JPH0936372A - Manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a terminal when oxidizing an anode without wiping the terminal with an organic solvent by forming a conductive resin film as a terminal so that the side surface of an electrode wiring can be partially covered and forming an anode oxide film on the side surface of the electrode wiring. SOLUTION: An insulation film such as silicon oxide element film 2 and a amorphous silicon film of intrinsic semiconductor are formed on an insulation film 1 and laser is applied, the amorphous silicon film is crystallized to polycrystalline silicon film 3, a pattern is formed in an island shape, and silicon oxide is formed as a gate insulation film 4 and a metal material film which can be subjected to anode oxidation is formed. Then, a resist pattern 6 is formed and an electrode wiring 5 is formed by etching and then a conductive resin 7 is applied to a region which becomes a terminal for conduction to the electrode wiring 5. And then, the electrode wiring 5 continues to the conductive resin 7 on the side surface, thus performing anode oxidation of the electrode wiring 5 with the conductive resin 7 as a terminal, thus automating a resist elimination process where a person directly touches the substrate and drastically improving massproducibility and hence improving degree of quality.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device such as a thin film transistor provided on an insulating substrate.

[0002]

2. Description of the Related Art Conventionally, in a semiconductor device such as a thin film transistor, an offset region is provided so that a gate electrode is not located on a source region and a drain region, so that a leak current between the source region and the drain region is prevented. It is known that it can be reduced.

However, as fine processing is required to form a high-performance semiconductor device, the conventional method of forming an offset by using a resist mask has a problem in that the shift in etching and the precision in the photolithography process are difficult. Due to the nonuniformity, the positional relationship between the gate electrode and the source and drain regions could not be controlled sufficiently. for that reason,
After forming the gate electrode using an anodizable material,
A non-porous anodic oxide film is formed around the gate electrode (side surface and upper surface of the gate electrode) in a solution of tartaric acid in ethylene glycol. A method of obtaining an offset between the gate electrode and the source region and the drain region by forming it has been proposed.

However, in the above method, in order to obtain an offset of 0.5 μm, it is necessary to apply a high voltage of 380 V to the gate electrode during anodic oxidation. In this case, part of the voltage is applied between the semiconductor layer where the source region and the drain region are formed and the gate electrode, which causes permanent breakdown of the gate insulating film and increase in interface state density. Has been done. On the other hand, it is generally known that the larger the offset width is, the smaller the leak current is. It is preferable that the offset width is 0.5 μm or more.

With respect to the above-mentioned problems, for example, Japanese Patent Laid-Open No. Hei 6
In the method described in JP-A-338612, the electrolytic solution at the time of anodic oxidation is set to 120% in a citric acid solution at a formation voltage of 120%.
As V, it is proposed to obtain a porous anodic oxide film having a thickness of 0.5 μm or more by performing anodic oxidation. In this case, after forming the gate electrode, it is desirable to perform porous anodic oxidation with the resist for forming the pattern of the gate electrode being left on the upper surface of the gate electrode. This is because in the absence of the resist, a porous anodic oxide film is also formed on the upper surface of the gate electrode, and a considerably large step is formed due to the swelling of the porous anodic oxide film. ), Disconnection and poor coverage occur.

[0006]

However, in the case of forming a semiconductor device having the above-mentioned structure, if it is desired to perform anodic oxidation only on the side surface of the gate electrode, the upper surface of the gate electrode is made of an insulating organic material. Was covered with. Therefore, a terminal for passing an electric current cannot be secured at the time of anodization, and a part of this organic material is wiped off by using an organic solvent such as acetone to expose a metal material film to be an electrode wiring such as a gate electrode. , The terminal was secured at the time of anodization.

In view of the above problems, it is an object of the present invention to provide means for securing terminals during anodization without manually wiping a part of the resist pattern with an organic solvent such as acetone.

[0008]

According to a first aspect of the present invention, there is provided a semiconductor device manufacturing method comprising: a first insulating film on an insulating substrate;
A step of sequentially forming a semiconductor layer to be an active region, a second insulating film, and an anodizable electrode wiring material film, and a photoresist is applied to the entire surface, and then an electrode wiring pattern is formed by a photolithography step. Using the pattern as a mask, the step of etching the electrode wiring material film to form the electrode wiring, and forming a conductive resin film so as to cover at least a part of the side surface of the electrode wiring, and the conductive resin film is formed. And a step of forming an anodized film on the side surface of the electrode wiring as a terminal.

