JP2005084312A - Resist patterning method and method for manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist patterning method yielding finer resist patterns than resolution of an exposure apparatus and capable of processing, in a relatively short process, even a multilayer photoresist film (having a plurality of layers), and to provide a method for manufacturing a semiconductor device. <P>SOLUTION: The method for manufacturing a semiconductor device includes the steps of: applying a first positive photoresist film 4 on an interlayer insulating film 3; applying a second positive photoresist film 5 having a sensitivity lower than that of the first positive resist film 4 on the first positive photoresist film 4; exposing and developing the first and second positive photoresist films together to form a resist pattern 7 on the interlayer insulating film 3; and etching the interlayer insulating film 3 by using the resist pattern 7 as a mask to form a pattern of holes 3a in the interlayer insulating film 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a resist patterning method and a semiconductor device manufacturing method. In particular, the present invention relates to a resist patterning method and a semiconductor device manufacturing method that can obtain a fine resist pattern compared to the resolution of an exposure apparatus and that can be processed in a relatively short process even when a multilayer (multiple layer) photoresist film is used. .

Hereinafter, a conventional method for manufacturing a semiconductor device will be described.
First, a film to be etched is formed on a silicon substrate (wafer). As the film to be etched, various films such as an insulating film and a conductive film are used. Next, a single layer of a photoresist film is applied on the etching target film, and the photoresist film is exposed and developed to form a resist pattern on the etching target film.

  Next, the etched film is etched using the resist pattern as a mask, thereby processing the etched film into a desired pattern shape. Next, the resist pattern is removed. In this way, an etched film processed into a desired pattern shape is formed on the silicon substrate.

  In the conventional method for manufacturing a semiconductor device, since a resist pattern is formed by a single layer of a photoresist film, only a fine resist pattern corresponding to the resolution of the exposure apparatus can be obtained. Therefore, it is difficult to obtain a fine resist pattern if the exposure apparatus has a low resolution.

Next, another conventional method for manufacturing a semiconductor device will be described.
First, a film to be etched is formed on a silicon substrate (wafer). Next, a first photoresist film having no photosensitivity is applied on the etching target film and baked, and then a second photoresist film having photosensitivity on the first photoresist film is applied. In order to prevent intermixing between the first photoresist film and the second photoresist film, an intermediate such as SOG (spin on glass) is provided between the first photoresist film and the second photoresist film. Layers may be inserted.

  Next, by exposing and developing the second photoresist film, a first resist pattern is formed on the first photoresist film. Next, by etching the first photoresist film using the first resist pattern as a mask, a second resist pattern made of the first photoresist film having the same pattern as the first resist pattern is formed. .

  Next, by etching the film to be etched using the first and second resist patterns as a mask, the film to be etched is processed into a desired pattern shape. Next, the first and second resist patterns are removed. In this way, an etched film processed into a desired pattern shape is formed on the silicon substrate.

  In the other conventional semiconductor device manufacturing methods, since the two-layer photoresist film is used, the thickness of the second photoresist film that is photosensitive compared to the above-described conventional semiconductor device manufacturing method is reduced. Can be thinned. This makes it possible to form a fine resist pattern as compared with the conventional method for manufacturing a semiconductor device.

  However, since a step of etching the first photoresist film is required, there is a problem that the process becomes longer and complicated as compared with the conventional method for manufacturing a semiconductor device.

JP 2002-124448 A

As described above, in the conventional method for manufacturing a semiconductor device, it is difficult to obtain a fine resist pattern as compared with the resolution of the exposure apparatus. Another conventional method for manufacturing a semiconductor device has a problem that the process becomes long and complicated when a two-layer photoresist film is used.
The present invention has been made in consideration of the above-described circumstances, and an object thereof is to obtain a fine resist pattern as compared with the resolution of an exposure apparatus and to use a multilayer (multiple layer) photoresist film. Another object of the present invention is to provide a resist patterning method and a semiconductor device manufacturing method that can be processed in a relatively short process.

In order to solve the above problems, a resist patterning method according to the present invention includes a first step of applying a first positive photoresist film on a substrate or a base film,
A second step of applying a second positive photoresist film having a lower sensitivity than the first positive photoresist film on the first positive photoresist film;
A third step of forming a resist pattern on the substrate or the base film by collectively exposing and developing the first and second positive photoresist films;
It comprises.

