrode and the drain electrode of the transistor was 3 V, an off-current as low as several tens of yA / μm was obtained. Therefore, the transistor using the oxide semiconductor film with high purity for the channel region has an extremely small off-current. For the source electrode 110 and the drain electrode 112, as the conductive material, a single metal composed of aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, or tungsten, or an alloy having this as the main component is used in a single-layer structure or a laminated structure. For example, a single-layer structure of an aluminum film containing silicon, a two-layer structure in which a titanium film is laminated on an aluminum film, a two-layer structure in which a titanium film is laminated on a tungsten film, a two-layer structure in which a copper film is laminated on a copper-magnesium-aluminum alloy film, a titanium film or a titanium nitride film, and an aluminum film or a copper film is laminated on the titanium film or the titanium nitride film, and a titanium film or a titanium nitride film is further formed thereon, a three-layer structure, a molybdenum film or a molybdenum nitride film, and an aluminum film or a copper film is laminated on the molybdenum film or the molybdenum nitride film, and a molybdenum film or a molybdenum nitride film is further formed thereon, there are three-layer structures and the like. In addition, a transparent conductive material containing indium oxide, tin oxide, or zinc oxide may be used.

[0119]

[0120] In this embodiment, the source electrode 110 and the drain electrode 112 are placed in the semiconductor layer 108 Although it is shown above, it may also be placed between the gate insulating film 106 and the semiconductor layer 108.

[0121] The first interlayer insulating film 114 is an oxide semiconductor film used as the semiconductor layer 108. To improve surface properties, it is preferable to use an oxide insulating film. First interlayer insulating film 11 4 refers to silicon oxide films and silicon oxide-nitride films with a thickness of 150 nm to 400 nm. , aluminum oxide film, hafnium oxide film, gallium oxide film, or Ga-Zn metal acid A oxide film or the like can be used. In addition, the first interlayer insulating film 114 can be an oxide insulating film. A laminated structure of a nitride insulating film may also be used. For example, as the first interlayer insulating film 114, an acid A laminated structure of silicon nitride film and silicon nitride film can be formed.

[0122] The second interlayer insulating film 116 may be an acrylic resin, a polyimide resin, or a benzocyclo Heat-resistant organic insulating materials such as butene resins, polyamide resins, and epoxy resins. It can be used. Furthermore, by stacking multiple insulating films formed from these materials, A second interlayer insulating film 116 may be formed. By using the second interlayer insulating film 116 This makes it possible to flatten the irregularities of the first transistor 101, etc.

[0123] The capacitive electrode 118 is made of indium oxide containing tungsten oxide, tungsten oxide Indium zinc oxide containing titanium oxide, indium oxide containing titanium oxide, titanium oxide containing Indium tin oxide, indium tin oxide (hereinafter referred to as ITO), indium zinc acid Using transparent conductive materials such as indium tin oxide with added silicon dioxide and silicon dioxide. It is possible.

[0124] The third interlayer insulating film 120 may be a silicon oxide film, a silicon oxide nitride film, or a silicon oxide nitride film. Inorganic insulating materials such as silicon nitride films and aluminum oxide films can be used. In particular, the third interlayer insulating film 120 may be a silicon nitride film, a silicon nitride oxide film, or an acid Preferably, it is one of the aluminum oxide films selected from among the silicon nitride films. A third interlayer insulator is made of either a silicon nitride film or an aluminum oxide film. By using it as film 120, the release of hydrogen and water from the second interlayer insulating film 116 is suppressed. It can be controlled.

[0125] The same material as the material shown for the capacitive electrode 118 can be used for the pixel electrode 122. The materials used for the capacitive electrode 118 and the pixel electrode 122 may be the same material or different materials. While other materials may be used, using the same material is preferable because it reduces manufacturing costs.

[0126] The first alignment film 124 and the second alignment film 164 are acrylic resins, polyimide resins, etc. Resins, benzocyclobutene resins, polyamide resins, epoxy resins, etc., which have heat resistance. Organic materials can be used.

[0127] The liquid crystal layer 162 can be a thermotropic liquid crystal, a low molecular weight liquid crystal, a polymer liquid crystal, or a polymer dispersion. Liquid crystal materials such as crystalline liquid crystals, ferroelectric liquid crystals, and antiferroelectric liquid crystals can be used. Depending on the conditions, the crystalline material can be classified into cholesteric phase, smectic phase, cubic phase, and chiral phase. It exhibits nematic phase, isotropic phase, etc.

[0128] Also, when adopting the horizontal electric field method, a liquid crystal showing a blue phase without using an alignment film (the first alignment film 124 and the second alignment film 16 4) may be used. The blue phase is one of the liquid crystal phases. When the cholesteric liquid crystal is heated up, it appears immediately before the transition from the cholesteric phase to the isotropic phase . Since the blue phase appears only in a narrow temperature range, a liquid crystal composition mixed with a chiral agent of several weight % or more is used for the liquid crystal layer in order to improve the temperature range. A liquid crystal composition containing a liquid crystal showing a blue phase and a chiral agent has a short response speed and is optically isotropic , so that alignment treatment is unnecessary and the viewing angle dependency is small. Also, since an alignment film does not need to be provided, rubbing treatment is also unnecessary, so that electrostatic breakdown caused by rubbing treatment can be prevented . Therefore, defects and damages of the liquid crystal display device during the manufacturing process can be reduced. Thus, it becomes possible to improve the productivity of the liquid crystal display device. A transistor using an oxide semiconductor film may have its electrical characteristics significantly fluctuated by the influence of static electricity and deviate from the design range . Therefore, it is more effective to use a liquid crystal material of the blue phase for a liquid crystal display device having a transistor using an oxide semiconductor film . Also, the intrinsic resistance of the liquid crystal material is 1×10 Ω·cm or more, preferably 1×10 Ω·cm or more, and more preferably 1×10 Ω·cm or more. The value of the intrinsic resistance in this specification is the value measured at 20°C . Also, the size of the holding capacitance provided in the display device is the lead of the transistor arranged in the pixel region .

[0129] 9 1 1 12

[0130] ​​​​​​​The current and other factors are taken into consideration to set the capacity to hold the charge for a predetermined period. Therefore, the settings should be adjusted considering the transistor's off-current, etc. This also applies to the formation of high purity and oxygen deficiency. By using a transistor having an oxide semiconductor layer that suppresses the following, for example, a display element and When using liquid crystal elements, the liquid crystal capacitance in each pixel should be 1 / 3 or less, preferably. It is sufficient to provide a storage capacity that is 1 / 5 or less of the current capacity.

[0131] Furthermore, the highly purified oxide semiconductor used in this embodiment, which suppresses the formation of oxygen vacancies, is semi-semiconductor. The transistors used in the conductive layer should have a low current value in the off state (off current value). This allows for longer holding times of electrical signals such as image signals, and enables power-on behavior. In this state, the write interval can also be set to be longer. Therefore, the frequency of refresh operations can be reduced. This allows for reduced power consumption.

