JPS61112316A - Formation of pattern - Google Patents

Abstract

PURPOSE:To avoid trouble by extraneous matter to a mask by a method wherein an organic high molecular layer is formed onto a substrate, a resist layer containing silicon is shaped onto the organic high molecular layer, the resist layer is coated with a water-soluble resin layer and the resin layer is exposed adhesively, developed and transferred. CONSTITUTION:An organic high molecular layer 2, a resist layer 3 containing silicon and a water-soluble resin layer 4 are formed onto a substrate 1 in predetermined thickness through a spin coating method in succession. The organic high molecular layer 2 is constituted by a polyimide resin in 1-2mum thickness, the resist layer 3 containing silicon by a resist containing positive type silicon in 0.3-0.4mum thickness consisting of a novolac group resin containing silicon atoms and a sensitizer, and the water-soluble resin layer 4 by polyvinyl alcohol in 0.1mum thickness. A mask 5 is fast stuck and exposed, the water-soluble resin layer 4 is removed by using hot water, and an exposed section in the resist layer 3 including silicon is removed by employing a prescribed developer. A pattern is transferred by using a reactive oxygen-ion etching device, thus obtaining a fine pattern.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a pattern forming method applied to the manufacture of semiconductor devices, magnetic puzzle memories, etc. are manufactured primarily by optical lithography. Various exposure methods are used in this optical lithography, but the high-density Mu element method has superior resolution compared to other exposure methods, and can be said to be the most suitable method for forming fine patterns.

On the other hand, in recent years, a two-layer resist method has been proposed as a method for forming fine patterns.This method involves forming an organic polymer layer on a substrate, then providing a silicon-containing resist layer thereon, and then exposing and developing it. .

By applying the two-layer resist method, which forms a fine pattern by transfer, to an optical ring 2 film using a contact exposure method, it becomes possible to form a finer pattern than before. It is possible to manufacture semiconductor elements with higher integration density, and the effect is extremely large.

However, in the contact exposure method, since the mask and resist come into direct contact, the resist adheres to the mask surface, which is known to cause manufacturing noise. Since the mask can be easily cleaned through the chemical process, manufacturing problems due to adhesion can be avoided. However, since the two-layer resist method uses a silicon-containing resist, the conventional ashing process cannot completely remove the resist adhered to the mask. As described above, when applying the two-layer resist method to optical lithography to obtain fine patterns, the problem of deposits on the mask becomes a major practical obstacle.

<Purpose of the Invention> The present invention provides a pattern that can easily avoid obstacles caused by deposits on a mask when applying a two-layer resist method to optical lithography, particularly optical links and 9Fs that employ a contact exposure method. The purpose of this paper is to provide a method of formation.

<Structure of the Invention> The pattern forming method of the present invention involves forming an organic polymer layer on a substrate, providing a silicon-containing resist layer thereon, and further covering it with a water-soluble resin layer, followed by contact exposure, It consists of developing and transferring.

<Detailed description of the structure> As mentioned above, the present invention provides a mouthpiece characterized in that a protective layer made of a water-soluble resin is provided when a two-layer resist method is applied to optical lithography that uses a contact exposure method. The protective layer can prevent the silicon-containing resist from adhering to the mask, thereby avoiding problems caused by the adhesion of the silicon-containing resist to the mask.Also, although the water-soluble resin as a protective layer may adhere to the mask, This does not pose any new problems as it can be easily removed through a conventional ashing process.

The purpose of using a water-soluble resin as a protective layer is to avoid interaction with silicon/containing resist.

That is, since the silicon-containing resist is water-insoluble, it mixes with the water-soluble resin of the protective layer during the coating process.

Create a clean interface without any scratches 〇The water-soluble resin used as the protective layer may be any material as long as it does not have any negative effects such as light absorption during exposure and can be completely removed through the ashing process. Therefore, polyvinyl alcohol resin can be said to be a suitable resin for the present invention.
,・1°Next, the present invention will be specifically explained based on examples.

Ru.

<Example> FIG. 1 shows the process of pattern formation. (Figure a1 shows the structure according to the present invention. On the substrate l, an organic polymer layer 2, a link-containing resist layer 3, a water-soluble resin layer 4)
is formed to a predetermined thickness using the spin cord method. Here, as the organic polymer layer 2, a polyimide resin is used to a thickness of 1 to 2 μm, and as a silicon-containing resist layer 3, a positive type silicon-containing resist made of a novolak resin containing silicon atoms and a photosensitive agent shown below is used to a thickness of 1 to 2 μm. 0.3～
Polyvinyl alcohol was used as the water-soluble resin WI4 to have a thickness of 0.1 μm.

The composition of the silicon-containing resist is as follows.

・・・・・・・・・10m! The lid was then brought into close contact with the mask 5t, as shown in FIG. Thereafter, water-soluble resin #4 was first removed using warm water, and then the exposed portion of the silicon-containing resist layer 3 was removed using a predetermined working solution. The result (
Shown in Figure c1. Next, the pattern was transferred using a reactive oxygen ion etching device, and a desired fine pattern was obtained as shown in Figure (d).

Further, no difference in pattern formation was observed depending on the presence or absence of the water-soluble resin layer 4.

Next, in order to investigate the effect of the gripping layer according to the present invention, the following study was conducted.

Using the same mask, the above-described pattern forming process according to the present invention up to exposure was repeatedly performed until deposits were visually confirmed on the mask. When the thus obtained mask with deposits was passed through a normal ashing process, a clean mask as originally obtained was obtained.

On the other hand, when a Si-containing resist is artificially attached to the surface of a mask and subjected to the same ashing process, it is observed that a residue remains on the surface. According to the present invention, when forming fine patterns by applying the two-layer resist method to optical lithography, especially contact exposure type optical lithography, a mask is required for the water-soluble resin layer provided on the surface. Since the problem of deposits on the substrate can be easily solved, a method of forming a fine pattern that can be put to practical use becomes possible.

[Brief explanation of the drawing]

FIG. 1 (al to (d+) are cross-sectional views showing the steps of pattern formation according to the present invention. 1...Substrate, 2...Organic polymer layer, 3...Silicon-containing resist layer, 4...Water-soluble 5...Mask, 6...Exposure light beam port

Claims (1)

[Claims] A pattern forming method characterized by forming an organic polymer layer on a substrate, providing a silicon-containing resist layer thereon, further covering the layer with a water-soluble resin layer, and then performing contact exposure, development, and transfer. .