JP2019179862A - Method for manufacturing field effect transistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a field-effect transistor capable of forming an oxide layer efficiently with time. A method for manufacturing a field-effect transistor, comprising manufacturing a field-effect transistor having an oxide layer provided on a substrate, for a plurality of substrates, wherein the oxide forming the oxide layer is provided. A layer forming step, wherein the oxide layer forming step is performed by applying an oxide layer forming coating solution for forming the oxide layer to a predetermined number of substrates as one unit. A drying process of drying the dried film for a first time to form a dried film; and drying the dried film for the first time at a time for a plurality of substrates each including a plurality of the one units. A heating process for heating for a longer second time; and a temporary storage process for temporarily storing the substrate after the drying process until the number of the plurality of units subjected to the heating process is reached. [Selection diagram] FIG. 1B

Description

  The present invention relates to a method for manufacturing a field effect transistor.

  A field effect transistor (FET) has a low gate current and has a planar structure, and thus can be easily manufactured and integrated as compared with a bipolar transistor. Therefore, FETs are indispensable elements in integrated circuits used in current electronic devices. For example, an active matrix in which field effect transistors are arranged in a matrix is used as a driving circuit for a display such as a liquid crystal display. It has been.

  An example of a method for producing a field effect transistor is a method for producing a field effect transistor in which a first oxide layer and a second oxide layer, one of which is an oxide semiconductor layer, are adjacent to each other. A step of forming a first oxide layer, and a step of forming the second oxide layer on the first oxide layer, wherein the formation temperature of the second oxide layer is: A method of manufacturing a field effect transistor that can reduce the SS value by setting the temperature to be equal to or lower than the formation temperature of the first oxide layer is known (see, for example, Patent Document 1).

  When manufacturing a field effect transistor having an oxide layer, the time required to form the oxide layer greatly affects the time required to manufacture the field effect transistor. Therefore, in order to efficiently manufacture many field effect transistors, it is important how to form an oxide layer in a time efficient manner.

  An object of this invention is to provide the manufacturing method of the field effect transistor which can form an oxide layer efficiently in time.

Means for solving the problems are as follows. That is,
The method for producing a field effect transistor according to the present invention includes:
Including an oxide layer forming step of forming the oxide layer;
The oxide layer forming step includes
An undried film formed by applying an oxide layer forming coating solution for forming the oxide layer to a predetermined number of substrates as one unit is dried in a first time to form a dried film. A drying process to form,
A heat treatment for heating the dry film at a second time longer than the first time at a time with respect to a plurality of units of the substrate in which a plurality of the units are collected.
And a temporary storage process of temporarily storing the substrate subjected to the drying process until the number of the plurality of units to be subjected to the heating process is reached.

  According to the present invention, it is possible to provide a method for manufacturing a field effect transistor capable of forming an oxide layer in a time-efficient manner.

FIG. 1A is a schematic view (top view) for explaining an example of a method for producing a field effect transistor of the present invention. FIG. 1B is a schematic view (side view) for explaining an example of the method for producing the field-effect transistor of the present invention. FIG. 2 is a schematic view showing a state in the temporary storage device. FIG. 3 is a schematic view showing the inside of the heating device. FIG. 4 is a flowchart for explaining an example in which a gate insulating layer is formed as an oxide layer. FIG. 5 is a schematic view (top view) for explaining another example of the method for producing a field effect transistor of the present invention. FIG. 6 is a schematic view showing a state in which the substrate is held in the holding device. FIG. 7 is a cross-sectional view illustrating the field effect transistor according to the first embodiment. FIG. 8 is a cross-sectional view illustrating a field effect transistor according to a modification of the first embodiment. FIG. 9 is a schematic configuration diagram showing an example of a television device as a system of the present invention. FIG. 10 is a diagram (part 1) for explaining the image display device in FIG. FIG. 11 is a diagram (part 2) for explaining the image display device in FIG. FIG. 12 is a diagram (No. 3) for explaining the image display device in FIG. 9. FIG. 13 is a diagram for explaining an example of the display element of the present invention. FIG. 14 is a schematic configuration diagram illustrating an example of a positional relationship between an organic EL element and a field effect transistor in a display element. FIG. 15 is a schematic configuration diagram illustrating another example of the positional relationship between the organic EL element and the field effect transistor in the display element. FIG. 16 is a schematic configuration diagram illustrating an example of an organic EL element. FIG. 17 is a diagram for explaining the display control apparatus. FIG. 18 is a diagram for explaining a liquid crystal display. FIG. 19 is a diagram for explaining the display element in FIG.

(Method for producing field-effect transistor)
The method for producing a field effect transistor of the present invention is a method for producing a field effect transistor provided on a substrate on a plurality of substrates.
The field effect transistor has an oxide layer.

When forming an oxide layer from an oxide layer forming coating solution for forming an oxide layer, the oxide layer forming coating solution is usually applied to form an undried film. The film is dried to form a dry film, and the dry film is heated to convert to an oxide to obtain an oxide layer. At that time, heating (heating treatment) takes more time than drying (drying treatment). Therefore, if the step of forming the oxide layer is sequentially performed for each field effect transistor in the order of the drying treatment and the heat treatment, the time required for the heat treatment can be reduced. The ratio to the time required for the manufacturing increases, and the time efficiency in manufacturing the field effect transistor deteriorates.
Therefore, the present inventors have conducted an intensive study, and by combining a plurality of dry films at one time in the heat treatment, and temporarily storing the dry films until reaching the number subjected to the heat treatment, The inventors have found that an oxide layer can be formed in a time efficient manner, and have completed the present invention.

  The manufacturing method of the field effect transistor of the present invention includes at least an oxide layer forming step, and further includes other steps as necessary.