[0132] Furthermore, in the display devices shown in Figures 1 and 2, the driving mode of the liquid crystal element 150 is as follows: TN (Twisted Nematic) mode, IPS (In-Plane-Swiss) Ching mode, FFS (Fringe Field Switching) mode , ASM(Axially Symmetric aligned Micro-cel l) Mode, OCB (Optical Compensated Birefringence) nce) mode, FLC (Ferroelectric Liquid Crystal ) mode, AFLC (AntiFerroelectric Liquid Cryst Modes such as al) can be used. In particular, to obtain a wide field of view, use FFS mode. It would be preferable if that were the case.

[0133] Furthermore, normally black liquid crystal display devices, such as those employing vertical alignment (VA) mode, are also available. It may also be used as a transmissive liquid crystal display device. Several vertical orientation modes are possible, For example, MVA (Multi-Domain Vertical Alignment) Mode, PVA (Patterned Vertical Alignment) mode These can be used. Also, pixels can be divided into several subpixels. This involves dividing the molecule into parts and devising a method to tilt each part in a different direction, known as multi-domainization or multi- A method called multi-domain design may also be used.

[0134] Furthermore, although not shown in Figures 1 and 2, polarizing members, phase difference members, and anti-reflective elements are also present. Optical components (optical substrates) such as members may be provided as appropriate. For example, polarizing substrates and phase difference Circularly polarized light from a substrate may also be used. Furthermore, backlights, sidelights, etc., may be used as light sources. You may use it.

[0135] Furthermore, the display method in pixel area 142 can be either progressive or interlaced. These can be used. Also, when displaying in color, the color elements controlled by pixels include R It is not limited to the three colors GB (R stands for red, G for green, and B for blue). For example, RGBW (W is (representing white), or RGB with one or more additional colors such as yellow, cyan, magenta, etc. The size of the display area for each dot of the color element may differ. However, The invention described is not limited to a color display device, but also includes a monochrome display device. It can also be applied to...

[0136] Furthermore, a spacer 160 is formed below the second substrate 152, and the first substrate 1 Provided to control the distance (also called the cell gap) between 02 and the second substrate 152 It is present. Furthermore, the thickness of the liquid crystal layer 162 is determined by the cell gap. 60 is a columnar spacer obtained by selectively etching an insulating film, a spherical You can use spacers of any shape, such as spacers.

[0137] Furthermore, the colored film 153 functions as a so-called color filter. The colored film 153 functions as follows: Any material that exhibits transparency to light in a specific wavelength range can be used, such as an organic material containing dyes or pigments. A resin film or the like can be used.

[0138] Furthermore, the light-shielding film 154 functions as a so-called black matrix. It is sufficient if the light emitted between adjacent pixels is blocked, and it does not contain a metal film, black dye, or black pigment. An organic resin film having the above can be used. In this embodiment, a black pigment is used. An example of a light-shielding film 154 containing an organic resin film is shown.

[0139] Furthermore, the organic protective insulating film 156 is made of ionic material contained in the colored film 153, which is the liquid crystal layer. It is provided so as not to diffuse into 162. However, the organic protective insulating film 156 is not limited to this configuration. It is also acceptable to have a configuration that does not include this feature.

[0140] Furthermore, the sealing material 166 may be a thermosetting resin or an ultraviolet curing resin. This is possible. In the sealing region of the sealing material 166 shown in Figure 2, the first substrate 10 Between 2 and the second substrate 152, there is a gate insulating film 106, a source electrode 110 and a drain electrode 1 Electrode 113, first interlayer insulating film 114, and second interlayer insulating film formed in the same process as 12 The example given is a configuration in which a film 116 is provided, but it is not limited to this. For example, the gate insulating film 106 and Alternatively, the structure may consist only of the first interlayer insulating film 114. Furthermore, the second interlayer insulating film 116 may be omitted. Removing it prevents moisture and other substances from entering from the outside, as shown in Figure 2, the second interlayer A structure in which a portion of the insulating film 116 is removed or partially receded is preferred.

[0141] As described above, the display device shown in this embodiment has a pixel region and a drive circuit region. A transistor, a first interlayer insulating film formed on the transistor, and a first layer A second interlayer insulating film formed on the interlayer insulating film, and a third layer formed on the second interlayer insulating film. The third interlayer insulating film is provided on a portion of the pixel region, and the third interlayer insulating film is provided on a portion of the pixel region. The film's edges are formed inside the drive circuit region. This suppresses the degassing from the second interlayer insulating film from entering the transistor side, resulting in high reliability. It can be used as a display device. Furthermore, the first interlayer insulating film provides a second interlayer insulating film. This prevents degassing from the film from entering the transistor.

[0142] The configuration shown in this embodiment can be appropriately combined with the configurations shown in other embodiments or examples. It can be used.

[0143] (Embodiment 2) In this embodiment, as one form of display device, a display device using an organic EL panel is described. This will be explained using Figures 3 and 4. Note that the same parts as in the configuration shown in Embodiment 1 are the same. The symbols are added, and their detailed explanations are omitted.

[0144] As one form of the display device, a top view of the display device is shown in Figure 3, and a cross-sectional view of the display device is shown in Figure 4. These are shown. Note that Figure 4 corresponds to the cross-sectional view of X2-Y2 in Figure 3.

[0145] In the display device shown in Figure 3, a pixel region 142 is provided on the first substrate 102, and The drive circuit region is adjacent to the outside of the pixel region 142 and supplies signals to the pixel region 142. A sealing material is placed around the source driver circuit section 140 and the source driver circuit section 144. 166 is provided and is sealed by the second substrate 152. Also, the pixel region 142 and , a first substrate on which a gate driver circuit section 140 and a source driver circuit section 144 are provided. A second substrate 152 is provided opposite to 102. Therefore, the pixel region 142 and The gate driver circuit section 140 and the source driver circuit section 144 are connected to the first substrate 102 and The display element is sealed together with the sealing material 166 and the second substrate 152.

[0146] In this way, part or all of the drive circuit including the transistor is the same as pixel region 142. It can be integrally formed on the first substrate 102 to form a system-on-panel.

[0147] Next, using Figure 4, which corresponds to the cross-sectional view of X2-Y2 in Figure 3, pixel region 142, and The configuration of the gate driver circuit section 140 will be explained in detail below.

[0148] In the pixel region 142, the first substrate 102 and a game formed on the first substrate 102 A gate electrode 104, a gate insulating film 106 formed on the gate electrode 104, and the gate insulating film A semiconductor layer 108 is provided in a position that is in contact with 106 and overlaps with the gate electrode 104, and the gate Source electrode 110 and drain electrode 1 formed on insulating film 106 and semiconductor layer 108 12 and form the first transistor 101.

[0149] Furthermore, in the pixel region 142, on the first transistor 101, more specifically, the gate is isolated The edge film 106, the semiconductor layer 108, the source electrode 110, and the drain electrode 112 are inorganic A first interlayer insulating film 114 made of insulating material, and an organic insulating film on the first interlayer insulating film 114. A second interlayer insulating film 116 formed of a material, and an inorganic insulating material on the second interlayer insulating film 116. A third interlayer insulating film 120 formed by, a second interlayer insulating film 116, and a third interlayer insulating film A partition wall 126 formed on the film 120, a third interlayer insulating film 120, and a third interlayer insulating film formed on the partition wall 126 The formed pixel electrode 122, the light-emitting layer 128 formed on the pixel electrode 122, and the light-emitting layer 12 An electrode 130 is formed on 8.

