JP3071401B2 - Fine pattern forming material, method of manufacturing semiconductor device using the same, and semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material for a finely divided resist pattern which reduces the pattern separation size or hole opening size when a resist pattern is formed in a semiconductor process, and a fine separation pattern using the same. The present invention relates to a formation method, a method of manufacturing a semiconductor device using the finely separated resist pattern, and a semiconductor device manufactured by the method.

[0002]

2. Description of the Related Art As semiconductor devices become more highly integrated, wiring and isolation widths required for a manufacturing process are extremely reduced. Generally, a fine pattern is formed by forming a resist pattern by photolithography technology,
Then, using the formed resist pattern as a mask,
It is performed by a method of etching various underlying thin films.

Therefore, photolithography is very important in forming a fine pattern. The photolithography technology is composed of resist coating, mask alignment, exposure, and development, and there is a limit in miniaturization due to the restriction on the exposure wavelength. Further, in the conventional lithography process, it is difficult to control the etching resistance of the resist, and it is not possible to control the surface shape by controlling the etching resistance, for example, to roughen the pattern side wall surface after etching. It was possible.

[0004]

As described above,
With the conventional photolithography technology using exposure, it has been difficult to form a fine resist pattern exceeding the wavelength limit. The present invention provides a water-soluble material that does not dissolve the underlying resist, which realizes the formation of a fine separation resist pattern that enables the formation of a pattern exceeding the wavelength limit in the miniaturization of the separation pattern and the hole pattern.
An object of the present invention is to provide a technique for forming a finely divided resist pattern using the same, and to provide a method for roughening the surface shape of a pattern side wall after etching, which is difficult to control with conventional lithography techniques. It is another object of the present invention to provide a method of manufacturing a semiconductor device using the fine separation resist pattern forming technique, and to provide a semiconductor device manufactured by this manufacturing method.

[0005]

Means for Solving the Problems The fine pattern forming material of the present invention comprises, as a main component, one type of water-soluble resin except polyvinyl alcohol, and comprises water or water and a water-soluble organic solvent.
Dissolve the mixed solvent as a solvent and supply the acid
The first resist pattern formed on the strike pattern
In contact with the first resist pattern by the acid from the resist
A cross-linking reaction occurs at the portion to form a cross-linked film, and the non-cross-linked portion
It is characterized by being peeled off . Further, the fine pattern forming material of the present invention, as the water-soluble resin,
Polyacrylic acid, polyvinyl acetal, Poribinirupi <br/> Rorido down, Po Li ethyleneimine, polyethylene oxide, styrene - maleic anhydride copolymer, polyvinyl amine, polyallylamine, oxazoline group-containing water-soluble resin, water-soluble melamine resins, water sex urea resins, alkyd resins, one kind, and Hakodate these salts of sulfonamide
Or any one of them as a main component.

Further, the fine pattern forming material of the present invention, a mixture of two or more water-soluble resin, or a copolymer with two or more kinds of the water-soluble resin as a main component, water
Alternatively, use a mixed solvent of water and a water-soluble organic solvent
Construed, formed on the first resist pattern supplying acid
The first resist pattern and acid from the first resist pattern.
Rack caused a crosslinking reaction with a portion in contact with the resist pattern
A bridge film is formed, and the non-crosslinked portion is peeled off . Further, the fine pattern forming material of the present invention, as the water-soluble resin, polyacrylic acid, polyvinyl acetal, polyvinyl pyrrolidone, polyvinyl alcohol, polyethylene imine, polyethylene oxide,
One of styrene-maleic anhydride copolymer, polyvinylamine, polyallylamine, oxazoline group-containing water-soluble resin, water-soluble melamine resin, water-soluble urea resin, alkyd resin, sulfonamide, or two of these
It is characterized by a mixture of more than one kind or a salt thereof as a main component.

[0007] The fine pattern forming material of the present invention comprises, as a main component, one kind of water-soluble crosslinking agent or a mixture of two or more kinds of the above-mentioned water-soluble crosslinking agents, and contains water or water and a water-soluble organic compound.
Dissolving a mixed solvent with a solvent as a solvent and supplying an acid;
It made form over the first resist pattern first resist
To the first resist pattern by acid from the pattern
A cross-linking reaction occurs at the contacting part to form a cross-linked film,
The part is peeled off . Also,
The material for forming a fine pattern according to the present invention is characterized in that, as the water-soluble crosslinking agent, one of melamine derivatives, urea derivatives, benzoguanamine, and glycoluril or a mixture of two or more thereof is used as a main component. It is.

[0008] The fine pattern forming material of the present invention is characterized in that the melamine derivative contains one of melamine and alkoxymethylenemelamine or a mixture thereof as a main component. Further, the fine pattern forming material of the present invention comprises, as a main component, one of urea, alkoxymethylene urea, N-alkoxymethylene urea, ethylene urea, ethylene urea carboxylic acid, or a mixture of two or more thereof as the urea derivative. It is characterized by doing.

Further, the fine pattern forming material of the present invention is mainly composed of a mixture of one or more kinds of one or more kinds of water-soluble resin and a water-soluble crosslinking agent, water
Alternatively, use a mixed solvent of water and a water-soluble organic solvent
Construed, formed on the first resist pattern supplying acid
The first resist pattern and acid from the first resist pattern.
Rack caused a crosslinking reaction with a portion in contact with the resist pattern
A bridge film is formed, and the non-crosslinked portion is peeled off . Further, the fine pattern forming material of the present invention uses any one of polyvinyl acetal, polyvinyl alcohol, or a mixture of polyvinyl alcohol and polyvinyl acetal as the water-soluble resin, and a melamine derivative, a urea derivative, or It is characterized in that one of a mixture of a melamine derivative and a urea derivative is used.

The material for forming a fine pattern according to the present invention is characterized by containing a plasticizer as an additive. Further, the fine pattern forming material of the present invention is characterized by containing a surfactant as an additive.

Next, a method of manufacturing a semiconductor device according to the present invention includes a step of forming a first resist pattern capable of supplying an acid onto a semiconductor substrate by using a first resist;
The resist pattern according to any one of claims 1 to 12,
Forming a second layer using the fine pattern forming material described above, and forming a crosslinked film on a portion of the second layer in contact with the first resist pattern by supplying an acid from the first resist pattern. A processing step, a step of peeling off a non-crosslinked portion of the second layer to form a second resist pattern, and a step of etching the semiconductor base material using the second resist pattern as a mask. It is a feature.

Further, the method of manufacturing a semiconductor device according to the present invention is characterized in that the first resist pattern is formed of a resist which generates an acid by heat treatment. Further, a method of manufacturing a semiconductor device according to the present invention is characterized in that the first resist pattern is formed of a resist that generates an acid upon exposure.

In the method of manufacturing a semiconductor device according to the present invention, the first resist pattern is formed of a resist containing an acid. Further, in the method of manufacturing a semiconductor device according to the present invention, the first resist pattern is formed of a resist that has been subjected to a surface treatment with an acidic liquid or an acidic gas.

Further, the method of manufacturing a semiconductor device according to the present invention is characterized in that a resist mainly containing a mixture of a novolak resin and a naphthoquinonediazide-based photosensitizer is used as the first resist. Further, a method of manufacturing a semiconductor device according to the present invention is characterized in that a chemically amplified resist having a mechanism for generating an acid is used as the first resist.

Further, according to a method of manufacturing a semiconductor device of the present invention, the fine pattern forming material according to claim 9 or 10 is used as the second layer , and the water-soluble resin and the water-soluble crosslinking agent are used. The amount of reaction with the first resist is controlled by adjusting the mixing amount.

Further, in the method of manufacturing a semiconductor device according to the present invention, the second layer is formed by using the fine pattern forming material according to claim 10 and adjusting the degree of acetalization of the polyvinyl acetal, thereby forming the second layer . The amount of reaction with the first resist is controlled.

