Indication device

Abstract

A semiconductor device having a capacitive element that has a high aperture ratio and can increase the capacitance value. We provide a suitable location. We also provide a semiconductor device with low manufacturing costs. [Solution] A transistor comprising a first oxide semiconductor film and a second oxide semiconductor film, A semiconductor device having a capacitive element with an insulating film between a pair of electrodes, wherein the transistor is , a first oxide semiconductor film, and a gate insulating film provided in contact with the first oxide semiconductor film, A second is provided in contact with the gate insulating film and is positioned to overlap with the first oxide semiconductor film. An oxide semiconductor film, and a source electrode and a drain electrode connected to the first oxide semiconductor film. , wherein one of the pair of electrodes of the capacitive element is provided on the same surface as the second oxide semiconductor film. It can be done.

Description

[Technical Field]

[0001] The present invention relates to a product, method, or method of manufacture. Or, the present invention relates to a process, machine, The present invention relates to a manufacture or composition of matter. The embodiments include semiconductor devices, display devices, electronic devices, methods for manufacturing them, or methods for driving them. This relates to, in particular, one aspect of the present invention, for example, a semiconductor having transistors and capacitive elements. Regarding the device. [Background technology]

[0002] It is used in many flat panel displays, such as liquid crystal displays and light-emitting displays. The transistors being described are amorphous silicon, single-crystal silicon formed on a glass substrate. It is made of silicon semiconductors such as silicon or polycrystalline silicon. Transistors, which use semiconductors, are also used in integrated circuits (ICs), among other applications.

[0003] In recent years, metal oxides exhibiting semiconductor properties have been used in transistors instead of silicon semiconductors. The technology is attracting attention. In this specification, metal oxides exhibiting semiconductor properties are referred to as oxides. We will refer to them as semiconductors. For example, as oxide semiconductors, zinc oxide or In-Ga- A transistor was fabricated using a zinc oxide, and this transistor was used as a switch for the pixels of a display device. Technologies for use in chnothing elements and the like have been disclosed (see Patent Documents 1 and 2).

[0004] Furthermore, in order to increase the aperture ratio, it is provided on the same surface as the oxide semiconductor film of the transistor. The oxide semiconductor film and the pixel electrodes connected to the transistor are provided at a predetermined distance apart. A display device having a capacitive element is disclosed (see Patent Document 3).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] A capacitive element has a dielectric film provided between a pair of electrodes. Among the pair of electrodes, at least one of the electrodes is often formed of a conductive film having light-shielding properties such as a gate electrode, a source, or a drain that constitutes a transistor. Moreover, in order to increase the capacitance value of the capacitive element, there is a means of increasing the occupied area of the capacitive element, specifically, increasing the area where the pair of electrodes overlap. However,

[0007] in a display device, if the area of the light-shielding conductive film is increased to increase the area where the pair of electrodes overlap, the aperture ratio of the pixel decreases, and the display quality of the image deteriorates. Therefore, in view of the above problems, one aspect of the present invention is to provide a semiconductor device having a capacitive element with a high aperture ratio and capable of increasing the capacitance value. Another aspect is to provide a semiconductor device with low manufacturing costs. Or, one aspect is to provide a novel semiconductor device or the like.

[0008]

[0009] ​​​​ Furthermore, the description of these problems does not preclude the existence of other problems. One approach does not require that all of these issues be resolved. The title will become clear from the description in the specification, drawings, claims, etc. It is possible to extract other issues from the descriptions in the drawings, claims, etc. [Means for solving the problem]

[0010] One aspect of the present invention relates to a transient comprising a first oxide semiconductor film and a second oxide semiconductor film. A semiconductor device having a transistor and a capacitive element including an insulating film between a pair of electrodes, The zista consists of a first oxide semiconductor film and a gate insulating film provided in contact with the first oxide semiconductor film. The edge film and the gate insulating film are provided in contact with each other and are positioned to overlap with the first oxide semiconductor film. A second oxide semiconductor film is formed, and a source electrode and drain are connected to the first oxide semiconductor film. The device has an electrode and one of the pair of electrodes of the capacitive element is on the same surface as the second oxide semiconductor film. This semiconductor device is characterized by being provided in [location].

[0011] Another aspect of the present invention includes a first oxide semiconductor film and a second oxide semiconductor film. A semiconductor device having a transistor and a capacitive element including an insulating film between a pair of electrodes. The transistor consists of a gate electrode containing a second oxide semiconductor film, and a gate on the gate electrode. An insulating film, a first oxide semiconductor film at a position superimposed on the gate electrode on the gate insulating film, and a first The capacitive element has a source electrode and a drain electrode on an oxide semiconductor film, and the pair of electrodes A semiconductor device characterized in that one of the components is provided on the same surface as the second oxide semiconductor film. be.

[0012] Another aspect of the present invention includes a first oxide semiconductor film and a second oxide semiconductor film. A semiconductor device having a transistor and a capacitive element including an insulating film between a pair of electrodes. The transistor comprises a first oxide semiconductor film and a source electrode on the first oxide semiconductor film. A drain electrode, a gate insulating film on a first oxide semiconductor film, and a first on the gate insulating film It has a gate electrode including a second oxide semiconductor film at a position superimposed on the oxide semiconductor film, One of the pair of electrodes of the quantitative element is provided on the same surface as the second oxide semiconductor film. It is a semiconductor device that is characterized by its features.

[0013] Furthermore, in each of the above configurations, the other electrode of the pair of electrodes of the capacitive element is connected to the first oxide semiconductor film. It is preferable that they be provided on the same surface. Furthermore, the capacitive element has light transmittance in visible light. And that is preferable.

[0014] Furthermore, in each of the above configurations, the first oxide semiconductor film and the second oxide semiconductor film are In -M-Zn oxide (where M is Al, Ti, Ga, Y, Zr, La, Ce, Nd, Sn, or H) It is preferable that it represents f.

[0015] Furthermore, a display device and electronic device using the semiconductor devices described above are also included in one aspect of the present invention. Born. [Effects of the Invention]

[0016] According to one aspect of the present invention, a capacitive element capable of having a high aperture ratio and an increased capacitance value It is possible to provide a semiconductor device having [a certain characteristic]. Furthermore, it is possible to provide a semiconductor device with low manufacturing costs. It is possible to do so. Alternatively, it is possible to provide novel semiconductor devices, etc.

[0017] Furthermore, the description of these effects does not preclude the existence of other effects. One embodiment does not necessarily have to possess all of these effects. Furthermore, other effects may be considered. This will become clear from the description in the specification, drawings, claims, etc., and the specification, drawings It is possible to extract effects other than those mentioned above from the descriptions in the surfaces, claims, etc. [Brief explanation of the drawing]

[0018] [Figure 1] A top view and a cross-sectional view showing one embodiment of a semiconductor device. [Figure 2] A cross-sectional view showing one aspect of a method for fabricating a semiconductor device. [Figure 3] A cross-sectional view showing one aspect of a method for fabricating a semiconductor device. [Figure 4] A top view and a cross-sectional view showing one embodiment of a semiconductor device. [Figure 5] A cross-sectional view showing one aspect of a method for fabricating a semiconductor device. [Figure 6] A cross-sectional view showing one aspect of a method for fabricating a semiconductor device. [Figure 7] A top view and a cross-sectional view showing one embodiment of a semiconductor device. [Figure 8] A top view and a cross-sectional view showing one embodiment of a semiconductor device. [Figure 9] A cross-sectional view showing one aspect of a method for fabricating a semiconductor device. [Figure 10] A cross-sectional view showing one aspect of a method for fabricating a semiconductor device. [Figure 11] A cross-sectional view and band diagram showing one form of a semiconductor device. [Figure 12] Block diagrams and circuit diagrams illustrating the display device. [Figure 13] A diagram illustrating the display module. [Figure 14] A diagram illustrating electronic devices. [Figure 15] A cross-sectional view showing one aspect of a semiconductor device. [Figure 16] A cross-sectional view showing one aspect of a semiconductor device. [Figure 17] A top view and a cross-sectional view showing one embodiment of a semiconductor device. [Figure 18] A top view and a cross-sectional view showing one embodiment of a semiconductor device. [Figure 19] A cross-sectional view showing one aspect of a semiconductor device. [Figure 20] A cross-sectional view showing one aspect of a semiconductor device. [Figure 21] A cross-sectional view showing one aspect of a semiconductor device. [Figure 22] A cross-sectional view showing one aspect of a semiconductor device. [Modes for carrying out the invention]

[0019] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention One aspect is not limited to the following description, and without departing from the spirit and scope of the present invention, It will be readily apparent to those skilled in the art that the form and details can be changed in various ways. Therefore, this One aspect of the invention is not limited to the description of the embodiments shown below. Furthermore, in the embodiments described below, the same part or a part having a similar function is The same reference numerals or hatch patterns are used in common across different drawings, and their repetition is prohibited. The explanation will be omitted.

[0020] In each figure described herein, the size, film thickness, or region of each component is clearly indicated. It may be exaggerated for clarity. Therefore, it is not necessarily limited to that scale. .

[0021] Furthermore, the ordinal numbers such as "1st," "2nd," etc. used in this specification are used to avoid mixing of constituent elements. This is a selection and not a numerical limit. Therefore, for example, "the first" This can be explained by substituting "the second" or "the third" as appropriate.

[0022] Note that the "source" and "drain" functions of a transistor are different for transistors with opposite polarities. When adopting this method, or when the direction of current changes during circuit operation, the configuration may be reversed. Therefore, in this specification, the terms "source" and "drain" are interchangeable. It may be used in this way.

[0023] (Embodiment 1) In this embodiment, a semiconductor device according to one aspect of the present invention will be described using Figures 1 to 3. do.

[0024] <Example of semiconductor device configuration> Figure 1(A) is a top view of a semiconductor device according to one embodiment of the present invention, and Figure 1(B) is a top view of Figure 1(A) This corresponds to a cross-sectional view of the section between the dashed lines A and B, and between the dashed lines C and D. In Figure 1(A), to avoid complexity, some of the components of the semiconductor device (G The insulator and other components are omitted from the illustration.

[0025] The semiconductor device shown in Figures 1(A) and (B) consists of a first oxide semiconductor film 110a and a second oxide A transistor 150 including a semiconductor film 104a and a capacitor including an insulating film between a pair of electrodes. The device has an element 160. In the capacitive element 160, one of the pair of electrodes is a second acid A second oxide semiconductor film 104b is coplanar with the oxide semiconductor film 104a, and a pair of electrodes. The other is the first oxide semiconductor film 110b which is on the same plane as the first oxide semiconductor film 110a. be.

[0026] The transistor 150 has a gate electrode containing a second oxide semiconductor film 104a on the substrate 102. The electrode and the gate insulating film on the gate electrode, which includes a second oxide semiconductor film 104a, function as the electrode. The insulating film 108 and the gate electrode including the second oxide semiconductor film 104a on the insulating film 108 are superimposed The first oxide semiconductor film 110a at the position where it is laid, and the saw on the first oxide semiconductor film 110a It has a drain electrode 112a and a drain electrode 112b. In other words, transistor 150 This comprises a first oxide semiconductor film 110a and a component provided in contact with the first oxide semiconductor film 110a. An insulating film 108 that functions as a gate insulating film, and a first provided in contact with the insulating film 108 A second oxide semiconductor film 104a is provided at a position superimposed on the oxide semiconductor film 110a, Source electrode 112a and drain electrode 112 connected to the first oxide semiconductor film 110a It has b. Note that the transistor 150 shown in Figures 1(A) and (B) is a so-called bottom gate It has a T-structure.

[0027] Furthermore, the first oxide semiconductor film 110a is used as the channel region of the transistor 150. It is capable of. Furthermore, the second oxide semiconductor film 104a serves as the gate electrode of the transistor 150. Therefore, the second oxide semiconductor film 104 functions better than the first oxide semiconductor film 110a. The resistivity of a is low. Also, the first oxide semiconductor film 110a and the second oxide semiconductor film 104 It is preferable that a has the same metal element. The first oxide semiconductor film 110a and the second oxide By making the semiconductor film 104a have the same metal element, the manufacturing equipment (for example, This allows for the common use of membrane equipment, processing equipment, etc., thereby reducing manufacturing costs. It is possible.

[0028] Therefore, transistor 150 has a first oxide semiconductor film 110a and a first oxide An insulating film 108 in contact with the semiconductor film 110a, and a first oxide semiconductor film in contact with the insulating film 108 The first oxide semiconductor film has a second oxide semiconductor film 104a at a position superimposed on 110a. The body film 110a and the second oxide semiconductor film 104a have the same metallic element, and the first oxide The resistivity of the second oxide semiconductor film 104a is lower than that of the semiconductor film 110a.

[0029] Furthermore, wiring etc. formed separately with a metal film etc. is formed on the second oxide semiconductor films 104a and 104b. They may be connected. For example, the transistors and pixels of the display device shown in Figure 1 of the semiconductor device When used in capacitive elements, the routing wiring or gate wiring etc. is formed of a metal film, and the metal A configuration in which second oxide semiconductor films 104a and 104b are connected to the film may also be used. By forming the wiring or gate wiring with a metal film, the wiring resistance can be reduced. This makes it possible to suppress signal delays and other issues.

[0030] Also, on transistor 150, more specifically, the first oxide semiconductor film 110a, source Insulating films 114, 116, and 118 are formed on electrode 112a and drain electrode 112b. The insulating films 114, 116, and 118 function as protective insulating films for transistor 150. It has.

[0031] The capacitive element 160 functions as one of a pair of electrodes on the substrate 102. The oxide semiconductor film 104b and the second oxide semiconductor film 104b function as a dielectric film The insulating film 108 and the position where it overlaps with the second oxide semiconductor film 104b via the insulating film 108 A first oxide semiconductor film 110b having the function of the other electrode of a pair of electrodes, and Furthermore, a protective layer is placed on the capacitive element 160, or more specifically, on the first oxide semiconductor film 110b. An insulating film 118, which functions as an insulating film, is formed.

[0032] As mentioned above, the insulating film 108 in transistor 150 is the gate insulating film and It functions as such, and in the capacitive element 160, it functions as a dielectric film. Furthermore, in this embodiment In this case, the insulating film 108 has a laminated structure of insulating film 106 and insulating film 107. Furthermore, the present invention is not limited thereto, and the insulating film 108 may have a single-layer structure or a multilayer structure of three or more layers. A layered structure is also acceptable.

