JP3332005B2 - Method for manufacturing semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention particularly relates to a method for forming a TFT above a light-shielding film by arranging a light-shielding film on a substrate and covering the film with an interlayer film. The present invention relates to a semiconductor device and a semiconductor manufacturing method for reducing the number of semiconductor devices.

[0002]

FIG. 4 is a plan view of a conventional semiconductor device, and FIG.
4 is a cross-sectional view of the semiconductor device of FIG. 4 taken along the line AA ′ of FIG. 4, and FIG. 6 shows an etching residue generated in the semiconductor device of FIG. In a conventional semiconductor device, a light-shielding film 42 is formed on a glass substrate 41 as shown in FIG.
As shown in (1), an interlayer film 45 is formed with a thickness of about 1 μm to form a TFT 44 (thin film transistor). At this time, the light-shielding film 42 formed along the gate line G and the data line D so as to go around the pixel electrode 50 is formed in a grid pattern as shown in FIG.

[0003]

However, the prior art has the following problems. The first problem is
The step is caused by the light-shielding film 42, and the flatness is deteriorated.

[0004] The second problem is that a step occurs due to the light-shielding film 42, so that when the light-shielding film 42 is formed in a grid pattern, the area without the light-shielding film 42 becomes a hole. In each of the subsequent steps, problems such as poor cleaning and etching residues 61 occur as shown in FIG.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a light-shielding film on a substrate, cover the film with an interlayer film, and form a TFT above the light-shielding film. It is an object of the present invention to provide a semiconductor device and a semiconductor manufacturing method for reducing a step caused by a light-shielding film that adversely affects the formation of a TFT.

[0006]

The gist of the present invention resides in a step of forming a dug portion on the surface of a transparent insulating substrate, and a step of forming a metal film having a thickness not less than the depth of the dug portion. A step of forming a film, a step of flattening the surface of the metal film, and anodizing the metal film to leave the metal film inside the dug portion and an area other than the inside of the dug portion. And a step of forming a thin film transistor on the metal film. According to a second aspect of the present invention, there is provided a method of manufacturing a semiconductor device according to the first aspect, wherein the step of flattening the surface of the metal film is performed by polishing. According to a third aspect of the present invention, there is provided a method of manufacturing a semiconductor device according to the first aspect, wherein aluminum is used for the metal film. According to a fourth aspect of the present invention, there is provided a method of forming a dug portion on a surface of a transparent insulating substrate using a photoresist as a mask, forming a first metal film, and forming the dug portion using a lift-off method. Leaving the first metal film only in the recessed portion, forming a second metal film over the entire upper surface of the transparent insulating substrate including the region of the recessed portion, There is provided a method of manufacturing a semiconductor device, comprising: a step of anodizing all of them; and a step of forming a thin film transistor on the first metal film. The gist of claim 5 of the present invention is a step of forming a dug portion on a surface of a transparent insulating substrate using a photoresist as a mask, and forming a metal film having a thickness equal to or less than the depth of the dug portion. A step of leaving the metal film only in the dug portion using a lift-off method, and anodizing the metal film to leave the metal film at a lower portion inside the dug portion, and inside the dug portion. Forming a transparent insulating layer on the upper part, forming an insulating film on the entire upper surface of the transparent insulating substrate including the region of the dug portion, and forming a thin film transistor on the metal film. There is provided a method for manufacturing a semiconductor device, characterized in that:

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The feature of each embodiment described below is that a metal film is formed in a dug portion formed on a transparent insulating substrate.
Comprising shielding film is formed is to be prevented poor cleaning etching residues in a stepped and processes as a conventional light-shielding film by flat manufactured simultaneously transparent insulating layer. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a process diagram for explaining a semiconductor device and a semiconductor manufacturing method according to a first embodiment of the present invention. , Generally in FIG.
The figure shows the vicinity of two TFTs in the portion A '. First, as shown in FIG. 1 (a), a transparent insulating substrate
After forming a dug portion 2 at a depth of, for example, about 200 nm on the glass substrate 1 by using general photolithography and etching, aluminum 3 is formed to a thickness of about 600 nm by using a sputtering method. . Subsequently, FIG.
As shown in (b), for example, CMP is applied to the aluminum 3.
Polishing is performed using (chemical mechanical polishing) method to form aluminum 31 having a flat upper surface. At this time, the thickness of the aluminum 3 left on the glass substrate 1 other than the dug portion 2 is, for example, about 350 nm. Subsequently, as shown in FIG. 1C, anodization of the aluminum 31 is performed to oxidize the aluminum 31 in a region other than the dug portion 2 to form the transparent insulating layer 32, and at the same time, the light shielding film 35 is formed. Subsequently, as shown in FIG. 1D, a TFT 4 is manufactured using a general TFT manufacturing process. After that, although not shown, an LCD (liquid crystal display) substrate can be manufactured by forming an interlayer film contact hole and a transparent electrode. In the first embodiment, a polishing method such as a CMP (Chemical Mechanical Polishing) method is used as shown in FIG. 1B. However, the present invention is not particularly limited thereto. For example, a reflow method is used. It is also possible.