  According to the resist patterning method, since the second positive photoresist film uses a low-sensitivity resist material, the portion where the second positive photoresist film is dissolved by the developer is irradiated with exposure light. It is a slightly narrower area than the part. In contrast, since the first positive photoresist film uses a highly sensitive resist material, the portion where the first positive photoresist film is dissolved by the developer is slightly more than the portion irradiated with the exposure light. It becomes a wide area. Therefore, a fine resist pattern can be obtained even with an exposure apparatus having a low resolution. In the resist patterning method, the first and second positive photoresist films are exposed and developed in a lump, so that the step of etching the underlying photoresist as in the prior art becomes unnecessary. Therefore, even if a multilayer (multiple layers) photoresist film is used, it can be processed in a relatively short process.

The resist patterning method according to the present invention preferably further includes a step of heating and curing the first positive photoresist film between the first step and the second step.
In the resist patterning method according to the present invention, a step of performing an alkali treatment by immersing the first positive photoresist film in a developer between the heating and curing step and the second step. It is also possible to further comprise.

The resist patterning method according to the present invention may further include a step of heating and curing the first positive photoresist film between the alkali treatment step and the second step. It is.
The resist patterning method according to the present invention further includes a step of heating and curing the first and second positive photoresist films between the second step and the third step. It is preferable.

The resist patterning method according to the present invention includes a first step of applying a first negative photoresist film on a substrate or a base film,
Applying a second negative photoresist film having higher sensitivity than the first negative photoresist film on the first negative photoresist film; and
A third step of forming a resist pattern on the substrate or the base film by exposing and developing the first and second negative photoresist films in a lump;
It comprises.

  According to the resist patterning method, since the second negative photoresist film uses a highly sensitive resist material, the portion where the second negative photoresist film is not dissolved by the developer is irradiated with exposure light. It becomes a slightly larger area than the marked part. On the other hand, since the first negative photoresist film uses a low-sensitivity resist material, the portion where the first negative photoresist film is not dissolved by the developer is more than the portion irradiated with the exposure light. It becomes a somewhat narrow area. Therefore, a fine resist pattern can be obtained even with an exposure apparatus having a low resolution. Further, since the first and second negative photoresist films are exposed and developed in a lump, the step of etching the underlying photoresist as in the prior art becomes unnecessary. Therefore, even if a multilayer (multiple layers) photoresist film is used, it can be processed in a relatively short process.

A method of manufacturing a semiconductor device according to the present invention includes a step of applying a first positive photoresist film on a film to be etched,
Applying a second positive photoresist film having a lower sensitivity than the first positive photoresist film on the first positive photoresist film;
Forming a resist pattern on the etched film by exposing and developing the first and second positive photoresist films at once; and
Etching the etched film using the resist pattern as a mask to form a pattern made of the etched film; and
It comprises.

  According to the semiconductor device manufacturing method, a fine resist pattern can be obtained even with an exposure apparatus having a low resolution. That is, even when the same exposure apparatus is used, a fine resist pattern can be obtained as compared with the conventional resist patterning method. A fine pattern can be formed by using the resist pattern. In the semiconductor device manufacturing method, since the first and second positive photoresist films are exposed and developed in a lump, the step of etching the underlying photoresist as in the prior art becomes unnecessary. . Therefore, even if a multilayer (multiple layers) photoresist film is used, it can be processed in a relatively short process.

A method of manufacturing a semiconductor device according to the present invention includes a step of applying a first positive photoresist film on a substrate or a base film,
Applying a second positive photoresist film having a lower sensitivity than the first positive photoresist film on the first positive photoresist film;
Forming a resist pattern on the substrate or the base film by exposing and developing the first and second positive photoresist films in a lump;
Introducing impurities into the substrate or the base film using the resist pattern as a mask;
It comprises.

A method of manufacturing a semiconductor device according to the present invention includes a step of applying a first negative photoresist film on a film to be etched,
Applying a second negative photoresist film having higher sensitivity than the first negative photoresist film on the first negative photoresist film;
Forming a resist pattern on the etched film by exposing and developing the first and second negative photoresist films at once;
Etching the etched film using the resist pattern as a mask to form a pattern made of the etched film; and
It comprises.

  According to the semiconductor device manufacturing method, a fine resist pattern can be obtained even with an exposure apparatus having a low resolution. That is, even when the same exposure apparatus is used, a fine resist pattern can be obtained as compared with the conventional resist patterning method. A fine pattern can be formed by using the resist pattern. Further, in the semiconductor device manufacturing method, since the first and second negative photoresist films are exposed and developed in a lump, the step of etching the underlying photoresist as in the prior art becomes unnecessary. . Therefore, even if a multilayer (multiple layers) photoresist film is used, it can be processed in a relatively short process.