[0150] Furthermore, the light-emitting element 170 is formed by the pixel electrode 122, the light-emitting layer 128, and the electrode 130. It has been done.

[0151] Furthermore, a filler material 172 is provided on the light-emitting element 170, or more specifically, on the electrode 130. A second substrate 152 is provided on the filler material 172. That is, the first substrate 102 The structure is such that the light-emitting element 170 and the filler material 172 are sandwiched between the second substrate 152. ru.

[0152] Furthermore, in the gate driver circuit section 140, the first substrate 102 and the first substrate 102 A gate electrode 104 formed on top, and a gate insulating film 10 formed on the gate electrode 104 6 and a semiconductor located in a position that is in contact with the gate insulating film 106 and overlaps with the gate electrode 104. Layer 108, gate insulating film 106, and source electrode 110 formed on semiconductor layer 108 and drain electrode 112, thereby the second transistor 103 and the third transistor Ta105 is formed.

[0153] Furthermore, in the gate driver circuit section 140, the second transistor 103 and the third transistor On the transistor 105, more specifically the gate insulating film 106, and the semiconductor layer 108, and the source electric A first interlayer insulating film 11 is formed of an inorganic insulating material on the electrode 110 and the drain electrode 112. 4 and a second interlayer insulating film 116 formed of an organic insulating material on the first interlayer insulating film 114 It is formed.

[0154] In other words, the third interlayer insulating film 120 is provided on a part of the pixel region 142, and the third layer The end of the inter-insulating film 120 is shaped to be inward from the gate driver circuit section 140, which is the drive circuit area. It will be accomplished.

[0155] This configuration allows moisture to be taken in from the outside, or inside the display device. The resulting moisture, hydrogen, and other gases are then removed from the second interlayer insulating film 116 of the gate driver circuit section 140. Therefore, the first transistor 101 and the second transistor Moisture, hydrogen, and other gases are introduced into transistor 103 and the third transistor 105. This can be suppressed.

[0156] Furthermore, the second interlayer insulating film 116, formed from an organic insulating material, constitutes the display device. To reduce irregularities in transistors, highly flat organic insulating materials are required. However, when heated, the organic insulating material releases hydrogen, moisture, or organic components as gases. It will be released.

[0157] However, if the semiconductor layer 108 is, for example, a silicon film which is a silicon-based semiconductor material In transistors, the aforementioned hydrogen, moisture, or organic gases pose a significant problem. The possibility is low. However, in one embodiment of the present invention, an oxide semiconductor film is applied to the semiconductor layer 108. To use this, gas from the second interlayer insulating film 116 formed of organic insulating material is released to the outside. It is necessary to release it appropriately. Note that the edge of the third interlayer insulating film 120 is in the drive circuit region. The configuration formed inside the gate driver circuit section 140 is such that the semiconductor layer 108 is made of oxide When formed with a semiconductor film, it exhibits excellent effects. However, the semiconductor layer 108 Materials other than oxide semiconductors (for example, amorphous silicon, which is a silicon-based semiconductor material, crystalline silicon) Similar effects can be obtained in transistors formed from materials such as silicon.

[0158] Furthermore, the third interlayer insulating film 120 formed on the second interlayer insulating film 116 is in the form of this embodiment. In this state, the gas emitted from the second interlayer insulating film 116 enters the light-emitting element 170 side. To suppress this, and / or the adhesion between the pixel electrode 122 and the second interlayer insulating film 116 It is formed to improve the light-emitting element 170 side. This can suppress the entry of gases such as hydrogen and moisture from the interlayer insulating film 116 of layer 2.

[0159] However, the second method uses the third interlayer insulating film 120 in the gate driver circuit section 140. A second interlayer insulating film 116 formed on transistor 103 and the third transistor 105 When this is achieved, the gas released from the organic insulating material used in the second interlayer insulating film 116 is spread to the outside. Unable to disperse, the second transistor 103 and the third transistor 105 I get completely absorbed in it.

[0160] When the aforementioned gas enters the oxide semiconductor used in the semiconductor layer 108 of the transistor, acid It is incorporated as an impurity in the semiconductor film, and the characteristics of a transistor using the semiconductor layer 108 Sexual orientation changes.

[0161] However, as shown in Figure 4, the second transistor used in the gate driver circuit section 140 The configuration in which the third interlayer insulating film 120 on transistors 103 and 105 is open, In other words, the third interlayer insulating film 120 is provided in a part of the pixel region 142, and the third interlayer insulating The end of the film 120 is formed to be inside the gate driver circuit section 140. Therefore, the structure is designed to allow the gas emitted from the second interlayer insulating film 116 to diffuse to the outside. It is possible.

[0162] Furthermore, as shown in Figure 4, in the first transistor 101 used in the pixel region 142 Furthermore, a third interlayer insulating film 120 is formed of an inorganic insulating material at the position where the semiconductor layer 108 overlaps. A configuration in which the organic insulating material is removed is preferred. The gas released from the second interlayer insulating film 116 enters the first transistor 101. This can be suppressed.

[0163] Here, regarding the other components of the display device shown in Figures 3 and 4, see the table shown in Embodiment 1. A detailed explanation of configurations that differ from those shown in the diagram is provided below.

[0164] The partition wall 126 is formed using an organic insulating material or an inorganic insulating material. In particular, photosensitive Using a resin material, an opening is formed on the pixel electrode 122, and the side wall of the opening is a continuous curve It is preferable to form the surface in a way that creates an inclined surface with a certain ratio.

[0165] As for the filler 172, in addition to inert gases such as nitrogen and argon, UV-curing resin is also used. Alternatively, thermosetting resins can be used, such as PVC (polyvinyl chloride) and acrylic resins. Polyimide resins, epoxy resins, silicone resins, PVB (polyvinyl butyral resins) ) or EVA (ethylene vinyl acetate) can be used. For example, filler 17 For option 2, nitrogen can be used.

[0166] As the light-emitting element 170, a light-emitting element that utilizes electroluminescence is applied. This is possible. Electroluminescent light-emitting devices use organic compounds as their light-emitting material. They are distinguished by whether they are organic or inorganic compounds; generally, the former are organic EL elements, and the latter are These are called inorganic EL elements. Here, we will explain using organic EL elements.

[0167] Organic EL elements are activated by applying a voltage to the light-emitting element, which generates a pair of electrodes (pixel electrodes 122) Electrons and holes are injected from the electrode 130 into layers containing a luminescent organic compound, respectively. , an electric current flows. And, by the recombination of these carriers (electrons and holes), A luminescent organic compound forms an excited state, and emits light when that excited state returns to the ground state. Due to this mechanism, such light-emitting devices are called current-excited light-emitting devices.

[0168] The light-emitting element 170 has at least one pair of electrodes (pixel electrode 122 or It is sufficient if one side of the electrode 130 is translucent. And from the side opposite to the first substrate 102 The process includes top emission to extract light, bottom emission to extract light from the side of the first substrate 102, and A double-sided emission structure that extracts light from both the side of substrate 102 and the side opposite to the first substrate 102. There are various light-emitting elements, and any light-emitting element with an injection structure can be applied.

