JPH0926669A - Production of photoresist film pattern and production of processed body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production technique of a photoresist film pattern with which a body to be processed can be easily and precisely processed. SOLUTION: This method includes the following processes. After a photoresist film 11 is formed on a wiring layer 10 as the material to be processed, the photoresist film 11 is subjected to surface treatment by using HMDS to form a photoresist modified film 13 on the surface of the resist film 11. After a photoresist film 14 is formed on the photoresist modified film 13, the photoresist film 11 and the photoresist film 14 are selectively removed by a photolithographic technique to form a patterned photoresist film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a photoresist film pattern and a method of manufacturing an object to be processed using the same, and particularly to a method of selectively etching an object to be processed which requires fine processing. The present invention relates to a technique effectively applied to a technique for manufacturing a photoresist film pattern used as an etching mask.

[0002]

2. Description of the Related Art In a manufacturing process of a semiconductor integrated circuit device, it is often used to selectively etch a work piece by using a photolithography technique and a selective etching technique.

In this case, it is necessary to form a photoresist film serving as an etching mask on the surface of the object to be processed.

In the manufacturing process of a semiconductor integrated circuit device studied by the present inventor, a photoresist film pattern is formed by spin coating a single layer photoresist film on an object to be processed such as a semiconductor substrate or a wiring layer. After that, an exposure and development process is performed to form a pattern serving as an etching mask on the photoresist film.

The above-mentioned single-layer resist method has a low resolution and a low contrast and is susceptible to reflected light from the object to be processed, which causes problems such as halation. Multi-layer resist method or PCM using anti-reflection film to prevent reflection
(Portable Comformable Mask) method is considered.

[0006] As a document describing the photolithography technique using photoresist, for example, Press Journal Co., Ltd., issued November 2, 1989, "'90 latest semiconductor process technology" p113 to p1.
17 are listed.

[0007]

However, the present inventor has found that the above-described method for forming a photoresist film pattern has various problems.

That is, when the etching selectivity is low when selectively removing an unnecessary region by using a photoresist film as an etching mask on a workpiece such as a semiconductor substrate or a wiring layer to selectively etch the workpiece. In, the photoresist film is also etched, so that a thick photoresist film pattern is required.

In this case, the single-layer resist method has a problem that the resolution of the photoresist film decreases as the film thickness increases.

In the multi-layer resist method, the problems in the single-layer resist method described above can be avoided, but the complicated manufacturing process and the use of a high-priced photoresist film cause economic and mass production problems. .

Further, in the multi-layer resist method, when the photoresist film is formed by applying it by using a spin coating device such as an ordinary spinner, the mutual effect of the laminated photoresist films causes a mutual chemical reaction. There arises a problem that a photoresist film having a multilayer structure cannot be formed in a separated state.

An object of the present invention is to provide a technique for manufacturing a photoresist film pattern, which allows a work piece to be simply and finely processed.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0014]

The typical ones of the inventions disclosed in the present invention will be outlined below.

According to the method of manufacturing a photoresist film pattern of the present invention, after the first photoresist film is formed on the object to be processed, the surface treatment of the first photoresist film is performed.
Forming a modified photoresist film on the surface of the photoresist film, and after forming a second photoresist film on the modified photoresist film, the first photoresist film and the second photoresist film are exposed to light. And a step of forming a patterned photoresist film by selectively removing using a lithographic technique.

[0016]

According to the above-described method of manufacturing a photoresist film pattern of the present invention, after the first photoresist film is formed on the object to be processed, the surface treatment of the first photoresist film is performed to make the first photoresist film. Forming a photoresist modified film on the surface of the photoresist film, forming a second photoresist film on the photoresist modified film, and then patterning with the first photoresist film and the second photoresist film And a step of forming a photoresist film formed on the first photoresist film.
It is possible to obtain a laminated structure in which the first photoresist film and the second photoresist film are chemically separated from each other without being dissolved at the time of application of the photoresist film.

As a result, the photoresist film having a laminated structure can be easily manufactured and the photoresist films chemically separated from each other can be formed.
Since the second photoresist film can be thinned, a high resolution photoresist film pattern can be easily manufactured.

According to the above-described method for producing a photoresist film pattern of the present invention, a photoresist film pattern having a high resolution can be produced. Therefore, the photoresist film pattern is used as an etching mask to selectively etch an object to be processed. A fine pattern can be formed when forming the pattern of the processed body.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. In all the drawings for explaining the embodiments, those having the same function are designated by the same reference numerals, and a duplicate description will be omitted.