A method of manufacturing a semiconductor device according to the present invention includes a step of applying a first negative photoresist film on a substrate or a base film,
Applying a second negative photoresist film having higher sensitivity than the first negative photoresist film on the first negative photoresist film;
Forming a resist pattern on the substrate or the base film by exposing and developing the first and second negative photoresist films at once; and
Introducing impurities into the substrate or the base film using the resist pattern as a mask;
It comprises.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described below with reference to the drawings.
(Embodiment 1)
1A to 1D are cross-sectional views illustrating a method for manufacturing a semiconductor device according to a first embodiment of the present invention. This method for manufacturing a semiconductor device includes a resist patterning method.

  First, as shown in FIG. 1A, a first interlayer insulating film 1 made of a silicon oxide film or the like is formed on a silicon substrate (wafer) (not shown) by a CVD (chemical vapor deposition) method. An Al alloy film is formed on the first interlayer insulating film 1 by sputtering, and the Al alloy wiring 2 is formed on the first interlayer insulating film 1 by patterning the Al alloy film.

Next, a second interlayer insulating film 3 made of a silicon oxide film or the like is formed on the Al alloy wiring 2 and the first interlayer insulating film 1 by a CVD method.
Next, a first positive photoresist film 4 is applied on the second interlayer insulating film 3 by a spin coater (spin coat or spinner) (not shown). That is, after a predetermined amount of the first photoresist solution is dropped on the second interlayer insulating film 3, the silicon substrate is rotated to apply the first photoresist solution to the entire upper surface of the second interlayer insulating film 3. Expand to be uniform. In this way, the first positive type photoresist film 4 is applied on the second interlayer insulating film 3.

Next, the first positive photoresist film 4 is cured by heating at 60 ° C. for 10 minutes.
Thereafter, as shown in FIG. 1B, a second positive photoresist film 5 is applied on the first positive photoresist film 4 by a spin coater (not shown) (spin coater or spinner). That is, after a predetermined amount of the second photoresist liquid is dropped on the first positive photoresist film 4, rotation is applied to the silicon substrate, and the second photoresist liquid is applied to the first positive photoresist film 4. It is expanded to be uniform over the entire top surface. In this way, the second positive photoresist film 5 is applied on the first positive photoresist film 4.

  A resist material having a lower sensitivity than the first positive photoresist film 4 is used for the second positive photoresist film 5. That is, the second positive photoresist film 5 is made of a resist material having a relatively low sensitivity, and the first positive photoresist film 4 is made of a resist material having a relatively high sensitivity.

Next, the baking process which heats at the temperature of 60 degreeC for 2 hours is performed. The purpose of this baking process is to solidify the first and second positive photoresist films 4 and 5 and to improve the adhesion between the first positive photoresist film 4 and the second interlayer insulating film 3. That is.
Next, the first and second positive photoresist films 4 and 5 are collectively exposed by irradiating exposure light (ultraviolet rays) 6 through a photomask (not shown).

  Thereafter, as shown in FIG. 1C, the first and second positive photoresist films 4 and 5 are collectively developed using a developer. Thereby, a resist pattern 7 is formed on the second interlayer insulating film 3. The resist pattern 7 is formed by a pattern 4a made of a first positive photoresist film and a pattern 5a made of a second positive photoresist film.

  Since the second positive photoresist film 5 uses a low-sensitivity resist material, the portion where the second positive photoresist film is dissolved by the developing solution is slightly narrower than the portion irradiated with the exposure light 6. It becomes. On the other hand, since the first positive photoresist film 4 uses a highly sensitive resist material, the portion where the first positive photoresist film is dissolved by the developer is the portion irradiated with the exposure light 6. It becomes a slightly wider area. Therefore, a fine resist pattern 7 can be obtained even with an exposure apparatus having a low resolution.

  Next, as shown in FIG. 1D, holes (openings) 3a are formed in the second interlayer insulating film 3 by dry etching the second interlayer insulating film 3 using the resist pattern 7 as a mask. It is formed. In this way, the holes 3 a having a fine pattern can be formed in the second interlayer insulating film 3.

  According to the first embodiment, a fine resist pattern 7 can be obtained even with an exposure apparatus having a low resolution as described above. In other words, if the resist patterning method of this embodiment is used, a fine resist pattern can be obtained as compared with the conventional resist patterning method even when the same exposure apparatus is used. By using the resist pattern, a pattern such as a fine hole can be formed.

  In the present embodiment, since the first and second positive photoresist films 4 and 5 are exposed and developed in a lump, there is no need to etch the underlying photoresist as in the prior art. Become. Therefore, even if a multilayer (multiple layers) photoresist film is used, it can be processed in a relatively short process.