In this embodiment, the thickness of the light-shielding film 35 against the light leakage of the TFT 4 is determined by the depth of the dug portion 2, and the thickness of the polished aluminum 3 on the glass substrate 1 and the thickness of the aluminum 3 The thickness of the transparent insulating layer 32 can be specified by the
2 can be made flat. Therefore, there is no step difference unlike the case of the conventional method. Therefore,
The flatness of the LCD substrate is improved by alleviating the unevenness.
The light shielding film 35 in the TFT manufacturing process performed thereafter
The problems such as poor cleaning and etching residue caused by the step can be solved.

As described above, the first embodiment has the following advantages. The first effect is that the unevenness of the LCD substrate is reduced by improving the flatness.
Because of the flatness, problems such as poor cleaning and etching residues caused by steps of the light-shielding film 35 do not occur. The second effect is that the relationship between the light-shielding film 35 and the transparent insulating layer 32 can be arbitrarily determined from the depth of the dug portion 2, the thickness of the aluminum 3 and the polishing amount.

(Second Embodiment) FIG. 2 is a process diagram for explaining a semiconductor device and a semiconductor manufacturing method according to a second embodiment of the present invention. , Generally in FIG.
The figure shows the vicinity of two TFTs in the portion A '. First, as shown in FIG. 2 (a), a transparent insulating substrate
After a photoresist (PR) 11 is applied to the glass substrate 1 thus formed, the dug portion 2 is formed to a depth of, for example, about 200 nm using a general photolithography and etching technique.
To form Subsequently, as shown in FIG. 2B, aluminum 3 is formed to a thickness of about 200 nm by using a sputtering method. Subsequently, as shown in FIG. 2C, after leaving aluminum 3 only inside the dug portion 2 using a lift-off method, aluminum 33 is formed to a thickness of about 350 nm using a sputtering method. I do. Subsequently, FIG.
As shown in FIG. 6, the anodic oxidation of the aluminum 33 is performed to oxidize the aluminum 33 in a region other than the dug portion 2 to form the transparent insulating layer 34 and simultaneously form the light shielding film 35. Subsequently, as shown in FIG. 2E, a TFT 4 is manufactured using a general TFT manufacturing process. Thereafter, a not-shown interlayer film contact hole, a transparent electrode, and the like are formed to manufacture an LCD substrate. In the second embodiment, aluminum 33 is sputtered after lift-off is performed as shown in FIG.
During this time, it is also possible to perform stronger flattening by performing reflow by polishing or laser irradiation.

As described above, according to the second embodiment, the following effects can be obtained. The first effect is that the unevenness of the LCD substrate is reduced by improving the flatness.
Because of the flatness, problems such as poor cleaning and etching residues caused by steps of the light-shielding film 35 do not occur. The second effect is that the relationship between the light-shielding film 35 and the transparent insulating layer 34 can be arbitrarily determined from the depth of the dug portion 2, the film thickness of the aluminum 3, and the polishing amount.

Third Embodiment FIG. 3 is a process diagram for explaining a semiconductor device and a semiconductor manufacturing method according to a third embodiment of the present invention. , Generally in FIG.
The figure shows the vicinity of two TFTs in the portion A '. First, as shown in FIG. 3 (a), a transparent insulating substrate
After the photoresist (PR) 11 is applied to the glass substrate 1 thus formed, the dug portion 2 is formed to a depth of, for example, about 200 nm by using general photolithography and etching. Subsequently, as shown in FIG. 3B, aluminum 3 is formed to a thickness of about 150 nm using a sputtering method. Subsequently, as shown in FIG. 3 (c), the aluminum 36 is formed only inside the dug portion 2 using the lift-off method.
Leave. Subsequently, as shown in FIG. 3D, anodization of the aluminum 36 is performed to form the transparent insulating layer 37 and simultaneously form the light shielding film 35, and the insulating film 38 is formed thereon. Subsequently, as shown in FIG.
The TFT 4 is manufactured using a manufacturing process. Thereafter, a not-shown interlayer film contact hole, a transparent electrode, and the like are formed to manufacture an LCD substrate.