Further, in the method of manufacturing a semiconductor device according to the present invention, the first resist pattern and the second layer formed on the first resist pattern are subjected to a heat treatment, The cross-linked film is formed in contact with the surface of the first resist pattern. Further, in the method of manufacturing a semiconductor device according to the present invention, by exposing a predetermined region from above the first resist pattern and the second layer formed on the first resist pattern, The cross-linked film is formed in the predetermined region of the first resist pattern.

Further, in the method of manufacturing a semiconductor device according to the present invention, an electron beam is irradiated to a region other than a predetermined region of the first resist pattern, and the second layer is formed on the first resist pattern irradiated with the electron beam. And the cross-linking film is formed in the predetermined region of the first resist pattern. Further, a semiconductor device according to the present invention is manufactured by the above-described method for manufacturing a semiconductor device.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a view showing an example of a mask pattern for forming a finely divided resist pattern which is the object of the present invention. FIG.
FIG. 1B shows a mask pattern 200 in a fine space, and FIG. 1C shows an isolated pattern 300. FIG.
FIG. 7 to FIG. 7 are process flow charts for explaining the method for forming a finely divided resist pattern according to the first embodiment of the present invention.

First, a method of forming a finely divided resist pattern of this embodiment and a method of manufacturing a semiconductor device using the same will be described with reference to FIGS. First, as shown in FIG. 2A, a semiconductor substrate (semiconductor wafer) 3 is coated with a first resist 1 having a mechanism for generating an acid therein by an appropriate heat treatment (for example, with a thickness of 0.1 mm). About 7 to 1.0 μm). The first resist 1 is applied on the semiconductor substrate 3 by spin coating or the like, and then
Prebake (heat treatment at 70 to 110 ° C. for about 1 minute) is performed to evaporate the solvent in the first resist 1.

Next, in order to form a first resist pattern, g-line, i-line, Deep-UV, KrF
Excimer, ArF excimer, EB (electron beam), X-ra
Using a light source corresponding to the sensitivity wavelength of the applied first resist 1 such as y, projection exposure is performed using a mask including a pattern as shown in FIG.

The material of the first resist 1 used here is:
Any resist may be used as long as it uses a mechanism that generates an acidic component inside the resist by an appropriate heat treatment, and may be either a positive resist or a negative resist. For example, as the first resist, a positive resist composed of a novolak resin, a naphthoquinonediazide-based photosensitive agent, or the like can be used. Further, as the first resist, a chemically amplified resist using a mechanism that generates an acid can be used, and any other resist material that uses a reaction system that generates an acid by heating may be used. .

After exposing the first resist 1, if necessary, PEB (post-exposure baking) is performed (for example, PEB).
B temperature: 50 to 130 ° C.) to improve the resolution of the resist 1. Next, development is performed using an alkaline water bath solution of about 0.05 to 3.0 wt% such as TMAH (tetramethylammonium hydroxide). FIG. 2B shows the first resist pattern 1a thus formed.

After the development, post-development baking may be performed as required (for example, the baking temperature is 60 to 120 ° C. for about 60 seconds). Since this heat treatment affects the subsequent mixing reaction, it is desirable to set the temperature to an appropriate temperature in accordance with the first resist or the second resist material to be used. The above process is the same as the formation of a resist pattern by a general resist process, except that the first resist 1 that generates an acid is used.

Next, as shown in FIG. 2C, the semiconductor substrate 1 was dissolved in a solvent mainly containing a crosslinkable material which is crosslinked by the presence of an acid and not dissolving the resist 1 of FIG. A second resist 2 (second layer, the same applies hereinafter) is applied. The method of applying the second resist 2 is not particularly limited as long as it can be applied uniformly on the first resist pattern 1a, and is applied by spraying, spin coating, or dipping in the second resist solution. It is also possible to apply by dipping. Next, after the application of the second resist 2, it is pre-baked as necessary (for example, at 85 ° C. for about 60 seconds), and the second resist layer 2 is formed.
To form

Next, as shown in FIG. 2D, the first resist pattern 1a formed on the semiconductor substrate 1 and the second resist 2 formed thereon are subjected to a heat treatment (mixing bake, The heating temperature is, for example, 85 ° C. to 150 ° C.) to promote the diffusion of the acid from the first resist pattern 1a and supply the second resist 2 into the second resist 2. A cross-linking reaction occurs at the interface between the second resist pattern 1a and the first resist pattern 1a. The mixing baking temperature / time in this case is, for example, 85 ° C to 1 ° C.
The temperature is 50 ° C./60 to 120 sec. The optimum conditions may be set depending on the type of the resist material used and the thickness of the required reaction layer. By this mixing baking, the crosslinked layer 4 having undergone a crosslinking reaction becomes the first resist pattern 1
a is formed in the second resist 2 so as to cover a.

Next, as shown in FIG. 2E, the non-crosslinked second resist 2 is developed and peeled off using a developing solution of water or an alkaline aqueous solution such as TMAH to form a second resist pattern. 2a is formed. Through the above processing, it is possible to obtain a resist pattern in which the hole inner diameter of the hole pattern or the separation width of the line pattern is reduced, or the area of the isolated pattern is enlarged. You.

As described above, in the method for forming a fine resist pattern described with reference to FIG.
A method has been described in which after the second resist layer 2 is formed on the first resist pattern 1a, an acid is generated in the first resist pattern 1a by appropriate heat treatment and diffused into the second resist 2. Next, a method of generating an acid by exposure instead of or prior to the heat treatment will be described. FIG. 3 is a process flow chart for explaining a method of forming a finely separated resist pattern in this case.
First, the steps of FIGS. 3A to 3C are performed in the steps of FIGS.
The description is omitted because it is the same as (c). In this case, as the first resist 1, a chemically amplified resist using a mechanism for generating an acid upon exposure can be used. In a chemically amplified resist, a reaction of generating an acid catalyst by light, electron beam, X-ray, or the like occurs, and an amplification reaction caused by the generated acid catalyst is used.

Next, after the second resist layer 2 shown in FIG. 3C is formed, H is again formed as shown in FIG.
The entire surface of the semiconductor substrate 1 is exposed to g-line or i-line of a g-lamp to generate an acid in the first resist pattern 1a, thereby contacting the first resist pattern 1a as shown in FIG. A crosslinked layer 4 is formed near the interface of the second resist 2.

As a light source used for exposure at this time, an Hg lamp, a KrF excimer, an ArF excimer, or the like can be used according to the photosensitive wavelength of the first resist 1, and an acid can be generated by the exposure. There is no particular limitation, and the exposure may be performed using a light source and an exposure amount according to the photosensitive wavelength of the first resist 1 used.

As described above, in the example of FIG. 3, exposure is performed after the application of the second resist 2 to generate an acid in the first resist pattern 1a. 2 is exposed in a state of being covered with the resist 2, the amount of acid generated in the first resist pattern 1a can be accurately controlled over a wide range by adjusting the exposure amount. It can be controlled with high accuracy.

Next, if necessary, the semiconductor substrate 1 is subjected to a heat treatment (for example, mixing baking at 60 to 130 ° C.). Thereby, the acid from the first resist pattern 1a is diffused and supplied into the second resist 2, and the second resist 2
At the interface between the first resist pattern 1a and the first resist pattern 1a. Mixing bake temperature in this case /
The time is 60 to 130 ° C./60 to 120 sec,
Optimal conditions may be set depending on the type of resist material used and the required thickness of the reaction layer. By this mixing baking, the second resist 2 is formed such that the crosslinked layer 4 having undergone the crosslinking reaction covers the first resist pattern 1a.
Formed in

Next, the step of FIG. 3 (f) is the same as that of FIG. 2 (e). Through the above processing, it is possible to obtain a resist pattern in which the hole inner diameter or the separation width of the line pattern is reduced, or the area of the isolated pattern is enlarged.

As in the example of the method described with reference to FIG. 3, the step of generating an acid component in the first resist pattern 1a by exposure is performed by the first resist 1 and the second resist 1 to be applied. Both are particularly suitable when the reactivity is relatively low, when the required thickness of the crosslinked layer is relatively thick, or when the crosslinking reaction is made uniform.