<Oxide layer forming step>
The oxide forming step includes at least a drying process, a temporary storage process, and a heating process, and further includes other processes such as a coating process and a second temporary storage process as necessary.

<< Coating process >>
The coating process is a process of applying an oxide layer forming coating solution for forming the oxide layer to form an undried film.
Usually, the coating process is performed on one substrate.
There is no restriction | limiting in particular as an application | coating method, According to the objective, it can select suitably, For example, the dip coating method, the spin coat method, the die coat method etc. are mentioned.

  The oxide layer is not particularly limited and may be appropriately selected depending on the purpose. The oxide layer may be an oxide semiconductor layer, a gate insulating layer, or a protective layer. Good.

<< second temporary storage process >>
The second temporary storage process is a process of temporarily storing the substrate that has undergone the coating process until it reaches the number of one unit, which will be described later, used for the drying process.
The second temporary storage process is usually performed when the number of the predetermined number of substrates, which is one unit, is plural.

  In the second temporary storage process, the storage time is not particularly limited and can be appropriately selected according to the purpose.

  The second temporary storage process is preferably performed in a space in which temperature, humidity, and atmosphere are controlled.

The unit is preferably a number equal to or greater than a ratio (T1 / T3) of a first time (T1) described later and a time (T3) required for the coating process, and is greater than the ratio (T1 / T3). It is preferable that it is an integer.
For example, when the first time (T1) is 10 minutes and the time (T3) required for the coating process is 1 minute, the unit (N ₀ ) is N ₀ ≧ 10 (T1 / T3). Preferably there is.
By doing so, even when the drying time by the drying process is significantly longer than the application time by the coating process, it is possible to prevent the number of substrates waiting for the drying process from increasing cumulatively.

<< Drying process >>
In the drying process, an undried film formed by applying an oxide layer forming coating solution for forming the oxide layer to a predetermined number of substrates as one unit is dried in a first time. This is a process for forming a dry film.

Here, the number of the predetermined number of substrates may be one or plural.
Examples of the number of the predetermined number of substrates include 1 to 10.

There is no restriction | limiting in particular as said 1st time, According to the objective, it can select suitably.
Examples of the drying method include heat drying and reduced pressure drying. The heating temperature in heat drying is not particularly limited as long as the volatile component contained in the oxide layer forming coating solution is volatilized, and can be appropriately selected according to the purpose. The degree of decompression in the drying under reduced pressure is not particularly limited as long as the degree of decompression is such that the volatile component contained in the coating liquid for forming an oxide layer volatilizes, and can be appropriately selected according to the purpose.
In the present invention, drying does not require complete removal of the volatile components in the film, and the volatile components in the film are removed to such an extent that problems caused by the volatile components during the heat treatment are prevented. Just do it.
The dry film does not need to be a film from which the volatile matter in the film has been completely removed, and the volatile matter in the film has been removed to such an extent as to prevent problems caused by the volatile matter during the heat treatment. That's fine.

<< Heat treatment >>
The heat treatment is a process of heating the dry film at a second time longer than the first time on a plurality of units of substrates in which a plurality of the one units are gathered.
Through the heat treatment, the dry film is converted into an oxide. The obtained oxide is used as the oxide layer as it is or processed into the oxide layer by photolithography, for example.

The second time in the heat treatment is not particularly limited as long as the dry film can be converted into an oxide, and can be appropriately selected depending on the purpose.
The heating temperature in the heat treatment is not particularly limited as long as the dry film can be converted into an oxide, and can be appropriately selected according to the purpose.

  There is no restriction | limiting in particular as an upper limit of the number of the board | substrates used for the said heat processing, It selects suitably according to said 1st time, said 2nd time, and ratio (T2 / T1) mentioned later. For example, the number of substrates subjected to the heat treatment may be 100 or less, 50 or less, or 30 or less.

The number of units of the plurality of units may be an integer or a small number or a fraction, but is preferably an integer.
The number of units of the plurality of units is preferably a number equal to or greater than the ratio (T2 / T1) between the second time (T2) and the first time (T1), and the ratio (T2 / T1). It is preferable that it is an integer above.
For example, when the first time (T1) is 10 minutes and the second time (T2) is 100 minutes, the unit number (N) is N ≧ 10 (T2 / T1). preferable.
By doing so, even when the heating time by the heat treatment is significantly longer than the drying time by the drying treatment, it is possible to prevent the number of substrates waiting for the heat treatment from increasing cumulatively.

<< Temporary storage process >>
The temporary storage process is a process of temporarily storing the substrate that has undergone the previous drying process until the number of the plurality of units to be subjected to the heating process is reached.

  In the temporary storage process, the storage time is not particularly limited and can be appropriately selected according to the purpose.

  The temporary storage process is preferably performed in a space in which temperature, humidity, and atmosphere are controlled. By doing so, in the oxide layer obtained through the dry film, it is possible to reduce the occurrence of changes that impair the homogeneity (for example, oxidation, excessive progress of drying, excessive moisture absorption, etc.).