[0169] Furthermore, to prevent oxygen, hydrogen, moisture, carbon dioxide, etc. from entering the light-emitting element 170, the electrodes A protective film may be formed on 130 and on the partition wall 126. The protective film may be a silicon nitride film. A silicon nitride oxide film and the like can be formed. Also, the first substrate 102, the second substrate The space sealed by 152 and the sealing material 166 is provided with a filler material 172 and sealed. It is designed to be highly airtight and have minimal degassing, preventing exposure to the outside air. Packaging (sealing) with film (laminated film, UV-curing resin film, etc.) or cover material. It is preferable to include it.

[0170] Furthermore, if necessary, a polarizing plate or circular polarizing plate (elliptical polarizing plate) can be placed on the emission surface of the light-emitting element 170. (including), phase difference plates (λ / 4 plate, λ / 2 plate), and optical films such as color filters are appropriately provided. It may also be done. Alternatively, an anti-reflective coating may be provided on the polarizing plate or circular polarizing plate. For example, the surface recesses The convex shape diffuses reflected light, allowing for an anti-glare treatment that reduces reflections.

[0171] Furthermore, the light-emitting layer 128 is a light-emitting material that converts triplet excitation energy into light emission. A guest material and a phosphorus with a higher triplet excitation energy level (T1 level) than the guest material. It is preferable to use an organic compound containing a material. Note that the light-emitting layer 128 is a multiple light-emitting layer. Structures with multiple layers (so-called tandem structures), and functional layers other than the light-emitting layer (hole injection layer, hole transport layer) The configuration may include layers such as electron transport layers, electron injection layers, and charge generation layers.

[0172] Furthermore, the sealing material 166 includes, in addition to the material shown in Embodiment 1, a glass material. Glass is formed by melting and solidifying materials, such as powdered glass (also called frit glass). A stainless steel can also be used. Such a material can effectively suppress the permeation of moisture and gas. Therefore, when a light-emitting element 170 is used as a display element, the degradation of the light-emitting element 170 is suppressed. This allows for the creation of highly reliable display devices.

[0173] Furthermore, in the sealing region of the sealing material 166 shown in Figure 4, the first substrate 102 and the second substrate Although an example configuration has been given in which only the gate insulating film 106 is provided between the plates 152, the configuration is not limited to this. For example, a configuration in which the gate insulating film 106 and the first interlayer insulating film 114 are stacked may also be used. However, as shown in Figure 4, in the region where the second interlayer insulating film 116 has been removed, A configuration in which the rib material 166 is arranged is preferred.

[0174] As described above, the display device shown in this embodiment has a pixel region and a drive circuit region. A transistor, a first interlayer insulating film formed on the transistor, and a first layer A second interlayer insulating film formed on the interlayer insulating film, and a third layer formed on the second interlayer insulating film. The third interlayer insulating film is provided on a portion of the pixel region, and the third interlayer insulating film is provided on a portion of the pixel region. The film's edges are formed inside the drive circuit region. This suppresses the degassing from the second interlayer insulating film from entering the transistor side, resulting in high reliability. It can be used as a display device. Furthermore, the first interlayer insulating film provides a second interlayer insulating film. This prevents degassing from the film from entering the transistor.

[0175] The configuration shown in this embodiment can be appropriately combined with the configurations shown in other embodiments or examples. It can be used.

[0176] (Embodiment 3) In this embodiment, an image display that can be combined with the display device shown in the previous embodiment is provided. Let me explain the sensor.

[0177] Figure 5(A) shows an example of a display device with an image sensor. This is an equivalent circuit showing one pixel of a display device with a "S" label.

[0178] The photodiode element 4002 has one electrode connected to the reset signal line 4058, and the other electrode connected to the reset signal line 4058. The pole is electrically connected to the gate electrode of transistor 4040. Transistor 404 0 means that either the source electrode or the drain electrode is at the power supply potential (VDD), or the source electrode or The other drain electrode is connected to either the source electrode or the drain electrode of transistor 4056. They are electrically connected. Transistor 4056 has its gate electrode connected to gate selection line 4057. The source electrode or the other drain electrode is electrically connected to the output signal line 4071. .

[0179] Furthermore, the first transistor 4030 is a transistor for pixel switching, and One of the electrode, either the source electrode or the drain electrode, is connected to the video signal line 4059, and the other is connected to the source electrode or the drain electrode. The other electrode is electrically connected to the capacitive element 4032 and the liquid crystal element 4034. The gate electrode of the first transistor 4030 is electrically connected to the gate wire 4036. ru.

[0180] Furthermore, the first transistor 4030, the capacitive element 4032, and the liquid crystal element 4034 are as follows: A structure similar to that of the display device shown in Embodiment 1 can be applied.

[0181] Figure 5(B) shows a cross-sectional view of a portion of a pixel in a display device with an image sensor, and the driving circuit. This is a cross-sectional view of the part, and in the pixel region 5042, a photodie is placed on the first substrate 4001. An diode element 4002 and a first transistor 4030 are provided. In the gate driver circuit section 5040, which is a path, the second gate driver circuit is located on the first substrate 4001. A transistor 4060 and a third transistor 4062 are provided.

[0182] Furthermore, the photodiode element 4002 in the pixel region 5042, and the first transient On the sta 4030 are a first interlayer insulating film 4014, a second interlayer insulating film 4016, and a third An interlayer insulating film 4020 is formed on the second interlayer insulating film 4016. A capacitive element 4032 is formed using the interlayer insulating film 4020 as the dielectric.

[0183] That is, the third interlayer insulating film 4020 is provided in a part of the pixel region 5042, and the third The end of the interlayer insulating film 4020 is formed inside the gate driver circuit section 5040. This configuration allows the second interlayer insulating film 4016 to emit The structure can be made to allow the gas to diffuse to the outside. Therefore, the second interlayer insulating film 40 This prevents degassing from 16 from entering the transistor side, resulting in a more reliable display device. It is possible.

[0184] Furthermore, the photodiode element 4002 is the source electrode of the first transistor 4030 and The lower electrode is formed in the same process as the drain electrode, and the pixel electrode of the liquid crystal element 4034 is the same An upper electrode formed in a single process and a pair of electrodes, with a diode between the pair of electrodes. It has that configuration.

[0185] The diode that can be used in the photodiode element 4002 is a p-type semiconductor. Film, pn-type diode including stacked n-type semiconductor films, p-type semiconductor film, i-type semiconductor film, n-type semiconductor film You can use a pin-type diode or Schottky diode that includes a conductive film layer. .

[0186] Furthermore, the photodiode element 4002 has a first alignment film 4024 and a liquid crystal layer 4096. , second alignment film 4084, counter electrode 4088, organic insulating film 4086, colored film 4085, A circuit board 4052 and the like are provided.

[0187] Furthermore, for PIN-type diodes, using the p-type semiconductor film side as the light-receiving surface results in higher photoelectric conversion characteristics. This is because hole mobility is smaller than electron mobility. Then, from the surface of the second substrate 4052, through the colored film 4085, the liquid crystal layer 4096, etc., This example illustrates a configuration that converts light incident on a diode element 4002 into an electrical signal. However, it is not limited to this. For example, a configuration without the colored film 4085 may be used.