According to a second aspect of the present invention, there is provided a method of manufacturing a semiconductor device in which a first insulating film, a semiconductor layer to be an active region, a second insulating film, and an anodizable electrode wiring material are formed on an insulating substrate. Steps of sequentially forming films, a conductive resin film having an electrode wiring pattern is formed on the electrode wiring material film, and the electrode wiring material film is etched by using the conductive resin film as a mask to form electrode wiring. And a step of forming an anodic oxide film on the side surface of the electrode wiring using the conductive resin film as a terminal.

Further, in the method for manufacturing a semiconductor device of the present invention according to claim 3, after the porous anodic oxide film is formed by the anodic oxide film forming step, the porous anodic oxide film and the electrode wiring are formed. 3. The method for manufacturing a semiconductor device according to claim 1, further comprising the step of forming a non-porous anodic oxide film on the upper surface of the electrode wiring.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail based on the embodiments of the invention.

FIG. 1 is a manufacturing process drawing of the first embodiment of the present invention, FIG. 2 is a manufacturing process drawing of the second embodiment of the present invention, and FIG. Step b) and FIG.
4C is a partial plan view of the semiconductor device in a state where the conductive resin 7 is applied between the step shown in FIG. 4C and FIG. 3B is a sectional view taken along line AA in FIG. Is Figure 2
FIG. 4 is a plan view of the semiconductor device during the step shown in FIG.
6B is a sectional view taken along line BB in FIG. 5A, FIG. 5 is a schematic diagram of a screen printing process of applying a conductive resin, and FIG. 6 is a schematic diagram of a dispenser coating process of applying a conductive resin. Is.

The manufacturing process of the semiconductor device according to the first embodiment of the present invention will be described below with reference to FIG.

First, impurities contained in the insulating substrate 1 on the insulating substrate 1 (for example, "# 7059" manufactured by Corning Incorporated) such as glass, which has been thoroughly washed, are filled with a channel region, a source region,
As a film for preventing diffusion into the semiconductor layer in which the drain region is formed, 100 to 500 nm is formed by the sputtering method.
An insulating film such as the silicon oxide film 2 is formed. Thereafter, a semiconductor layer is formed on the insulating substrate 1 by plasma CVD or low pressure CVD so as to have a film thickness of 30 to 200 nm. In this embodiment, an amorphous silicon film of an intrinsic semiconductor is formed so as to have a film thickness of 50 nm. To film.

Thereafter, laser irradiation is performed to crystallize the amorphous silicon film into the polycrystalline silicon film 3. After crystallization by laser, the polycrystalline silicon film 3 is patterned into an island shape by dry etching using CF ₄ gas or O ₂ gas. After that, silicon oxide having a film thickness of 50 to 200 nm, for example, 100 nm is formed by a plasma CVD method or a sputtering method to form the gate insulating film 4 (FIG. 1).
(A)).

Next, a metal material film capable of anodizing and having a film thickness of 300 to 800 nm is formed by the sputtering method. As the metal material, aluminum or aluminum alloy is used because of its low specific resistance and ease of processing. After that, a resist pattern 6 for forming an electrode wiring is formed, and the metal material film is etched using the resist pattern 6 as a mask to form the electrode wiring 5 (FIG. 1).
(B)).

Next, an anodic oxidation process for forming an oxide film on the side surface of the electrode wiring 5 is performed. The insulating resist pattern 6 is formed on the upper surface of the patterned electrode wiring 5 by the process shown in FIG. 1B. Therefore, it is impossible to take a terminal for anodic oxidation as it is. Therefore, FIG.
As shown in (a) and (b), a conductive resin 7 is applied to a region to be a terminal to establish electrical continuity with the electrode wiring 5. At this time, since the electrode wiring 5 is electrically connected to the conductive resin 7 on the side surface, the electrode wiring 5 can be anodized using the conductive resin 7 as a terminal.