Here, the material used for the second resist 2 will be described. As the second resist, a crosslinkable water-soluble resin alone or a mixture of two or more thereof can be used. Further, a single water-soluble crosslinking agent or a mixture of two or more thereof is used. Further, a mixture of these water-soluble resins and a water-soluble crosslinking agent is used. When a mixture is used as the second resist, the material composition thereof is not particularly limited as long as the optimum composition is set according to the first resist material to be applied or the set reaction conditions.

Specific examples of the water-soluble resin composition used for the second resist include polyacrylic acid, polyvinyl acetal, polyvinyl pyrrolidone, and the like as shown in FIG.
Polyvinyl alcohol, polyethylene imine, polyethylene oxide, styrene-maleic acid copolymer, polyvinylamine resin, polyallylamine, oxazoline group-containing water-soluble resin, water-soluble melamine resin, water-soluble urea resin,
Alkyd resin, sulfonamide resin, etc. can be effectively applied, and if a cross-linking reaction occurs in the presence of an acidic component or no cross-linking reaction occurs, it can be mixed with a water-soluble cross-linking agent. if, not a particularly limited.

These water-soluble resins are polyvinyl alcohol
May be used alone , or as a mixture of two or more types.
Can be appropriately adjusted depending on the reaction amount, reaction conditions, and the like. These water-soluble resins may be used in the form of a salt such as a hydrochloride for the purpose of improving the solubility in water.

Next, specific examples of the water-soluble crosslinking agent that can be used for the second resist include urea, alkoxymethylene urea, N-alkoxymethylene urea, ethylene urea, and ethylene urea as shown in FIG. Urea-based crosslinking agents such as carboxylic acids, melamine-based crosslinking agents such as melamine and alkoxymethylenemelamine, and amino-based crosslinking agents such as benzoguanamine and glycoluril can be applied. However, the crosslinking agent is not particularly limited to an amino-based crosslinking agent, and is not particularly limited as long as it is a water-soluble crosslinking agent that causes crosslinking by an acid.

Further, as a specific water-soluble resist material used for the second resist, a water-soluble resin as described above alone or as a mixture and a water-soluble crosslinker as described above alone or as a mixture may be used. It is also effective to use a mixture of these. For example, specifically, as the second resist, a polyvinyl acetal resin is used as the water-soluble resin composition, and methoxymethylol melamine, or a mixture of ethylene urea and the like is used as the water-soluble crosslinking agent. . In this case, since the water solubility is high, the storage stability of the mixed solution is excellent. The material applied to the second resist may be any material that is water-soluble or soluble in a water-soluble solvent that does not dissolve the first resist pattern, and that causes a crosslinking reaction in the presence of an acid component. It is not particularly limited.

It is to be noted that the crosslinking reaction can be realized only by heat treatment without generating acid by re-exposure to the first resist pattern 1a, as described above. An appropriate material having high reactivity is selected as the resist 2 and an appropriate heat treatment (for example, 85 ° C. to 1
(50 ° C.). In this case, for example, specifically, as the second resist material, a polyvinyl acetal resin, ethylene urea, polyvinyl alcohol and ethylene urea, or a water-soluble material composition in which these are mixed at an appropriate ratio may be used. It is valid.

Next, in the present invention, controlling the cross-linking reaction between the first resist 1 and the second resist 2 and controlling the thickness of the cross-linked layer 4 formed on the first resist pattern 1a. is important. The control of the crosslinking reaction depends on the reactivity between the first resist 1 and the second resist 2 to be applied,
It is desirable to optimize according to the shape of the resist pattern 1a, the required thickness of the crosslinking reaction layer 4, and the like.

The control of the cross-linking reaction between the first resist and the second resist can be controlled by adjusting the process conditions,
There is a method of adjusting the composition of the resist material. Effective methods for controlling the crosslinking reaction include (1) adjusting the amount of exposure to the first resist pattern 1a, and (2) adjusting the MB (mixing bake) temperature and the processing time. is there. In particular, it is possible to control the thickness of the cross-linked layer by adjusting the time for the cross-linking by heating (MB time), and it can be said that this is a technique with very high reaction controllability. From the viewpoint of the material composition used for the second resist, (3) mixing two or more suitable water-soluble resins and adjusting the mixing ratio to control the reaction amount with the first resist. (4) An appropriate water-soluble cross-linking agent is mixed with a water-soluble resin, and the mixing ratio is adjusted to obtain the first resin.
For example, a method of controlling the amount of reaction with the resist is effective.

However, the control of these crosslinking reactions is not determined centrally, but (1) the reactivity between the second resist material and the applied first resist material,
Various conditions such as (2) the shape and thickness of the first resist pattern, (3) the required thickness of the crosslinked layer, (4) usable exposure conditions or MB conditions, and (5) application conditions. It is necessary to decide in consideration of. In particular, it has been known that the reactivity between the first resist and the second resist is affected by the composition of the first resist material. Therefore, when the present invention is actually applied, the above-described reaction is performed. It is desirable to optimize the second resist composition in consideration of the factors. Therefore, the type of water-soluble material used for the second resist and the composition ratio thereof are not particularly limited, and are optimized according to the type of material used, heat treatment conditions, and the like.

Incidentally, a plasticizer such as ethylene glycol, glycerin or triethylene glycol may be added to the second resist material as an additive. Further, with respect to the second resist material, a surfactant,
For example, a water-soluble surfactant such as Florad manufactured by 3M or Nonipol manufactured by Sanyo Kasei may be added as an additive.

Next, the solvent used for the second resist will be described. It is necessary that the solvent used for the second resist not dissolve the pattern of the first resist and further sufficiently dissolve the water-soluble material. Absent. For example, as a solvent of the second resist, water (pure water), water and an alcohol solvent such as IPA, or N-
A single or mixed solution of a water-soluble organic solvent such as methylpyrrolidone may be used.

The solvent to be mixed with water is not particularly limited as long as it is water-soluble. For example, alcohols such as ethanol, methanol and isopropyl alcohol, γ-butyrolactone, acetone and the like can be used. It is only necessary to mix the first resist pattern in a range that does not dissolve the first resist pattern in accordance with the solubility of the material used for the second resist.

In the above example, a method of forming a fine resist pattern over the entire surface of the semiconductor substrate 1 has been described. Next, a method of selectively forming a fine resist pattern only on a desired region of the semiconductor substrate 1 will be described. I do. FIG. 6 is a process flow chart of the manufacturing method in this case.
First, the steps of FIGS. 6A to 6C are performed in the steps of FIGS.
Same as (c). After forming the second resist layer 2 as shown in FIG. 6 (c), next, as shown in FIG. 6 (d), a part of the semiconductor substrate 3 is shielded from light by the light-shielding plate 5 and selected. The region is again exposed to g-line or i-line of an Hg lamp to generate an acid in the first resist pattern 1a. Thus, as shown in FIG. 6E, a crosslinked layer 4 is formed near the interface of the second resist 2 in contact with the first resist pattern 1a in the exposed portion.

The subsequent step of FIG. 6 (f) corresponds to the step of FIG. 3 (f).
Since the steps are the same as those in the above, the description is omitted. In this way, as shown in FIG. 6 (f), the cross-linking layer 4 is formed on the first resist pattern 1a in a selected region of the semiconductor substrate 3, and the first resist pattern is formed in other regions. No cross-linking layer can be formed. According to such a forming method, by using an appropriate exposure mask, the semiconductor substrate 1 is selectively exposed to light to distinguish an exposed portion from an unexposed portion, and the second resist pattern is formed by the first resist. In a boundary portion with the pattern, a crosslinked region and a non-crosslinked region can be formed. As a result, fine holes or fine spaces having different dimensions can be formed on the same semiconductor substrate.