[0033] Furthermore, the capacitive element 160 is light-transmitting. That is, the capacitive element 160 has the first The oxide semiconductor film 110b, the second oxide semiconductor film 104b, and the insulating film 108 are Each is made of a light-transmitting material. Thus, the capacitive element 160 is light-transmitting. This results in the formation of large (over a large area) regions in the area of ​​the pixel other than where the transistor is formed. Therefore, it is possible to obtain a semiconductor device that increases capacitance while increasing aperture ratio. This allows for the creation of a semiconductor device with excellent display quality. As for 0, it can be manufactured by utilizing the manufacturing process of transistor 150. Therefore, This allows for the production of semiconductor devices with low manufacturing costs.

[0034] Furthermore, the insulating film 106 used in the transistor 150 and the capacitive element 160, and the transistor The insulating film 118 provided on the sta 150 and the capacitive element 160 contains at least hydrogen An insulating film containing this is used. Also, an insulating film 10 is used for the transistor 150 and the capacitive element 160. 7, and insulating films 114, 116 provided on transistor 150 and capacitive element 160 As such, an insulating film containing at least oxygen is used. In this way, transistor 150 and Insulating film used in the capacitive element 160, and used on the transistor 150 and the capacitive element 160 By using an insulating film having the above-described configuration, the transistor 150 and the capacitive element Controlling the resistivity of the first oxide semiconductor film and the second oxide semiconductor film possessed by 160. It is possible.

[0035] Specifically, in transistor 150, the first oxide semiconductor film 110a is channel To be used as a region, the first oxide semiconductor film 110b and the second oxide semiconductor film 104 a has a higher resistivity compared to 104b. On the other hand, the first oxide semiconductor film 110b and the second Since the oxide semiconductor films 104a and 104b have the function of electrodes, the first oxide semiconductor It has a lower resistivity compared to conductive film 110a.

[0036] Here, the first oxide semiconductor film 110a, 110b and the second oxide semiconductor film 104 The method for controlling the resistivity of a, 104b will be explained below.

[0037] <Method for controlling the resistivity of oxide semiconductors> First oxide semiconductor film 110a, 110b, and second oxide semiconductor film 104a, 10 The oxide semiconductor film that can be used in 4b is one that has oxygen vacancies and / or hydrogen and water in the film. It is a semiconductor material whose resistivity can be controlled by the concentration of impurities such as [specific impurities]. Therefore, First oxide semiconductor films 110a, 110b, and second oxide semiconductor films 104a, 104 b) Treatment that increases oxygen deficiency and / or impurity concentration, or oxygen deficiency and / or impurity concentration By selecting a process that reduces the degree of oxidation, each oxide semiconductor formed in the same process can be processed in the same way. It is possible to control the resistivity of the body membrane.

[0038] Specifically, the second oxide semiconductor film 1 functions as the gate electrode of transistor 150. 04a, a second oxide semiconductor film 104b that functions as an electrode for the capacitive element 160, and capacitance Oxide semiconductor film used for the first oxide semiconductor film 110b that functions as an electrode of the element 160 Plasma treatment is performed to increase oxygen vacancies in the oxide semiconductor film, and / or By increasing the amount of impurities such as hydrogen and water in the oxide semiconductor film, the carrier density can be increased. Furthermore, an oxide semiconductor film with low resistivity can be formed. A hydrogen-containing insulating film is formed in contact with the oxide semiconductor film, and hydrogen is diffused from the hydrogen-containing insulating film to the oxide semiconductor film. This allows for the creation of an oxide semiconductor film with high carrier density and low resistivity.

[0039] On the other hand, the first oxide semiconductor film 110 functions as the channel region of transistor 150. a is provided with insulating films 107, 114, and 116, thereby providing an insulating film 106 containing hydrogen. The configuration shall not come into contact with 118. Oxygen shall be added to at least one of the insulating films 107, 114, and 116. By applying an insulating film containing oxygen, in other words, an insulating film capable of releasing oxygen, the first Oxygen can be supplied to the oxide semiconductor film 110a. The first oxide to which oxygen has been supplied The semiconductor film 110a is an oxide semiconductor film in which oxygen vacancies in the film or at the interface are filled and the resistivity is high. This is the result. Furthermore, examples of insulating films capable of releasing oxygen include silicon oxide films. Alternatively, a silicon oxide nitride film can be used.

[0040] Furthermore, to obtain oxide semiconductor films with low resistivity, ion implantation and ion doping methods are used. Using methods such as plasma immersion ion implantation, hydrogen, boron, and ly N or nitrogen may be implanted into the oxide semiconductor film.

[0041] Furthermore, in order to obtain an oxide semiconductor film with low resistivity, the oxide semiconductor film is subjected to plasma treatment. It is permissible to do so. For example, typical plasma treatments include those using noble gases (He, Ne, A). Plasma treatment using a gas containing one selected from r, Kr, Xe, hydrogen, and nitrogen. Reasons for this include plasma processing in an Ar atmosphere, and mixed gas of Ar and hydrogen. Plasma treatment under a saturated atmosphere, plasma treatment under an ammonia atmosphere, Ar and ammonia Examples include plasma treatment in a mixed gas atmosphere or plasma treatment in a nitrogen atmosphere. It is possible.

[0042] As a result of the plasma treatment described above, the oxide semiconductor film has a lattice from which oxygen has been removed (or oxygen has been removed This creates an oxygen deficiency in the separated portion. This oxygen deficiency can be a factor in the generation of carriers. In some cases, this can occur in the vicinity of the oxide semiconductor film, or more specifically, on the underside of the oxide semiconductor film. When hydrogen is supplied from the insulating film in contact with the upper side, the above oxygen vacancy and hydrogen combine, In some cases, electrons, which act as carriers, are generated.

[0043] On the other hand, oxide semiconductor films in which oxygen deficiencies are compensated and hydrogen concentration is reduced are highly purified intrinsically. Alternatively, it can be described as a substantially high-purity intrinsically purified oxide semiconductor film. Here, substantially intrinsically purified means The carrier density of an oxide semiconductor film is 1 × 10⁻⁶ 17 pieces / cm 3 Preferably less than 1 x 10 13 pieces / cm3 less than, more preferably 1×10 -9 pieces / cm 3 or more 1×10 11 pieces / cm 3 refers to being less than. A highly pure intrinsic or substantially highly pure oxide semiconductor film has few carrier generation sources, so the carrier density can be lowered. Also, a highly pure intrinsic or substantially highly pure oxide semiconductor film has a low density of defect energy levels, so the trap energy level density can be reduced.

[0044] Also, a highly pure intrinsic or substantially highly pure oxide semiconductor film has an extremely small off-current. Even for a device with a channel width of 1×10 μm and a channel length L of 10 μm, when the voltage between the source electrode and the drain electrode (drain voltage) is in the range of 1 V to 10 V, 6 the off-current can be below the measurement limit of the semiconductor parameter analyzer, that is, 1×10 A or less. -13 A or less Thus, the transistor 150 using the first oxide semiconductor film 110a which is the above-mentioned highly pure intrinsic or substantially highly pure oxide semiconductor film in the channel region has small fluctuations in electrical characteristics and becomes a highly reliable transistor.

[0045] As the insulating film 106, for example, an insulating film containing hydrogen, in other words, an insulating film capable of releasing hydrogen, typically a silicon nitride film, is used to supply hydrogen to the second oxide semiconductor films 104a and 104b. Also, as the insulating film 118, for example, an insulating film containing hydrogen similar to the insulating film 106 is used to supply hydrogen to the first oxide semiconductor film 110b. As an insulating film capable of releasing hydrogen, the contained water in the film The elementary cardinality is 1 × 10 22 atoms / cm 3 It is preferable that such an insulating film is Formed in contact with the two oxide semiconductor films 104a, 104b and the first oxide semiconductor film 110b. By doing so, the second oxide semiconductor film 104a, 104b and the first oxide semiconductor film 110 Hydrogen can be effectively incorporated into b. In this way, the second oxide semiconductor film 104 By changing the configuration of the insulating film in contact with a, 104b and the first oxide semiconductor film 110b, This allows us to control the resistivity of oxide semiconductor films.

[0046] The hydrogen contained in the oxide semiconductor film reacts with the oxygen bonded to the metal atoms to form water. This forms an oxygen vacancy in the lattice (or the part from which oxygen has been removed). When hydrogen enters, electrons, which act as carriers, are sometimes generated. Also, some of the hydrogen In some cases, by bonding with oxygen atoms that bond with metal atoms, electrons, which act as carriers, can be generated. Therefore, the second oxide semiconductor film 104 is provided in contact with the insulating film containing hydrogen. a, 104b and the first oxide semiconductor film 110b are more than the first oxide semiconductor film 110a. This also results in an oxide semiconductor film with a high carrier density.

[0047] The first oxide semiconductor film 110a, on which the channel region of transistor 150 is formed, is water It is preferable that the element is reduced as much as possible. Specifically, the first oxide semiconductor film 11 In 0a, secondary ion mass spectrometry (SIMS) is used. The hydrogen concentration obtained by s Spectrometry is 2 × 10 20 atom / cm 3 The following is preferably 5 × 10 19atoms / cm 3 More preferably 1 × 10 19 atoms / cm 3 Below, 5 x 10 18 atoms / cm 3 Less than 1 × 1 0 18 atoms / cm 3 The following is more preferable: 5 x 10 17 atoms / cm 3 below, More preferably 1 × 10 16 atoms / cm 3 The following applies:

[0048] On the other hand, the second function functions as the gate electrode of transistor 150 and the electrode of capacitive element 160. The oxide semiconductor films 104a and 104b, and the oxide semiconductor films that function as electrodes for the capacitive element 160. The conductive film 110b has a higher hydrogen concentration and / or oxygen deficiency than the first oxide semiconductor film 110a. It is an oxide semiconductor film with a high concentration and low resistivity.

[0049] Furthermore, the first oxide semiconductor films 110a and 110b, and the second oxide semiconductor film 104a, 104b has the same metallic element. The first oxide semiconductor films 110a and 110b, and the By making the oxide semiconductor films 104a and 104b of 2 having the same metal element, This is preferable because it can reduce manufacturing costs. However, the first oxide semiconductor films 110a and 110b And, even if the second oxide semiconductor films 104a and 104b have the same metal element, the composition The process may differ. For example, during the manufacturing process of transistors and capacitive elements, the metal element in the film may differ. In some cases, elements may be removed, resulting in a different metal composition.

[0050] Thus, in a semiconductor device according to one aspect of the present invention, the gate electrode of the transistor is In other words, a conductive film that functions as a conductive film and a conductive film that functions as an electrode for a capacitive element are formed simultaneously. This includes a conductive film that functions as the gate electrode of a transistor and an electrode that functions as the electrode of a capacitive element. By forming a conductive film on the same surface, manufacturing costs can be reduced. Furthermore, A conductive film that functions as the gate electrode of a transistor, and a conductive film that functions as the electrode of a capacitive element. The film has a structure that includes an oxide semiconductor film. By performing an appropriate treatment on the oxide semiconductor film, A conductive film with low resistivity and light transmission can be obtained. This can impart light transmittance to transistors and / or capacitive elements.

[0051] Here, we will provide details on the other components of the semiconductor device shown in Figures 1(A) and 1(B). The following explanation will be given.

[0052] <Circuit board> There are no major restrictions on the material of the substrate 102, but it should at least be able to withstand subsequent heat treatment. It must have heat resistance. For example, glass substrates, ceramic substrates, quartz substrates, etc. A fire substrate or the like may be used as the substrate 102. Alternatively, silicon or silicon carbide may be used as the material. Single-crystal semiconductor substrates, polycrystalline semiconductor substrates, and compound semiconductors such as silicon germanium are used as materials. It is also possible to apply substrates, SOI substrates, etc., and semiconductor elements are provided on these substrates. The prepared material may be used as the substrate 102. Note that a glass substrate may be used as the substrate 102. If available, 6th generation (1500mm x 1850mm), 7th generation (1870mm x 220 0mm), 8th generation (2200mm x 2400mm), 9th generation (2400mm x 280 By using large-area substrates such as 0mm, 10th generation (2950mm x 3400mm), Large-scale display devices can be manufactured. Furthermore, a flexible substrate can be used as the substrate 102. The transistor 150, capacitive element 160, etc., may be formed directly on the flexible substrate.

[0053] In addition to these, various substrates can be used as substrate 102 to form transistors. This is possible. The type of circuit board is not limited to a specific one. As an example of such a circuit board... This includes plastic substrates, metal substrates, stainless steel substrates, and stainless steel wheels. Substrates having foil, tungsten substrates, substrates having tungsten foil, flexible substrates, Examples include laminated films, paper containing fibrous materials, or base films. Glass substrates. Examples include barium borosilicate glass, aluminoborosilicate glass, or soda glass. Examples include IMU glass. An example of a flexible substrate is polyethylene terephthalate (PE). T) Polyethylene naphthalate (PEN) and polyethersulfone (PES) are representative examples. These include plastics, or flexible synthetic resins such as acrylic. Examples of films include polypropylene, polyester, polyvinyl fluoride, or poly Examples include polyvinyl chloride. Examples of base films include polyester, polyamide, and poly These include imides, inorganic vapor-deposited films, or papers. In particular, semiconductor substrates, single crystal substrates, or By manufacturing transistors using SOI substrates, characteristics, size, or shape can be improved. To manufacture transistors with less variation in specifications, high current capacity, and small size. This is possible. When a circuit is constructed using such transistors, the power consumption of the circuit can be reduced, and This allows for higher integration of circuits.

[0054] Furthermore, a transistor is formed using one substrate, and then the transistor is transferred to another substrate. The transistor may be placed on one of the substrates on which the transistor is transposed. Examples include, in addition to the substrates on which the transistors described above can be formed, paper substrates, cellophane Fan substrates, stone substrates, wood substrates, fabric substrates (natural fibers (silk, cotton, linen), synthetic fibers (nylon)) , polyurethane, polyester) or regenerated fibers (acetate, cupro, rayon, These include recycled polyester, leather substrates, or rubber substrates. By using this method, it is possible to form transistors with good characteristics and transistors with low power consumption. This allows for the manufacture of durable devices, improved heat resistance, weight reduction, and thinner designs.

[0055] <First oxide semiconductor film and second oxide semiconductor film> First oxide semiconductor film 110a, 110b, and second oxide semiconductor film 104a, 10 4b contains at least indium (In), zinc (Zn), and M(Al, Ti, Ga, Y, It is represented as an In-M-Zn oxide containing metals such as Zr, La, Ce, Sn, or Hf. It is preferable that the film is included. Alternatively, it is preferable that both In and Zn are included. To reduce variations in the electrical characteristics of transistors using synthetic semiconductors, along with them, It is preferable to include a stabilizer.