[0188] The photodiode element 4002 shown in this embodiment is a photodiode element 400 This utilizes the fact that when light enters the photodiode, an electric current flows between the pair of electrodes. The light detection element 4002 allows information about the detected object to be read.

[0189] The display device with an image sensor shown in this embodiment is used for purposes such as the fabrication of transistors, etc. By standardizing the processes for equipment and image sensors, productivity can be increased. However, the display device shown in the previous embodiment and the image sensor shown in this embodiment are different. It may also be fabricated on a substrate. Specifically, in the display device shown in the previous embodiment... Alternatively, the image sensor can be fabricated on the second substrate.

[0190] This embodiment can be appropriately combined with the configurations described in other embodiments or other examples. It is possible to implement this.

[0191] (Embodiment 4) This embodiment describes an example of a tablet terminal using a display device according to one aspect of the present invention. do.

[0192] Figures 6(A) and 6(B) show a foldable tablet device. Figure 6(A) is The tablet device is in an open state. The tablet device consists of casing 8630 and casing 86 30 includes a display unit 8631a, a display unit 8631b, and a display mode switching switch. 8034, Power switch 8035, Power saving mode switch 8036, Fastener 80 It has 33 and an operating switch 8038.

[0193] One aspect of the present invention is a display device that is applied to display unit 8631a and display unit 8631b. It is possible.

[0194] The display unit 8631a can function as a touch panel in whole or in part. Input can be performed by touching the indicated operation keys. For example, all of the display unit 8631a Keyboard buttons are displayed on the surface, allowing it to function as a touch panel, and the display unit 8631b is displayed. You may use it as a screen.

[0195] Furthermore, similar to the display unit 8631a, part or all of the display unit 8631b can be made into a touch panel. It can be made to function as such.

[0196] Furthermore, the touch panel area of ​​display unit 8631a and the touch panel area of ​​display unit 8631b You can also touch and input multiple areas simultaneously.

[0197] Additionally, the display mode switch 8034 selects the display orientation, such as portrait or landscape. You can switch between modes, select between black and white and color display, etc. Power saving mode switching Switch 8036 responds to ambient light detected by a light sensor built into the tablet device. This allows the display brightness to be optimized. Note that tablet devices use a light sensor. Furthermore, it may also have other detection devices, such as a gyroscope or accelerometer capable of detecting tilt. .

[0198] Furthermore, Figure 6(A) shows an example where the areas of display unit 8631b and display unit 8631a are the same. However, this is not particularly limited. Often, the display quality can differ. For example, one can display a higher resolution than the other. It can also be used as a display panel.

[0199] Figure 6(B) shows the tablet device in a closed state. The tablet device has a housing 86 30 and a solar cell 8633 and a charge / discharge control circuit 8634 provided in the housing 8630 , has. Note that in Figure 6(B), battery 86 is shown as an example of the charge / discharge control circuit 8634. 35. A configuration having a DC-DC converter 8636 is shown.

[0200] Note that the tablet device is foldable, so when not in use, the casing 8630 is closed. This can be done. Therefore, the display units 8631a and 8631b can be protected. It boasts excellent durability and reliability from a long-term use perspective.

[0201] In addition, the tablet devices shown in Figures 6(A) and 6(B) can also display various information. Features for displaying (still images, videos, text images, etc.), calendar, date or time, etc. A function to display information on the display unit, and a touch input operation or editing function for the information displayed on the display unit. It has input capabilities, and the ability to control processing through various software (programs). It is possible.

[0202] The tablet device uses the power obtained from the solar cell 8633 to power the tablet device. It can be used for operation. Alternatively, the power can be stored in the battery 8635. It is possible to configure the solar cell 8633 to be installed on two sides of the housing 8630. Furthermore, if a lithium-ion battery is used for the 8635 battery, it would be possible to make it smaller. What are the advantages?

[0203] Furthermore, the configuration and operation of the charge / discharge control circuit 8634 shown in Figure 6(B) are shown in Figure 6(C). A block diagram is shown and explained below. Figure 6(C) shows the solar cell 8633 and the battery 863 5, DC-DC converter 8636, converter 8637, switch SW1, and This shows switch SW2, switch SW3, and display unit 8631. Figure 6(C) Battery 8635, DC-DC converter 8636, converter 8637, switch SW1, switch SW2, and switch SW3 are connected to the charge / discharge control circuit 86 shown in Figure 6(B). Corresponds to 34.

[0204] When electricity is generated by solar cell 8633, the electricity generated by the solar cell is stored in battery 8 The 8636 DC-DC converter is used to boost or buck the voltage to provide the voltage needed to charge the 635. Next, switch SW1 is turned on, and the converter 8637 provides the optimal power to the display unit 8631. The voltage is increased or decreased. Also, if the display unit 8631 is not displayed, switch S Turn off W1 and turn on switch SW2 to charge the 8635 battery.

[0205] Although solar cell 8633 is shown as an example of a power generation method, it is not particularly limited to this, and pressure By replacing it with other power generation methods such as electrical elements (piezoelectric elements) or thermoelectric conversion elements (Peltier elements) That's also fine. For example, a contactless power transmission module that charges by sending and receiving power wirelessly (contactless). It may also be configured to combine other charging methods, such as a wired charger.

[0206] This embodiment can be appropriately combined with the configurations described in other embodiments or other examples. It is possible to implement this.

[0207] (Embodiment 5) In this embodiment, the example of an electronic device equipped with a display device, etc., as shown in the previous embodiment, I will explain.

[0208] Figure 7(A) shows a portable information terminal. The portable information terminal shown in Figure 7(A) has a housing 930 0, button 9301, microphone 9302, display unit 9303, speaker 93 It is equipped with 04 and a camera 9305, and has the function of a portable telephone. Display unit 93 03 Applies to the display device and / or display device with an image sensor as shown in the previous embodiment. It can be used.

[0209] Figure 7(B) shows the display. The display shown in Figure 7(B) is housed in enclosure 9310. The system comprises a display unit 9311 and the display unit 9311. Alternatively, a display device with an image sensor can be applied.

[0210] Figure 7(C) shows a digital still camera. The components include the housing 9320, the button 9321, the microphone 9322, and the display unit 9323. , comprising: Display unit 9323 has the display device or / or image shown in the previous embodiment A display device with a sensor can be applied.

[0211] By using one aspect of the present invention, the reliability of electronic devices can be improved.

[0212] This embodiment can be appropriately combined with the configurations described in other embodiments or other examples. It is possible to implement this. [Examples]

[0213] In this embodiment, acrylic is a typical organic resin that can be used in display devices. We investigated the gases released from the resin.

[0214] The sample was prepared by coating a glass substrate with acrylic resin and heating it at 250°C under a nitrogen gas atmosphere for 1 hour. The intermediate heat treatment was performed. The acrylic resin was then treated to a thickness of 1.5 μm. It was formed in this way.

[0215] For the prepared sample, TDS (Thermal Desorption Spectr The emitted gas was measured using oscopy (temperature-controlled desorption gas spectroscopy).