An example of a method for producing a field effect transistor according to the present invention will be described with reference to the drawings.
1A and 1B are schematic views for explaining an example of a method for producing a field effect transistor according to the present invention. 1A is a top view and FIG. 1B is a side view.
In FIG. 1A and FIG. 1B, the drying apparatus 1, the temporary storage apparatus 2, and the heating apparatus 3 are arrange | positioned.
In this example, one unit is one substrate, and the plurality of units is four units (four).
The substrate 4 (1 unit = 1 sheet) having an undried film obtained through the coating process is carried into the drying apparatus 1 and subjected to the drying process. In the drying apparatus 1, drying such as reduced pressure drying and heat drying is performed. The substrate 4 having a dry film obtained by the drying process is carried into the temporary storage device 2, held by the holding device 5, and temporarily stored in the temporary storage device 2. A plurality of substrates 4 having an undried film are subjected to a drying process, and the obtained substrates 4 having a dried film are sequentially carried into the temporary storage device 2 and subjected to heat treatment (4 units = 4 sheets). Is held in the holding device 5 and temporarily stored in the temporary storage device 2 until reaching the above.
When the number of substrates 4 held by the holding device 5 reaches the number used for the heat treatment (4 units = 4), the holding device 5 is unloaded from the temporary storage device 2 and loaded into the heating device 3. The number of substrates 4 to be subjected to the heat treatment is heated. As a result, the dry film is converted to an oxide. The obtained oxide is used, for example, as the oxide layer as it is or processed into the oxide layer by photolithography.
In addition, after the number of the substrates 4 held by the holding device 5 in the temporary storage device 2 reaches the number used for the heat treatment (4 units = 4), the holding device 5 is immediately attached to the temporary storage device 2. You may carry it out of. That is, in the temporary storage process in the oxide layer forming step of the present invention, when the number of substrates subjected to the drying process reaches the number of the plurality of units to be subjected to the heating process, the temporary storage is immediately completed. Also good. The same applies to the second temporary storage process.
In FIG. 1B, the holding tool 5 between the temporary storage device 2 and the heating device 3 holds four substrates 4.

FIG. 2 is a schematic diagram showing the inside of the temporary storage device 2. A holding device 5 is placed in the temporary storage device 2, and the holding device 5 holds two substrates 4 each having a dry film. That is, two substrates 4 having a dry film are temporarily stored in the temporary storage device 2.
For example, when the number of substrates 4 having a dry film to be subjected to the heat treatment is four, two more substrates 4 (substrates having a dry film) have been transported to the temporary storage device 2 through the drying process. And held by the holding device 5 in the temporary storage device 2. When the four substrates are held by the holding device 5 in the temporary storage device 2, the holding device 5 holding the four substrates 4 is unloaded from the temporary storage device 2 and carried into the heating device 5. (FIG. 3). Then, the four substrates 4 are heated together with the holding device 5 (FIG. 3).

  In FIG. 1B, FIG. 2 and FIG. 3, the holding device 5 is configured such that the substrates 4 are arranged in the vertical direction (gravity direction), but the holding device 5 has the substrate 4 in the horizontal direction (horizontal direction). You may be comprised so that it may rank.

In order to prevent the space in the temporary storage device 2 from undergoing changes that impair the homogeneity (for example, oxidation, excessive progress of drying, excessive moisture absorption, etc.) in the oxide layer obtained through the dry film. Furthermore, it is preferable that the temperature, humidity, and atmosphere are controlled spaces.
For example, the temperature is preferably about 22 ° C. ± 2 ° C.
For example, if clean air is supplied into the temporary storage device 2, the humidity is preferably about 45% RH ± 10% RH. Clean air can be produced, for example, by passing air through a high performance filter such as a HEPA filter.
For example, if the inert gas is supplied in the temporary storage device 2, the humidity is preferably about 10% RH or less.

Hereinafter, an example of forming a gate insulating layer as an oxide layer in the present invention will be described with reference to a flowchart. The flowchart of FIG. 4 is an example in which a gate insulating layer is formed over a gate electrode.
S1 to S6 correspond to the step of forming the gate electrode, and S11 to S19 correspond to the step of forming the gate insulating layer. The step of forming the gate insulating layer corresponds to the oxide layer forming step.
First, a metal film is formed on a substrate (S1).
Next, a predetermined resist pattern is formed on the metal film (S2).
Next, etching is performed using the resist pattern as a protective film to obtain a desired metal pattern (S3).
Next, the resist is peeled off (S4).
Next, substrate cleaning (S5) and substrate drying (S6) are performed.
Thus, a plurality of gate electrodes are formed on the substrate.
Next, a gate insulating layer forming coating solution (GI coating solution) is applied onto the substrate on which the plurality of gate electrodes are formed (S11).
Next, the undried film formed by coating is dried (S12).
Note that S12 is performed for each substrate, for example.
Next, the substrate having the dried film obtained by drying is stored in a temporary storage device (S13). At this time, a plurality of substrates having a dry film are produced, and the substrates having the dry film are stored in a temporary storage device until the number of substrates having the dry film reaches the number subjected to heat treatment (S13).
Next, when the number of substrates stored in the temporary storage device reaches the number of substrates subjected to the heat treatment, they are moved to the heating device and heated (S14).
Next, a predetermined resist pattern is formed on the oxide film obtained by heating (S15).
Next, etching is performed using the resist pattern as a protective film to obtain a desired oxide layer pattern (S16).
Next, the resist is peeled off (S17).
Next, substrate cleaning (S18) and substrate drying (S19) are performed.
As described above, a substrate on which a plurality of gate electrodes and a plurality of gate insulating layers corresponding to the plurality of gate electrodes are formed is obtained.