[0056] As stabilizers, metals such as gallium (Ga), sulfite, and sulfite are used, including the metals listed in M ​​above. Zirconium (Sn), hafnium (Hf), aluminum (Al), or zirconium (Zr) These are some examples. Other stabilizers include lanthanides, such as lanthanum (La). , Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Samarium (Sm), Europium (Eu), Gadolinium (Gd), Terbium (Tb), Dysprosium ( Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium Examples include (Yb), lutetium (Lu), etc.

[0057] First oxide semiconductor film 110a, 110b, and second oxide semiconductor film 104a, 10 Examples of oxide semiconductors that make up 4b include In-Ga-Zn oxides and In-Al- Zn oxides, In-Sn-Zn oxides, In-Hf-Zn oxides, In-La-Z n-based oxides, In-Ce-Zn-based oxides, In-Pr-Zn-based oxides, In-Nd-Zn-based oxides In-Sm-Zn oxides, In-Eu-Zn oxides, In-Gd-Zn oxides Oxides, In-Tb-Zn oxides, In-Dy-Zn oxides, In-Ho-Zn acids In-Er-Zn oxides, In-Tm-Zn oxides, In-Yb-Zn oxides Materials, In-Lu-Zn ​​oxides, In-Sn-Ga-Zn oxides, In-Hf-Ga- Zn oxides, In-Al-Ga-Zn oxides, In-Sn-Al-Zn oxides, I n-Sn-Hf-Zn oxides and In-Hf-Al-Zn oxides can be used. .

[0058] In this context, In-Ga-Zn oxides are those that have In, Ga, and Zn as their main components. It means an oxide, and the ratio of In, Ga, and Zn is not specified. Other metal elements besides n may be present.

[0059] Furthermore, the first oxide semiconductor films 110a and 110b, and the second oxide semiconductor film 104a, 104b has the same metal element as the above oxide. First oxide semiconductor film 110 a, 110b and the second oxide semiconductor films 104a, 104b are made of the same metallic element. This allows for a reduction in manufacturing costs. For example, targeting metal oxides with the same metal composition By using a metal acid with the same metal composition, manufacturing costs can be reduced. By using an oxide target, the etching gas used when processing oxide semiconductor films Alternatively, the etching solution can be used in common.

[0060] <Insulated film> The insulating film functions as the gate insulating film of transistor 150 and the dielectric film of capacitive element 160. For the border films 106 and 107, silica oxide is produced by plasma CVD, sputtering, etc. Concealing film, silicon oxide nitride film, silicon nitride oxide film, silicon nitride film, aluminum oxide Film, hafnium oxide film, yttrium oxide film, zirconium oxide film, gallium oxide film, acid Tantalum oxide film, magnesium oxide film, lanthanum oxide film, cerium oxide film, and neodymium oxide film Insulating layers containing one or more types of film can be used. Instead of using the laminated structure described in 7, a single insulating layer selected from the materials mentioned above may be used.

[0061] Furthermore, the first oxide semiconductor film 110 functions as the channel region of transistor 150. The insulating film 107 in contact with a is preferably an oxide insulating film, and is more than a stoichiometric composition. It is more preferable to have a region containing an excess of oxygen (an oxygen-rich region). In other words, The insulating film 107 is an insulating film that can release oxygen. To create an excess region, for example, an insulating film 107 can be formed in an oxygen atmosphere. Alternatively, oxygen may be introduced into the insulating film 107 after film formation to form an oxygen-rich region. Methods of administration include ion implantation, ion doping, and plasma immersion ion implantation. Methods such as plasma treatment can be used.

[0062] Furthermore, when hafnium oxide is used as insulating film 106 and 107, the following effects are achieved. Hafnium oxide has a higher dielectric constant compared to silicon oxide and silicon oxide / nitride. Therefore, the physical film thickness can be made larger than the equivalent oxide film thickness, so the equivalent oxide film thickness can be increased to 10n Even when the size is less than m or less than 5 nm, the leakage current due to tunnel current is reduced. This makes it possible to realize transistors with low off-current. Furthermore, Hafnium oxide with a crystalline structure has a higher crystalline structure compared to hafnium oxide with an amorphous structure. It possesses relative permittivity. Therefore, in order to make a transistor with a small off-current, the crystal structure It is preferable to use hafnium oxide having a specific structure. Examples of crystal structures include monoclinic and Examples include cubic crystal systems. However, one aspect of the present invention is not limited to these.

[0063] In this embodiment, a silicon nitride film is formed as the insulating film 106, and the insulating film 107 It forms a silicon oxide film. Compared to the silicon oxide film, the silicon nitride film has a relative dielectric constant. Because the rate is high and the thickness required to obtain capacitance equivalent to that of a silicon oxide film is large, Insulating film 108 functions as the gate insulating film of the zistor 150 and the dielectric film of the capacitive element 160. Therefore, by including a silicon nitride film, the insulating film can be physically made thicker. Furthermore, the decrease in dielectric breakdown voltage of transistor 150 and capacitive element 160 is suppressed, and the dielectric breakdown voltage is This can be improved to suppress electrostatic discharge breakdown of the transistor 150 and the capacitive element 160. .

[0064] <Source electrode and drain electrode> Materials that can be used for the source electrode 112a and the drain electrode 112b include: Aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum A single metal consisting of tungsten, silver, tantalum, or silver, or a compound with these as the main component. Gold can be used in a single-layer or multi-layer structure. For example, gold can be used on an aluminum film. Two-layer structure with stacked tungsten films, two-layer structure with a titanium film stacked on top of a tungsten film, molybdenum A two-layer structure in which a copper film is laminated on a tungsten film, or a copper film is laminated on an alloy film containing molybdenum and tungsten. Layered two-layer structure, a two-layer structure in which a copper film is laminated on a copper-magnesium-aluminum alloy film, A titanium film or titanium nitride film, and aluminum layered on top of the titanium film or titanium nitride film. A three-layer structure in which a titanium film or copper film is laminated, and then a titanium film or titanium nitride film is formed on top of that. Molybdenum film or molybdenum nitride film and the molybdenum film or molybdenum nitride film An aluminum film or copper film is layered on top, and then a molybdenum film or nitride film is placed on top of that. There are also three-layer structures that form a molybdenum film. Furthermore, the source electrode 112a and the drain electrode... When the 112b pole has a three-layer structure, the first and third layers consist of titanium, titanium nitride, and molybdenum. Den, tungsten, molybdenum and tungsten-containing alloys, molybdenum and zirconium A film is formed using an alloy containing or molybdenum nitride, and the second layer is made of copper, aluminum, gold Alternatively, it is preferable to form a film made of a low-resistance material such as silver or an alloy of copper and manganese. Furthermore, transparent conductive materials containing indium oxide, tin oxide, or zinc oxide may be used. The materials that can be used for the source electrode 112a and the drain electrode 112b are, for example, It can be formed using the sputtering method.

[0065] <Protective insulating film> Insulating films 114, 116, 118 and a capacitor that function as protective insulating films for transistor 150 The insulating film 118, which functions as a protective insulating film for the element 160, is a plasma CVD method, By methods such as puttering, silicon oxide film, silicon oxide nitride film, silicon nitride oxide film, Silicon nitride film, aluminum oxide film, hafnium oxide film, yttrium oxide film, dioxide gallium film, gallium oxide film, tantalum oxide film, magnesium oxide film, lanthanum oxide film The insulating layers include one or more cerium oxide films and neodymium oxide films, respectively. can.

[0066] Furthermore, in the capacitive element 160, the insulating film 118 functions as an electrode of the capacitive element 160. It also has the function of reducing the resistivity of the first oxide semiconductor film 110b.

[0067] Furthermore, the first oxide semiconductor film 110 functions as the channel region of the transistor 150. The insulating film 114 in contact with a is preferably an oxide insulating film, and is able to release oxygen. Use an insulating film that can release oxygen. In other words, an insulating film that can release oxygen is a stoichiometric compound. This insulating film has a region containing an excess of oxygen (oxygen-rich region). To create an oxygen-rich region in the film 114, for example, the insulating film 114 is formed under an oxygen atmosphere. Alternatively, oxygen can be introduced into the insulating film 114 after film formation to form an oxygen-rich region. Good. Methods for introducing oxygen include ion implantation, ion doping, and plasma immersion. Ion implantation, plasma treatment, and other methods can be used.

[0068] By using an insulating film capable of releasing oxygen as the insulating film 114, the transient Oxygen is transferred to the first oxide semiconductor film 110a which functions as a channel region of 150. This makes it possible to reduce the amount of oxygen vacancies in the first oxide semiconductor film 110a. Heat treatment to which the surface temperature is 100°C to 700°C, preferably 100°C to 500°C. Oxygen measured by thermal desorption gas analysis (hereinafter referred to as TDS analysis) performed at the laboratory. The amount of molecules released is 1.0 × 10⁻⁶ 18 molecules / cm 3 By using the above insulating film, the first The amount of oxygen vacancies in the oxide semiconductor film 110a can be reduced.

[0069] Furthermore, the thickness of the insulating film 114 is 5 nm or more and 150 nm or less, preferably 5 nm or more and 50 nm or less. The thickness of the insulating film 116 can be less than or equal to nm, preferably between 10 nm and 30 nm. The wavelength should be between 30 nm and 500 nm, preferably between 150 nm and 400 nm. It is possible.

[0070] Furthermore, insulating films 114 and 116 can be made of the same type of insulating material, thus providing insulation. In some cases, the interface between film 114 and insulating film 116 cannot be clearly identified. Therefore, in this implementation... In the diagram, the interface between insulating film 114 and insulating film 116 is shown with a dashed line. In the embodiment, a two-layer structure of insulating film 114 and insulating film 116 was described, but It is not limited to the above, but for example, a single-layer structure of insulating film 114, a single-layer structure of insulating film 116, or 3 A layered structure with more than one layer is also acceptable.

[0071] Furthermore, the source electrode 112a and the drain electrode 112b, and the first oxide semiconductor film 110 An insulating film 122 may be provided between a and (a). An example of this case is shown in Figures 17(A) and (B). The source electrode 112a and the drain electrode 112b, and the first oxide semiconductor film 110a They are connected via contact holes provided in the insulating film 122. Insulating film 122 The same materials and film properties as those described in insulating film 108 can be used.

[0072] <Method for manufacturing a display device> Next, regarding an example of a semiconductor device fabrication method shown in Figures 1(A) and 1(B), see Figures 2 and 3. We will explain using this method.

[0073] First, a gate electrode containing a second oxide semiconductor film 104a and a pair of electrodes are placed on the substrate 102. A second oxide semiconductor film 104b is formed, which functions as one of the electrodes. Then, the substrate 1 02, and the second oxide semiconductor film 104a, 104b, containing insulating films 106, 107 A border film 108 is formed (see Figure 2(A)).

[0074] Note that the substrate 102, the second oxide semiconductor films 104a, 104b, and the insulating film 106, 1 As for 07, it can be formed by selecting from the materials listed above. In terms of form, a glass substrate is used as the substrate 102, and a second oxide semiconductor film 104a , 104b is an In-Ga-Zn oxide film (In:Ga:Zn=1:1:1 metal Using an oxide target, the insulating film 106 can release hydrogen. A silicon nitride film is used, and the insulating film 107 is an oxidative nitride capable of releasing oxygen. A silicon film is used.

[0075] The second oxide semiconductor film 104a, 104b is silicon nitride capable of releasing hydrogen. By placing the films in contact with each other, the resistivity of the second oxide semiconductor films 104a and 104b is reduced. This becomes possible.

[0076] Furthermore, the second oxide semiconductor films 104a and 104b are formed on the substrate 102. After film formation, the oxide semiconductor film is patterned so that the desired region remains, and then the unwanted region is removed. It is formed by etching.

[0077] Next, the electrode containing the second oxide semiconductor film 104a on the insulating film 108 is superimposed on the electrode. A first oxide semiconductor film 110a is placed on top of the insulating film 108, and a second oxide semiconductor film 104b is placed on top of the insulating film 108. A first oxide semiconductor film 110b and are formed at positions where they overlap (see Figure 2(B)). (see).

[0078] The first oxide semiconductor films 110a and 110b are selected from the materials listed above. It can be formed by doing so. In this embodiment, the first oxide semiconductor film 110a , 110b is an In-Ga-Zn oxide film (In:Ga:Zn=1:1:1 metal Use an oxide target.

[0079] Furthermore, the first oxide semiconductor films 110a and 110b are oxide semiconductor films on the insulating film 108. After forming the film, the oxide semiconductor film is patterned so that the desired region remains, and then the unwanted region is patterned. It is formed by etching the area.

[0080] Furthermore, the first oxide semiconductor film 110a and the first oxide semiconductor film 110b are made of the same acid Since it is formed by processing from an oxide semiconductor film, it has at least the same metallic element. During the etching process of the first oxide semiconductor films 110a and 110b, over-etching occurs. This causes a portion of the insulating film 107 (the area exposed from the first oxide semiconductor films 110a and 110b) to be exposed. The area may be etched, causing a decrease in film thickness.

[0081] It is preferable to perform heat treatment after forming the first oxide semiconductor films 110a and 110b. The temperature is preferably 250°C to 650°C, more preferably 300°C to 500°C, and more preferably 250°C to 650°C. The temperature is between 350°C and 450°C, in an inert gas atmosphere, with an oxidizing gas concentration of 10 ppm or higher. The treatment can be carried out in an atmosphere containing or under reduced pressure. Furthermore, the heat treatment atmosphere should be an inert gas atmosphere. After heat treatment with gas, the oxygen desorbed from the first oxide semiconductor films 110a and 110b is To compensate, the procedure may be carried out in an atmosphere containing 10 ppm or more of an oxidizing gas. That is, at least the insulating films 106, 107 and the first oxide semiconductor films 110a, 110b Furthermore, impurities such as hydrogen and water can be removed from the first acid. This may be done before processing the ionized semiconductor films 110a and 110b into island shapes.

[0082] Furthermore, the transistor 150, which has the first oxide semiconductor film 110a as its channel region, is stable. In order to impart the desired electrical properties, impurities in the first oxide semiconductor film 110a are reduced. It is effective to make the first oxide semiconductor film 110a intrinsic or substantially intrinsic.

[0083] Next, conductive films are deposited on the insulating film 108 and the first oxide semiconductor films 110a and 110b. Then, the conductive film is patterned so that the desired area remains, and the unwanted area is etched away. By doing so, the source electrode 112a is placed on the insulating film 108 and the first oxide semiconductor film 110a. And the drain electrode 112b is formed (see Figure 2(C)).

