JPH01187927A - Forming method for pattern - Google Patents

Abstract

PURPOSE:To enhance a resolution level, to form a pattern on the order of submicrons, and to obtain a pattern having excellent heat resistance by employing a novolak polymer as a resist film, heat-treating it simultaneously upon exposure with a light having short wavelength, and then dissolving an unexposed part. CONSTITUTION:A substrate to be formed with a pattern, such as a semiconductor substrate 11 or a mask substrate is coated with resist using novolak polymer to form a resist film 12. Then, the film 12 is irradiated with a light 13 having a short wavelength to form a desired pattern by lithography or transfer, and heat-treated simultaneously upon the exposure. Thereafter, the unexposed part of the film 12 is dissolved with predetermined developing solution 15 for development. For example, the film 12 is irradiated with a light 13 having a short wavelength near 250 or 360nm of wavelength for exposure, and heat-treated by suitable heating means 14 simultaneously upon the exposure. Subsequently, the unexposed part of the film 12 is developed with predetermined developing agent (resist solvent) 15.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a pattern forming method applied in manufacturing a semiconductor device, and more specifically, to a pattern forming method using a resist film on a semiconductor substrate or a mask substrate. This is related to the improvement of.

(Prior Art) The main steps of this type of pattern forming method using a conventional positive resist are sequentially shown in FIGS. 2(a) to 2(c).

That is, in the conventional methods shown in FIGS. 2(a) to 2(c), a resist pattern is first formed on a pattern-forming substrate such as a semiconductor substrate or a mask substrate, in this case, the semiconductor substrate 1. Then, a photo-crosslinkable positive resist film 2 is coated to form a coating, and in order to pattern this positive resist film 2, G-ray light 3 is irradiated to draw a desired pattern or By performing transfer and exposure processing, the photosensitizer in the positive resist film 2 is decomposed and made alkali-soluble (see Figure (a)). A predetermined developing solution (resist solvent) 4 is applied to the mold resist film 2 to develop it (FIG. 2(b)),
After this development process, the developer 4 is removed to form a desired resist pattern 5 (FIG. 3(C)).

[Problem to be solved by the invention]

However, in the conventional pattern forming method performed as described above, since the wavelength used in the G-ray light 3 used for pattern drawing or transfer is long, the resolvable level of the pattern is low. It is difficult to form submicron-level patterns, and the resist pattern 5 formed in this way also has poor heat resistance.
1 for etching in the secondary process after pattern formation.
When heat treatment is performed, there is a problem in that the shape of the resist pattern may sag due to heat sag or the like, causing the resist pattern to collapse.

This invention was made to solve these conventional problems, and its purpose is to achieve a high resolution level and enable submicron level pattern formation, as well as to Excellent heat resistance. It is an object of the present invention to provide a pattern forming method of this type.

(Means for Solving the Problems) In order to achieve the above object, a pattern forming method according to the present invention includes a resist film coated on a substrate to be patterned, such as a semiconductor substrate or a mask substrate. First, using a novolak-based polymer, the resist film is first irradiated with light of a short wavelength, for example, around 250 nm, to draw a desired pattern, or
Transfer is performed and exposed, and in conjunction with this exposure, a desired heat treatment is simultaneously performed, and then the unexposed portions of the resist film are dissolved and developed using a prescribed developing solution (resist solvent). It was designed so that

[For production]

That is, in the method of the present invention, a novolak-based polymer is used as a resist film, and in order to expose the resist film to a desired pattern by drawing or transferring a desired pattern with short wavelength light, the resist pattern is finely divided. At the same time, because the desired heat treatment is performed, the resist pattern has regained heat resistance due to the so-called deep knee cure (Deep V Cure) effect. is obtained.

(Example) Hereinafter, an example of the pattern forming method according to the present invention will be described in detail with reference to FIGS. 1(a) to C).

FIGS. 1(a) to 1(c) are cross-sectional views schematically showing the main steps of the pattern forming method to which this embodiment is applied.

That is, also in the embodiment methods shown in FIGS. 1(a) to C), a resist pattern is first formed on a pattern formation substrate such as a semiconductor substrate or a mask substrate, in this example, a semiconductor substrate II. In order to pattern the resist film 12 by applying a resist film 12 made of a novolac polymer, for example, a wavelength of 250 nm or 360 nm is applied.
A short wavelength light 13 in the vicinity is irradiated to form a desired pattern drawing or transfer and exposure, and at the same time as this exposure operation, heat treatment is performed using an appropriate heating means 14 (FIG. 2(a)). Then, the unexposed portion of the resist film 12 that has been exposed in this way is developed with a predetermined developing solution (resist solvent) 15, that is, in this S, it is subjected to a dissolution treatment (FIG. 2(b)), and further After this development process, the developer solution 15 is removed to form the desired resist pattern I6 (FIG. 1(C)).

Therefore, in the case of the embodiment method, which is processed in this way, the resist film 12 made of a novolac polymer is irradiated with light 13 having a short wavelength of around 250 r+m or 360 nm to form a desired pattern. Since the exposure process is performed by drawing or transferring, it is possible to perform fine processing of the resist pattern, and
At the same time as this exposure process, the heating means 14 performs the desired heat treatment, so that the so-called deep
Due to the Deep UV Cure effect, a resist pattern 16 with excellent heat resistance can be obtained.

〔Effect of the invention〕

As described in detail above, according to the method of the present invention, a resist film using a novolac polymer is first applied to a substrate to be patterned, such as a semiconductor substrate or a mask substrate, to cover the resist film. After forming the resist film, the resist film is irradiated with light having a short wavelength of, for example, 250 nm or 360 nII+ to draw or transfer a desired pattern and perform an exposure process. At the same time, the unexposed portions of the resist film were subjected to heat treatment, and then the unexposed portions of the resist film were dissolved and developed using a predetermined developing solution. By drawing a desired pattern or performing a transfer and exposure process, the resolution level can be dramatically improved, making it possible to microfabricate resist patterns, and easily forming submicron-level patterns. And also,
By performing the desired heat treatment at the same time as this exposure treatment, a resist pattern with excellent heat resistance can be obtained due to the so-called deep knee cure effect, and the forming process itself is relatively simple and easy. It has excellent features such as being able to be implemented easily.

[Brief explanation of the drawing]

FIGS. 1(a) to (C) are cross-sectional views schematically showing the main steps of a pattern forming method to which an embodiment of the present invention is applied, and FIG. 2 is a pattern forming method according to a conventional example. FIG. 3 is a cross-sectional view schematically showing the main steps of the method. 11...Semiconductor substrate, I2...Resist film made of novolac polymer, 13...Short wavelength light,
14...Heating means, 15...Developing solution (resist solvent), 16...Resist pattern. Agent Masuo Oiwa Figure 1 15 Ring family defender (Resistoshi Shufugu) 16. Resomatato/~°Turn Figure 2 11↓↓ [11↓! IIIHI~4

Claims (1)

[Claims] A process of coating a resist film using a novolac polymer on a substrate to be patterned such as a semiconductor substrate or a mask substrate, and applying short wavelength light to this resist film. A step of irradiating the desired pattern to form a desired pattern or transfer and subjecting it to exposure treatment, and simultaneously heat-treating the exposure treatment;
1. A pattern forming method comprising the step of dissolving and developing an unexposed portion of a resist film with a predetermined developing solution.