  In the first embodiment, after the first positive photoresist film 4 is applied and the first positive photoresist film 4 is heated and cured, the second positive photoresist film 4 is applied. Although the resist film 5 is applied, the first positive photoresist film 4 is applied, and the first positive photoresist film 4 is heated and cured to be baked to obtain the first positive photoresist. After the film 4 is immersed in a developing solution and subjected to alkali treatment to make the first positive photoresist film insoluble, a second positive photoresist film is applied onto the first positive photoresist film. It is also possible. Thus, the resist pattern can be made finer by performing the process of making the first positive photoresist film insoluble.

  In the first embodiment, after the first positive photoresist film 4 is applied and the first positive photoresist film 4 is heated and cured, the second positive photoresist film 4 is applied. Although the resist film 5 is applied, the first positive photoresist film 4 is applied, and the first positive photoresist film 4 is heated and cured to be baked to obtain the first positive photoresist. After the film 4 is immersed in a developing solution and subjected to an alkali treatment to make the first positive photoresist film insoluble, and further, the first positive photoresist film 4 is baked to be cured by heating. It is also possible to apply a second positive photoresist film on the first positive photoresist film. Thereby, the resist pattern can be further miniaturized.

  In the first embodiment, after the first positive photoresist film 4 is applied and the first positive photoresist film 4 is heated and cured, the second positive photoresist film 4 is applied. Although the resist film 5 is applied, the first positive type photoresist film 4 is applied, and the first positive type photoresist film 4 is immersed in a developer to perform an alkali treatment, thereby performing the first positive type. After making the photoresist film insoluble and baking the first positive photoresist film 4 by heating and curing, a second positive photoresist film is applied on the first positive photoresist film It is also possible to do. Thereby, the resist pattern can be further miniaturized.

  In the first embodiment, the second interlayer insulating film 3 is etched using the resist pattern 7 as a mask. However, the conductive film is etched using the resist pattern as a mask to form a fine gate electrode or fine wiring. Etc. can also be formed.

  In the first embodiment, the present invention is applied to the process of etching the second interlayer insulating film 3 using the resist pattern 7 as a mask. However, the present invention is not limited to such an etching process. In addition, the present invention can be applied to a process of introducing impurities into a silicon substrate or a base film using a resist pattern as a mask.

(Embodiment 2)
2A to 2D are cross-sectional views showing a method of manufacturing a semiconductor device according to the second embodiment of the present invention. The same reference numerals are given to the same parts as in FIG. 1, and only different parts will be described. .

  As shown in FIG. 2A, a first negative photoresist film 8 is applied on the second interlayer insulating film 3 by a spin coater (spin coater or spinner) (not shown). That is, after a predetermined amount of the first photoresist solution is dropped on the second interlayer insulating film 3, the silicon substrate is rotated to apply the first photoresist solution to the entire upper surface of the second interlayer insulating film 3. Expand to be uniform. In this way, the first negative photoresist film 8 is applied on the second interlayer insulating film 3.

Next, the first negative photoresist film 8 is cured by heating at 60 ° C. for 10 minutes.
Thereafter, as shown in FIG. 2B, a second negative photoresist film 9 is applied on the first negative photoresist film 8 by a spin coater (spin coater or spinner) (not shown).

A resist material having a higher sensitivity than that of the first negative photoresist film 8 is used for the second negative photoresist film 9. That is, the second negative photoresist film 9 is made of a resist material having a relatively high sensitivity, and the first negative photoresist film 8 is made of a resist material having a relatively low sensitivity.
Next, the baking process which heats at the temperature of 60 degreeC for 2 hours is performed.

Next, the first and second negative photoresist films 8 and 9 are collectively exposed by irradiating exposure light (ultraviolet rays) 6 through a photomask (not shown).
Thereafter, as shown in FIG. 2C, the first and second negative photoresist films 8 and 9 are collectively developed using a developer. As a result, a resist pattern 10 is formed on the second interlayer insulating film 3. The resist pattern 10 is formed by a pattern 8a made of a first negative photoresist film and a pattern 9a made of a second negative photoresist film.

  Since the second negative photoresist film 9 uses a highly sensitive resist material, the portion where the second negative photoresist film is not dissolved by the developer is slightly wider than the portion irradiated with the exposure light 6. It becomes an area. In contrast, since the first negative photoresist film 8 uses a low-sensitivity resist material, the portion where the first negative photoresist film was not dissolved by the developer was irradiated with the exposure light 6. The area is slightly narrower than the area. Therefore, a fine resist pattern 10 can be obtained even with an exposure apparatus having a low resolution.