As a method of applying the conductive resin 7,
It can be performed by a screen printing method, a dispenser coating method, or the like. As shown in FIG. 5, the screen printing method
A screen 21 serving as a mask is placed on a substrate 20 to which the conductive resin 7 is applied, the conductive resin 7 is placed in a plate frame 22, and a spatula-shaped rubber plate 23 called a squeegee is pressed. As a result, the conductive resin 7 is extruded onto the substrate 20 through the screen 21, and the pattern of the conductive resin 7 becomes
For example, it is formed as shown in FIG. FIG.
In the dispenser coating method, the conductive resin 7 is placed in a syringe-like container 24, the conductive resin 7 is extruded in a fixed amount with nitrogen, and then coated on the substrate 20, as shown in FIG. The pattern accuracy is
Although not as good as the screen printing method, it is possible to sufficiently form a pattern of about the terminal at the time of anodization.

Next, after forming terminals for anodization,
The conductive resin 7 is sandwiched between clips and 3 to 20%, for example, 3
% Oxalic acid aqueous solution was used for anodic oxidation. This anodic oxidation is carried out at a constant voltage of 5 to 50 V, for example 8 V, at a rate of 10 to 2
It was performed under the condition of 00 minutes, for example, 45 minutes. as a result,
The anodic oxide film was not formed on the upper surface of the electrode wiring 5, but the porous anodic oxide film 8 having a film thickness of about 0.5 to 2.0 μm was uniformly formed only on the side surface. After that, the resist pattern 6 and the conductive resin 7 are removed with a normal stripping solution (FIG. 1C).

Next, anodic oxidation is carried out again in an ethylene glycol solution of 3% tartaric acid to form a dense non-porous anodic oxide film 9 on the side surface and the upper surface of the electrode wiring 5. The non-porous anodic oxide film 9 can suppress hillocks and peeling of the porous anodic oxide film 8 in the subsequent heating step. The step of forming the non-porous anodic oxide film 9 may be omitted.

Then, using phosphine (PH ₃ ) as a doping gas in the ion doping method, the acceleration voltage is 60 to 80 KV, for example 65 KV, and the dose amount is 1 × 1.
0 ¹⁵ to 8 × 10 ¹⁵ cm ^-2 , for example 5 × 10 ¹⁵ cm ^-2 ,
Impurities are implanted into the polycrystalline silicon film 3 which is the active region. At this time, the anodic oxide films 8 and 9 and the electrode wiring 5 act as a mask at the time of ion implantation, and the impurity regions 10 to be the source region and the drain region are formed. Then, the impurity region 10 is annealed by irradiation with laser light.
Are activated (FIG. 1 (d)). In FIG. 1D, 3a is an offset area. This offset region 3a is very effective in reducing the leak current, and further,
The offset length can be freely set by changing the formation voltage at the time of anodic oxidation.

Next, an interlayer insulating film 11 made of silicon oxide or silicon nitride having a film thickness of 300 to 800 nm is formed. After that, when a liquid crystal display is formed, it is necessary to form pixels. Therefore, the transparent electrode 12 is formed in a portion corresponding to the pixel portion. After that, the interlayer insulating film 11 on the impurity region 10 and a part of the gate insulating film 4 are etched to form a contact hole, and a metal material such as an aluminum alloy is deposited by a sputtering method to form the wiring 13 (FIG. 1 (e)).

The manufacturing process of the semiconductor device according to the second embodiment of the present invention will be described below with reference to FIG.

First, similar to the manufacturing process of the first embodiment of the present invention described above, a silicon oxide film 2, a polycrystalline silicon film 3, and a gate insulating film 4 are provided on an insulating substrate 1 such as glass that has been thoroughly washed. Are sequentially formed (FIG. 2A).

Next, by using the sputtering method, a metal material film having a film thickness of 300 to 800 nm and capable of anodizing is formed in the same manner as in the case of the first embodiment. Thereafter, as shown in FIGS. 4A and 4B, a conductive film patterned by screen printing is formed on the metal material film as a mask for forming a gate electrode (FIG. 2).
(B)). At this time, the electrode wiring 5 is in direct contact with the conductive resin 7 and is electrically connected. After that, the metal film is etched using the conductive resin 7 as a mask to pattern the gate electrode.

Next, in the above state, anodization is performed using a part of the conductive resin as a terminal. The conditions are the same as in the first embodiment, and the anodic oxide film 8 is formed on the side surface of the electrode wiring 5.
Are formed (FIG. 2C). Although the screen printing method is used in the present embodiment, the product name "OFPR-800 / 10cp" is used as the photosensitive resin on the entire surface.
(Manufactured by Tokyo Ohka Co., Ltd.), and after applying a conductive resin composed of a mixture of tetracyanoquinodimethane and tetrathiofulvalene in an equimolar ratio of 3% thereto, It is also possible to form a desired electrode wiring pattern by using the photolithography process.