FIG. 7 is a process flow chart of another forming method for selectively forming a fine resist pattern only in a desired region of the semiconductor substrate 1. First, FIG.
The step (c) is the same as in FIGS. 2 (a) to 2 (c). After forming the second resist layer 2 as shown in FIG.
Next, as shown in FIG. 7D, the selected area of the semiconductor substrate 3 is shielded by the electron beam shielding plate 6, and the other area is irradiated with an electron beam. Next, in the step of FIG.
When the heat treatment is performed, a crosslinked layer is not formed in a region irradiated with the electron beam, and a crosslinked layer is formed only in a predetermined region shielded from the electron beam irradiation.

The subsequent step of FIG. 7F is the same as that of FIG.
Since the steps are the same as those in the above, the description is omitted. In this way, as shown in FIG. 7 (f), the cross-linking layer 4 is formed on the first resist pattern 1a in a selected region of the semiconductor substrate 3, and the first resist pattern is formed in other regions. No cross-linking layer can be formed. As a result, fine holes or fine spaces having different dimensions can be formed on the same semiconductor substrate.

The method of forming a finely divided resist pattern on the semiconductor substrate 3 has been described in detail above. However, the finely divided resist pattern of the present invention is not limited to the semiconductor substrate 3 but may be formed by a semiconductor device manufacturing process. Depending on the situation, it may be formed on an insulating layer such as a silicon oxide film, or may be formed on a conductive layer such as a polysilicon film. As described above, the formation of the finely divided resist pattern of the present invention is not limited to the base film, and can be applied in any case as long as it is on a substrate on which a resist pattern can be formed. It is formed on a substrate. These are collectively referred to as a semiconductor substrate.

In the present invention, a semiconductor substrate such as an underlying semiconductor substrate or various thin films is etched using the fine separation resist pattern formed as described above as a mask, and a fine space or a fine hole is formed in the semiconductor substrate. Are formed to manufacture a semiconductor device. Further, the material and material composition of the second resist, or the MB temperature is appropriately set, and the semiconductor substrate is etched using the finely divided resist pattern obtained by forming a crosslinked layer on the first resist as a mask. By doing so, there is an effect that the surface of the substrate pattern side wall after etching is roughened.

Embodiment 2 FIG. 8 is a process flow chart for explaining a method for forming a finely divided resist pattern according to Embodiment 2 of the present invention. 1 and 8, a method of forming a finely divided resist pattern according to the second embodiment and a method of manufacturing a semiconductor device using the same will be described.

First, as shown in FIG. 8A, a first resist 11 containing a slight amount of an acidic substance is applied to the inside of a semiconductor substrate 3. The first resist 11 is subjected to a pre-bake (heat treatment at 70 to 100 ° C. for about 1 minute),
Projection exposure is performed using a g-line or i-line of a g-lamp and a mask including a pattern as shown in FIG. 1 (omitted in FIG. 8). FIG. 8B shows the first resist pattern 11a thus formed. First resist 1 used here
The material described in Embodiment 1 is effectively used as the material of (1). The detailed description is omitted to avoid duplication. Further, as the acid contained in the first resist 11, specifically, a carboxylic acid-based low molecular acid or the like is suitable.

Thereafter, if necessary, PEB (10 to 13)
0 ° C.) to improve the resolution of the resist,
Develop using a water bath solution of about 2.0% dilution of TMAH (tetramethylammonium hydroxide). After this,
Post-development baking may be performed as necessary. Since this heat treatment affects the subsequent mixing reaction, it is necessary to set an appropriate temperature. The above is the same as the process of forming a resist pattern by a conventional resist process except that the resist 11 containing an acid is used.

Next, after forming the pattern of FIG.
As shown in (c), a first resist 1 is formed on a semiconductor substrate 3 with a crosslinkable material that is crosslinked by the presence of an acid as a main component.
Second resist 12 dissolved in a solvent that does not dissolve 1
(The second layer, the same applies hereinafter) . The second used here
Of the resist 12 and its solvent are the same as those in the first embodiment.
The same ones as described above can be applied and are effective. The detailed description is omitted to avoid duplication. . Next, after the application of the second resist 12, it is pre-baked as necessary. Since this heat treatment affects the subsequent mixing reaction, it is desirable to set the temperature to an appropriate temperature.

Next, as shown in FIG. 8D, the semiconductor substrate 3 is subjected to a heat treatment (60 to 130 ° C.), and the second resist is supplied by supplying an acid from a slight acidic substance contained in the first resist pattern 11a. Resist pattern 1 of resist 12
A cross-linking reaction is caused near the interface with 1a. As a result, a crosslinked layer 14 that has undergone a crosslinking reaction so as to cover the first resist pattern 11a is formed in the second resist 12.

Next, as shown in FIG. 8 (f), the uncrosslinked portion of the second resist 12 is developed and removed using water or a developing solution such as TMAH. Through the above processing, it is possible to obtain a resist pattern in which the hole inner diameter of the hole pattern or the separation width of the line pattern is reduced, or a resist pattern in which the area of the isolated pattern is enlarged.

As described above, the first resist 11 in the second embodiment does not need to generate an acid by exposure, and is adjusted so that the resist film 11 itself contains an acid. Are diffused and crosslinked. As the acid to be contained in the first resist 11, a carboxylic acid-based low molecular acid or the like is preferable.
There is no particular limitation as long as it can be mixed with the resist solution.

Further, this finely separated resist pattern is
Formed on various semiconductor base materials and used as a mask,
Forming a fine separation space or a fine hole on the semiconductor substrate is the same as in the first embodiment described above.

Embodiment 3 FIG. 9 is a process flow chart for describing a method for forming a finely divided resist pattern according to Embodiment 3 of the present invention. A method of forming a finely divided resist pattern according to the third embodiment and a method of manufacturing a semiconductor device using the same will be described with reference to FIGS.

First, as shown in FIG. 9A, a first resist 21 is applied to the semiconductor substrate 3. After subjecting the first resist 21 to a pre-bake (heat treatment at 70-100 ° C. for about 1 minute), for example, using a g-line or an i-line of an Hg lamp according to the photosensitive wavelength of the first resist 21, Projection exposure is performed using a mask including a pattern as shown in FIG. 1 (not shown in FIG. 9). As the material of the first resist 21 used here, the material described in the first embodiment is effectively used. The detailed description is omitted to avoid duplication.

Next, if necessary, PEB (10 to 13)
0 ° C) to improve the resolution of the resist.
Develop using an approximately 2.0% dilute aqueous solution of AH (tetramethylammonium hydroxide). FIG. 9B shows the pattern 21a of the first resist thus formed. Thereafter, post-development baking may be performed as needed. Since this heat treatment affects the subsequent mixing reaction, it is necessary to set an appropriate temperature. The above is
The process is the same as the formation of a resist pattern by a conventional resist process.

After the pattern of FIG. 9B is formed, next, FIG.
As shown in (c), the semiconductor substrate 3 is immersed in an acidic solution. The processing method may be an ordinary paddle development method. Further, it may be carried out by vaporizing (spraying) the acidic solution. Further, the surface treatment may be performed with an acidic gas. In this case, the acidic solution or acidic gas may be either an organic acid or an inorganic acid. Specifically, for example, low-concentration acetic acid is a preferred example. In this step, the acid permeates near the interface of the first resist pattern 21a, and a thin layer containing the acid is formed. Thereafter, rinsing is performed using pure water as needed.

Thereafter, as shown in FIG. 9 (e), on the first resist pattern 21, a cross-linkable material which is cross-linked by the presence of an acid is used as a main component and dissolved in a solvent which does not dissolve the first resist 21. Second resist 22 (second layer,
The same applies hereinafter) . Second resist 2 used here
As the material 2 and its solvent, the same materials as those described in Embodiment 1 are effectively used. To avoid duplication,
Detailed description is omitted. Next, the second resist 22
After the application, the second resist 22 is pre-baked as necessary. Since this heat treatment affects the subsequent mixing reaction, it is set to an appropriate temperature.