[0216] Figure 8 shows the results for each mass-to-charge ratio (also known as M / z) at a substrate surface temperature of 250°C. This shows the ionic intensity of the emitted gas. In Figure 8, the horizontal axis represents the mass-to-charge ratio, and the vertical axis represents the intensity (arbitrary unit). The positions are shown respectively. From Figure 8, the sample showed a mass-to-charge ratio of 18 (H) which is thought to be water-related. The gas (2O) and the mass-to-charge ratios, which are thought to be due to hydrocarbons, are 28 (C2H4) and 44 (C3H4). 8) and 56 (C4H8) gases were detected. Furthermore, near each mass-to-charge ratio, The respective fragment ions were detected.

[0217] Similarly, Figure 9 shows the mass-to-charge ratios (18, 28, 44, and 56) with respect to the substrate surface temperature. This shows the ionic intensity. In Figure 9, the horizontal axis is the substrate surface temperature (°C), and the vertical axis is the intensity (arbitrary unit). The positions are shown respectively. When the substrate surface temperature is in the range of 55°C to 270°C, water-induced and Ionic intensities with a mass-to-charge ratio of 18 are observed at temperatures between 55°C and 100°C, and above 150°C. It was found that there is a peak below 270°C. On the other hand, the mass charge, which is thought to be due to hydrocarbons, was found to be Ionic intensities with ratios of 28, 44, and 56 have peaks between 150°C and 270°C. I found out.

[0218] As shown above, undesirable substances for oxide semiconductor films, such as water and hydrocarbons from organic resins, are present. It was found that pure substances are released. In particular, water is released even at relatively low temperatures between 55°C and 100°C. It was found that they are released. In other words, impurities originating from the organic resin reach the oxide semiconductor film. This suggests that it could degrade the electrical characteristics of the transistor.

[0219] Furthermore, organic resins can be used to create films that do not allow water, hydrocarbons, or other released gases to pass through (silicon nitride films, nitride films, silicon nitride films). When covered with a silicon oxide film, aluminum oxide film, etc., gas is released from the organic resin. This increases the pressure on the membrane that does not allow released gases such as water and hydrocarbons to pass through, ultimately resulting in the release of water and hydrocarbons. The film that does not allow release gases such as hydrogen cyanide to pass through is destroyed, resulting in a transistor shape defect. It was suggested. [Examples]

[0220] In this example, a transistor was fabricated and its cross-sectional shape and electrical characteristics were evaluated.

[0221] Each sample contains an oxide semiconductor with a bottom-gate, top-contact channel etch structure. A transistor using a film is provided. This transistor is provided on a glass substrate. A gate electrode, a gate insulating film provided on the gate electrode, and a gate insulating film that connects to the gate An oxide semiconductor film provided on an electrode, and a part located on the oxide semiconductor film and in contact with the oxide semiconductor film. It has a pair of electrodes provided therein. Here, the gate electrode has a tungsten film, The insulating film is a silicon nitride film, and a silicon oxide nitride film on the silicon nitride film, and an oxide semiconductor The body membrane is an In-Ga-Zn oxide film, the pair of electrodes are tungsten films, and on the tungsten film... An aluminum film and a titanium film on top of the aluminum film were used, respectively.

[0222] A protective insulating film (a silicon oxidizride film with a thickness of 450 nm) is placed on the pair of electrodes. A silicon nitride film with a thickness of 50 nm is provided on the silicon film.

[0223] In the example sample, an acrylic resin layer with a thickness of 2 μm is provided on a protective insulating film. Nitriding was performed on the acrylic resin to a thickness of 200 nm, exposing a portion of the acrylic resin's surface. A silicon film is provided. In addition, the comparative example sample has a protective insulating film with a thickness of 1.5 μm. An acrylic resin is provided, and on top of the acrylic resin, 200n is applied to cover the acrylic resin. A silicon nitride film with a thickness of m is provided.

[0224] Figure 10 shows a TEM transmission electron image of a magnified portion of the comparative example sample. Electron (TE) image: Also called a TE image. It shows the cross-sectional shape. This was performed using the "Hitachi Ultra-Thin Film Evaluation System HD-2300" manufactured by Hitachi High-Technologies Corporation. Note that in Figure 10, only one electrode of the pair of electrodes is shown. Focusing on the electrode shown and the protective insulating film provided to cover the electrode, the steps formed by the electrode It was found that a crack had formed in the protective insulating film from the difference area. Since the example sample and the comparative example sample have substantially similar structures, the cross-sectional shape of the example sample is omitted.

[0225] Therefore, the example sample has a structure that allows the gas released from the acrylic resin to escape to the outside of the example sample. Furthermore, the comparative example sample has a structure that prevents the gas released from the acrylic resin from escaping to the outside of the comparative example sample. In other words, in the comparative example sample, the gas released from the acrylic resin does not escape to the outside, providing protective insulation. It was discovered that the transistor could be reached through cracks in the film.

[0226] Next, the electrical characteristics of the transistor for each sample are gate voltage (Vg) - drain current (I d) Characteristics were measured. The Vg-Id characteristics were measured with a channel length of 3 μm and a channel width of 3 μm. Measurements were taken using a transistor. Note that in measuring the Vg-Id characteristics, the drain voltage ( The gate voltage (Vg) was swept from -20V to 15V, with Vd) set to 1V or 10V.

[0227] Figure 11 shows the Vg-Id characteristics of each sample. Note that the glass substrate is 600 mm × 720 mm. In this experiment, the Vg-Id characteristics of 20 transistors were measured as evenly as possible. Figure 11(A) shows the Vg-Id characteristics and field-effect mobility of the transistor of the example sample. Figure 11(B) shows the Vg-Id characteristics of the transistor of the comparative example sample. Note that Figure 11(A) The field-effect mobility shown is the value at a drain voltage (Vd) of 10V. Also, Figure 11 In (B), the calculation of the field effect mobility was difficult, so it is omitted.

[0228] As shown in Figure 11(A), the transistor in the example sample exhibited good switching characteristics. It was found that... Also, from Figure 11(B), the transistor of the comparative example sample... It was found that the desired characteristics could not be obtained, and the device was always on.

[0229] By comparing with the example sample, the poor switching characteristics of the comparative sample were found to be due to the acrylic resin. It appears that the emitted gas affected the transistor. Specifically, the acrylic resin or Due to the influence of the emitted gases, the carrier density of the oxide semiconductor film increases, and the electric field from the gate electrode Therefore, it is presumed that the transistor could not be turned off.