1 to 9 are sectional views showing a manufacturing process of a semiconductor integrated circuit device according to an embodiment of the present invention. The method for manufacturing a photoresist film pattern of the present invention and the method for manufacturing a semiconductor integrated circuit device as a workpiece using the same will be specifically described with reference to FIG.

First, as shown in FIG. 1, a field formed of a silicon oxide film is applied to an element isolation region, which is a selective region on the surface of a semiconductor substrate 1 made of, for example, p-type silicon single crystal, by using a thermal oxidation process. The insulating film 2 is formed. Although not shown, a channel stopper layer for preventing inversion is formed under the field insulating film 2.

Next, as shown in FIG. 2, a gate insulating film 3 made of silicon oxide is formed in the active region surrounded by the field insulating film 2, and a gate electrode made of polycrystalline silicon is formed on the gate insulating film 3. 4 is formed. The gate electrode 4 is formed by sequentially depositing an insulating film 5 made of a polycrystalline silicon film and a silicon oxide film on the semiconductor substrate 1 and etching these sequentially. Thereafter, a sidewall insulating film 6 made of silicon oxide is formed on the side wall of the gate electrode 4.

Next, an n-type impurity such as phosphorus (P) is ion-implanted into the semiconductor substrate 1 to form an n-type semiconductor region 7 serving as a source and a drain.

Next, as shown in FIG. 3, an insulating film 8 is formed on the semiconductor substrate 1. As the insulating film 8, a silicon oxide film or the like formed by the CVD method can be used.

In the manufacturing process of the semiconductor integrated circuit device described above, a p-channel MOS is used as a semiconductor element on the semiconductor substrate 1.
Although a FET is formed, an n-channel MOSFET other than a p-channel MOSFET, a CM is formed on the semiconductor substrate 1.
A mode in which various semiconductor elements such as an OSFET, a bipolar transistor, and a capacitive element are formed can be adopted.

Further, as a substrate for forming a semiconductor element, for example, an SOI (Silico) which is a substrate different from the semiconductor substrate is used.
An SOI substrate in which a single crystal thin film of silicon is formed on an insulating region having a non-insulator structure can be used.

The manufacturing process of the semiconductor integrated circuit device described above can be performed by combining various prior arts. The main part of the method for manufacturing a semiconductor integrated circuit device of the present invention is a manufacturing technique for processing a wiring layer of the semiconductor integrated circuit device using a photoresist film pattern. In view of this, in order to simplify the description from now on, the semiconductor substrate 1 formed by the above-described manufacturing process is comprehensively illustrated as the substrate 9 in which the p-channel MOSFET is formed as the starting material, and the internal structure is shown. The internal structure of the base body 9 having the above is omitted, and the dimensions shown in the drawing are reduced.

Next, as shown in FIG. 4, the first wiring layer 10 is formed on the surface of the substrate 9. First wiring layer 10
For example, an aluminum layer is formed by a sputtering method.

As the material of the wiring layer 10, in order to secure the characteristics of stress migration resistance and electromigration resistance, a titanium nitride (TiN) layer or the like is used as the lower or upper layer of the aluminum layer as the wiring layer 10. A wiring layer in which a wiring structure is laminated by using a refractory metal layer can be used. Also,
As the wiring layer 10, it is possible to use a combination of a polycrystalline silicon layer or a layer having a polycrystal silicon layer and a high melting point silicide layer and having electrical conductivity, for example.

The wiring layer 10 includes a wiring layer electrically connected to the n-type semiconductor region 7 through a through hole provided in the insulating film 8 in a region (not shown). It also includes a wiring layer to be used.

Next, a photoresist film 11 is formed on the surface of the wiring layer 10 by a spin coating method.

As the photoresist film 11, a positive type photoresist film made of a material having a high light absorption property so as to function as an antireflection film is used.

Various photoresist films can be used as the photoresist film 11. However, since the photoresist film 11 has a laminated structure, it does not lose its photosensitivity even when subjected to various high temperature baking treatments. It is better to use one. It is also preferable to use a photoresist film having a low hydrophilic group content.

Since the photoresist film 11 is formed by a spin coating method using a spin coating device such as a spinner, its surface can be flattened.

Further, even if the surface of the workpiece such as the wiring layer 10 as the base is not flattened, it can be flattened by the photoresist film 11.

Next, the photoresist film 11 is prebaked.