Next, as shown in FIG. 9F, the semiconductor substrate 3 is subjected to a heat treatment (60 to 130 ° C.) to perform a cross-linking bake, and supply of an acid from the first resist pattern 21a to
A cross-linking reaction is caused near the interface between the second resist 22 and the first resist pattern 21a. Thereby, the first
A cross-linking layer 4 having undergone a cross-linking reaction so as to cover the resist pattern 21a is formed in the second resist 22.

Next, as shown in FIG. 9 (g), the uncrosslinked portion of the second resist 22 is developed and peeled off using water or a developing solution such as TMAH. Through the above processing, it is possible to obtain a resist pattern in which the hole inner diameter of the hole pattern or the separation width of the line pattern is reduced.

As described above, according to the third embodiment, the step of generating an acid in the first resist by the exposure processing is not required, and the second resist 22 is formed on the first resist pattern 21a. Before film formation, a surface treatment with an acidic liquid or an acidic gas is performed, and the acid is diffused by a heat treatment in a later step to crosslink.

Further, the fine separation resist pattern thus formed is formed on various semiconductor substrates, and using this as a mask, a fine separation space or a fine hole is formed on the semiconductor substrate. Is similar to the first and second embodiments.

[0070]

Next, examples related to the first to third embodiments will be described. One example may relate to one or more embodiments, and will be described together. First, Examples 1 to 5 relating to the first resist material will be described. Embodiment 1 FIG. As a first resist, a resist pattern was formed using an i-line resist composed of a novolak resin and naphthoquinonediazide and using ethyl lactate and propylene glycol monoethyl acetate as a solvent. First, after the resist is dropped and spin-coated on the Si wafer,
Prebaking was performed at 85 ° C./70 seconds, and the solvent in the resist was evaporated to form a first resist having a thickness of about 1.0 μm. Next, the first resist was exposed using an i-line reduction projection exposure apparatus as an exposure apparatus and using a mask as shown in FIG. 1 as an exposure mask. Next, at 120 ° C / 7
PEB treatment was performed at 0 seconds, and then development was performed using an alkaline developer (NMD3 manufactured by Tokyo Ohka Kogyo Co., Ltd.).
A resist pattern having a separation size as shown in FIG.

Embodiment 2 FIG. As a first resist, a resist pattern was formed using an i-line resist composed of a novolak resin and naphthoquinonediazide and using 2-heptanone as a solvent. First, the resist was dropped on a Si wafer and spin-coated to form a film having a thickness of about 0.8 μm.
Next, prebaking was performed at 85 ° C./70 seconds, and the solvent in the resist was dried. Subsequently, exposure was performed using an i-line reduction projection exposure apparatus using a mask as shown in FIG. Next, PEB treatment was performed at 120 ° C./70 seconds, and then development was performed using an alkali developing solution (NMD3 manufactured by Tokyo Ohka Co., Ltd.) to obtain a resist pattern having a separation size as shown in FIG. .

Embodiment 3 FIG. As a first resist, a resist pattern was formed using an i-line resist composed of a novolak resin and naphthoquinonediazide and using a mixed solvent of ethyl lactate and butyl acetate as a solvent. First, the resist was dropped on a Si wafer and spin-coated to form a film having a thickness of about 1.0 μm. Next, prebaking was performed at 100 ° C./90 seconds, and the solvent in the resist was dried. Subsequently, exposure was performed using a stepper manufactured by Nikon Corporation and a mask as shown in FIG. Next, PE at 110 ° C./60 seconds.
B treatment was performed, and subsequently, development was performed using an alkaline developer (NMD3, manufactured by Tokyo Ohka Co., Ltd.) to obtain a resist pattern as shown in FIG.

Embodiment 4 FIG. A resist pattern was formed using a chemically amplified excimer resist manufactured by Tokyo Ohkasha as the first resist. First, the resist was dropped on a Si wafer and spin-coated to form a film having a thickness of about 0.8 μm. next,
Prebaking was performed at 90 ° C./90 seconds, and the solvent in the resist was dried. Subsequently, exposure was performed using a mask as shown in FIG. 1 using a KrF excimer reduction projection exposure apparatus. Next, PEB treatment is performed at 100 ° C./90 seconds,
Subsequently, an alkaline developer (NMD-W manufactured by Tokyo Ohkasha)
Then, a resist pattern as shown in FIG. 11 was obtained.

Embodiment 5 FIG. As a first resist, a chemically amplified resist (MELKER, J. Vac. Sci. T) manufactured by Ryoden Kasei Co., Ltd., which is composed of t-Boc polyhydroxystyrene and an acid generator.
echnol. , B11 (6) 2773, 1993) to form a resist pattern. First, the resist was dropped on a Si wafer and spin-coated to form a film having a thickness of about 0.52 μm. Next, at 120 ° C /
The baking was performed for 180 seconds, and the solvent in the resist was dried. Subsequently, the resist was spin-coated in the same manner as Showa Denko KK ESPACER ESP-100 as an antistatic film, and baked at 80 ° C. for 120 seconds. Next, writing was performed at 17.4 μC / cm ² using an EB writing apparatus. Next, after performing PEB at 80 ° C./120 seconds, the antistatic film was peeled off using pure water.
The resist pattern was developed using an H alkaline developer (NMD-W manufactured by Tokyo Ohka Co., Ltd.). As a result, an EB resist pattern of about 0.2 μm was obtained as shown in FIG.

Next, a second resist (second layer, hereinafter the same)
E ) Examples 6 to 13 relating to materials will be described. Embodiment 6 FIG. Using a 1 L volumetric flask as the second resist material,
Sekisui Chemical Co., Ltd. polyvinyl acetal resin Esrec K
20 wt% aqueous solution of W3 and KW1: 100 each
g of pure water: 400 g, and stirred and mixed at room temperature for 6 hours.
5 wt% aqueous solutions of polyvinyl acetal resins KW3 and KW1 were obtained.

Embodiment 7 FIG. As the second resist material, a polyvinyl alcohol resin or an oxazoline-containing water-soluble resin (Nippon Shokubai Co., Ltd., Epocross W) was used instead of the polyvinyl acetal resin of Example 6.
S500), styrene-maleic anhydride copolymer (AR
SMA1000, 1440, manufactured by COchemical
H) in the same manner as in Example 6 using 5 w
A t% aqueous solution was obtained.

Embodiment 8 FIG. Using a 1 L volumetric flask as a second resist material, 100 g of methoxymethylolmelamine (manufactured by Mitsui Sinamide Co., Cymel 370) and 780 g of pure water, I
PA: 40 g was stirred and mixed at room temperature for 6 hours, and about 10 wt.
% Methylolmelamine aqueous solution was obtained.

Embodiment 9 FIG. Using a 1 L volumetric flask as a second resist material, (N-methoxymethyl) methoxyethylene urea: 1
00 g, (N-methoxymethyl) hydroxyethylene urea: 100 g, and N-methoxymethyl urea: 100 g, respectively, 860 g of pure water and 40 g of IPA were stirred and mixed at room temperature for 6 hours. An ethylene urea aqueous solution was obtained.

Embodiment 10 FIG. As the second resist material, 160 g of the aqueous solution of polyvinyl acetal obtained in Example 6 in KW3, 20 g of the aqueous solution of methoxymethylolmelamine obtained in Example 8, and pure water:
20 g was stirred and mixed at room temperature for 6 hours to obtain a mixed solution of a water-soluble resin and a water-soluble crosslinking agent.

Embodiment 11 FIG. As the second resist material, an aqueous KW3 solution of the polyvinyl acetal obtained in Example 6: 160 g, an aqueous solution of (N-methoxymethyl) methoxyethylene urea obtained in Example 9: 20 g, and (N-methoxymethyl) hydroxyethylene urea: 20 g And 20 g of N-methoxymethyl urea were mixed with stirring at room temperature for 6 hours at room temperature to obtain a mixed solution of a water-soluble resin and a water-soluble crosslinking agent.