Another example of the method for producing a field effect transistor of the present invention will be described with reference to the drawings.
5 and 6 are schematic views for explaining an example of the method for producing a field effect transistor according to the present invention. FIG. 5 is a top view.
In FIG. 5, the coating device 6, the second temporary storage device 7, the drying device 1, the temporary storage device 2, and the heating device 3 are arranged.
In this example, the one unit is four substrates, and the plurality of units is four units (16 substrates).
First, using the coating device 6, an oxide layer forming coating solution is coated on the substrate 4 to form an undried film (coating treatment). The substrate 4 on which the undried film is formed is transferred from the coating device 6 into the second temporary storage device 7, held by the holding tool 8, and temporarily stored in the second temporary storage device 7. The coating process is performed on the plurality of substrates 4, and the obtained substrates 4 having undried films are sequentially carried into the second temporary storage device 7 and are used for the drying process (1 unit = 4). The second temporary storage device 7 temporarily holds the sheet until it reaches the sheet).
When the number of the substrates 4 held by the holding device 8 of the second temporary storage device 2 reaches the number of one unit (1 unit = 4 sheets) used for the drying process, the holding device 8 performs the second temporary storage. It is unloaded from the device 7 and loaded into the drying device 1 to perform a drying process.
In the drying apparatus 1, drying such as reduced pressure drying and heat drying is performed. The substrate 4 (1 unit = 4 sheets) having a dry film obtained by the drying process is carried into the temporary storage device 2, held by the holding device 5, and temporarily stored in the temporary storage device 2. A plurality of substrates 4 having an undried film are subjected to a drying process for each unit, and sequentially, one unit of the substrate 4 having a dried film is transported into the temporary storage device 2 to be subjected to a heating process ( It is held by the holding device 5 and temporarily stored in the temporary storage device 2 until it reaches 4 units = 16 sheets).
When the number of substrates 4 held by the holding device 5 in the temporary storage device 2 reaches the number used for the heat treatment (4 units = 16 sheets), the holding device 5 is unloaded from the temporary storage device 2 and heated. The number of substrates 4 carried into the apparatus 3 and subjected to heat treatment is heated. As a result, the dry film is converted to an oxide. The obtained oxide is used as the oxide layer as it is or processed into the oxide layer by photolithography, for example.
In FIG. 6, the holding device 5 between the temporary storage device 2 and the heating device 3 holds 16 substrates 4 (four per plate × four steps).

<Field effect transistor>
An example of a field effect transistor manufactured according to the present invention will be described below. In the drawings described below, one field effect transistor is formed on a substrate. Usually, a plurality of field effect transistors are formed on a substrate.
FIG. 7 is a cross-sectional view illustrating the field effect transistor according to the first embodiment. Referring to FIG. 7, the field effect transistor 10 includes a base 11 that is a substrate, a gate electrode 12, a gate insulating layer 13, a semiconductor layer 14, a source electrode 15, and a drain electrode 16. This is a gate / top contact type field effect transistor. The field effect transistor 10 is a typical example of the field effect transistor according to the present invention.

  In the field effect transistor 10, a gate electrode 12 is formed on an insulating substrate 11, and a gate insulating layer 13 is formed so as to cover the gate electrode 12. A semiconductor layer 14 is formed on the gate insulating layer 13, and a source electrode 15 and a drain electrode 16 are formed on the semiconductor layer 14 so that a channel is formed in the semiconductor layer 14. Hereinafter, each component of the field effect transistor 10 will be described in detail.

  In this embodiment, for convenience, the semiconductor layer 14 side is defined as the upper side or one side, and the substrate 11 side is defined as the lower side or the other side. Further, the surface on the semiconductor layer 14 side of each part is defined as the upper surface or one surface, and the surface on the substrate 11 side is defined as the lower surface or the other surface. However, the field effect transistor 10 can be used upside down, or can be arranged at an arbitrary angle. Moreover, planar view refers to viewing the object from the normal direction of the upper surface of the base material 11, and planar shape refers to the shape of the object viewed from the normal direction of the upper surface of the base material 11. . Further, a cross section cut in the stacking direction of each part on the base material 11 is a longitudinal cross section, and a cross section cut in a direction perpendicular to the stacking direction of each part on the base material 11 (a direction parallel to the upper surface of the base material 11). A cross section.

<< Base material (substrate) >>
There is no restriction | limiting in particular as a shape of the base material 11, a structure, and a magnitude | size, According to the objective, it can select suitably.

  There is no restriction | limiting in particular as a material of the base material 11, Although it can select suitably according to the objective, For example, a glass base material, a plastic base material, a film base material etc. can be used. There is no restriction | limiting in particular as a glass base material, Although it can select suitably according to the objective, For example, an alkali free glass, a silica glass, etc. are mentioned. Moreover, there is no restriction | limiting in particular as a plastic base material or a film base material, Although it can select suitably according to the objective, For example, a polycarbonate (PC), a polyimide (PI), a polyethylene terephthalate (PET), a polyethylene naphthalate (PEN) and the like. In addition, as for the base material 11, it is preferable that pretreatments, such as oxygen plasma, UV ozone, and UV irradiation washing | cleaning, are performed from the point of the cleaning of a surface, and adhesive improvement.

<< Gate electrode >>
The gate electrode 12 is formed in a predetermined region on the base material 11.
The gate electrode 12 is an electrode for applying a gate voltage.
The material for the gate electrode 12 is not particularly limited and may be appropriately selected depending on the intended purpose. For example, platinum, palladium, gold, silver, copper, zinc, aluminum, nickel, chromium, tantalum, molybdenum, titanium And the like, alloys thereof, mixtures of these metals, and the like. In addition, conductive oxides such as indium oxide, zinc oxide, tin oxide, gallium oxide, and niobium oxide, composite compounds thereof, mixtures thereof, and the like can be given.

  As a method for forming the gate electrode 12, for example, a conductor film is formed on the base material 11 by a vacuum deposition method or the like, and the formed conductor film is patterned by photolithography and etching to form a gate electrode 12 having a predetermined shape. The method of forming etc. are mentioned.

  There is no restriction | limiting in particular as average thickness of the gate electrode 12, Although it can select suitably according to the objective, 40 nm-2 micrometers are preferable, and 70 nm-1 micrometer are more preferable.

<< Gate insulation layer >>
The gate insulating layer 13 is an oxide insulating layer that is provided between the gate electrode 12 and the semiconductor layer 14 and insulates the gate electrode 12 and the semiconductor layer 14.
The gate insulating layer 13 is, for example, the oxide layer of a field effect transistor manufactured by the method for manufacturing a field effect transistor of the present invention.
Examples of the material of the gate insulating layer 13 include an element A that is an alkaline earth metal, and an element B that is at least one of gallium (Ga), scandium (Sc), yttrium (Y), and a lanthanoid. An oxide film at least contained can be used.