Next, the same process as in the first embodiment, that is, anodic oxidation is performed again to form a dense non-porous oxide film on the side surface and the upper surface of the electrode wiring 5, and then the ion doping method is used. Then, impurities are implanted into the polycrystalline silicon film 3 which is the active region, and the impurity regions 10 which become the source region and the drain region are formed. After that, annealing is performed by laser light irradiation to activate the impurity regions 10 (FIG. 2).
(D)).

Next, an interlayer insulating film 11 made of silicon oxide or silicon nitride and having a film thickness of 300 to 800 nm is formed. After that, when an LED is formed, it is necessary to form a pixel. Therefore, the transparent electrode 12 is formed in a portion corresponding to the pixel portion. After that, the interlayer insulating film 11 on the impurity region 10
A part of the gate insulating film 4 is etched to form a contact hole, and a metal material is formed by a sputtering method.
For example, an aluminum alloy is deposited to form the wiring 13 (FIG. 2E).

[0029]

As described above in detail, since the resist removing process for securing terminals for anodic oxidation, which is directly touched by a person, is automated, mass productivity is greatly improved. Since it is mechanized, dust generated from the human body is reduced, and the rate of non-defective products can be expected to improve.

Furthermore, since it is not necessary to perform a step of wiping the resist with a solvent such as acetone, it is possible to remove the solvent by volatilizing the solvent.
Anodization failure caused by redeposition of the dissolved organic material on the element can be suppressed.

Therefore, it is possible to contribute to the manufacture of a semiconductor device such as an LCD, which has a problem of reducing the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram of a first embodiment of the present invention.

FIG. 2 is a manufacturing process diagram of the second embodiment of the present invention.

FIG. 3A is a plan view of the semiconductor device in a conductive resin coating step between the step shown in FIG. 1B and the step shown in FIG. 1C, and FIG. 3 is a sectional view taken along line AA of FIG.

4A is a plan view of the semiconductor device at the time of the step shown in FIG. 2B, and FIG. 4B is a sectional view taken along line BB of FIG. 4A.

FIG. 5 is a schematic diagram of a screen printing process of applying a conductive resin.

FIG. 6 is a schematic view of a dispenser coating step of coating a conductive resin.

[Explanation of symbols]

 1 Insulating Substrate 2 Silicon Oxide Film 3 Polycrystalline Silicon Film 3a Offset Region 4 Gate Insulating Film 5 Electrode Wiring 6 Resist Pattern 7 Conductive Resin 8 Porous Anodic Oxide Film 9 Nonporous Anodic Oxide Film 10 Impurity Region 11 Interlayer Insulation Membrane 12 Transparent electrode 13 Wiring 20 Substrate 21 Screen 22 Plate frame 23 Spatula-shaped rubber plate 24 Syringe-like container

Claims (3)

[Claims] 1. A step of sequentially forming a first insulating film, a semiconductor layer to be an active region, a second insulating film and an anodizable electrode wiring material film on an insulating substrate, and a photoresist is applied on the entire surface. After that, a step of forming an electrode wiring pattern by a photolithography process, etching the electrode wiring material film using the pattern as a mask to form an electrode wiring, and at least partially covering a side surface of the electrode wiring. Forming a conductive resin film and forming an anodized film on the side surface of the electrode wiring using the conductive resin film as a terminal. 2. A step of sequentially forming a first insulating film, a semiconductor layer to be an active region, a second insulating film and an anodizable electrode wiring material film on an insulating substrate, and a conductive layer having an electrode wiring pattern. A step of forming a resin film on the electrode wiring material film, etching the electrode wiring material film using the conductive resin film as a mask to form electrode wiring; and a step of forming the electrode wiring using the conductive resin film as a terminal. A method of manufacturing a semiconductor device, comprising a step of forming an anodic oxide film on a side surface of a wiring. 3. A non-porous anodic oxide film is formed between the porous anodic oxide film and the electrode wiring and on the upper surface of the electrode wiring after forming the porous anodic oxide film by the anodic oxide film forming step. 3. The method for manufacturing a semiconductor device according to claim 1, further comprising: