KR100876858B1 - Micro pattern formation method of semiconductor device - Google Patents

Abstract

The present invention relates to a method for forming a micropattern of a semiconductor device. The method for forming a micropattern of a semiconductor device according to the present invention includes applying a photosensitive film on a lower layer and then performing a primary exposure and development process using a photolithography process technology. Forming a photoresist pattern; Forming a polymer solution layer containing any one of a thermal radical generator and a cross-linking agent on the lower layer including the photoresist pattern; Baking to form a crosslinked photoresist pattern; And performing a secondary development process to form a desired final photoresist pattern. The crosslinking agent may be any one of a multifunctional ether and a multifunctional alkyl halo compound.

Description

Method for forming fine pattern of semiconductor device

1 to 4 are cross-sectional views for each process for explaining a method for forming a micropattern of a semiconductor device according to an embodiment of the present invention.

5 to 8 are cross-sectional views of processes for describing a method of forming a fine pattern of a semiconductor device according to another exemplary embodiment of the present invention.

[Description of Drawing Reference]

11: lower layer 13: photosensitive film pattern

15: polymer solution layer 17: thermal radical generator

19: radical 21: final photoresist pattern (cross-linked photoresist pattern)

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a fine pattern of a semiconductor device, and more particularly, to a method of improving roughness of line edges using radical cross-links of a resist.                         

As semiconductor devices are gradually integrated, the size of patterns to be formed in photolithography becomes smaller, and thus line edge roughness of resist patterns has become an important problem that can cause variations in device operation.

The roughness of the edges of these lines originates from the uneven development speed of the extraction method of the resist polymer aggregate. Therefore, preventing such a non-uniform phenomenon of the aggregate is an important factor that can immediately give uniformity of device operation.

Therefore, as a method of preventing such an uneven phenomenon of aggregates, first, there is a method of reducing roughness due to the small size even if the size of the aggregate is reduced and the non-uniform development speed is shown by the extraction method. There is a way to reduce the speed of unevenness caused by the extraction method.

The first method is by the resist material self-development, and the second method may be possible by the material self-development method and the process method. That is, the second method can be achieved by reducing the difference in developing speed between the aggregate and the surrounding resist in some way.

This approach is possible by increasing the crosslink of the resist, and two methods of this crosslink have been applied.

One of them is to use a crosslinked polymer for the resist material itself. However, this may cause problems such as resist residues and resist performance itself depending on the amount of crosslinks.

In addition, one method is to form crosslinks using UV-baking equipment after patterning, in which case additional equipment is required that is not used in other processes, and incomplete crosslinking due to UV intensity changes. This situation has various problems in terms of fairness.

Accordingly, an object of the present invention is to provide a method of forming a fine pattern of a semiconductor device capable of reducing edge roughness of a pattern forming line by using thermal radical generation and diffusion. There is this.

According to an aspect of the present invention, there is provided a method of forming a fine pattern of a semiconductor device, the method including: forming a photoresist pattern by applying a photoresist film on a lower layer and then performing a first exposure and development process using a photolithography process technique; Forming a polymer solution layer containing any one of a thermal radical generator and a cross-linking agent on the lower layer including the photoresist pattern; Baking to form a crosslinked photoresist pattern; And performing a secondary development process to form a desired final photoresist pattern; wherein the crosslinking agent is one of a multifunctional ether and a multifunctional alkyl halo compound, and the multifunctional alkyl halo compound Is characterized in that any one of an alkyl chloro compound, an alkyl bromo compound and an alkyl rho compound.

(Example)

Hereinafter, a method of forming a fine pattern of a semiconductor device according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 to 4 are cross-sectional views illustrating a method of forming a fine pattern of a semiconductor device according to the present invention.

The method of forming a fine pattern of a semiconductor device according to an embodiment of the present invention, as shown in Figure 1, first applied a photosensitive film (not shown) on the pattern forming lower layer 11 and then the same as the general photolithography process Through the exposure and development processes, the desired photoresist pattern 13 is formed. At this time, the line edge portion of the photoresist pattern 13 has a rough surface.

Next, as shown in FIG. 2, the polymer solution containing the thermal radical generator 17 is coated on the lower layer 11 including the photoresist pattern 13 thus formed to form the polymer solution layer 15. At this time, the polymer solution to be applied should be a water soluble polymer solution or a thermal radical generation agent similar to the anti-reflective layer (arc) commonly used in the photolithography process, The solvent of the solution is water.

Subsequently, as shown in FIG. 3, after the polymer solution layer 15 is applied, baking is performed by setting a temperature range that enables generation and diffusion of desired thermal radicals. In this case, as the radical generation and diffusion method, an oven or a hot plate heating method is used. In the case of the oven method, the oven temperature and the hot plate method maintain the hot plate temperature at 50 to 250 ° C.

In addition, radicals 19 are generated in the thermal radical generator 17 in the polymer solution through baking, and the radicals 19 diffuse into the photosensitive film pattern 13 previously formed by heat. On the other hand, AlBN is used as the thermal radical generator 17.