Embodiment 12 FIG. As a second resist material, a KW3 aqueous solution of the polyvinyl acetal obtained in Example 6: 160 g, and 10 g, 20 g, and 30 of the methoxyethylene urea aqueous solution obtained in Example 9 were used.
g and pure water: 20 g were mixed at room temperature for 6 hours. As a result, the concentration of methoxyethylene urea, which is a water-soluble cross-linking agent for the polyvinyl acetal resin, becomes about 1 liter.
Three types of second resist aqueous solutions of wt%, 20 wt%, and 27 wt% were obtained.

Embodiment 13 FIG. As a second resist, 0 g, 35.3 g of a 5 wt% aqueous solution of a polyvinyl alcohol resin of the water-soluble resin solution obtained in Example 7 was added to 100 g of the 5 wt% aqueous solution of the polyvinyl acetal resin obtained in Example 6, 72.2 g were mixed and stirred and mixed at room temperature for 6 hours to obtain three kinds of mixed solutions having different mixing ratios of the polyvinyl acetal resin and the polyvinyl alcohol resin.

Next, Examples 14 to 22 of forming a fine resist pattern will be described. Embodiment 14 FIG. S on which the first resist pattern obtained in Example 3 was formed
The second resist material obtained in Example 12 was dropped and spin-coated on the i-wafer, and then prebaked at 85 ° C./70 seconds to form a second resist film. next,
Mixing bake (MB) at 120 ° C / 90 seconds,
The crosslinking reaction was allowed to proceed. Next, development is performed using pure water, the non-crosslinked layer is peeled off by development, and then post-baking is performed at 90 ° C./90 seconds to form a second resist crosslinked layer on the first resist pattern. As shown in FIG. 13, a second resist pattern was formed. In FIG. 13, the resist pattern size after the formation of the crosslinked layer was measured by changing the mixing ratio of the water-soluble resin, using the hole diameter of the second resist pattern as a measurement location. The results are shown in the table of FIG. In this case, by changing the mixing amount of the polyvinyl acetal resin and the polyvinyl alcohol resin,
It can be seen that it is possible to control the thickness of the crosslinked layer formed on the first resist.

Embodiment 15 FIG. S on which the first resist pattern obtained in Example 2 was formed
The resin solution of KW1 obtained in Example 6 was dropped on the i-wafer as a second resist material, spin-coated, and prebaked at 85 ° C./70 seconds to form a second resist film. Next, the entire surface of the wafer was exposed using an i-line exposure apparatus. Further, mixing baking (MB) was performed at 150 ° C./90 seconds to advance a crosslinking reaction. Next, development is performed using pure water, the non-crosslinked layer is developed and peeled off, and then post-baking is performed at 110 ° C./90 seconds, thereby forming the first resist pattern in the same manner as shown in FIG. A second resist crosslinked layer was formed on the hole pattern. Using the hole diameter of the second resist pattern shown in FIG. 13 as the length measurement location, the resist pattern size after the formation of the crosslinked layer was measured with and without exposure to the entire surface. The result is shown in the table of FIG.
As a result, the resist hole pattern size of the first 0.4 μm before forming the crosslinked layer is about 0.14 μm when the entire surface is exposed, and about 0.11 μm when the entire surface is not exposed. Was shrinking. In this case, by performing the entire surface exposure before the MB baking, the crosslinking reaction proceeded more than in the case where the MB exposure was not performed, and a thick crosslinked layer was formed on the first resist surface.

Embodiment 16 FIG. S on which the first resist pattern obtained in Example 2 was formed
On the i-wafer, a mixed solution of the polyvinyl acetal resin obtained in Example 11 and ethylene urea was used as a second resist. After the second resist material was dropped and spin-coated, prebaking was performed at 85 ° C./70 seconds to form a second resist film. Next, 105 ° C./90 seconds, 115
Mixing baking (MB) was performed under three conditions of ° C / 90 seconds and 125 ° C / 90 seconds to perform a crosslinking reaction. next,
By performing development using pure water, developing and peeling off the non-crosslinking agent, and then performing post-baking at 90 ° C./90 seconds, a second resist is formed on the first resist pattern as shown in FIG. A crosslinked layer was formed. Using the hole diameter of the second resist pattern, the space in the line pattern, and the space in the isolated pattern shown in FIG. 16 as a measurement location, the temperature of the mixing bake (MB) was changed to measure the resist pattern size after forming the crosslinked layer. The results are shown in the table of FIG. As a result, the 0.4 μm
The inner diameter of the hole pattern of the size and the size of the space in the line pattern and the isolated pattern are reduced as shown in FIG. 17 in the resist pattern after the cross-linking layer is formed. It is increasing as it becomes. From this, it can be seen that the crosslinking reaction can be accurately controlled by controlling the MB temperature.

Embodiment 17 FIG. S on which the first resist pattern obtained in Example 3 was formed
On the i-wafer, the aqueous solution of the polyvinyl acetal obtained in Example 6, the aqueous solution of the mixed polyvinyl acetal resin and ethylene urea obtained in Example 12, and the mixed solution of the aqueous solution of the polyvinyl alcohol resin and the mixed ethylene urea having different concentrations of ethylene urea were used. Used as a second resist. Second
After dropping the resist material and spin coating, 85 ° C
A pre-bake was performed at / 70 seconds to form a second resist film. Next, mixing baking (MB) was performed at 65 ° C./70 seconds + 100 ° C./90 seconds to perform a crosslinking reaction. Next, development is performed using pure water, and the non-crosslinked layer is peeled off by development.
Subsequently, by performing post-baking at 90 ° C./90 seconds, a second resist crosslinked layer was formed on the first resist pattern in the same manner as shown in FIG. Using the hole diameter of the second resist pattern shown in FIG. 13 as a measurement location, the amount of the water-soluble cross-linking agent was changed, and the resist pattern size after forming the cross-linked layer was measured. The results are shown in the table of FIG. As a result, it was found that the thickness of about 0.
The inner diameter of the hole pattern having a size of 4 μm is reduced as shown in FIG. 18, and the reduction amount increases as the mixing amount of the water-soluble crosslinking agent increases. This indicates that the crosslinking reaction can be accurately controlled by adjusting the mixing ratio of the water-soluble materials. Further, it can be seen that, even when the amount of the crosslinking agent is the same, the reduction amount can be controlled by changing the type of the water-soluble resin.

Embodiment 18 FIG. S on which the first resist pattern obtained in Example 3 was formed
On the i-wafer, the aqueous solution of the polyvinyl acetal obtained in Example 6, the aqueous solution of the polyvinyl acetal resin obtained in Example 11, and a mixed aqueous solution of N-methoxymethyl-methoxyethylene urea as a water-soluble crosslinking agent, and (N-methoxymethyl) hydroxyethylene urea , N-methoxymethyl urea was used as a second resist. After the second resist material was dropped and spin-coated, prebaking was performed at 85 ° C./70 seconds to form a second resist film. next,
Mixing bake (MB) was performed at 65 ° C./70 seconds + 100 ° C./90 seconds to perform a crosslinking reaction. Next, development is performed using pure water, and the non-crosslinked layer is peeled off by development.
By performing post-baking for 90 seconds, a second resist crosslinked layer was formed on the first resist pattern in the same manner as shown in FIG. Using the hole diameter of the second resist pattern shown in FIG. 13 as a measurement location, the size of the resist pattern after the formation of the crosslinked layer was measured by changing the water-soluble crosslinking agent. The result is shown in the table of FIG. as a result,
The inner diameter of the hole pattern having a size of about 0.4 μm formed in Example 3 is reduced as shown in FIG. 19, and the reduction amount is different depending on the difference of the water-soluble crosslinking agent.
This indicates that the crosslinking reaction can be controlled depending on the type of the water-soluble material to be mixed.