Next, as shown in FIG. 5, the photoresist film 11 is subjected to a surface treatment using HMDS (Hexa Methyl DiSilazane hexamethyldisilazane) 12, and then baked to form a photoresist altered film 13
To form

The step of forming the photoresist altered film 13 by subjecting the photoresist film 11 to the surface treatment is performed by the HM
As a pretreatment or a posttreatment for the surface treatment using DS, a dehydration baking treatment may be performed to remove the adsorbed moisture. The process of removing the adsorbed moisture may be performed by setting the substrate 9 in a wafer state in a closed container containing silica gel and vacuum-treating the inside of the closed container.

Next, as shown in FIG. 6, a photoresist film 14 is formed on the photoresist altered film 13 by a spin coating method.

As the photoresist film 14, a positive type photoresist film made of a material having a sensitivity lower than that of the photoresist film 11 formed in the previous step but having a high resolution is used.

Next, the photoresist film 14 is prebaked.

In this case, since the altered photoresist film 13 is formed on the photoresist film 11,
It is possible to obtain a laminated structure in which the photoresist film 14 is not dissolved during application and the photoresist film 11 and the photoresist film 14 are chemically separated from each other.

Next, as shown in FIG. 7, a photomask 15 having a chrome pattern 16 is formed by using a projection exposure apparatus.
Is used to irradiate the positive type photoresist film 14 and the positive type photoresist film 11 thereunder with ultraviolet rays 17 to perform exposure.

Next, as shown in FIG. 8, the photoresist film 14 and the photoresist film 11 thereunder are subjected to a developing treatment to remove the exposed portion, so that the positive photoresist film 11 as the non-exposed portion is removed. Then, the patterns of the altered photoresist film 13 and the positive photoresist film 14 are formed. This patterned photoresist film is
It functions as an etching mask.

In this case, the positive photoresist film 11
Has a higher sensitivity than the positive type photoresist film 14, so that the pattern width a of the lower photoresist film 11 can be formed smaller than the pattern width b of the upper photoresist film 14.

Further, since the positive type photoresist film 14 has a higher resolution than the positive type photoresist film 11, the resolution of the photoresist film pattern as a whole depends on the performance of the upper photoresist film 14. Can be defined by

In the above-described development processing step of this embodiment, the photoresist film 14 and the photoresist film 11 thereunder are processed.
Although the developing treatment of 1 is performed in the same step, the developing treatment of different steps may be performed depending on the materials of the photoresist film 14 and the photoresist film 11 thereunder.

Next, as shown in FIG. 9, the surface is exposed by using the photoresist film pattern of the laminated structure composed of the photoresist film 11, the photoresist alteration film 13 and the photoresist film 14 as an etching mask. The patterned wiring layer 10 is formed by selectively etching and removing the existing wiring layer 10 using a selective etching technique such as dry etching.

Next, the work of removing the photoresist film 11, the photoresist altered film 13, and the photoresist film 14, which are unnecessary photoresist film patterns, is performed.

Next, a plurality of interlayer insulating films and upper wiring layers are formed on the wiring layer 10 if necessary, and then a surface protective film (for example, a nitric oxide film) is formed on the uppermost wiring layer. By omitting), the manufacturing process of the semiconductor integrated circuit device is completed.

The following effects can be achieved in the technique of manufacturing the photoresist film pattern in the manufacturing process of the semiconductor integrated circuit device of the present embodiment described above.

(1) After the photoresist film 11 is formed on the wiring layer 10 which is the object to be processed, the surface treatment of the photoresist film 11 is performed and the photoresist alteration film 13 is formed on the surface of the photoresist film 11. And a step of forming a photoresist film 14 on the photoresist altered film 13 and then forming a photoresist film patterned by the photoresist film 11 and the photoresist film 14. Since the photoresist-altered film 13 is formed on the photoresist film 11, the photoresist film 14 is not dissolved during application, and the photoresist film 11 and the photoresist film 14 are chemically separated from each other. A laminated structure of the state can be used.

As a result, it is possible to easily manufacture a photoresist film having a laminated structure and to form photoresist films which are chemically separated from each other.
Since the photoresist film 14 can be thinned, a high resolution photoresist film pattern can be easily manufactured.

(2) Since the lower photoresist film 11 in the photoresist film pattern of the laminated structure can have a function as an antireflection film, the wiring layer 10 or the like as a base is covered during the exposure process. It is possible to prevent the reflected light from the processed body and to eliminate the need for the photoresist film 14 to have the light absorption performance, so that the resolution can be improved.

(3) Since a photoresist film pattern having a high resolution can be formed on the wiring layer 10 which is the object to be processed, it can be used as an etching mask and the photoresist layer pattern which is the object to be processed, for example the wiring layer 10. A fine pattern can be formed when the pattern of the wiring layer 10, which is the object to be processed, is formed by performing selective etching.