This diffusion causes radical crosslinking between the hydroxystyrene polymers in the pattern, and the pattern edge is developed at a slow speed due to a small amount of photoacid generator decomposed by heat.

Then, as shown in FIG. 4, when the secondary development is carried out with TMAH in this state, a small amount of development is performed very slowly in the state where the edges of the patterns are crosslinked to obtain a final photoresist pattern 21 having reduced pattern edge roughness. do.

At this time, the process is performed in the in-line track (in-line track), there is an advantage that does not need to consider additional equipment investment, such as UV-baking equipment and the process time.

Meanwhile, the method of forming a fine pattern of a semiconductor device according to another embodiment of the present invention is as shown in FIGS. 5 to 8.

5 to 8 are cross-sectional views of processes for describing a method of forming a fine pattern of a semiconductor device according to another exemplary embodiment of the present invention.

The method of forming a micropattern of a semiconductor device according to an embodiment of the present invention, as shown in FIG. 5, is the same as the general photolithography process after first applying a photosensitive film (not shown) on the pattern forming lower layer 31. Through the exposure and development processes, the desired photoresist pattern 33 is formed.

Next, as shown in FIG. 6, a polymer solution containing a crosslinkable agent 37 is coated on the lower layer 31 including the photoresist pattern 33 thus formed to apply the polymer solution layer 35. Form. At this time, the polymer solution to be applied should be a water soluble polymer solution or a thermal radical generation agent similar to the upper anti-reflective film (arc) generally used in the photolithography process, the solvent of the solution is water to be.

Subsequently, as shown in FIG. 7, the polymer solution layer 37 is applied in this manner, and then baking is performed by setting a temperature range that enables proper diffusion of a desired crosslinkable agent. In this case, as the diffusion method of the cross-linking agent 37, an oven or a hot plate heating method is used. In the case of the oven method, the oven temperature and the hot plate method maintain the hot plate temperature at 50 to 250 ° C. In addition, as the crosslinking agent 37, a multi-functional ether or a multi-functional alkyl halo compound is used. In this case, methyl ether is used as the multi-functional ether, and an alkyl chloro compound, an alkyl bromo compound, or an alkyl lodo compound is used as the multi-functional alkyl halo compound.

In addition, through the baking process, the crosslinking agent 37 in the polymer solution diffuses into the preformed pattern by heat.

This diffusion causes crosslinking between the -OH groups of the styrene polymer inside the pattern, and the pattern edge is developed at a slow speed due to a small amount of photoacid generator decomposed by heat.

Then, as shown in FIG. 8, when the secondary development is carried out with TMAH in this state, a small amount of development is performed very slowly in the state where the edges of the patterns are crosslinked to obtain a final photoresist pattern 21 having reduced pattern edge roughness. do.

At this time, since the process is carried out in the in-line track (in-line track) as in the instant of the present invention, there is an advantage that does not need to consider the investment and processing time of additional devices such as UV-baking equipment.

As described above, the method of forming a fine pattern of a semiconductor device according to the present invention has the following effects.

According to the method of forming a fine pattern of a semiconductor device according to an embodiment of the present invention, the roughness of the edge of the line is reduced only by a simple track process using a thermal radical generation and a radical diffusion process or a diffusion process using a cross-linking agent. Reduced and stable resist profile and CD control is easy, and there is an effect of improving device development and production yield due to process stability.

On the other hand, the present invention is not limited to the above-described specific preferred embodiments, and various changes can be made by those skilled in the art without departing from the gist of the invention claimed in the claims. will be.

Claims (10)

Forming a photoresist pattern by applying a photoresist on the lower layer and then performing a first exposure and development process using a photolithography process technique; Forming a polymer solution layer containing any one of a thermal radical generator and a cross-linking agent on the lower layer including the photoresist pattern; Baking to form a crosslinked photoresist pattern; And Performing a secondary development process to form a desired final photoresist pattern; Including; As the crosslinking agent, any one of a multifunctional ether and a multifunctional alkyl halo compound may be used, and the multifunctional alkyl halo compound may be any one of an alkyl chloro compound, an alkyl bromo compound, and an alkyl rho compound. A fine pattern forming method of a semiconductor device. 2. The semiconductor device according to claim 1, wherein when the polymer solution layer contains a thermal radical generator, a material used for thermal radical generation and diffusion uses a water-soluble polymer solution and a thermal radical generating agent. Pattern formation method. The method of claim 1, wherein the diffusion of the thermal radical generator or the crosslinking agent is performed by an oven or a hot plate heating method. The method of claim 3, wherein the oven temperature and the hot plate temperature are maintained at 25 to 250 ° C. 5. The method of claim 1, wherein AlBN is used as the thermal radical generator. delete delete The method of forming a fine pattern of a semiconductor device according to claim 1, wherein methyl alcohol or ethyl ether is used as the multifunctional ether. delete The method of claim 1, wherein the baking is performed to generate and diffuse thermal radicals to form a cross-linked photoresist pattern.

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