[0084] The source electrode 112a and the drain electrode 112b are selected from the materials listed above. It can be formed by selecting from. In this embodiment, the source electrode 112a, and The drain electrode 112b consists of three layers: a titanium film, an aluminum film, and another titanium film. A layered structure is used.

[0085] Next, insulating film 108, first oxide semiconductor films 110a, 110b, source electrode 112a And insulating films 114 and 116 are formed on the drain electrode 112b (see Figure 2(D)).

[0086] The insulating films 114 and 116 can be formed by selecting from the materials listed above. In this embodiment, the insulating films 114 and 116 are designed to release oxygen. A silicon oxide nitride film capable of this is used.

[0087] Next, the pattern is created so that the desired regions of the insulating films 114 and 116 remain, and then the unwanted regions are left as they are. The region is etched to form the opening 140 (see Figure 3(A)).

[0088] The opening 140 is formed so that the first oxide semiconductor film 110b is exposed. For example, a dry etching method can be used as a method for forming 140. However, The method for forming the opening 140 is not limited to this, and may include wet etching or dry etching. A formation method combining the dry etching method and the wet etching method may also be used. The etching process for forming the opening 140 is performed on the first oxide semiconductor film 110b. The film thickness may decrease.

[0089] It is preferable to perform a heat treatment after this. This heat treatment will remove the insulating film 114 or the insulating film. A portion of the oxygen contained in film 116 is transferred to the first oxide semiconductor film 110a, and the first oxidation It is possible to fill the oxygen vacancies in the semiconductor film 110a. As a result, the first oxide The amount of oxygen vacancies contained in the semiconductor film 110a can be reduced. On the other hand, the insulating film 114 and Since the amount of oxygen vacancy in the first oxide semiconductor film 110b that is not in contact is not reduced, the first oxide The semiconductor film 110b contains more oxygen vacancies than the first oxide semiconductor film 110a. The heat treatment conditions are as follows: This can be done in the same way as the processing.

[0090] Next, the insulating film 116 and the first oxide semiconductor film 110b are placed so as to cover the opening 140. An insulating film 118 is formed on top of this (see Figure 3(B)).

[0091] The insulating film 118 can be formed by selecting from the materials listed above. In this embodiment, the insulating film 118 is a nitride capable of releasing hydrogen. A recon film is used. Hydrogen contained in the insulating film 118 diffuses into the first oxide semiconductor film 110b. As a result, the resistivity of the first oxide semiconductor film 110b decreases. As the resistivity of film 110b decreases, the first oxide semiconductor film shown in Figures 3(A) and 3(B) The hatching of 110b has been changed for this illustration.

[0092] The resistivity of the first oxide semiconductor film 110b is at least that of the first oxide semiconductor film 110a Lower than, preferably 1 × 10-3 Ωcm or more, 1 × 10 4 Less than Ωcm, even better ku is 1 x 10 -3 Ωcm or more, 1 × 10 -1 It is preferable that it be less than Ωcm. Note that insulating film 11 8 is the case where external impurities, such as water, alkali metals, alkaline earth metals, etc., are transient. This also has the effect of preventing diffusion into the first oxide semiconductor film 110a contained in STA 150.

[0093] Furthermore, the silicon nitride film used as the insulating film 118 in this embodiment is a blocking type. To enhance this, it is preferable to deposit the film at a high temperature, for example, 100°C or higher above the strain point of the substrate. More preferably, the film is formed by heating at a temperature of 300°C to 400°C. .

[0094] Furthermore, a capacitive element 160 is fabricated in conjunction with the formation of the first oxide semiconductor film 110b. The element 160 has a structure in which a dielectric layer is sandwiched between a pair of electrodes, and one of the pair of electrodes The second oxide semiconductor film 104b is the other electrode of the pair, and the first oxide semiconductor film 110 b. In addition, the insulating film 108 functions as a dielectric layer for the capacitive element 160.

[0095] Through the above process, the transistor 150 and the capacitive element 160 are formed on the same substrate. It is possible.

[0096] The configurations and methods described in this embodiment are similar to those described in other embodiments. They can be used in combination as appropriate.

[0097] (Embodiment 2) In this embodiment, the semiconductor device according to one aspect of the present invention is the semiconductor shown in Embodiment 1. Modified examples of the apparatus will be explained using Figures 4 to 6. Note that Figures 1 to 6 of Embodiment 1 are also shown. The same reference numerals are used for parts that are the same as or have the same function as those shown in Figure 3. I will omit the explanation of that repetition.

[0098] <Example of semiconductor device configuration (modification example 1)> Figure 4(A) is a top view of a semiconductor device according to one embodiment of the present invention, and Figure 4(B) is a top view of Figure 4(A) This corresponds to a cross-sectional view of the section between the dashed lines EF and GH. In Figure 4(A), to avoid complexity, some of the components of the semiconductor device (G The insulator and other components are omitted from the illustration.

[0099] The semiconductor device shown in Figures 4(A) and (B) consists of a first oxide semiconductor film 110a and a second oxide A transistor 151 including a semiconductor film 104a and a capacitor including an insulating film between a pair of electrodes. It has an element 161. In the capacitive element 161, one of the pair of electrodes is a second acid A first oxide semiconductor film 104b is coplanar with the oxide semiconductor film 104a, and a pair of electrodes. The other is the conductive film 120.

[0100] Transistor 151 has a gate electrode containing a second oxide semiconductor film 104a on the substrate 102. The electrode and the gate insulating film on the gate electrode, which includes a second oxide semiconductor film 104a, function as the electrode. The insulating film 108 and the gate electrode including the second oxide semiconductor film 104a on the insulating film 108 are superimposed The first oxide semiconductor film 110a at the position where it is laid, and the saw on the first oxide semiconductor film 110a It has a drain electrode 112a and a drain electrode 112b. (See Figures 4(A) and (B)) Transistor 151 has a so-called bottom-gate structure.

[0101] Also, on transistor 151, more specifically, the first oxide semiconductor film 110a, source Insulating films 114, 116, and 118 are formed on electrode 112a and drain electrode 112b. The insulating films 114, 116, and 118 function as protective insulating films for transistor 151. It has an opening that reaches the drain electrode 112b in the insulating films 114, 116, and 118. An opening 142 is formed, and a conductive film 120 is formed on the insulating film 118 so as to cover the opening 142. This is achieved. The conductive film 120 functions, for example, as a pixel electrode.

[0102] Capacitive element 161 functions as one of a pair of electrodes on the substrate 102. The oxide semiconductor film 104b and the second oxide semiconductor film 104b function as a dielectric film insulating films 108, 114, 116, 118 and insulating films 108, 114, 116, 118 As the other electrode of the pair of electrodes superimposed on the second oxide semiconductor film 104b via It has a conductive film 120 that has a function, and that is, the conductive film 120 as a pixel electrode It has both functional and capacitive electrode properties.

[0103] As mentioned above, the insulating film 108 in transistor 151 is the gate insulating film and It functions as such, and in the capacitive element 161, it functions as part of the dielectric film. 114, 116, and 118 function as protective insulating films in transistor 151. In the capacitive element 161, it functions as part of the dielectric film. (See Figures 4(A) and (B)) In this configuration, insulating films 114, 116, and 118 are provided as part of the dielectric film. The examples given are not limited to those provided. For example, during the manufacturing process of transistor 151, When forming the opening 142, the insulating films 114, 116, and 118 of the capacitor element 161 may be removed. .

[0104] Also, the capacitor element 161 has translucency. That is, the second oxide semiconductor film 104b, insulating films 108, 114, 116, 118, and conductive film 120 of the capacitor element 161 are each composed of a translucent material. Thus, since the capacitor element 161 has translucency, it can be formed largely (in a large area) in a region other than the location where the transistor in the pixel is formed, so that a semiconductor device with an increased capacitance value while increasing the aperture ratio can be obtained. As a result, a semiconductor device with excellent display quality can be obtained. Also, the capacitor element 161 can be fabricated by using the fabrication process of the transistor 151. Therefore, a semiconductor device with low manufacturing cost can be obtained.

[0105] Note that, as the insulating films 106 and 118, an insulating film containing at least hydrogen is used. Also, as the insulating films 107, 114, and 116, an insulating film containing at least oxygen is used. Thus, by making the insulating films used for the transistor 151 and the capacitor element 161 or the insulating films contacting the transistor 151 and the capacitor element 161 be insulating films with the above-described configurations, the resistivity of the first oxide semiconductor film and the second oxide semiconductor film of the transistor 151 and the capacitor element 161 can be controlled.

[0106] Note that, regarding the resistivity of the first oxide semiconductor film 110a and the second oxide semiconductor films 104a and 104b, it can be controlled by referring to the description in Embodiment 1.

[0107] The semiconductor device shown in Figures 1(A) and 1(B) of Embodiment 1, and the semiconductor device shown in Figures 4(A) and 4(B) The main difference in the semiconductor device is that the other electrode of the capacitive element 161 is made of a conductive film 120. Yes. Thus, the other electrode of the pair of electrodes of the capacitive element 161 functions as a conductive electrode. It may also be referred to as film 120.

[0108] Thus, in a semiconductor device according to one aspect of the present invention, the gate electrode of the transistor is In other words, a conductive film that functions as a conductive film and a conductive film that functions as an electrode for a capacitive element are formed simultaneously. This includes a conductive film that functions as the gate electrode of a transistor and an electrode that functions as the electrode of a capacitive element. By forming a conductive film on the same surface, manufacturing costs can be reduced. Furthermore, A conductive film that functions as the gate electrode of a transistor, and a conductive film that functions as the electrode of a capacitive element. The film has a structure that includes an oxide semiconductor film. By performing an appropriate treatment on the oxide semiconductor film, A conductive film with high conductivity and light transmission can be obtained. This can impart light transmittance to transistors and / or capacitive elements.

[0109] Furthermore, the source electrode 112a and the drain electrode 112b, and the first oxide semiconductor film 110 An insulating film 122 may be provided between a and (a). An example of this case is shown in Figures 18(A) and (B). vinegar.

[0110] Furthermore, conductive film 1 was formed simultaneously with conductive film 120, etched simultaneously, and formed simultaneously. 20a may be positioned so as to overlap with the transistor's channel region. An example of this is shown in Figure. As shown in Figures 15(A) and 19(A), conductive film 120a is, for example, the same as conductive film 120. Because the film is sometimes deposited, etched, and formed simultaneously, it has the same material. Therefore, an increase in the process steps can be suppressed. However, one aspect of the embodiment of the present invention is not limited thereto. The conductive film 120a may be formed in a process different from that of the conductive film 120 . The conductive film 120a has a region overlapping with the channel region of the transistor. Thus , the conductive film 120a has a function as the second gate electrode of the transistor . Therefore, the conductive film 120a may be connected to the second oxide semiconductor film 104a . Alternatively, the conductive film 120a may be supplied with a different signal or a different potential from the second oxide semiconductor film 104a without being connected to the second oxide semiconductor film 104a.

[0111] Here, the details of the other components of the semiconductor device shown in FIGS. 4(A) and (B) will be described below.

[0112] <Conductive film> The conductive film 120 has a function as a pixel electrode. As the conductive film 120, for example, a material having translucency in visible light may be used. Specifically, a material containing one selected from indium (In), zinc (Zn), and tin (Sn) may be used. Further, as the conductive film 120, for example, indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, indium tin oxide (ITO), indium zinc oxide, indium tin oxide added with silicon oxide, or the like a conductive material having translucency can be used. Further, as the conductive film 120, for example, it can be formed by using a sputtering method.

[0113] <Method for manufacturing a display device (Modification 1)>​​​​​​​​ Next, an example of a method for manufacturing the semiconductor device shown in Figures 4(A) and 4(B) is described in Figures 5 and 6. We will explain using this method.

[0114] First, a gate electrode containing a second oxide semiconductor film 104a and a pair of electrodes are placed on the substrate 102. A second oxide semiconductor film 104b is formed which functions as one of the electrodes. Then the second An insulating film 108 containing insulating films 106 and 107 is formed on oxide semiconductor films 104a and 104b. (See Figure 5(A)).

[0115] Next, the electrode containing the second oxide semiconductor film 104a on the insulating film 108 is superimposed on the electrode. A first oxide semiconductor film 110a is formed in this position (see Figure 5(B)).

[0116] The first oxide semiconductor film 110a is formed by depositing an oxide semiconductor film on an insulating film 108, and the oxidation The semiconductor film is patterned so that the desired region remains, and then the unwanted region is etched away. It is formed by doing so.

[0117] Furthermore, during the etching process of the first oxide semiconductor film 110a, over-etching occurs. Therefore, a part of the insulating film 107 (the region exposed from the first oxide semiconductor film 110a) is etched. This can cause a reduction in film thickness.

[0118] It is preferable to perform a heat treatment after forming the first oxide semiconductor film 110a. This can be done by taking into consideration the heat treatment after the formation of the first oxide semiconductor film 110a in form 1. Cut.

[0119] Next, a conductive film is formed on the insulating film 108 and the first oxide semiconductor film 110a, and the conductive film is formed on the insulating film 108. By patterning the film so that the desired region remains, and then etching away the unwanted region... A source electrode 112a and a drain electrode 112b are formed on the first oxide semiconductor film 110a. This is achieved (see Figure 5(C)).

[0120] Next, insulating film 108, first oxide semiconductor film 110a, source electrode 112a, and Dray Insulating films 114, 116, and 118 are formed on the in electrode 112b (see Figure 5(D)).

[0121] Next, the insulating films 114, 116, and 118 are patterned so that the desired regions remain. The opening 142 is formed by etching away the unnecessary areas (see Figure 6(A)).

[0122] The opening 142 is formed so that the drain electrode 112b is exposed. As a formation method, for example, a dry etching method can be used. However, for opening 1 The method for forming 42 is not limited to this, and may include wet etching or dry etching. A formation method combining the ching method and the wet etching method may also be used.

[0123] Next, a conductive film is formed on the insulating film 118 so as to cover the opening 142, and the desired area of ​​the conductive film is formed. Patterning and etching are performed while leaving the area intact to form the conductive film 120 (Figure 6(B) )reference).

[0124] Through the above process, the transistor 151 and the capacitive element 161 are formed on the same substrate. It is possible.

[0125] Alternatively, an insulating film 118a may be placed on top of the insulating film 118. Figure 15 shows an example of this case. (B), (C), and Figure 19(B), (C) are shown. Examples of insulating film 118a include, It can be formed using organic resin materials. Materials applicable to insulating film 118a include: Examples include acrylic resins, polyimide resins, and polyamide resins.