As described above, the invention made by the inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and can be variously modified without departing from the gist thereof. Needless to say.

For example, in the above-described embodiments, the manufacturing technology of the semiconductor integrated circuit device was used, but it can be applied to the manufacturing technology of the display device such as liquid crystal or the object to be processed which requires fine processing.

[0058]

Advantageous effects obtained by typical ones of the inventions disclosed by the present application will be briefly described as follows.
It is as follows.

(1) According to the method of manufacturing a photoresist film pattern of the present invention, after the first photoresist film is formed on the workpiece, for example, the wiring layer, the surface of the first photoresist film is formed. A step of performing a treatment to form a photoresist-altered film on the surface of the first photoresist film; and after forming a second photoresist film on the photoresist-altered film, the first photoresist film and the second photoresist film are formed. Since the photoresist alteration film is formed on the first photoresist film, the second photoresist film is formed on the first photoresist film. It is possible to obtain a laminated structure in which the first photoresist film and the second photoresist film are chemically separated from each other without being dissolved at the time of application.

As a result, the photoresist film having the laminated structure can be easily manufactured, and the photoresist films chemically separated from each other can be formed.
Since the photoresist film can be thinned, a high resolution photoresist film pattern can be easily manufactured.

(2) Since the first photoresist film under the photoresist film pattern of the laminated structure can have a function as an antireflection film, a wiring layer as a base or the like can be formed in the exposure process. It is possible to prevent the reflected light from the object to be processed and to eliminate the need for the second photoresist film to have the light absorption performance, so that the resolution can be increased.

(3) Since a photoresist film pattern having a high resolution can be formed on a wiring layer, which is an object to be processed, it can be used as an etching mask to selectively etch the wiring layer, which is an object to be processed. When performing the above to form a pattern of a wiring layer, which is the object to be processed, a finely processed pattern can be formed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a manufacturing process of a semiconductor integrated circuit device which is an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a manufacturing process of a semiconductor integrated circuit device which is an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a manufacturing process of a semiconductor integrated circuit device which is an embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a manufacturing process of a semiconductor integrated circuit device which is an embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a manufacturing process of a semiconductor integrated circuit device which is an embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a manufacturing process of a semiconductor integrated circuit device which is an embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a manufacturing process of a semiconductor integrated circuit device which is an embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a manufacturing process of a semiconductor integrated circuit device which is an embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a manufacturing process of a semiconductor integrated circuit device which is an embodiment of the present invention.

[Description of Reference Signs] 1 semiconductor substrate 2 field insulating film 3 gate insulating film 4 gate electrode 5 insulating film 6 sidewall insulating film 7 n-type semiconductor region 8 insulating film 9 substrate 10 wiring layer 11 photoresist film 12 HMDS 13 photoresist alteration Film 14 Photoresist film 15 Photomask 16 Chrome pattern 17 Ultraviolet

Claims (7)

[Claims] 1. A step of forming a first photoresist film on an object to be processed, and a surface treatment of the first photoresist film.
Forming a modified photoresist film on the surface of the photoresist film, forming a second photoresist film on the modified photoresist film, the first photoresist film and the second photoresist film And a step of forming a patterned photoresist film by selectively removing the resist film using a photolithography technique. 2. The method of manufacturing a photoresist film pattern according to claim 1, wherein the surface treatment of the first photoresist film is a surface treatment using HMDS. Method. 3. The method of manufacturing a photoresist film pattern according to claim 1, wherein the first photoresist film is a photoresist film having a higher sensitivity than the second photoresist film. A method for manufacturing a photoresist film pattern, comprising: 4. The method of manufacturing a photoresist film pattern according to claim 1, 2 or 3, wherein the first photoresist film and the second photoresist film are capable of being developed in the same process. A method of manufacturing a photoresist film pattern, comprising: 5. The method of manufacturing a photoresist film pattern according to claim 1, 2, 3 or 4, wherein the first photoresist film is a photoresist film having a function as an antireflection film. A method for producing a characteristic photoresist film pattern. 6. A step of forming a first photoresist film on a body to be processed, and a surface treatment of the first photoresist film
Forming a modified photoresist film on the surface of the photoresist film, forming a second photoresist film on the modified photoresist film, the first photoresist film and the second photoresist film A step of forming a patterned photoresist film by selectively removing the resist film using a photolithography technique, and the surface is exposed by using the patterned photoresist film as an etching mask And a step of patterning the object to be processed by removing the object to be processed by etching. 7. The method for manufacturing a work piece according to claim 6, wherein the work piece is a work piece for manufacturing a semiconductor integrated circuit device.