[0230] In this embodiment, the organic resin is used to form a film that does not allow water, hydrocarbons, or other released gases to pass through (here, thickness When covered with a 200nm silicon nitride film, the transients are affected by the gases released from the organic resin. It can be seen that this causes poor switching characteristics. Also, the organic resin is covered with water, A portion of the membrane, which is impermeable to released gases such as hydrocarbons, is designed to allow the released gases to escape to the outside of the sample. This avoids poor switching characteristics of the transistor, resulting in good switching characteristics. It becomes clear that sex can be obtained. [Explanation of Symbols]

[0231] 101 First Transistor 102 First substrate 103 Second transistor 104 Guard gate 105 The third transistor 106 Gate Insulator 107 Capacitive elements 108 Semiconductor layer 110 Source Electrode 112 Drain electrode 113 Electrode 114 First interlayer insulating film 116 Second interlayer insulating film 118 Capacitive electrode 120 Third interlayer insulating film 122 Pixel Electrodes 124 First alignment layer 126 Bulkhead 128 Emitting layer 130 electrodes 140 Gate driver circuit section 142 pixel area 144 Source Driver Circuit Section 146 FPC terminal section 148 FPC 150 liquid crystal elements 152 Second substrate 153 Colored film 154 Light-shielding film 156 Organic protective insulating film 158 Counter electrode 160 Spacer 162 liquid crystal layer 164 Second alignment layer 166 Sealant 170 light-emitting elements 172 Filling material 4001 First substrate 4002 Photodiode element 4014 First interlayer insulating film 4016 Second interlayer insulating film 4020 Third interlayer insulating film 4024 First alignment layer 4030 First transistor 4032 Capacitive element 4034 liquid crystal elements 4036 Gate Line 4040 transistor 4052 Second substrate 4056 Transistor 4057 Gate Selection Line 4058 Reset signal line 4059 Video signal line 4060 Second Transistor 4062 Third Transistor 4071 Output signal line 4084 Second alignment layer 4085 Colored film 4086 Organic insulating film 4088 Opposing electrode 4096 Liquid Crystal Layer 5040 Gate Driver Circuit Section 5042 pixel area 8033 Fastener 8034 switch 8035 Power switch 8036 Switch 8038 Operation switch 8630 cabinet 8631 Display section 8631a Display section 8631b Display section 8633 Solar Cell 8634 Charge / Discharge Control Circuit 8635 Battery 8636 DC-DC Converter 8637 Converter 9300 cabinet 9301 button 9302 Microphone 9303 Display section 9304 Speaker 9305 Camera 9310 enclosure 9311 Display section 9320 enclosure 9321 button 9322 Microphone 9323 Display section

Claims

1. A pixel region having a first transistor, A display device having a drive circuit region adjacent to the outside of the pixel region and having a second transistor, A first conductive film having a region in contact with the upper surface of the substrate and functioning as the gate electrode of the first transistor, A second conductive film having a region in contact with the upper surface of the substrate and functioning as the gate electrode of the second transistor, A first insulating film having a region in contact with the upper surface of the first conductive film and a region in contact with the upper surface of the second conductive film, and having the function of a gate insulating film of the first transistor and the function of a gate insulating film of the second transistor, A first oxide semiconductor layer having a region in contact with the upper surface of the first insulating film and functioning as a channel formation region of the first transistor, A second oxide semiconductor layer having a region in contact with the upper surface of the first insulating film and functioning as a channel formation region for the second transistor, A third conductive film having a region in contact with the upper surface of the first oxide semiconductor layer and functioning as either the source electrode or the drain electrode of the first transistor, A fourth conductive film having a region in contact with the upper surface of the first oxide semiconductor layer and functioning as the other of the source electrode or drain electrode of the first transistor, A fifth conductive film having a region in contact with the upper surface of the second oxide semiconductor layer and functioning as either the source electrode or the drain electrode of the second transistor, A sixth conductive film having a region in contact with the upper surface of the second oxide semiconductor layer and functioning as the other of the source electrode or drain electrode of the second transistor, A second insulating film having a region in contact with the upper surface of the third conductive film, a region in contact with the upper surface of the fourth conductive film, a region in contact with the upper surface of the fifth conductive film, and a region in contact with the upper surface of the sixth conductive film, A third insulating film having a region in contact with the upper surface of the second insulating film, A seventh conductive film having a region in contact with the upper surface of the third insulating film, A fourth insulating film having a region in contact with the upper surface of the third insulating film and a region in contact with the upper surface of the seventh conductive film, An eighth conductive film having a region in contact with the upper surface of the fourth insulating film and functioning as a pixel electrode, The eighth conductive film has a region that contacts the upper surface of the second conductive film or the third conductive film through the first opening in the third insulating film and the second opening in the fourth insulating film. The first and second openings do not have a region that overlaps with the first oxide semiconductor layer. The diameter of the first opening is larger than the diameter of the second opening. The end of the fourth insulating film is located between the pixel region and the drive circuit region. The first conductive film and the second conductive film each have a laminated structure comprising a film containing nitrogen and tantalum, and a tungsten film. The first insulating film has a laminated structure comprising an insulating film having nitrogen and silicon, and an insulating film having oxygen and silicon. The first oxide semiconductor layer and the second oxide semiconductor layer each have a stacked structure of a first oxide semiconductor film and a second oxide semiconductor film, The third conductive film, the fourth conductive film, the fifth conductive film, and the sixth conductive film each have a laminated structure of a titanium film, an aluminum film, and a titanium film. The second insulating film has a laminated structure comprising an insulating film having oxygen and silicon, and an insulating film having nitrogen and silicon. The third insulating film comprises an organic insulating material, The seventh conductive film and the eighth conductive film each contain indium, tin, and oxygen. The display device comprises nitrogen and silicon as the fourth insulating film.

2. A pixel region having a first transistor, A display device having a drive circuit region adjacent to the outside of the pixel region and having a second transistor, A first conductive film having a region in contact with the upper surface of the substrate and functioning as the gate electrode of the first transistor, A second conductive film having a region in contact with the upper surface of the substrate and functioning as the gate electrode of the second transistor, A first insulating film having a region in contact with the upper surface of the first conductive film and a region in contact with the upper surface of the second conductive film, and having the function of a gate insulating film of the first transistor and the function of a gate insulating film of the second transistor, A first oxide semiconductor layer having a region in contact with the upper surface of the first insulating film and functioning as a channel formation region of the first transistor, A second oxide semiconductor layer having a region in contact with the upper surface of the first insulating film and functioning as a channel formation region for the second transistor, A third conductive film having a region in contact with the upper surface of the first oxide semiconductor layer and functioning as either the source electrode or the drain electrode of the first transistor, A fourth conductive film having a region in contact with the upper surface of the first oxide semiconductor layer and functioning as the other of the source electrode or drain electrode of the first transistor, A fifth conductive film having a region in contact with the upper surface of the second oxide semiconductor layer and functioning as either the source electrode or the drain electrode of the second transistor, A sixth conductive film having a region in contact with the upper surface of the second oxide semiconductor layer and functioning as the other of the source electrode or drain electrode of the second transistor, A second insulating film having a region in contact with the upper surface of the third conductive film, a region in contact with the upper surface of the fourth conductive film, a region in contact with the upper surface of the fifth conductive film, and a region in contact with the upper surface of the sixth conductive film, A third insulating film having a region in contact with the upper surface of the second insulating film, A seventh conductive film having a region in contact with the upper surface of the third insulating film, A fourth insulating film having a region in contact with the upper surface of the third insulating film and a region in contact with the upper surface of the seventh conductive film, An eighth conductive film having a region in contact with the upper surface of the fourth insulating film and functioning as a pixel electrode, The eighth conductive film has a region that contacts the upper surface of the second conductive film or the third conductive film through the first opening in the third insulating film and the second opening in the fourth insulating film. The first and second openings do not have a region that overlaps with the first oxide semiconductor layer. The diameter of the first opening is larger than the diameter of the second opening. The end of the fourth insulating film does not overlap with the drive circuit region. The first conductive film and the second conductive film each have a laminated structure comprising a film containing nitrogen and tantalum, and a tungsten film. The first insulating film has a laminated structure comprising an insulating film having nitrogen and silicon, and an insulating film having oxygen and silicon. The first oxide semiconductor layer and the second oxide semiconductor layer each have a stacked structure of a first oxide semiconductor film and a second oxide semiconductor film, The third conductive film, the fourth conductive film, the fifth conductive film, and the sixth conductive film each have a laminated structure of a titanium film, an aluminum film, and a titanium film. The second insulating film has a laminated structure comprising an insulating film having oxygen and silicon, and an insulating film having nitrogen and silicon. The third insulating film comprises an organic insulating material, The seventh conductive film and the eighth conductive film each contain indium, tin, and oxygen. The display device comprises nitrogen and silicon as the fourth insulating film.