  Next, as shown in FIG. 2D, holes (openings) 3a are formed in the second interlayer insulating film 3 by dry etching the second interlayer insulating film 3 using the resist pattern 10 as a mask. It is formed. In this way, the holes 3 a having a fine pattern can be formed in the second interlayer insulating film 3.

In the second embodiment, the same effect as in the first embodiment can be obtained.
That is, as described above, a fine resist pattern 10 can be obtained even with an exposure apparatus having a low resolution. In other words, if the resist patterning method of this embodiment is used, a fine resist pattern can be obtained as compared with the conventional resist patterning method even when the same exposure apparatus is used. By using the resist pattern, a pattern such as a fine hole can be formed.

In the present embodiment, since the first and second negative photoresist films 8 and 9 are exposed and developed in a lump, there is no need to etch the underlying photoresist as in the prior art. Become. Therefore, even if a multilayer (multiple layers) photoresist film is used, it can be processed in a relatively short process.
The present invention is not limited to the first and second embodiments described above, and various modifications can be made without departing from the spirit of the present invention.

Sectional drawing which shows the manufacturing method of the semiconductor device by Embodiment 1 of this invention. Sectional drawing which shows the manufacturing method of the semiconductor device by Embodiment 2 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... 1st interlayer insulation film, 2 ... Al alloy wiring, 3 ... 2nd interlayer insulation film, 4 ... 1st positive photoresist film, 4a ... Pattern by 1st positive photoresist film, 5 ... 2nd positive type photoresist film, 5a ... pattern by 2nd positive type photoresist film, 6 ... exposure light, 7 ... resist pattern, 8 ... 1st negative type photoresist film, 8a ... 1st negative type Pattern by photoresist film, 9 ... second negative photoresist film, 9a ... pattern by second negative photoresist film, 10 ... resist pattern

Claims (10)

A first step of applying a first positive photoresist film on a substrate or a base film;
A second step of applying a second positive photoresist film having a lower sensitivity than the first positive photoresist film on the first positive photoresist film;
A third step of forming a resist pattern on the substrate or the base film by collectively exposing and developing the first and second positive photoresist films;
A resist patterning method comprising: The resist patterning method according to claim 1, further comprising a step of heating and curing the first positive photoresist film between the first step and the second step. 3. The resist patterning according to claim 2, further comprising a step of performing an alkali treatment by immersing the first positive photoresist film in a developer between the heating and curing step and the second step. Method. The resist patterning method according to claim 3, further comprising a step of heating and curing the first positive photoresist film between the step of performing the alkali treatment and the second step. 5. The method according to claim 1, further comprising a step of heating and curing the first and second positive photoresist films between the second step and the third step. 6. Resist patterning method. A first step of applying a first negative photoresist film on a substrate or a base film;
Applying a second negative photoresist film having higher sensitivity than the first negative photoresist film on the first negative photoresist film; and
A third step of forming a resist pattern on the substrate or the base film by exposing and developing the first and second negative photoresist films in a lump;
A resist patterning method comprising: Applying a first positive photoresist film on the film to be etched;
Applying a second positive photoresist film having a lower sensitivity than the first positive photoresist film on the first positive photoresist film;
Forming a resist pattern on the etched film by exposing and developing the first and second positive photoresist films at once; and
Etching the etched film using the resist pattern as a mask to form a pattern made of the etched film; and
A method for manufacturing a semiconductor device comprising: Applying a first positive type photoresist film on a substrate or a base film;
Applying a second positive photoresist film having a lower sensitivity than the first positive photoresist film on the first positive photoresist film;
Forming a resist pattern on the substrate or the base film by exposing and developing the first and second positive photoresist films in a lump;
Introducing impurities into the substrate or the base film using the resist pattern as a mask;
A method for manufacturing a semiconductor device comprising: Applying a first negative photoresist film on the film to be etched;
Applying a second negative photoresist film having higher sensitivity than the first negative photoresist film on the first negative photoresist film;
Forming a resist pattern on the etched film by exposing and developing the first and second negative photoresist films at once;
Etching the etched film using the resist pattern as a mask to form a pattern made of the etched film; and
A method for manufacturing a semiconductor device comprising: Applying a first negative photoresist film on a substrate or undercoat;
Applying a second negative photoresist film having higher sensitivity than the first negative photoresist film on the first negative photoresist film;
Forming a resist pattern on the substrate or the base film by exposing and developing the first and second negative photoresist films at once; and
Introducing impurities into the substrate or the base film using the resist pattern as a mask;
A method for manufacturing a semiconductor device comprising:

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