[0126] Furthermore, as shown in Figures 15(C) and 19(C), a conductive film 121 may be provided. The film 121 may be provided so as to overlap with the channel region of the transistor. The conductive film 121 is The conductive film 121 may be formed using a material similar to that described for conductive film 120. It has a region that overlaps with the channel region of the transistor. Therefore, the conductive film 121 is It functions as the second gate electrode of the transistor. Therefore, the conductive film 121, It may be connected to a second oxide semiconductor film 104a. Alternatively, the conductive film 121 may be connected to a second The oxide semiconductor film 104a is not connected to the second oxide semiconductor film 104a, and a different signal is connected to the second oxide semiconductor film 104a. Different potentials may be supplied.

[0127] Furthermore, conductive film 1 was formed simultaneously with conductive film 121, etched simultaneously, and formed simultaneously. 21a may be provided so as to overlap with the electrodes of the capacitive element to constitute a capacitive element. Examples are shown in Figures 20(A), (B), and (C). As a result, the capacitance value of the capacitive element can be increased. It is possible.

[0128] The configurations and methods described in this embodiment are similar to those described in other embodiments. They can be used in combination as appropriate.

[0129] (Embodiment 3) In this embodiment, the semiconductor device according to one aspect of the present invention is the semiconductor shown in Embodiment 1. A modified example of the apparatus will be explained using Figure 7. Note that the same method is shown in Figures 1 to 3 of Embodiment 1. For parts that are similar to or have a similar function to the same code, the same code shall be used. I will omit repeated explanations.

[0130] <Example of semiconductor device configuration (modified version 2)> Figure 7(A) is a top view of a semiconductor device according to one embodiment of the present invention, and Figure 7(B) is a top view of Figure 7(A) This corresponds to a cross-sectional view of the section between the dashed lines IJ and KL. In Figure 7(A), to avoid complexity, some of the components of the semiconductor device (G The insulator and other components are omitted from the illustration.

[0131] The semiconductor device shown in Figures 7(A) and (B) consists of a first oxide semiconductor film 110a and a second oxide A transistor 152 including a semiconductor film 104a and a capacitor including an insulating film between a pair of electrodes. It has element 162 and

[0132] The transistor 152 has a gate electrode containing a second oxide semiconductor film 104a on the substrate 102. The electrode and the gate insulating film on the gate electrode, which includes a second oxide semiconductor film 104a, function as the electrode. The insulating film 108 and the gate electrode including the second oxide semiconductor film 104a on the insulating film 108 are superimposed The first oxide semiconductor film 110a at the position where it is laid, and the saw on the first oxide semiconductor film 110a It has a drain electrode 112a and a drain electrode 112b. (See Figures 7(A) and 7(B)) Transistor 152 has a so-called bottom-gate structure.

[0133] Also, on transistor 152, more specifically, the first oxide semiconductor film 110a, source Insulating films 114, 116, and 118 are formed on electrode 112a and drain electrode 112b. The insulating films 114, 116, and 118 function as protective insulating films for transistor 152. It has an opening that reaches the drain electrode 112b in the insulating films 114, 116, and 118. An opening 142 is formed, and a conductive film 120 is formed on the insulating film 118 so as to cover the opening 142. This is achieved. The conductive film 120 functions, for example, as a pixel electrode.

[0134] Furthermore, in the capacitive element 162, one of the pair of electrodes is made of the second oxide semiconductor film 104b Yes, the other of the pair of electrodes is the conductive film 120. Also, the capacitive element 162 is between the pair of electrodes. It further has an electrode. The electrode is formed on the same plane as the first oxide semiconductor film 110a. This is the first oxide semiconductor film 110b.

[0135] In this way, by providing an additional electrode between the pair of electrodes, the area of ​​the capacitive element can be reduced. The capacitance can be increased without increasing the capacitance. Examples of the capacitance element 162 are as follows: This can be seen as the structure. The capacitive element 162 is composed of a second oxide semiconductor film 104b and a first A first capacitive element having an insulating film 108 sandwiched between oxide semiconductor films 110a as a dielectric film, The insulating film 118 sandwiched between the first oxide semiconductor film 110a and the conductive film 120 is a dielectric film. The structure is such that a second capacitive element is stacked and provided.

[0136] As mentioned above, the insulating film 108 is used as the gate insulating film in the transistor 152. It functions as part of the dielectric film in the capacitive element 162. 4, 116, and 118 function as protective insulating films in transistor 152. The insulating film 118 functions as part of the dielectric film in the capacitive element 162.

[0137] Furthermore, the capacitive element 162 is light-transmitting. That is, the capacitive element 162 has first The oxide semiconductor film 110b, the second oxide semiconductor film 104b, insulating films 108, 118, and The conductive film 120 is composed of a light-transmitting material. Because child 162 is translucent, the region other than the area where the transistor is formed within the pixel Because it can be formed on a large scale (large area), it increases the volume while increasing the opening ratio. A conductive device can be obtained. As a result, a semiconductor device with excellent display quality can be obtained. Furthermore, the capacitive element 162 can be manufactured by utilizing the manufacturing process of the transistor 152. It can be manufactured. Therefore, semiconductor devices with low manufacturing costs can be obtained.

[0138] Furthermore, insulating films containing at least hydrogen are used as insulating films 106 and 118. As insulating films 107, 114, and 116, insulating films containing at least oxygen are used. Sea urchin, insulating film used for transistor 152 and capacitive element 162 or transistor 152 And by making the insulating film in contact with the capacitive element 162 an insulating film with the above configuration, The first oxide semiconductor film and the second oxide semiconductor film of the zista 152 and the capacitive element 162 The resistivity of the film can be controlled.

[0139] Furthermore, the first oxide semiconductor film 110a, 110b and the second oxide semiconductor film 104a, The resistivity of 104b can be controlled by referring to the description in Embodiment 1. Cut.

[0140] The semiconductor device shown in Figures 1(A) and 1(B) of Embodiment 1, and the semiconductor device shown in Figures 7(A) and 7(B) The main difference in semiconductor devices lies in the electrode structure of the capacitive element 162.

[0141] In one embodiment of the present invention, a semiconductor device that functions as the gate electrode of a transistor is provided. In other words, a transient The conductive film that functions as the gate electrode of the sta and the conductive film that functions as the electrode of the capacitive element are the same. By forming it on the surface, it becomes possible to reduce manufacturing costs. Also, transistors The conductive film that functions as the gate electrode and the conductive film that functions as the electrode of the capacitive element are made of oxide. The structure includes a semiconductor film. By performing appropriate treatment on the oxide semiconductor film, the conductivity is increased. Furthermore, it can be made into a conductive film that is light-transmitting. By using this conductive film, the transient Transmittance can be imparted to the tamper and / or capacitive elements.

[0142] The method for fabricating the semiconductor device shown in Figures 7(A) and 7(B) is as follows: Combine the semiconductor device shown in Figure 4 and the method for manufacturing the semiconductor device shown in Figures 4(A) and 4(B). This can be formed.

[0143] Furthermore, similar to Figure 15(A), the conductive film 120a overlaps with the channel region of the transistor. It may be provided in this manner. Examples of this case are shown in Figures 16(A) and 19(A).

[0144] Also, similar to Figures 15(B) and (C), insulating film 118a is placed on top of insulating film 118. This is also acceptable. Examples of this case are shown in Figures 16(B), (C) and 19(B), (C).

[0145] The configurations and methods described in this embodiment are similar to those described in other embodiments. They can be used in combination as appropriate.

[0146] (Embodiment 4) In this embodiment, the semiconductor device according to one aspect of the present invention is the semiconductor shown in Embodiment 1. Modified examples of the apparatus will be explained using Figures 8 to 10. Note that Figure 1 of Embodiment 1 is For parts with the same or similar functions as those shown in Figure 3, the same reference numerals are used. We will use it, and omit the explanation of its repetition.

[0147] <Example of semiconductor device configuration (modification example 3)> Figure 8(A) is a top view of a semiconductor device according to one embodiment of the present invention, and Figure 8(B) is a top view of Figure 8(A) This corresponds to a cross-sectional view of the section between the dashed lines MN and OP. In Figure 8(A), to avoid complexity, some of the components of the semiconductor device (G The insulator and other components are omitted from the illustration.

[0148] The semiconductor device shown in Figures 8(A) and (B) consists of a first oxide semiconductor film 210 and a second oxide A transistor 250 including a monocrystalline semiconductor film 204a and a capacitance element including an insulating film between a pair of electrodes It has a sub-element 260. In addition, in the capacitive element 260, one of the pair of electrodes is a second oxidation A second oxide semiconductor film 204b is coplanar with the monocrystalline semiconductor film 204a, and a pair of electrodes The other is the conductive film 220.

[0149] Transistor 250 is an insulating film 216 on substrate 202 and a first oxide on insulating film 216 A monocrystalline semiconductor film 210, and a source electrode 212a and drain on the first oxide semiconductor film 210. Electrode 212b and insulating film 2 which functions as a gate insulating film on the first oxide semiconductor film 210 08 and the second oxide semiconductor film at a position superimposed on the first oxide semiconductor film 210 on the insulating film 208 It has a gate electrode containing a conductive film 204a. Note that the transistors shown in Figures 8(A) and (B) The Zista 250 has what is known as a top-gate structure.

[0150] Furthermore, on transistor 250, more specifically, a second oxide semiconductor film 204a is included. Insulating films 218 and 217 are applied to the source electrode 212a and drain electrode 212b. The insulating films 218 and 217 are formed as protective insulating films for the transistor 250. It has the ability to do so. In addition, the insulating films 218 and 217 have an opening 240 that reaches the drain electrode 212b. A conductive film 220 is formed on the insulating film 217 so as to cover the opening 240. The conductive film 220 functions, for example, as a pixel electrode.

[0151] The capacitive element 260 has an insulating film 216 on the substrate 202 and an insulating film 208 on the insulating film 216. , a second oxide semiconductor film 204 having the function of one of a pair of electrodes on the insulating film 208 b and insulating films 218, 217 which function as dielectric films on the second oxide semiconductor film 204b And a pair of positions where the second oxide semiconductor film 204b is superimposed on the insulating film 218, 217. It has a conductive film 220 that functions as the other electrode of the electrode. That is, conductive film 220 It has the function of both a pixel electrode and a capacitive element electrode.

[0152] As mentioned above, the insulating film 208 in transistor 250 is the gate insulating film and It functions as such, and in the capacitive element 260, it functions as part of the dielectric film. 218 and 217 function as protective insulating films in transistor 250, and capacitive elements In 260, it functions as part of the dielectric film. Note that in Figures 8(A) and (B) The example given was one in which insulating films 218 and 217 are provided as part of the dielectric film, but It is not limited to this. For example, during the manufacturing process of transistor 250, the capacitive element 260 Parts of the insulating films 218 and 217 may be removed.

[0153] Furthermore, the capacitive element 260 is light-transmitting. That is, the capacitive element 260 has insulating properties. Films 216, 206, 207, 218, and 217 are each composed of a light-transmitting material. This is done. In this way, because the capacitive element 260 is light-transmitting, the transistors within the pixel Because it can be formed over a large area in regions other than where it is initially formed, the aperture ratio can be increased. A semiconductor device can be obtained that increases capacitance while maintaining this capacitance. As a result, a semiconductor device with excellent display quality can be obtained. A semiconductor device can be obtained. Also, as the capacitive element 260, the transistor 250 It can be manufactured by utilizing the manufacturing process. Therefore, semiconductor devices with low manufacturing costs can be obtained. It is possible.

[0154] Furthermore, insulating films containing at least hydrogen are used as insulating films 207 and 218. As insulating films 216, 206, and 217, insulating films containing at least oxygen are used. Sea urchin, insulating film used in transistor 250 and capacitive element 260 or transistor 250 And by making the insulating film in contact with the capacitive element 260 an insulating film with the above configuration, The first oxide semiconductor film and the second oxide semiconductor film of the zista 250 and the capacitive element 260 The resistivity of the film can be controlled.

[0155] Specifically, in transistor 250, the first oxide semiconductor film 210 is a channel To be used as a formation region, the resistivity is compared with the second oxide semiconductor films 204a and 204b. It is expensive. On the other hand, the second oxide semiconductor films 204a and 204b have the function of electrodes. It has low resistance.

[0156] Here, the first oxide semiconductor film 210 and the second oxide semiconductor films 204a, 204b The method for controlling the resistivity is explained below.

[0157] <Method 2 for controlling the resistivity of oxide semiconductors> Used in the first oxide semiconductor film 210 and the second oxide semiconductor films 204a and 204b Oxide semiconductors that can perform this function have oxygen vacancies and / or impurity concentrations such as hydrogen and water in the film. This is a semiconductor material whose resistivity can be controlled by [method]. Therefore, the first oxide semiconductor Oxygen deficiencies and / or impurities in the conductive film 210 and the second oxide semiconductor films 204a and 204b Select a process that increases the concentration of a substance, or a process that reduces oxygen deficiency and / or impurity concentration. This allows for the control of the resistivity of each oxide semiconductor.

[0158] Specifically, the second oxide semiconductor film 2 functions as the gate electrode of transistor 250. 04a, Acid used for the second oxide semiconductor film 204b which functions as an electrode for the capacitive element 260 Plasma treatment is performed on an oxide semiconductor film to increase oxygen vacancies in the oxide semiconductor film. By increasing impurities such as hydrogen and water in the oxide semiconductor film, It is possible to create an oxide semiconductor with high ion density and low resistance. In addition, hydrogen can be added to the oxide semiconductor. An insulating film containing hydrogen is formed in contact with the oxide semiconductor, and hydrogen is diffused from the hydrogen-containing insulating film to the oxide semiconductor. This allows for the creation of oxide semiconductors with high carrier density and low resistivity.

[0159] On the other hand, the first oxide semiconductor film 2 functions as a channel formation region for transistor 250. 10 is provided with insulating films 216 and 206 so as not to come into contact with the insulating film 218 containing hydrogen. The structure is such that at least one of the insulating films 216 and 206 releases oxygen. By making it a possible insulating film, oxygen can be supplied to the first oxide semiconductor film 210. The first oxide semiconductor film 210, to which oxygen has been supplied, has oxygen deficiencies in the film or at the interface filled. This results in a highly resistive oxide semiconductor. Furthermore, examples of insulating films capable of releasing oxygen include... For example, a silicon oxide film or a silicon oxide nitride film can be used.

[0160] Thus, in a semiconductor device according to one aspect of the present invention, the gate electrode of the transistor is In other words, a conductive film that functions as a conductive film and a conductive film that functions as an electrode for a capacitive element are formed simultaneously. This includes a conductive film that functions as the gate electrode of a transistor and an electrode that functions as the electrode of a capacitive element. By forming a conductive film on the same surface, manufacturing costs can be reduced. Furthermore, A conductive film that functions as the gate electrode of a transistor, and a conductive film that functions as the electrode of a capacitive element. The film has a structure that includes an oxide semiconductor film. By performing an appropriate treatment on the oxide semiconductor film, A conductive film with high conductivity and light transmission can be obtained. This can impart light transmittance to transistors and / or capacitive elements.

[0161] Here, we will provide details on the other components of the semiconductor device shown in Figures 8(A) and 8(B). The following explanation will be given.

[0162] <Insulated film> As the insulating film 216, the materials listed for the insulating film 116 in Embodiment 1 can be used. It can be formed. Also, as insulating films 206 and 207, they are the same as in Embodiment 1. It can be formed by using the materials listed in insulating films 106 and 107.

[0163] <First oxide semiconductor film and second oxide semiconductor film> The first oxide semiconductor film 210 is the first oxide semiconductor film 110a of Embodiment 1. It can be formed by using the materials listed above. Also, the second oxide semiconductor film 2 As 04a and 204b, the second oxide semiconductor films 104a and 104b of Embodiment 1 are It can be formed by using the listed materials.

[0164] <Source electrode and drain electrode> The source electrode 212a and drain electrode 212b are the source electrode 1 of Embodiment 1 It can be formed by using the materials listed for 12a and the drain electrode 112b. .

[0165] <Conductive film> As the conductive film 220, the materials listed for the conductive film 120 in Embodiment 2 can be used. It can be formed.

[0166] <Method for manufacturing a display device (modified version 2)> Next, an example of a method for manufacturing the semiconductor device shown in Figures 8(A) and 8(B) is described in Figures 9 and 1. Let's explain using 0.

[0167] First, an insulating film 216 is formed on the substrate 202, and then an oxide semiconductor film is deposited on the insulating film 216. Then, the oxide semiconductor film is patterned so that the desired region remains, and then the unnecessary parts are removed. The first oxide semiconductor film 210 is formed by etching the region (see Figure 9(A)). ).

[0168] Next, a conductive film is formed on the insulating film 216 and the first oxide semiconductor film 210, and the conductive film The desired area is patterned, and then the unwanted area is etched away. The drain electrode 212a and drain electrode 212b are formed (see Figure 9(B)).

[0169] Next, insulating film 216, first oxide semiconductor film 210, source electrode 212a, and drain An insulating film 208 containing insulating films 206 and 207 is placed on electrode 212b, and a second oxide semiconductor film Deposition of 204 (see Figure 9(C)).

[0170] Next, a resist mask is formed on the second oxide semiconductor film 204, and the second oxide semiconductor The film 204 is patterned so that the desired region remains, and then the unwanted region is etched away. This forms the second oxide semiconductor films 204a and 204b. The insulating films 206 and 207 beneath the conductive films 204a and 204b are also etched simultaneously, separating into island-like segments. These are the separated insulating films 206 and 207 (see Figure 9(D)).

[0171] Next, the insulating film 216, the source electrode 212a, the drain electrode 212b, and the second oxide Insulating films 218 and 217 are formed on semiconductor films 204a and 204b (see Figure 10(A)). .

[0172] Next, a resist mask is formed on the insulating film 217, and the desired regions of the insulating films 218 and 217 are formed. The pattern is created so that the desired area remains, and then the unnecessary area is etched away to create the 240 opening. Form it. Note that the opening 240 is formed so as to reach the drain electrode 212b. See Figure 10(B).

[0173] Next, a conductive film is formed on the insulating film 217 so as to cover the opening 240, and a resist is applied to the conductive film. A mask is formed, and the conductive film is patterned so that the desired area remains, and then the unwanted area is removed. The conductive film 220 is formed by etching (see Figure 10(C)).

[0174] Through the above process, the transistor 250 and the capacitive element 260 are formed on the same substrate. It is possible.

[0175] The configurations and methods described in this embodiment are similar to those described in other embodiments. They can be used in combination as appropriate.

[0176] (Embodiment 5) In this embodiment, the semiconductor device according to one aspect of the present invention is the semiconductor shown in Embodiment 1. A modified example of the apparatus will be explained using Figure 11.

[0177] <Example of semiconductor device configuration (modification 4)> The semiconductor device shown in Figure 11(A) includes the transistor 150 and capacitance element shown in Embodiment 1. The first oxide semiconductor films 110a and 110b of the child 160 are oxide multilayer films 410a and 410 The configuration is b. Therefore, the other components are transistor 150 and capacitive element 1 It is the same as 60, and a detailed explanation will be omitted.

[0178] Details of the oxide multilayer films 410a and 410b are described below.

[0179] The oxide multilayer films 410a and 410b consist of oxide semiconductor films 420a and 420b, and oxide film It has 422a, 422b and . In the following description, the oxide semiconductor film 420 a and 420b are oxide semiconductor film 420, and oxide films 422a and 422b are oxide film 422. Each will be written and explained.

[0180] The oxide semiconductor film 420 and the oxide film 422 have at least one identical constituent element. It is preferable to use a metal oxide. Alternatively, an oxide semiconductor film 420 and an oxide film 42 The constituent elements of 2 may be the same, but the compositions of the two may be different.

[0181] Oxide semiconductor film 420 is In-M-Zn oxide (M is Al, Ti, Ga, Y, Zr, L) In the case of a (representing Ce, Nd, Sn, or Hf), to form an In-M-Zn oxide film The atomic ratio of the metal elements in the sputtering target used satisfies In≧M and Zn≧M. It is preferable that the atomic ratio of the metal elements in such a sputtering target be, In:M:Zn=1:1:1, In:M:Zn=5:5:6(1:1:1.2), In: A ratio of M:Zn=3:1:2 is preferred. These represent the atomic ratio of the metal elements contained in the sputtering target mentioned above, as an error. This includes fluctuations of plus or minus 20%.

[0182] Furthermore, when the oxide semiconductor film 420 is an In-M-Zn oxide, the sum of In and M is When assumed to be 100 atomic%, the atomic ratio of In to M is preferably 25 at for In. 0% or more, M is less than 75 atomic%, and more preferably In is 34 atomic c% or greater, and M less than 66 atomic%.

[0183] The oxide semiconductor film 420 has an energy gap of 2 eV or more, preferably 2.5 eV or less. More preferably, it is 3 eV or more. Thus, oxide semiconductors with a wide energy gap By using a conductor, the off-current of the transistor can be reduced.

[0184] The thickness of the oxide semiconductor film 420 is 3 nm or more and 200 nm or less, preferably 3 nm or more. The wavelength should be 00 nm or less, and more preferably 3 nm to 50 nm.

[0185] Oxide films 422 are typically In-Ga oxide, In-Zn oxide, and In-MZ oxide. n oxide (where M represents Al, Ti, Ga, Y, Zr, La, Ce, Nd, Sn, or Hf) ) and the energy at the lower end of the conduction band is closer to the vacuum level than that of the oxide semiconductor film 420. Typically, the energy at the lower end of the conduction band of the oxide film 422 and the energy of the oxide semiconductor film 420 The energy difference from the lower end of the conduction band is 0.05 eV or more, 0.07 eV or more, and 0.1 eV. Above, or 0.15 eV or more and 2 eV or less, 1 eV or less, 0.5 eV or less, It is 0.4 eV or less. That is, the electron affinity of the oxide film 422 and the oxide semiconductor film 420 The difference from electron affinity is 0.05 eV or greater, 0.07 eV or greater, 0.1 eV or greater, or 0. 0.15eV or higher, and 2eV or lower, 1eV or lower, 0.5eV or lower, or 0.4eV or lower That is the case.

[0186] The oxide film 422 has the above element M in a higher atomic ratio than In, resulting in the following effects. (1) The energy gap of the oxide film 422 is increased. (2) (3) Reduce the electron affinity of the oxide film 422. (4) Shield against external impurities. Compared to oxide semiconductor film 420, it has higher insulating properties. Also, element M has a strong bonding force with oxygen. Because it is a strong metallic element, having M in a higher atomic ratio than In prevents oxygen deficiency. It becomes harder.

[0187] When oxide film 422 is In-M-Zn oxide, the sum of In and M is 100ato When expressed as mic%, the atomic ratio of In to M is preferably such that In is 50 atomic%. Less than , M is 50 atomic% or more, and more preferably In is less than 25 atomic%. M is set to 75% or higher.

[0188] Furthermore, the oxide semiconductor film 420 and the oxide film 422 are In-M-Zn oxide (where M is Al In the case of (representing Ti, Ga, Y, Zr, La, Ce, Nd, Sn or Hf), oxide semi-oxides Compared to the conductive film 420, the atomic ratio of M contained in the oxide film 422 is larger, and typically Compared to the atoms contained in the oxide semiconductor film 420, the amount is 1.5 times or more, preferably 2 times. More preferably, the atomic ratio is three times higher or more.

[0189] Furthermore, the oxide film 422 is In:M:Zn=x1:y1:z1 [atomic ratio], and the oxide semiconductor If the body membrane 420 is In:M:Zn=x2:y2:z2 [atomic ratio], then y1 / x1 is y It is greater than 2 / x², and preferably y1 / x1 is 1.5 times or more than y2 / x². More preferably, y1 / x1 is at least twice as large as y2 / x2, more preferably, y1 / x1 is more than 3 times larger than y2 / x2. At this time, the oxide semiconductor film 420 is Therefore, if y2 is greater than or equal to x2, the transistor using an oxide semiconductor will have stable electrical characteristics. This is preferable because it can be applied. However, if y2 is 3 times or more than x2, an oxide semiconductor is used. Because the field-effect mobility of the transistor decreases, y2 is less than 3 times x2. preferable.

[0190] When the oxide semiconductor film 420 and the oxide film 422 are In-M-Zn oxide, In-M- The atomic ratio of metal elements in the sputtering target used to deposit Zn oxide films is: It is preferable that M > In and Zn ≥ M be satisfied. Gold sputtering target such As for the atomic ratio of the group elements, In:Ga:Zn=1:3:2, In:Ga:Zn=1:3: 3, In:Ga:Zn=1:3:4, In:Ga:Zn=1:3:5, In:Ga:Zn =1:3:6, In:Ga:Zn=1:3:7, In:Ga:Zn=1:3:8, In: Ga:Zn=1:3:9, In:Ga:Zn=1:3:10, In:Ga:Zn=1:6 :4, In:Ga:Zn=1:6:5, In:Ga:Zn=1:6:6, In:Ga:Z n=1:6:7, In:Ga:Zn=1:6:8, In:Ga:Zn=1:6:9, In A Ga:Zn ratio of 1:6:10 is preferred. Furthermore, using the above sputtering target... The atomic ratio of metal elements contained in the deposited oxide semiconductor film 420 and oxide film 422 is Each of these involves an error in the atomic ratio of the metal elements contained in the sputtering target. Includes fluctuations of -20%.

[0191] Furthermore, this is not limited to the semiconductor characteristics and electrical characteristics (field effect) of the transistor as needed. A suitable composition should be used depending on the fruit mobility, threshold voltage, etc. To obtain the semiconductor characteristics of the transistor, the carrier density and impurities of the oxide semiconductor film 420 are important. The concentration of the material, defect density, atomic ratio of metal elements to oxygen, interatomic distance, density, etc., should be appropriate. It is preferable.

[0192] The oxide film 422 is acid-resistant when forming the insulating film 114 or insulating film 116 that will be formed later. It also functions as a damage mitigation film for the oxide semiconductor film 420. The thickness of the oxide film 422 is 3 The wavelength is between 100 nm and 3 nm and 50 nm, preferably between 3 nm and 50 nm.

[0193] In the oxide semiconductor film 420, silicon and carbon, which are among the Group 14 elements, are included. As a result, oxygen vacancies increase in the oxide semiconductor film 420, causing it to become n-type. Therefore, acid The concentration of silicon and carbon in the oxide semiconductor film 420, or the oxide film 422 and the oxide semiconductor film 420. The concentration of silicon and carbon near the interface with the conductive film 420 (obtained by secondary ion mass spectrometry) (The concentration) is 2 × 10 18 atoms / cm 3 The following is preferably 2 × 10 17 atoms / cm 3 The following applies:

[0194] Furthermore, in the oxide semiconductor film 420, alkali obtained by secondary ion mass spectrometry is also used. The concentration of metal or alkaline earth metal is 1 × 10⁻⁶ 18 atoms / cm 3 The following are preferable is 2 × 10 16 atoms / cm 3 The following applies: Alkali metals and alkaline earth metals are: When combined with oxide semiconductors, it can generate carriers, increasing the transistor's off-current. This can sometimes happen. For this reason, alkali metal or alkali in oxide semiconductor film 420 It is preferable to reduce the concentration of earth metals.

[0195] Furthermore, if nitrogen is present in the oxide semiconductor film 420, electrons, which act as carriers, are generated, Carrier density increases, making it easier to create an n-type semiconductor. As a result, oxide semiconductors containing nitrogen are used. Transistors that have been treated tend to exhibit normally-on characteristics. Therefore, the oxide semiconductor film 420 In this process, it is preferable that nitrogen is reduced as much as possible, for example, by secondary ion mass spectrometry. The nitrogen concentration obtained by this method is 5 × 10 18atoms / cm 3 It is preferable to do the following: stomach.

[0196] Furthermore, the oxide semiconductor film 420 and the oxide film 422 are not simply stacked layers, but rather connected. A junction (in this case, a structure in which the energy at the lower end of the conduction band changes continuously between each film) It is fabricated so that it is formed. That is, at the interface of each film, for the oxide semiconductor, Lamination without impurities that form defect levels such as hop centers or recombination centers. Let's assume that there are impurities between the stacked oxide semiconductor films 420 and 422. When they are mixed, the continuity of the energy bands is lost, and carriers are trapped at the interface. Alternatively, they might recombine and disappear.

[0197] To form continuous bonding, a multi-chamber type film deposition system equipped with a load lock chamber is required. By using a sputtering device, each film is continuously layered without being exposed to the atmosphere. This is necessary. Each chamber in the sputtering apparatus is for the oxide semiconductor film To remove impurities such as water as much as possible, an adsorption-type vacuum pump such as a cryopump is used. Using a pump to perform high vacuum evacuation (5×10 -7 Pa~1×10 -4 It is preferable to do so (up to approximately Pa). Alternatively, a turbomolecular pump and a cold trap can be combined to run the exhaust system from the chamber. - It is preferable to prevent gases, especially those containing carbon or hydrogen, from flowing back into the container. .

[0198] Here, the band structure of the oxide multilayer film will be explained using Figure 11(B).