3. A pixel region having a first transistor, A display device having a drive circuit region adjacent to the outside of the pixel region and having a second transistor, A first conductive film having a region in contact with the upper surface of the substrate and functioning as the gate electrode of the first transistor, A second conductive film having a region in contact with the upper surface of the substrate and functioning as the gate electrode of the second transistor, A first insulating film having a region in contact with the upper surface of the first conductive film and a region in contact with the upper surface of the second conductive film, and having the function of a gate insulating film of the first transistor and the function of a gate insulating film of the second transistor, A first oxide semiconductor layer having a region in contact with the upper surface of the first insulating film and functioning as a channel formation region of the first transistor, A second oxide semiconductor layer having a region in contact with the upper surface of the first insulating film and functioning as a channel formation region for the second transistor, A third conductive film having a region in contact with the upper surface of the first oxide semiconductor layer and functioning as either the source electrode or the drain electrode of the first transistor, A fourth conductive film having a region in contact with the upper surface of the first oxide semiconductor layer and functioning as the other of the source electrode or drain electrode of the first transistor, A fifth conductive film having a region in contact with the upper surface of the second oxide semiconductor layer and functioning as either the source electrode or the drain electrode of the second transistor, A sixth conductive film having a region in contact with the upper surface of the second oxide semiconductor layer and functioning as the other of the source electrode or drain electrode of the second transistor, A second insulating film having a region in contact with the upper surface of the third conductive film, a region in contact with the upper surface of the fourth conductive film, a region in contact with the upper surface of the fifth conductive film, and a region in contact with the upper surface of the sixth conductive film, A third insulating film having a region in contact with the upper surface of the second insulating film, A seventh conductive film having a region in contact with the upper surface of the third insulating film, A fourth insulating film having a region in contact with the upper surface of the third insulating film and a region in contact with the upper surface of the seventh conductive film, An eighth conductive film having a region in contact with the upper surface of the fourth insulating film and functioning as a pixel electrode, The eighth conductive film has a region that contacts the upper surface of the second conductive film or the third conductive film through the first opening in the third insulating film and the second opening in the fourth insulating film. The first and second openings do not have a region that overlaps with the first oxide semiconductor layer. The diameter of the first opening is larger than the diameter of the second opening. The end of the fourth insulating film does not overlap with the transistors in the drive circuit region. The first conductive film and the second conductive film each have a laminated structure comprising a film containing nitrogen and tantalum, and a tungsten film. The first insulating film has a laminated structure comprising an insulating film having nitrogen and silicon, and an insulating film having oxygen and silicon. The first oxide semiconductor layer and the second oxide semiconductor layer each have a stacked structure of a first oxide semiconductor film and a second oxide semiconductor film, The third conductive film, the fourth conductive film, the fifth conductive film, and the sixth conductive film each have a laminated structure of a titanium film, an aluminum film, and a titanium film. The second insulating film has a laminated structure comprising an insulating film having oxygen and silicon, and an insulating film having nitrogen and silicon. The third insulating film comprises an organic insulating material, The seventh conductive film and the eighth conductive film each contain indium, tin, and oxygen. The display device comprises nitrogen and silicon as the fourth insulating film.

4. A pixel region having a first transistor, A display device having a drive circuit region adjacent to the outside of the pixel region and having a second transistor, A first conductive film having a region in contact with the upper surface of the substrate and functioning as the gate electrode of the first transistor, A second conductive film having a region in contact with the upper surface of the substrate and functioning as the gate electrode of the second transistor, A first insulating film having a region in contact with the upper surface of the first conductive film and a region in contact with the upper surface of the second conductive film, and having the function of a gate insulating film of the first transistor and the function of a gate insulating film of the second transistor, A first oxide semiconductor layer having a region in contact with the upper surface of the first insulating film and functioning as a channel formation region of the first transistor, A second oxide semiconductor layer having a region in contact with the upper surface of the first insulating film and functioning as a channel formation region for the second transistor, A third conductive film having a region in contact with the upper surface of the first oxide semiconductor layer and functioning as either the source electrode or the drain electrode of the first transistor, A fourth conductive film having a region in contact with the upper surface of the first oxide semiconductor layer and functioning as the other of the source electrode or drain electrode of the first transistor, A fifth conductive film having a region in contact with the upper surface of the second oxide semiconductor layer and functioning as either the source electrode or the drain electrode of the second transistor, A sixth conductive film having a region in contact with the upper surface of the second oxide semiconductor layer and functioning as the other of the source electrode or drain electrode of the second transistor, A second insulating film having a region in contact with the upper surface of the third conductive film, a region in contact with the upper surface of the fourth conductive film, a region in contact with the upper surface of the fifth conductive film, and a region in contact with the upper surface of the sixth conductive film, A third insulating film having a region in contact with the upper surface of the second insulating film, A seventh conductive film having a region in contact with the upper surface of the third insulating film, A fourth insulating film having a region in contact with the upper surface of the third insulating film and a region in contact with the upper surface of the seventh conductive film, An eighth conductive film having a region in contact with the upper surface of the fourth insulating film and functioning as a pixel electrode, The eighth conductive film has a region that contacts the upper surface of the second conductive film or the third conductive film through the first opening in the third insulating film and the second opening in the fourth insulating film. The first and second openings do not have a region that overlaps with the first oxide semiconductor layer. The diameter of the first opening is larger than the diameter of the second opening. The edges of the fourth insulating film do not overlap with the second conductive film, the fifth conductive film, the sixth conductive film, or the second oxide semiconductor layer. The first conductive film and the second conductive film each have a laminated structure comprising a film containing nitrogen and tantalum, and a tungsten film. The first insulating film has a laminated structure comprising an insulating film having nitrogen and silicon, and an insulating film having oxygen and silicon. The first oxide semiconductor layer and the second oxide semiconductor layer each have a stacked structure of a first oxide semiconductor film and a second oxide semiconductor film, The third conductive film, the fourth conductive film, the fifth conductive film, and the sixth conductive film each have a laminated structure of a titanium film, an aluminum film, and a titanium film. The second insulating film has a laminated structure comprising an insulating film having oxygen and silicon, and an insulating film having nitrogen and silicon. The third insulating film comprises an organic insulating material, The seventh conductive film and the eighth conductive film each contain indium, tin, and oxygen. The display device comprises nitrogen and silicon as the fourth insulating film.

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