As described above, according to the third embodiment, the following effects can be obtained. The first effect is that the unevenness of the LCD substrate is reduced by improving the flatness.
Because of the flatness, problems such as poor cleaning and etching residues caused by steps of the light-shielding film 35 do not occur. The second effect is that the relationship between the light-shielding film 35 and the transparent insulating layer 37 can be arbitrarily determined from the depth of the dug portion 2, the thickness of the aluminum 3 and the polishing amount.

It should be noted that the present invention is not limited to the above embodiments, and it is clear that each embodiment can be appropriately modified within the scope of the technical idea of the present invention. Further, the number, position, shape, and the like of the constituent members are not limited to the above-described embodiment, and can be set to suitable numbers, positions, shapes, and the like for implementing the present invention. In each drawing, the same components are denoted by the same reference numerals.

[0016]

Since the present invention is configured as described above, the following effects can be obtained. The first effect is that the unevenness of the LCD substrate is reduced by the improvement of the flatness, and problems such as poor cleaning and etching residue due to the step of the light shielding film due to the flatness do not occur. And the second
The effect of (1) is that the relationship between the light-shielding film and the transparent insulating layer can be arbitrarily determined from the depth of the dug portion, the film thickness of aluminum and the polishing amount.

[Brief description of the drawings]

FIG. 1 is a process diagram for explaining a semiconductor device and a semiconductor manufacturing method according to a first embodiment of the present invention.

FIG. 2 is a process diagram illustrating a semiconductor device and a semiconductor manufacturing method according to a second embodiment of the present invention.

FIG. 3 is a process diagram illustrating a semiconductor device and a semiconductor manufacturing method according to a third embodiment of the present invention.

FIG. 4 is a plan view of a conventional semiconductor device.

FIG. 5 is a cross-sectional view of the semiconductor device of FIG. 4 taken along the line AA ′ of FIG. 4;

FIG. 6 shows an etching residue generated in the semiconductor device of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Glass substrate 2 ... Digging part 3 ... Aluminum 4 ... TFT (thin film transistor) 11 ... Photoresist (PR) 31 ... Aluminum 32 ... Transparent insulating layer 33 ... Aluminum 34 ... Transparent insulating layer 35 ... Light shielding film 36 ... Aluminum 37 ... Transparent insulating layer 38: insulating film D: gate line G: data line

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 29/786 H01L 21/336 G02F 1/1368

Claims (5)

(57) [Claims] 1. A step of forming a dug portion on the surface of a transparent insulating substrate, a step of forming a metal film having a thickness greater than the depth of the dug portion, and a step of flattening the surface of the metal film Anodizing the metal film to leave the metal film inside the dug portion, and forming a transparent insulating layer in a region other than the inside of the dug portion; Forming a thin film transistor. 2. The step of flattening the surface of the metal film,
The method according to claim 1, wherein the method is performed by polishing. 3. The method according to claim 1, wherein aluminum is used for the metal film. 4. A step of forming a dug portion on a surface of a transparent insulating substrate using a photoresist as a mask, forming a first metal film, and forming the first metal film only on the dug portion using a lift-off method. Leaving a metal film, forming a second metal film over the entire upper surface of the transparent insulating substrate including the region of the dug portion, and anodizing all of the second metal film. Forming a thin film transistor on the first metal film. 5. A step of forming a dug portion on a surface of a transparent insulating substrate using a photoresist as a mask, forming a metal film having a thickness equal to or less than a depth of the dug portion, and using a lift-off method. Leaving the metal film only in the dug portion, forming the transparent insulating layer on the inner upper portion of the dug portion, while anodizing the metal film to leave the metal film in the lower inner portion of the dug portion. Manufacturing a semiconductor device, comprising: forming an insulating film on the entire upper surface of the transparent insulating substrate including the region of the dug portion; and forming a thin film transistor on the metal film. Method.