[0199] Figure 11(B) shows a portion of the band structure of the oxide multilayer film and the insulating film in contact with the oxide multilayer film. This is shown schematically. Here, silicon oxide films are used as insulating film 107 and insulating film 114. The case where this is provided will be explained. Note that EcI1 shown in Figure 11(B) is the insulating film 107. This shows the energy at the lower end of the conduction band of the silicon oxide film used, where EcS1 is for the oxide semiconductor film 42 EcS2 represents the energy at the lower end of the conduction band for oxide film 422. This indicates that EcI2 is the energy at the lower end of the conduction band of the silicon oxide film used as the insulating film 114. — indicates.

[0200] As shown in Figure 11(B), in oxide semiconductor film 420 and oxide film 422, conduction The energy at the bottom of the belt changes smoothly without any barriers. In other words, it changes continuously. It can also be said that the oxide semiconductor film 420 and the oxide film 422 contain common elements. Furthermore, oxygen moves between the oxide semiconductor film 420 and the oxide film 422, causing mixing. This can be attributed to the formation of layers.

[0201] As shown in Figure 11(B), the oxide semiconductor film 420 becomes a well, and the channel region is acid It can be seen that it is formed on the oxide semiconductor film 420. Note that the oxide semiconductor film 420 and the oxide Because the energy at the lower end of the conduction band of film 422 is continuously changing, oxide semiconductor film 42 It could also be said that 0 and the oxide film 422 are continuously bonded together.

[0202] Furthermore, as shown in Figure 11(B), near the interface between the oxide film 422 and the insulating film 114 Tracking caused by impurities or defects in silicon or carbon, which are constituent elements of the insulating film 114. Although a PU level may be formed, the oxide film 422 is provided, thus the oxide semiconductor film 420 and the trap level can be kept apart. However, the distance between EcS1 and EcS2 When the energy difference is small, electrons in the oxide semiconductor film 420 exceed the energy difference and trap... The electrons can reach the trap level. When electrons are trapped at the trap level, a mycelium is created at the insulating film interface. A fixed charge is generated in the eggplant, causing the transistor's threshold voltage to shift in the positive direction. Therefore, the energy difference between EcS1 and EcS2 should be 0.1 eV or greater, preferably 0. Setting it to 15eV or higher reduces fluctuations in the transistor's threshold voltage, resulting in stable electrical characteristics. It is suitable because it is of a certain nature.

[0203] The configurations and methods described in this embodiment are similar to those described in other embodiments. They can be used in combination as appropriate.

[0204] (Embodiment 6) In this embodiment, the present invention is applicable to transistors and capacitive elements of a semiconductor device according to one aspect of the present invention. An example of a capable oxide semiconductor film will be described.

[0205] <Crystallization of oxide semiconductor films> The structure of oxide semiconductor films will be described below.

[0206] 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.

[0207] First, let's explain the CAAC-OS membrane.

[0208] CAAC-OS film is an oxide semiconductor film having multiple c-axis oriented crystalline regions. .

[0209] 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.

[0210] 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.

[0211] 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.

[0212] 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 happening.

[0213] 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°.

[0214] Furthermore, most of the crystalline parts contained in the CAAC-OS film are cubes with sides less than 100 nm long. It is small enough to fit inside the body. Therefore, the crystalline portion contained in the CAAC-OS membrane has sides of 10. This also includes cases where the size is less than nm, less than 5 nm, or less than 3 nm and fits within a cube. Furthermore, multiple crystalline regions contained in the CAAC-OS film connect to form one large crystalline region. A region may be formed. For example, in a planar TEM image, at 2500 nm 2 Above 5μm 2 or greater than 1000 μm 2 In some cases, crystal regions exceeding the above size may be observed.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] 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.

[0219] Furthermore, the distribution of c-axis oriented crystalline regions in the CAAC-OS film does not need to be uniform. For example, the crystalline portion of the CAAC-OS film may be formed by crystal growth from near the top surface of the CAAC-OS film. When formed in this manner, the region near the top surface will have a more c-axis-oriented crystal structure than the region near the surface being formed. The proportion of impurities can increase. Also, when impurities are added to the CAAC-OS film, impurities may occur. The region where the substance is added undergoes alteration, forming regions with a different proportion of partially c-axis-oriented crystals. It can happen.

[0220] 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 may occur. Peaks near 2θ of 36° indicate c-axis orientation in a portion of the CAAC-OS film. This indicates the presence of crystals that do not possess properties. The CAAC-OS film has a 2θ of approximately 31°. It is preferable that a peak is shown and that no peak is shown near 36° for 2θ.

[0221] 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.

[0222] 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.

[0223] 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.

[0224] Furthermore, transistors using CAAC-OS films exhibit electrical properties when irradiated with visible light or ultraviolet light. Sexual variation is small.

[0225] Next, we will explain microcrystalline oxide semiconductor films.

[0226] Microcrystalline oxide semiconductor films can be clearly observed using TEM. In some cases, this may not be possible. The crystalline portion contained in the microcrystalline oxide semiconductor film is between 1 nm and 100 nm. They are often smaller than 1 nm, or between 1 nm and 10 nm in size. In particular, between 1 nm and 10 nm Nanocrystals (nc: nanocrystals) are microcrystals of a size of 1 nm or less, or between 1 nm and 3 nm. An oxide semiconductor film having tal is made nc-OS (nanocrystalline O It is called an xide Semiconductor film. Also, an nc-OS film is, for example, T In some cases, grain boundaries may not be clearly visible in images obtained using EM (Electromagnetic Wave) imaging.

[0227] nc-OS films are used in minute regions (for example, regions between 1 nm and 10 nm, especially regions between 1 nm and 10 nm). The atomic arrangement has periodicity in the region of 3 nm or less. In addition, the nc-OS film is different There is no regularity in the crystal orientation between the crystalline regions. Therefore, no orientation is observed throughout the film. Therefore, depending on the analytical method, nc-OS films may be indistinguishable from amorphous oxide semiconductor films. There are cases where this occurs. For example, XRD using X-rays with a diameter larger than that of the crystalline region on an nc-OS film. When structural analysis is performed using the apparatus, the out-of-plane method analyzes the crystal planes. The indicated peak is not detected. Also, the probe diameter is larger than that of the crystalline region in the nc-OS film. Electron diffraction (also called limited-field electron diffraction) using electron beams (for example, 50 nm or longer). When this is done, a diffraction pattern resembling a halo pattern is observed. On the other hand, when applied to an nc-OS film... Furthermore, the probe diameter should be close to or smaller than the size of the crystal (for example, 1 nm to 30 nm). When electron diffraction (also called nanobeam electron diffraction) is performed using the electron beam shown below, spots A circular pattern is observed. Furthermore, when nanobeam electron diffraction is performed on the nc-OS film, a circular pattern is observed. In some cases, a ring-shaped region of high brightness may be observed. Also, compared to the nc-OS film... When nanobeam electron diffraction is performed, multiple spots may be observed within a ring-shaped region. be.

[0228] nc-OS films are oxide semiconductor films with higher orderliness than amorphous oxide semiconductor films. Therefore, nc-OS films have a lower defect level density than amorphous oxide semiconductor films. However, Furthermore, the nc-OS film does not show any regularity in crystal orientation between different crystalline regions. Therefore, nc- OS films have a higher defect level density compared to CAAC-OS films.

[0229] Note that oxide semiconductor films include, for example, amorphous oxide semiconductor films, microcrystalline oxide semiconductor films, and C The AAC-OS film may be a multilayer film having two or more types.

[0230] The oxide semiconductor film included in the transistor and capacitive element of a semiconductor device according to one embodiment of the present invention is Any of the above-mentioned crystalline states of oxide semiconductor films may be applied. Furthermore, a multilayer structure of oxides may also be used. If a semiconductor film is included, the crystalline state of each oxide semiconductor film may be different. However, A CAAC-OS film is applied to the oxide semiconductor film that functions as the channel region of the DISTA. Preferably, the oxide semiconductor film that functions as an electrode for the capacitive element is a transistor Because the impurity concentration is higher than that of the oxide semiconductor film contained within, crystallinity may be reduced.

[0231] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments. It is possible.

[0232] (Embodiment 7) In this embodiment, a display device using a semiconductor device according to one aspect of the present invention is shown in Figure 12. The following will be explained using these reference numerals. Note that parts with the same functions as those shown in Embodiment 1 will use the same reference numerals. I've added a note, and I'll omit the detailed explanation.

[0233] The display device shown in Figure 12(A) has a region having pixels of the display element (hereinafter referred to as the pixel portion 302 and ( ) and a circuit section ( ) which is located outside the pixel section 302 and has a circuit for driving the pixels. Hereinafter referred to as the drive circuit section 304, and a circuit that has a function to protect the element (hereinafter referred to as the protection circuit 304) It has a (6) and a terminal section 307. Note that the protection circuit 306 is not provided. That's fine.

[0234] Part or all of the drive circuit section 304 is formed on the same substrate as the pixel section 302. This is desirable. This allows for a reduction in the number of components and terminals. Drive circuit section 304 If part or all of it is not formed on the same substrate as the pixel section 302, the drive cycle Part or all of the road section 304 is COG (Chip On Glass) or TAB (T This can be implemented using APE (Automated Bonding).

[0235] The pixel section 302 is arranged in X rows (where X is a natural number greater than or equal to 2) and Y columns (where Y is a natural number greater than or equal to 2). It has a circuit for driving multiple display elements (hereinafter referred to as the pixel circuit 301), and the drive cycle The path section 304 is a circuit that outputs a signal (scan signal) for selecting pixels (hereinafter referred to as a gate driver). 304a) is used to supply signals (data signals) for driving the pixel display elements. It has a drive circuit such as the circuit (hereinafter referred to as source driver 304b).

[0236] The gate driver 304a has a shift register, etc. The gate driver 304a is A signal to drive the shift register is input via terminal 307, and the signal is output. For example, the gate driver 304a receives a start pulse signal, a clock signal, etc. The gate driver 304a outputs a pulse signal. The scanning signal is applied to the wiring (and It has the function of controlling the potential of the scan lines (referred to as GL_1 to GL_X) below. Multiple drivers 304a are provided, and multiple gate drivers 304a are used to control the scan line GL_1 The signal to GL_X may be divided and controlled. Alternatively, the gate driver 304a may use an initialization signal. It has the function of supplying, however, the gate driver 30 4a can also supply another signal.

[0237] The source driver 304b has a shift register, etc. The source driver 304b Through terminal 307, in addition to signals for driving the shift register, the data signals are generated. A signal (image signal) is input. The source driver 304b uses the image signal to create a pixel circuit. It has the function of generating data signals to write to 301. Also, source driver 304b The data signal is transmitted according to the pulse signal obtained by inputting the start pulse, clock signal, etc. It has the function of controlling the output of the number. In addition, the source driver 304b is given a data signal. It has the function of controlling the potential of the wiring (hereinafter referred to as data lines DL_1 to DL_Y). Alternatively, source driver 304b may have the ability to supply initialization signals. However, this is not limited to the source driver 304b, which may also supply other signals. It is possible.

[0238] The source driver 304b is configured using, for example, multiple analog switches. The source driver 304b sequentially turns on multiple analog switches, The image signal can be time-divided and output as a data signal. It can also use shift registers, etc. You may use this to configure source driver 304b.

[0239] Each of the multiple pixel circuits 301 receives a scan signal from one of the multiple scan lines GL. A pulse signal is input via one of several data lines DL to which a data signal is supplied. A data signal is input. Also, each of the multiple pixel circuits 301 is a gate driver 304a controls the writing and retention of data in the data signal. For example, m rows and n columns. The pixel circuit 301 of the eye is connected to the gate driver via the scan line GL_m (where m is a natural number less than or equal to X). A pulse signal is input from 304a, and the data line DL_n( A data signal is input from the source driver 304b via n (where n is a natural number less than or equal to Y).

[0240] The protection circuit 306 shown in Figure 12(A) is, for example, a gate driver 304a and a pixel circuit 3 It is connected to scan line GL, which is the wiring between 01. Alternatively, the protection circuit 306 is connected to source driver It is connected to the data line DL, which is the wiring between the light bar 304b and the pixel circuit 301. Alternatively, The protection circuit 306 is connected to the wiring between the gate driver 304a and the terminal section 307. Yes, it is possible. Alternatively, the protection circuit 306 provides a connection between the source driver 304b and the terminal section 307. It can be connected to a wire. The terminal section 307 is used to supply power and to the display device from an external circuit. This refers to the part equipped with terminals for inputting control signals and image signals.

[0241] The protection circuit 306, when a potential outside a certain range is applied to the wiring to which it is connected, This is a circuit that creates a conductive state between two wires.

[0242] As shown in Figure 12(A), the pixel section 302 and the drive circuit section 304 each have a protection circuit 30 By providing 6, ESD (Electrostatic Discharge: This can improve the resistance of display devices to overcurrents generated by electrostatic discharge, etc. However, the configuration of the protection circuit 306 is not limited to this, for example, the gate driver 304a Configuration with protection circuit 306 connected, or with protection circuit 306 connected to source driver 304b. This configuration is also possible. Alternatively, a configuration in which the protection circuit 306 is connected to the terminal section 307. It can also be done this way.

[0243] Furthermore, in Figure 12(A), the gate driver 304a and the source driver 304b are Therefore, although an example showing the formation of the drive circuit section 304 is shown, the configuration is not limited to this. For example, only the gate driver 304a is formed, and a separately prepared source driver circuit is formed. A substrate (for example, a drive circuit substrate formed from a single-crystal semiconductor film or a polycrystalline semiconductor film) is put into practice. It can also be used as a mounting configuration.

[0244] Furthermore, the multiple pixel circuits 301 shown in Figure 12(A) have, for example, the configuration shown in Figure 12(B). It can be done this way.

[0245] The pixel circuit 301 shown in Figure 12(B) consists of a liquid crystal element 370, a transistor 150, and It has a capacitance element 160. Note that the transistor 150 and the capacitance element 160 are of the same nature as in the embodiment. A semiconductor device with the configuration shown in Figure 1, which is part of Embodiment 1, can be used.

[0246] The potential of one of the pair of electrodes of the liquid crystal element 370 is set appropriately according to the specifications of the pixel circuit 301. The orientation state of the liquid crystal element 370 is set according to the data being written to it. A common potential is set on one of the pairs of electrodes of the liquid crystal element 370 that each of the pixel circuits 301 possesses. (Common potential) may be applied. Also, a pair of liquid crystal elements 370 of the pixel circuit 301 in each row One of the electrodes may be given a different potential.

[0247] For example, the driving method for a display device equipped with a liquid crystal element 370 is TN mode, STN mode Code, VA mode, ASM (Axially Symmetric Aligned Motor) icro-cell) mode, OCB (Optically Compensated Birefringence mode, FLC (Ferroelectric Liqu id Crystal) mode, AFLC (AntiFerroelectric Li) quid Crystal) mode, MVA mode, PVA (Patterned Ve (Critical Alignment) mode, IPS mode, FFS mode, or TBA You may also use modes such as (Transverse Bend Alignment). In addition, as a method of driving the display device, there is also ECB (Electric Ally Controlled Birefringence) mode, PDLC (P Olymer Dispersed Liquid Crystal (PNLC) mode, (Polymer Network Liquid Crystal) mode, guest host There are modes such as St Mode. However, this is not limited to these, and various types of liquid crystal elements and their driving methods exist. Various materials can be used.

[0248] Furthermore, a liquid crystal composition containing a liquid crystal exhibiting a blue phase and a chiral agent. The liquid crystal element may be constructed in this manner. The liquid crystal exhibiting the blue phase has a response speed of 1 msec or less. It is short. Furthermore, since the liquid crystal exhibiting the blue phase is optically isotropic, alignment processing is unnecessary. Furthermore, it has low dependence on the field of view.

[0249] In the pixel circuit 301 of row m and column n, the source electrode or drain electrode of transistor 150 One electrode is electrically connected to the data line DL_n, and the other is connected to a pair of liquid crystal elements 370. It is electrically connected to the other electrode. Also, the gate electrode of transistor 150 is connected to the scan line G It is electrically connected to L_m. Transistor 150 can be in an on state or an off state. This provides a function to control the writing of data to the data signal.

[0250] One of the pair of electrodes of the capacitive element 160 is connected to a wiring to which a potential is supplied (hereinafter referred to as the potential supply line VL). ) is electrically connected to the other end, and the other end is electrically connected to the other of the pair of electrodes of the liquid crystal element 370. The potential value of the potential supply line VL is set appropriately according to the specifications of the pixel circuit 301. The capacitive element 160 functions as a holding capacitor for storing the written data.

[0251] For example, in a display device having the pixel circuit 301 shown in Figure 12(A), the gate driver 304 By a, the pixel circuits 301 of each row are sequentially selected, and the transistor 150 is turned ON to data Write the data for the signal.

[0252] When data is written to the pixel circuit 301, the transistor 150 turns off. The image is then held. By performing this process row by row, the image can be displayed.

[0253] Although an example using a liquid crystal element 370 as the display element has been shown, the embodiments of the present invention are as follows: This is not the only possible aspect of this.

[0254] For example, in this specification, etc., display element, display device having a display element, light emission Light-emitting devices, which are devices having elements and light-emitting elements, can take various forms or various shapes. It can have such elements. Examples of display elements, display devices, light-emitting elements, or light-emitting devices include EL (electroluminescent) elements (EL elements including organic and inorganic materials, organic E L elements, inorganic EL elements), LEDs (white LEDs, red LEDs, green LEDs, blue LEDs, etc.) (,), transistor (a transistor that emits light in response to current), electron emission element, liquid crystal element, Electronic ink, electrophoretic elements, grating light bulbs (GLV), plasma displays Ray (PDP), MEMS (Micro-Electro-Mechanical Systems), Digital Micromirror devices (DMD), DMS (Digital Microshutter), IM OD (Interference Modulation) element, electrowetting element Piezoelectric ceramic displays, carbon nanotubes, etc., are generated by electromagnetic interaction. Some display media have properties such as contrast, brightness, reflectance, and transmittance that change. (EL) An example of a display device using an element is an EL display. Examples of such display devices include field emission displays (FEDs) or SEs. D-type flat-panel display (SED: Surface-conduction Electric) Examples include tron-emitter displays. One example is a liquid crystal display (transmissive liquid crystal display, semi-transmissive liquid crystal display). (Reflective liquid crystal displays, direct-view liquid crystal displays, projection liquid crystal displays, etc.) Yes, there are. An example of a display device using electronic ink or electrophoretic elements is electronic paper. There is.

[0255] Figure 21 shows an example where a liquid crystal element is used as the display element. The substrate 102a has a common power A electrode 124 is provided. And between the common electrode 124 and the conductive film 120 is a liquid crystal layer. 123 is provided.

[0256] Alternatively, an example in which a light-emitting element is used as a display element is shown in Figure 22. An insulating film 132, an emissive layer 125, and a common electrode 124 are provided.

[0257] The configuration shown in this embodiment may be used in appropriate combination with the configurations shown in other embodiments. It is possible.

[0258] (Embodiment 8) In this embodiment, a display module and electronic equipment using a semiconductor device according to one aspect of the present invention are provided. This will be explained using Figures 13 and 14.

[0259] The display module 8000 shown in Figure 13 consists of an upper cover 8001 and a lower cover 8002. In between, the touch panel 8004 connected to the FPC8003 and the FPC8005 are connected. Display panel 8006, backlight unit 8007, frame 8009, printed circuit board It has a board 8010 and a battery 8011.

[0260] A semiconductor device according to one aspect of the present invention can be used, for example, as a display panel 8006.

[0261] The upper cover 8001 and the lower cover 8002 are the touch panel 8004 and the display panel. The shape and dimensions can be appropriately modified to match the size of the 8006.

[0262] The touch panel 8004 is a display panel using either a resistive or capacitive touch panel. It can be used superimposed on 8006. Also, the opposing substrate (sealing substrate) of the display panel 8006 It is also possible to give the board a touch panel function. It is also possible to install a light sensor in each pixel of 006 to create an optical touch panel.

[0263] The backlight unit 8007 has a light source 8008. The light source 8008 is a backlight It may also be configured to use a light-diffusing plate, which is provided at the end of the light unit 8007.

[0264] Frame 8009 provides protection for the display panel 8006, as well as the movement of the printed circuit board 8010. It has the function of an electromagnetic shield to block electromagnetic waves generated by the operation. The 8009 may also function as a heat sink.

[0265] The printed circuit board 8010 contains power supply circuits and signals for outputting video and clock signals. It has a power processing circuit. The power supply that provides power to the power supply circuit is an external commercial power supply. Alternatively, a separate power source, battery 8011, may also be used. Item 1 can be omitted when using commercial power.

[0266] Furthermore, the display module 8000 includes components such as polarizing plates, phase difference plates, and prism sheets. They may also be provided.

[0267] Figures 14(A) through 14(H) show electronic devices. These electronic devices are enclosed in a casing. Body 5000, display unit 5001, speaker 5003, LED lamp 5004, operation keys 50 05 (including power switch or operation switch), connection terminal 5006, sensor 5007 ( Force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances , sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor It may have a microphone 5008 (or a device that includes a function to measure infrared rays), etc. can.

[0268] Figure 14(A) shows a mobile computer, and in addition to the above, it also has a switch 5009 It may have an infrared port 5010, etc. Figure 14(B) shows a portable recording device equipped with a recording medium. A strip-type image playback device (for example, a DVD player), and in addition to those mentioned above, see Table 2. It may have a display unit 5002, a recording medium reading unit 5011, etc. Figure 14(C) is a Go It is a group-type display, and in addition to the above, it includes a second display unit 5002 and a support unit 5012 It may have earphones 5013, etc. Figure 14(D) is a portable gaming machine, and above In addition to those described above, it may also have a recording medium reading unit 5011, etc. Figure 14(E) It is a digital camera with a television receiving function, and in addition to the above, it has an antenna 5014, It may have a shutter button 5015, an image receiving unit 5016, etc. Figure 14(F) is a portable It is a band-type gaming machine, and in addition to the above, it also has a second display unit 5002 and a recording medium reading unit 5011. , etc. Figure 14(G) is a television receiver, and in addition to the above, It may have a tuner, an image processing unit, etc. Figure 14(H) shows a portable television receiver. It is a device that, in addition to the above-mentioned components, includes a charger 5017 capable of transmitting and receiving signals, etc. It is possible.

[0269] The electronic devices shown in Figures 14(A) to 14(H) can have a variety of functions. For example, a function that displays various information (still images, videos, text images, etc.) on the display unit, Panel functions, calendar, date or time display functions, various software ( A function that controls processing by program, wireless communication function, and various functions using wireless communication function. Functions to connect to computer networks, and to transmit various data using wireless communication functions or The function of receiving data, reading programs or data recorded on the recording medium and displaying them on the display unit. It can have a display function, etc. Furthermore, in electronic devices having multiple display units In this system, one display unit primarily displays image information, and another display unit primarily displays text information. A function to display a three-dimensional image, or by displaying images that take parallax into account on multiple display units. It can have functions such as displaying images. Furthermore, in electronic devices having an image receiving unit... For example, it has functions for taking still images, recording videos, and automatically or manually enhancing the captured images. Correction function, function to save captured images to a recording medium (external or built into the camera), capture It can have functions such as displaying the image on the display unit. The functions that electronic devices shown in 4(H) may have are not limited to these, and may include a variety of functions. It is possible to have.

[0270] The electronic device described in this embodiment has a display unit for displaying some kind of information. It is characterized by the following.

[0271] The configuration shown in this embodiment may be used in appropriate combination with the configurations shown in other embodiments. It is possible. [Explanation of Symbols]

[0272] 102 circuit boards 102a substrate 104a Oxide semiconductor film 104b oxide semiconductor film 106 Insulating film 107 Insulating Film 108 Insulating Film 110a Oxide semiconductor film 110b oxide semiconductor film 112a Source electrode 112b Drain electrode 114 Insulating Film 116 Insulating film 118 Insulating Film 118a Insulated film 120 Conductive film 120a conductive film 121 Conductive film 121a Conductive film 122 Insulating film 132 Insulating film 140 Aperture 142 Aperture 150 transistors 151 transistors 152 transistors 160 Capacitive elements 161 Capacitive elements 162 Capacitive elements 202 circuit boards 204 oxide semiconductor film 204a oxide semiconductor film 204b oxide semiconductor film 206 Insulating film 207 Insulating film 208 Insulating film 210 Oxide semiconductor film 212a Source electrode 212b Drain electrode 216 Insulating film 217 Insulating film 218 Insulating film 220 Conductive film 240 aperture 250 transistors 260 Capacitive elements 301 Pixel Circuit 302 pixel section 304 Drive Circuit Section 304a Gate Driver 304b Source Driver 306 Protection circuit 307 Terminal section 370 liquid crystal elements 410a oxide multilayer film 410b oxide multilayer film 420 Oxide Semiconductor Film 420a Oxide Semiconductor Film 420b oxide semiconductor film 422 Oxide film 422a Oxide film 422b Oxide film 5000 cabinets 5001 Display section 5002 Display section 5003 Speaker 5004 LED Lamp 5005 Operation Keys 5006 Connection terminal 5007 Sensor 5008 Microphone 5009 Switch 5010 Infrared Port 5011 Recording medium reading unit 5012 Support part 5013 Earphones 5014 Antenna 5015 Shutter button 5016 Image receiving unit 5017 charger 8000 Display Module 8001 Top cover 8002 Lower cover 8003 FPC 8004 Touch Panel 8005 FPC 8006 Display Panel 8007 Backlight Unit 8008 light source 8009 Frame 8010 Printed Circuit Board 8011 Battery

Claims

1. A transistor, a capacitive element, and a display element are provided in at least one pixel. The source electrode or drain electrode of the transistor is always in electrical contact with the pixel electrode of the display element. A display device in which one of the source electrode or drain electrode of the transistor is always in electrical contact with one electrode of the capacitive element, A first conductive film having a region positioned above the insulating surface and functioning as one electrode of the capacitive element, A first insulating film having a region positioned above the first conductive film and functioning as a gate insulating film of the transistor, A first oxide semiconductor film having a region positioned above the first insulating film and having the channel region of the transistor, A second oxide semiconductor film having a region positioned above the first insulating film and functioning as the other electrode of the capacitive element, A second insulating film having a region in contact with the upper surface of the first oxide semiconductor film and a region in contact with the upper surface of the second oxide semiconductor film, A second conductive film having the function of either the source electrode or the drain electrode of the transistor, A third insulating film having a region positioned above the first oxide semiconductor film, a region positioned above the second oxide semiconductor film, a region positioned above the second conductive film, and a region in contact with the upper surface of the second insulating film, A third conductive film having a region positioned above the third insulating film and functioning as the pixel electrode, The second oxide semiconductor film is not electrically connected to the third conductive film. The upper surface of the second oxide semiconductor film has a region in contact with the second insulating film and a region in contact with the third insulating film. Display device.

2. A transistor, a capacitive element, and a display element are provided in at least one pixel. The source electrode or drain electrode of the transistor is always in electrical contact with the pixel electrode of the display element. A display device in which one of the source electrode or drain electrode of the transistor is always in electrical contact with one electrode of the capacitive element, A first conductive film having a region positioned above the insulating surface and functioning as one electrode of the capacitive element, A first insulating film having a region positioned above the first conductive film and functioning as a gate insulating film of the transistor, A first oxide semiconductor film having a region positioned above the first insulating film and having the channel region of the transistor, A second oxide semiconductor film having a region positioned above the first insulating film and functioning as the other electrode of the capacitive element, A second insulating film having a region in contact with the upper surface of the first oxide semiconductor film and a region in contact with the upper surface of the second oxide semiconductor film, A second conductive film having the function of either the source electrode or the drain electrode of the transistor, A third insulating film having a region positioned above the first oxide semiconductor film, a region positioned above the second oxide semiconductor film, a region positioned above the second conductive film, and a region in contact with the upper surface of the second insulating film, A third conductive film having a region positioned above the third insulating film and functioning as the pixel electrode, The first insulating film comprises a first layer containing nitrogen and silicon, and a second layer having a region located above the first layer and containing oxygen and silicon. The second oxide semiconductor film is not electrically connected to the third conductive film. The upper surface of the second oxide semiconductor film has a region in contact with the second insulating film and a region in contact with the third insulating film. Display device.

3. In claim 1 or claim 2, The third conductive film has a region that overlaps with the first conductive film and the second oxide semiconductor film, Display device.

4. In any one of claims 1 to 3, The first oxide semiconductor film and the second oxide semiconductor film each contain In, Ga, and Zn as their main components. Display device.

5. In any one of claims 1 to 4, The third insulating film comprises at least one of the following: silicon oxide film, silicon oxide nitride film, silicon nitride film, silicon nitride film, aluminum oxide film, hafnium oxide film, yttrium oxide film, zirconium oxide film, gallium oxide film, tantalum oxide film, magnesium oxide film, lanthanum oxide film, cerium oxide film, and neodymium oxide film. Display device.

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