  This oxide film preferably contains a C element that is at least one of Zr (zirconium) and Hf (hafnium), and further contains other components as necessary. The alkaline earth metal contained in the oxide film may be one type or two or more types.

  Examples of alkaline earth elements include beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).

  Lanthanoids include lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium. (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu).

  The oxide film preferably contains a paraelectric amorphous oxide or is formed of the paraelectric amorphous oxide itself. The paraelectric amorphous oxide is stable in the atmosphere and can stably form an amorphous structure in a wide composition range. However, crystals may be included in part of the oxide film.

  When the gate insulating layer 13 is the oxide layer, and the gate insulating layer 13 is formed from the oxide layer forming coating solution, the gate insulating layer 13 is formed by the drying process, the temporary storage process, and It is obtained through the oxide layer forming step including at least the heat treatment.

  When the gate insulating layer 13 is not the oxide layer, as a method for forming the gate insulating layer 13, for example, a sputtering method, a pulse laser deposition (PLD) method, a chemical vapor deposition (CVD) method, an atomic layer deposition is used. A vacuum process such as an (ALD) method can be used.

  There is no restriction | limiting in particular as average thickness of the gate insulating layer 13, Although it can select suitably according to the objective, 50 nm-3 micrometers are preferable, and 100 nm-1 micrometer are more preferable.

<< Semiconductor layer (oxide semiconductor layer) >>
The semiconductor layer 14 is an oxide semiconductor layer formed on the gate insulating layer 13 and is disposed so as to face the gate electrode 12 with the gate insulating layer 13 interposed therebetween.
The semiconductor layer 13 (oxide semiconductor layer) is, for example, the oxide layer of a field effect transistor manufactured by the method for manufacturing a field effect transistor of the present invention.
The semiconductor layer 14 can be formed from, for example, an n-type oxide semiconductor.

  The n-type oxide semiconductor constituting the semiconductor layer 14 has at least one of indium, zinc, tin, gallium, and titanium because high field effect mobility can be obtained and the electron carrier concentration can be easily controlled appropriately. It is preferable to contain an alkaline earth metal, and it is more preferable to contain indium and an alkaline earth metal.

  Examples of alkaline earth elements include beryllium (Be), Mg, calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).

  When the semiconductor layer 14 is the oxide layer, and the semiconductor layer 14 is formed from the coating liquid for forming an oxide layer, the semiconductor layer 14 is subjected to the drying process, the temporary storage process, and the heating process. It is obtained through the oxide layer forming step including at least.

  In the case where the semiconductor layer 14 is not the oxide layer, examples of the method for forming the semiconductor layer 14 include sputtering, pulse laser deposition (PLD), chemical vapor deposition (CVD), and atomic layer deposition (ALD). ) Method or other vacuum process can be used.

  There is no restriction | limiting in particular as average thickness of the semiconductor layer 14, Although it can select suitably according to the objective, 5 nm-1 micrometer are preferable and 10 nm-0.5 micrometer are more preferable.

<< source electrode and drain electrode >>
The source electrode 15 and the drain electrode 16 are formed on the semiconductor layer 14.
The source electrode 15 and the drain electrode 16 cover a part of the semiconductor layer 14 and are formed at a predetermined interval.
The source electrode 15 and the drain electrode 16 are electrodes for taking out current in response to application of a gate voltage to the gate electrode 12.
Note that the wiring connected to the source electrode 15 and the drain electrode 16 may be formed in the same layer together with the source electrode 15 and the drain electrode 16.

  The material for the source electrode 15 and the drain electrode 16 is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include the materials exemplified in the description of the gate electrode 12.

  There is no restriction | limiting in particular as average thickness of the source electrode 15 and the drain electrode 16, Although it can select suitably according to the objective, 10 nm-1 micrometer are preferable and 50 nm-300 nm are more preferable.

  FIG. 8 is a cross-sectional view illustrating a field effect transistor according to a modification of the first embodiment. Referring to FIG. 8, the field effect transistor 10A is different from the field effect transistor 10 (see FIG. 7) in that a protective layer 17 is provided. The field effect transistor 10A is a typical example of the field effect transistor according to the present invention.

<Protective layer>
The protective layer 17 is an oxide insulating layer provided on the semiconductor layer 14 so as to cover the source electrode 15 and the drain electrode 16.
The protective layer 17 is the said oxide layer of the field effect transistor manufactured by the manufacturing method of the field effect transistor of this invention, for example.

  Examples of the material of the protective layer 17 include at least the element A which is an alkaline earth metal exemplified as the material of the gate insulating layer 13, gallium (Ga), scandium (Sc), yttrium (Y), and lanthanoid. An oxide film containing at least any B element can be used.

  When the protective layer 17 is the oxide layer, and the protective layer 17 is formed from the coating liquid for forming the oxide layer, the protective layer 17 has the drying treatment, the temporary storage treatment, and the heat treatment. It is obtained through the oxide layer forming step including at least.

  When the protective layer 17 is not the oxide layer, the protective layer 17 may be formed by, for example, sputtering, pulse laser deposition (PLD), chemical vapor deposition (CVD), atomic layer deposition (ALD). ) Method or other vacuum process can be used.

  There is no restriction | limiting in particular as average thickness of the protective layer 17, Although it can select suitably according to the objective, 50 nm-3 micrometers are preferable, and 100 nm-1 micrometer are more preferable.

  The protective layer 17 has a function of isolating and protecting at least the semiconductor layer 14 from moisture, oxygen, and the like in the atmosphere. However, the protective layer 17 has a function of protecting not only the semiconductor layer 14 but also other components of the field effect transistor 10A (for example, the gate insulating layer 13, the source electrode 15, the drain electrode 16, and the gate electrode 12). May be. The protective layer 17 may have a function of protecting at least a part of the field effect transistor 10A from the material of the layer formed on the field effect transistor 10A and the formation process thereof.

  An example of a display element, an image display apparatus, and a system using a field effect transistor manufactured according to the present invention will be described below.

<Display element>
The display element of the present invention includes at least a light control element and a drive circuit that drives the light control element, and further includes other members as necessary.

<< light control element >>
The light control element is not particularly limited as long as it is an element that controls light output in accordance with a drive signal, and can be appropriately selected according to the purpose. For example, an electroluminescence (EL) element, electrochromic ( EC) element, liquid crystal element, electrophoretic element, electrowetting element and the like.

<< Driver circuit >>
The drive circuit is not particularly limited as long as it has a field effect transistor manufactured by the present invention, and can be appropriately selected according to the purpose.

<< Other parts >>
There is no restriction | limiting in particular as said other member, According to the objective, it can select suitably.

  Since the display element includes the field effect transistor of the present invention, high-speed driving is possible, long life is possible, and variation between elements can be reduced. In addition, the driving transistor can be operated with a constant gate voltage even if the display element changes with time.

<Image display device>
The image display device of the present invention includes at least a plurality of display elements, a plurality of wirings, and a display control device, and further includes other members as necessary.

<< Plural display elements >>
The plurality of display elements are not particularly limited as long as they are a plurality of the display elements of the present invention arranged in a matrix, and can be appropriately selected according to the purpose.

<< Plural wiring >>
The plurality of wirings are not particularly limited as long as the gate voltage and the signal voltage can be individually applied to each field effect transistor in the plurality of display elements, and can be appropriately selected according to the purpose.

<< Display control device >>
The display control device is not particularly limited as long as the gate voltage and the signal voltage of each field effect transistor can be individually controlled via the plurality of wirings according to image data. It can be selected appropriately.

<< Other parts >>
There is no restriction | limiting in particular as said other member, According to the objective, it can select suitably.
Since the image display device includes the display element of the present invention, it is possible to reduce variation between elements, and to display a high-quality image on a large screen.

<System>
The system of the present invention includes at least the image display device of the present invention and an image data creation device.
The image data creation device creates image data based on image information to be displayed, and outputs the image data to the image display device.
Since the system includes the image display device of the present invention, it is possible to display image information with high definition.

Hereinafter, a display element, an image display device, and a system of the present invention will be described with reference to the drawings.
First, a television device as a system of the present invention will be described with reference to FIG. Note that the configuration of FIG. 9 is an example, and the television apparatus as the system of the present invention is not limited to this.

In FIG. 9, a television apparatus 100 includes a main control device 101, a tuner 103, an AD converter (ADC) 104, a demodulation circuit 105, a TS (Transport Stream) decoder 106, an audio decoder 111, a DA converter (DAC) 112, an audio output. Circuit 113, speaker 114, video decoder 121, video / OSD synthesis circuit 122, video output circuit 123, image display device 124, OSD drawing circuit 125, memory 131, operation device 132, drive interface (drive IF) 141, hard disk device 142 An optical disk device 143, an IR light receiver 151, and a communication control device 152.
The video decoder 121, the video / OSD synthesis circuit 122, the video output circuit 123, and the OSD drawing circuit 125 constitute an image data creation device.

The main control device 101 includes a CPU, a flash ROM, a RAM, and the like, and controls the entire television device 100.
The flash ROM stores a program described by codes readable by the CPU, various data used for processing by the CPU, and the like.
The RAM is a working memory.

  The tuner 103 selects a preset channel broadcast from the broadcast waves received by the antenna 210.

  The ADC 104 converts the output signal (analog information) of the tuner 103 into digital information.

  The demodulation circuit 105 demodulates the digital information from the ADC 104.

  The TS decoder 106 performs TS decoding on the output signal of the demodulation circuit 105 and separates audio information and video information.

  The audio decoder 111 decodes the audio information from the TS decoder 106.

  The DA converter (DAC) 112 converts the output signal of the audio decoder 111 into an analog signal.

  The audio output circuit 113 outputs the output signal of the DA converter (DAC) 112 to the speaker 114.

  The video decoder 121 decodes the video information from the TS decoder 106.

  The video / OSD synthesis circuit 122 synthesizes the output signal of the video decoder 121 and the output signal of the OSD drawing circuit 125.

  The video output circuit 123 outputs the output signal of the video / OSD synthesis circuit 122 to the image display device 124.

  The OSD drawing circuit 125 includes a character generator for displaying characters and figures on the screen of the image display device 124. The OSD drawing circuit 125 receives a signal including display information in response to an instruction from the operation device 132 and the IR light receiver 151. Generate.

  AV (Audio-Visual) data and the like are temporarily stored in the memory 131.

  The operation device 132 includes, for example, an input medium (not shown) such as a control panel, and notifies the main control device 101 of various information input by the user.

  The drive IF 141 is a bidirectional communication interface, and is compliant with ATAPI (AT Attachment Packet Interface) as an example.

  The hard disk device 142 includes a hard disk and a drive device for driving the hard disk. The drive device records data on the hard disk and reproduces data recorded on the hard disk.

  The optical disk device 143 records data on an optical disk (for example, a DVD) and reproduces data recorded on the optical disk.

  The IR light receiver 151 receives the optical signal from the remote control transmitter 220 and notifies the main control device 101 of it.

  The communication control device 152 controls communication with the Internet. Various information can be acquired via the Internet.

FIG. 10 is a schematic configuration diagram showing an example of the image display apparatus of the present invention.
In FIG. 10, the image display device 124 includes a display device 300 and a display control device 400.
As shown in FIG. 11, the display device 300 includes a display 310 in which a plurality of (here, n × m) display elements 302 are arranged in a matrix.
Further, as shown in FIG. 12, the display 310 has n scanning lines (X0, X1, X2, X3,..., Xn-2, Xn) arranged at equal intervals along the X-axis direction. -1) and m data lines (Y0, Y1, Y2, Y3,..., Ym-1) arranged at equal intervals along the Y-axis direction, at equal intervals along the Y-axis direction. And m current supply lines (Y0i, Y1i, Y2i, Y3i,..., Ym-1i) arranged.
Therefore, the display element can be specified by the scanning line and the data line.

Hereinafter, the display element of the present invention will be described with reference to FIG.
FIG. 13 is a schematic configuration diagram showing an example of the display element of the present invention.
As shown in FIG. 13 as an example, the display element has an organic EL (electroluminescence) element 350 and a drive circuit 320 for causing the organic EL element 350 to emit light. The drive circuit 320 is a current-driven 2Tr-1C basic circuit, but is not limited thereto. That is, the display 310 is a so-called active matrix organic EL display.

  FIG. 14 shows an example of the positional relationship between the organic EL element 350 in the display element 302 and the field effect transistor 20 as a drive circuit. Here, the organic EL element 350 is disposed beside the field effect transistor 20. The field effect transistor 10 and the capacitor (not shown) are also formed on the same substrate.

Although not shown in FIG. 14, it is also preferable to provide a protective film on the active layer 22. As a material for the protective film, SiO ₂ , SiON, SiNx, Al ₂ O ₃ , a fluorine-based polymer, or the like can be used as appropriate.

Further, for example, as shown in FIG. 15, an organic EL element 350 may be disposed on the field effect transistor 20. In this case, since the transparent gate electrode 26 is required, the gate electrode _{26, ITO, In 2 O 3,} ZnO of SnO 2, ZnO, ZnO doped with Ga, Al is added, Sb A transparent oxide having conductivity such as SnO ₂ to which is added is used. Reference numeral 360 denotes an interlayer insulating film (flattening film). For this interlayer insulating film, polyimide, acrylic resin, or the like can be used.

FIG. 16 is a schematic configuration diagram illustrating an example of an organic EL element.
In FIG. 16, the organic EL element 350 includes a cathode 312, an anode 314, and an organic EL thin film layer 340.

  The material of the cathode 312 is not particularly limited and may be appropriately selected depending on the purpose. For example, aluminum (Al), magnesium (Mg) -silver (Ag) alloy, aluminum (Al) -lithium (Li) An alloy, ITO (Indium Tin Oxide), etc. are mentioned. A magnesium (Mg) -silver (Ag) alloy becomes a high reflectance electrode if it is sufficiently thick, and a semitransparent electrode if it is an extremely thin film (less than about 20 nm). Although light is extracted from the anode side in FIG. 16, light can be extracted from the cathode side by using a transparent or semi-transparent electrode for the cathode.

  There is no restriction | limiting in particular as a material of the anode 314, According to the objective, it can select suitably, For example, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), a silver (Ag) -neodymium (Nd) alloy, etc. Is mentioned. In addition, when a silver alloy is used, it becomes a high reflectance electrode and is suitable when taking out light from the cathode side.

  The organic EL thin film layer 340 includes an electron transport layer 342, a light emitting layer 344, and a hole transport layer 346. The electron transport layer 342 is connected to the cathode 312, and the hole transport layer 346 is connected to the anode 314. When a predetermined voltage is applied between the anode 314 and the cathode 312, the light emitting layer 344 emits light.

  Here, the electron transport layer 342 and the light emitting layer 344 may form one layer, an electron injection layer may be provided between the electron transport layer 342 and the cathode 312, and hole transport is further performed. A hole injection layer may be provided between the layer 346 and the anode 314.

  Further, the case of so-called “bottom emission” in which light is extracted from the substrate side has been described, but “top emission” in which light is extracted from the side opposite to the substrate may be used.

The drive circuit 320 in FIG. 13 will be described.
The drive circuit 320 includes two field effect transistors 10 and 20 and a capacitor 30.

  The field effect transistor 10 operates as a switch element. The gate electrode G of the field effect transistor 10 is connected to a predetermined scanning line, and the source electrode S of the field effect transistor 10 is connected to a predetermined data line. The drain electrode D of the field effect transistor 10 is connected to one terminal of the capacitor 30.

  The field effect transistor 20 supplies current to the organic EL element 350. The gate electrode G of the field effect transistor 20 is connected to the drain electrode D of the field effect transistor 10. The drain electrode D of the field effect transistor 20 is connected to the anode 314 of the organic EL element 350, and the source electrode S of the field effect transistor 20 is connected to a predetermined current supply line.

  The capacitor 30 stores the state of the field effect transistor 10, that is, data. The other terminal of the capacitor 30 is connected to a predetermined current supply line.

  Therefore, when the field effect transistor 10 is turned on, image data is stored in the capacitor 30 via the signal line Y2, and even after the field effect transistor 10 is turned off, the field effect transistor 10 is turned on. The organic EL element 350 is driven by holding 20 in the “on” state corresponding to the image data.

FIG. 17 is a schematic configuration diagram showing another example of the image display device of the present invention.
In FIG. 17, the image display device includes a display element 302, wiring (scanning line, data line, current supply line), and a display control device 400.
The display control device 400 includes an image data processing circuit 402, a scanning line driving circuit 404, and a data line driving circuit 406.
The image data processing circuit 402 determines the luminance of the plurality of display elements 302 in the display based on the output signal of the video output circuit 123.
The scanning line driving circuit 404 individually applies voltages to the n scanning lines in accordance with an instruction from the image data processing circuit 402.
The data line driving circuit 406 individually applies voltages to the m data lines in accordance with an instruction from the image data processing circuit 402.

  Moreover, although the said embodiment demonstrated the case where a light control element was an organic EL element, it is not limited to this, For example, a light control element may be an electrochromic element. In this case, the display is an electrochromic display.

  The light control element may be a liquid crystal element. In this case, the display is a liquid crystal display, and a current supply line to the display element 302 ′ is not required as shown in FIG. 18. Further, as shown in FIG. 19, the drive circuit 320 ′ can be configured by one field effect transistor 40 similar to the field effect transistors 10 and 20. In the field effect transistor 40, the gate electrode G is connected to a predetermined scanning line, and the source electrode S is connected to a predetermined data line. Further, the drain electrode D is connected to the capacitor 361 and the pixel electrode of the liquid crystal element 370.

  The light control element may be an electrophoretic element, an inorganic EL element, or an electrowetting element.

  As described above, the case where the system of the present invention is a television device has been described. However, the present invention is not limited to this, and the image display device 124 may be provided as a device for displaying images and information. For example, a computer system in which a computer (including a personal computer) and an image display device 124 are connected may be used.

  In addition, the image display device 124 is used as a display unit in a portable information device such as a mobile phone, a portable music player, a portable video player, an electronic BOOK, or a PDA (Personal Digital Assistant), or an imaging device such as a still camera or a video camera. Can be used. Further, the image display device 124 can be used as a display unit for various information in a mobile system such as a car, an aircraft, a train, and a ship. Furthermore, the image display device 124 can be used as a display unit for various information in a measurement device, an analysis device, a medical device, and an advertising medium.

Aspects of the present invention are as follows, for example.
<1> A method for producing a field effect transistor, comprising: producing a field effect transistor having an oxide layer provided on a substrate with respect to a plurality of substrates;
Including an oxide layer forming step of forming the oxide layer;
The oxide layer forming step includes
An undried film formed by applying an oxide layer forming coating solution for forming the oxide layer to a predetermined number of substrates as one unit is dried in a first time to form a dried film. A drying process to form,
A heat treatment for heating the dry film at a second time longer than the first time at a time with respect to a plurality of units of the substrate in which a plurality of the units are collected.
And a temporary storage process in which the substrate subjected to the drying process is temporarily stored until the number of the plurality of units to be subjected to the heat treatment is reached.
<2> The field effect according to <1>, wherein the number of units of the plurality of units is equal to or greater than a ratio (T2 / T1) of the second time (T2) and the first time (T1). This is a method for manufacturing a type transistor.
<3> The method for producing a field effect transistor according to any one of <1> to <2>, wherein the temporary storage treatment is performed in a space in which temperature, humidity, and atmosphere are controlled.
<4> The method for producing a field effect transistor according to any one of <1> to <3>, wherein the oxide layer is an oxide semiconductor layer.
<5> The method for producing a field-effect transistor according to any one of <1> to <3>, wherein the oxide layer is a gate insulating layer.
<6> The method for producing a field effect transistor according to any one of <1> to <3>, wherein the oxide layer is a protective layer.
<7> The oxide layer forming step further includes
About one substrate, a coating treatment for applying an oxide layer forming coating solution for forming the oxide layer and forming an undried film;
A second temporary storage process for temporarily storing the substrate subjected to the coating process until reaching the number of the one unit to be subjected to the drying process,
The method for producing a field effect transistor according to any one of <1> to <6>.

DESCRIPTION OF SYMBOLS 1 Drying device 2 Temporary storage device 3 Heating device 4 Substrate 5 Holding device 6 Coating device 7 Second temporary storage device 8 Holding device 10 Field effect transistor 11 Base material 12 Gate electrode 13 Gate insulating layer 14 Semiconductor layer 15 Source electrode 16 Drain electrode 17 Protective layer 302, 302 ′ Display element 310 Display 320, 320 ′ Drive circuit 370 Liquid crystal element 400 Display control device

JP 2018-14374 A

Claims (7)

A method of manufacturing a field effect transistor, which is provided on a substrate, and manufacturing a field effect transistor having an oxide layer with respect to a plurality of substrates,
Including an oxide layer forming step of forming the oxide layer;
The oxide layer forming step includes
An undried film formed by applying an oxide layer forming coating solution for forming the oxide layer to a predetermined number of substrates as one unit is dried in a first time to form a dried film. A drying process to form,
A heat treatment for heating the dry film at a second time longer than the first time at a time with respect to a plurality of units of the substrate in which a plurality of the units are collected.
And a temporary storage process in which the substrate subjected to the drying process is temporarily stored until the number of the plurality of units to be subjected to the heat treatment is reached.   2. The field-effect transistor according to claim 1, wherein the number of units of the plurality of units is equal to or greater than a ratio (T2 / T1) of the second time (T2) and the first time (T1). Method.   3. The method of manufacturing a field effect transistor according to claim 1, wherein the temporary storage process is performed in a space in which temperature, humidity, and atmosphere are controlled.   The method for manufacturing a field effect transistor according to claim 1, wherein the oxide layer is an oxide semiconductor layer.   4. The method for manufacturing a field effect transistor according to claim 1, wherein the oxide layer is a gate insulating layer.   The method for producing a field effect transistor according to claim 1, wherein the oxide layer is a protective layer. The oxide layer forming step further includes
About one substrate, a coating treatment for applying an oxide layer forming coating solution for forming the oxide layer and forming an undried film;
A second temporary storage process for temporarily storing the substrate subjected to the coating process until reaching the number of the one unit to be subjected to the drying process,
A method for manufacturing a field effect transistor according to claim 1.