Embodiment 19 FIG. S on which the first resist pattern obtained in Example 4 was formed
The aqueous solution of the polyvinyl acetal obtained in Example 6, the aqueous solution of the polyvinyl acetal resin obtained in Example 11, and the aqueous solution of methoxyethylene urea as the water-soluble crosslinking agent were used as the second resist on the i-wafer. After the second resist material was dropped and spin-coated, prebaking was performed at 85 ° C./70 seconds to form a second resist film. next,
Mixing baking (MB) was performed at a predetermined temperature for 90 seconds to perform a crosslinking reaction. Next, development is performed using pure water, the non-crosslinked layer is developed and peeled off, and then post-baking is performed at 90 ° C./90 seconds, thereby forming the first resist pattern as shown in FIG. A second crosslinked resist layer was formed thereon. Using the hole diameter of the second resist pattern shown in FIG. 13 as a measurement site, the amount of the water-soluble cross-linking agent and the reaction temperature were changed, and the resist pattern size after forming the cross-linked layer was measured. The result is shown in the table of FIG. As a result, the resist pattern size of about 0.3 μm formed in Example 4 was reduced as shown in FIG.
Differences are observed depending on the amount of the water-soluble crosslinking agent and the reaction temperature. This indicates that the resist pattern size can be controlled by a crosslinking reaction even when a chemically amplified resist that generates an acid by light irradiation is used.

Embodiment 20 FIG. S on which the first resist pattern obtained in Example 5 was formed
The aqueous solution of the polyvinyl acetal obtained in Example 6, the aqueous solution of the polyvinyl acetal resin obtained in Example 11, and the aqueous solution of methoxyethylene urea as the water-soluble crosslinking agent were used as the second resist on the i-wafer. After the second resist material was dropped and spin-coated, prebaking was performed at 85 ° C./70 seconds to form a second resist film. next,
Mixing bake at 105, 115 ° C / 90 seconds (MB)
And a crosslinking reaction was performed. Next, development is performed using pure water, the non-crosslinked layer is developed and peeled off, and then post-baking is performed at 90 ° C./90 seconds, as shown in FIG.
A second cross-linked resist layer was formed on the first resist pattern. Using the hole diameter of the second resist pattern shown in FIG. 13 as a measurement site, the amount of the water-soluble cross-linking agent and the reaction temperature were changed, and the resist pattern size after forming the cross-linked layer was measured. The results are shown in the table of FIG. As a result, the size of the resist pattern having a size of about 0.2 μm formed in Example 5 was reduced as shown in FIG. 21, and the reduced amount was different depending on the difference in the water-soluble material and the difference in the MB temperature. Is recognized. This indicates that the resist pattern size can be controlled by a crosslinking reaction even when a chemically amplified EB resist composed of t-Boc polyhydroxystyrene and an acid generator is used.

Embodiment 21 FIG. The first resist pattern obtained in Example 2 was selectively irradiated with an electron beam. The irradiation amount of the electron beam is 50 μC / cm
² were irradiated. Next, the aqueous solution of a polyvinyl acetal resin obtained in Example 11 and an aqueous solution of methoxyethylene urea as a water-soluble crosslinking agent were applied as a second resist on the first resist pattern irradiated with an electron beam. Application is
The second resist material was dropped, spin-coated, and then pre-baked at 85 ° C./70 seconds to form a second resist film. Further, mixing baking (MB) was performed at 120 ° C./90 seconds to perform a crosslinking reaction. Finally, development is performed using pure water, and the non-crosslinked layer is peeled off by development.
By performing post-baking at 110 ° C./70 seconds, a second resist crosslinked film was selectively formed on the first resist pattern in the same manner as shown in FIG. The hole diameter of the second resist pattern shown in FIG.
The resist pattern size after the formation of the crosslinked layer was measured. The result is shown in the table of FIG. As a result, Example 2
The resist pattern of about 0.4 μm formed in the step is reduced in the portion not irradiated with the electron beam as shown in FIG. 22, and the cross-linking reaction occurs in the portion selectively irradiated with the electron beam. No reduction in hole size was observed. From this, after forming the resist pattern,
By selectively irradiating the electron beam, since no reaction occurs in the pattern of the irradiated portion, it can be seen that the size of the resist pattern can be selectively controlled.

Embodiment 22 FIG. The first resist pattern obtained in Example 2 was formed on an Si wafer on which an oxide film was formed, and a first resist pattern as shown in FIG. 23 was formed. Next, after the second resist material obtained in Example 12 was dropped and spin-coated, prebaking was performed at 85 ° C./70 seconds, and then 105 ° C.
Mixing bake at / 90 sec, developing and peeling off the non-crosslinked layer with pure water, followed by post bake at 90 ° C / 90 sec to form a second resist crosslinked layer on the first resist pattern did. Further, the underlying oxide film was etched using an etching apparatus, and the pattern shape after the etching was observed. Further, as a comparative example, etching was similarly performed on a wafer on which the first resist pattern shown in FIG. 23 was not subjected to the treatment of the present invention. As a result, when the present invention is applied, as compared with FIG. 24 (a) where the present invention is not applied, FIGS.
As shown in (c), an oxide film pattern with a reduced side wall and a roughened side wall was obtained at the same time. Further, it can be seen that the degree of surface roughening can be controlled by the amount of the crosslinking agent mixed.

[0092]

As described above in detail, according to the present invention, a fine separation resist pattern forming method capable of forming a pattern exceeding a wavelength limit in miniaturization of a resist separation pattern and a hole pattern. A material and a method for forming a fine pattern using the material can be obtained. As a result, the hole diameter of the hole-based resist pattern can be made smaller than before, and the separation width of the space-based resist pattern can be made smaller than before. Further, using the fine separation resist pattern thus formed as a mask, finely separated spaces or holes can be formed on the semiconductor substrate. Further, a semiconductor device having finely separated spaces or holes can be obtained by such a manufacturing method.

[Brief description of the drawings]

FIG. 1 is a view of a mask pattern for explaining a resist pattern forming method according to a first embodiment of the present invention;

FIG. 2 is a process flow chart for describing a method of forming a resist pattern according to the first embodiment of the present invention.

FIG. 3 is a process flow chart for describing a resist pattern forming method according to the first embodiment of the present invention.

FIG. 4 is a process flow chart for describing a resist pattern forming method according to the first embodiment of the present invention.

FIG. 5 is a process flow chart for describing a method of forming a resist pattern according to the first embodiment of the present invention.

FIG. 6 is a process flow chart for describing a method of forming a resist pattern according to the first embodiment of the present invention.

FIG. 7 is a process flow chart for describing a method of forming a resist pattern according to the first embodiment of the present invention.

FIG. 8 is a process flow chart for describing a method of forming a resist pattern according to a second embodiment of the present invention.

FIG. 9 is a process flow chart for describing a method of forming a resist pattern according to a third embodiment of the present invention.

FIG. 10 shows a first resist pattern according to the first, second and third embodiments of the present invention.

FIG. 11 shows a first resist pattern according to a fourth embodiment of the present invention.

FIG. 12 shows a first resist pattern according to a fifth embodiment of the present invention.

FIG. 13 shows a second resist pattern according to Embodiment 14 of the present invention.

FIG. 14 is a diagram showing a mixing ratio of a water-soluble resin and a resist pattern size after forming a crosslinked layer in Example 14 of the present invention.

FIG. 15 is a diagram showing the presence / absence of exposure and the resist pattern size after forming a crosslinked layer in Example 15 of the present invention.

FIG. 16 shows a second resist pattern according to Embodiment 16 of the present invention.

FIG. 17 is a diagram showing a mixing bake temperature and a resist pattern size after forming a crosslinked layer in Example 16 of the present invention.

FIG. 18 is a diagram showing a mixing ratio of a water-soluble material and a resist pattern size after forming a crosslinked layer in Example 17 of the present invention.

FIG. 19 is a diagram showing types of water-soluble materials and a resist pattern size after a crosslinked layer is formed in Example 18 of the present invention.

FIG. 20 is a diagram showing the amounts of water-soluble materials, the mixing bake temperature, and the resist pattern size after forming a crosslinked layer in Example 19 of the present invention.

FIG. 21 is a diagram showing types of water-soluble materials and a resist pattern size after forming a crosslinked layer in Example 20 of the present invention.

FIG. 22 is a diagram showing the presence / absence of electron beam irradiation and the resist pattern size after forming a crosslinked layer in Example 21 of the present invention.

FIG. 23 is a view showing a second resist pattern in Embodiment 22 of the present invention.

FIG. 24 is a view showing a pattern shape after etching of a base oxide film in a working example 22 of the invention.

[Explanation of symbols]

1,11,21 1st resist, 1a, 2a, 3a
First resist pattern, 2, 12, 22 second resist (second layer) , 2a, 12a, 22a second
Resist pattern, 3 semiconductor substrate (semiconductor substrate), 4, 14, 24 cross-linked layer.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI H01L 21/302 H (72) Inventor Ayumi Minami 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Electric Corporation (56) References JP-A-57-84451 (JP, A) JP-A-63-138353 (JP, A) JP-A-5-241348 (JP, A) JP-A-6-250379 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) G03F 7/11 G03F 7/095 G03F 7/26 H01L 21/027 H01L 21/3065

Claims (25)

(57) [Claims] 1. A water-soluble organic solvent comprising water or water and a water-soluble organic solvent containing one type of water-soluble resin other than polyvinyl alcohol as a main component.
Dissolve the mixed solvent as a solvent and supply the acid
The first resist pattern formed on the distant pattern
Contact the first resist pattern with acid from
A cross-linking reaction occurs at the portion where
Is a fine pattern forming material characterized by being peeled off . As claimed in claim 2 wherein said water-soluble resin, polyacrylic acid, polyvinyl acetal, polyvinylpyrrolidone down, port <br/> Li ethyleneimine, polyethylene oxide, styrene -
Maleic anhydride copolymer, polyvinyl amine, polyallylamine, oxazoline group-containing water-soluble resin, water-soluble melamine resins, water soluble urea resins, alkyd resins, one kind of the sulfonamide, also Hakodate among these salts either
The material for forming a fine pattern according to claim 1, wherein one type is a main component. 3. A mixture mainly composed of a mixture of two or more water-soluble resins or a copolymer of two or more water-soluble resins, wherein water or a mixed solvent of water and a water-soluble organic solvent is dissolved.
First resist pattern that dissolves as a medium and supplies acid
On the acid from the first resist pattern formed on
Thus, a cross-linking reaction occurs at a portion in contact with the first resist pattern to form a cross-linked film, and a non-cross-linked portion is peeled off.
And a material for forming a fine pattern. 4. The water-soluble resin includes polyacrylic acid, polyvinyl acetal, polyvinyl pyrrolidone, polyvinyl alcohol, polyethylene imine, polyethylene oxide, styrene-maleic anhydride copolymer, polyvinylamine, polyallylamine, and oxazoline group-containing water-soluble resin. 4. The method according to claim 3, wherein the main component is one of a resin, a water-soluble melamine resin, a water-soluble urea resin, an alkyd resin, and a sulfonamide, or a mixture of two or more thereof, or a salt thereof. The material for forming a fine pattern according to the above. 5. A composition comprising one or more water-soluble crosslinking agents or a mixture of two or more of the above-mentioned water-soluble crosslinking agents as main components, and water or water.
Dissolve the mixed solvent with a water-soluble organic solvent as a solvent ,
The first resist pattern formed on the first resist pattern to be supplied;
The first resist by the acid from the resist pattern of
A cross-linking reaction occurs at the part in contact with the pattern to form a cross-linked film
And a non-crosslinked portion is peeled off . 6. The method according to claim 5, wherein the water-soluble crosslinking agent is mainly composed of one of melamine derivatives, urea derivatives, benzoguanamine, and glycoluril, or a mixture of two or more thereof. Fine pattern forming material. 7. The melamine derivative as the melamine,
The fine pattern forming material according to claim 6, wherein one of the alkoxymethylene melamines or a mixture thereof is used as a main component. 8. The method according to claim 1, wherein the urea derivative is mainly composed of one kind of urea, alkoxymethylene urea, N-alkoxymethylene urea, ethylene urea, ethylene urea carboxylic acid or a mixture of two or more kinds thereof. The material for forming a fine pattern according to claim 6. 9. A mixture comprising one or more water-soluble resins and one or more water-soluble crosslinking agents as a main component, and dissolving water or a mixed solvent of water and a water-soluble organic solvent.
First resist pattern that dissolves as a medium and supplies acid
On the acid from the first resist pattern formed on
Thus, a cross-linking reaction occurs at a portion in contact with the first resist pattern to form a cross-linked film, and a non-cross-linked portion is peeled off.
And a material for forming a fine pattern. 10. A method according to claim 1, wherein the water-soluble resin is polyvinyl acetal, polyvinyl alcohol, or a mixture of polyvinyl alcohol and polyvinyl acetal, and the water-soluble crosslinking agent is a melamine derivative, a urea derivative, or a melamine derivative and a urea derivative. 10. The fine pattern forming material according to claim 9, wherein any one of the following mixtures is used. 11. The fine pattern forming material according to claim 1, further comprising a plasticizer as an additive. 12. The fine pattern forming material according to claim 1, further comprising a surfactant as an additive. 13. A process of forming a first resist pattern capable of supplying an acid on a semiconductor substrate by a first resist, claims 1 to 12 over the first resist pattern
The second method according to the fine pattern forming material according to any one of
Forming a layer, and the process steps to form a crosslinked film on the acid moiety in contact with the first resist pattern of the second layer by supplying from the first resist pattern, the second layer A method for manufacturing a semiconductor device, comprising: a step of removing a non-crosslinked portion to form a second resist pattern; and a step of etching the semiconductor substrate using the second resist pattern as a mask. 14. The method according to claim 13, wherein the first resist pattern is formed of a resist that generates an acid by a heat treatment. 15. The method according to claim 13, wherein the first resist pattern is formed of a resist that generates an acid upon exposure. 16. The method according to claim 13, wherein the first resist pattern is formed of a resist containing an acid.
13. The method for manufacturing a semiconductor device according to item 5. 17. The method according to claim 13, wherein the first resist pattern is formed of a resist that has been subjected to a surface treatment with an acidic liquid or an acidic gas. 18. The method according to claim 13, wherein a resist mainly containing a mixture of a novolak resin and a naphthoquinonediazide-based photosensitizer is used as the first resist.
18. The method for manufacturing a semiconductor device according to any one of claims to 17. 19. The method according to claim 13, wherein a chemically amplified resist having a mechanism for generating an acid is used as the first resist. As claimed in claim 20 wherein said second layer, claim 9 or
Or the amount of reaction with the first resist is controlled by adjusting the mixing amount of the water-soluble resin and the water-soluble cross-linking agent, using the fine pattern forming material according to item 10. A method for manufacturing a semiconductor device according to claim 16. 21. The amount of reaction with the first resist is controlled by adjusting the degree of acetalization of the polyvinyl acetal by using the fine pattern forming material according to claim 10 as the second layer. The method for manufacturing a semiconductor device according to claim 16, wherein: 22. A surface of the first resist pattern by heat-treating the first resist pattern and the second layer formed on the first resist pattern. 22. The method according to claim 13, wherein the crosslinked film is formed in contact with the semiconductor device. 23. Exposure of a predetermined region from above the first resist pattern and the second layer formed on the first resist pattern to form the first resist 22. The method according to claim 13, wherein the cross-linking film is formed in the predetermined region of the pattern. 24. Irradiating an area other than a predetermined area of the first resist pattern with an electron beam, forming the second layer on the first resist pattern irradiated with the electron beam,
22. The cross-linking film is formed in the predetermined region of the resist pattern.
The method for manufacturing a semiconductor device according to any one of the above. 25. A semiconductor device manufactured by the method of manufacturing a semiconductor device according to claim 13.