JPS5999720A - Forming method of resist image - Google Patents

Abstract

PURPOSE:To form the distinct resist image, in which there is no positive type radiation resist residue, by executing two-stage rinsing treatment using a specific rinsing liquid to a positive type radiation resist consisting of the polymer of monomers shown in a specific Formula. CONSTITUTION:The single polymer of the monomer shown in formula or one kinds or more copolymers of said polymer and other vinyl group monomers are applied on a substrate. A desired section is irradiated by radiation, and developed and treated. Rinising treatment at two stages shown in the following is executed in the process of rinsing treatment. A first stage: Rinsing treatment by an isopropyl alcohol (IPA)-methyl isobutyl ketone (MIBK) mixed liquid, the concentration of MIBK therein is 50% (a volume ratio) or less. A second stage: Rinsing treatment by single IPA. Accordingly, a distinct resist pattern through which a resist residue is not generated is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a rinsing process for a high-sensitivity positive radiation resist, and more specifically, the present invention relates to a rinsing process for a halogen-containing radiation-sensitive positive resist having a specific structure. The present invention relates to a method for forming a resist image, which is characterized by forming a resist pattern with no resist residue and clearer than before by applying a process.

[Prior art and its problems]

Conventionally, photolithography using ultraviolet light with a wavelength of 4000A or more has been used as a microfabrication technology for manufacturing semiconductor devices, magnetic bubble devices, and optical components, but in recent years, the density of semiconductor devices has increased.

With the increase in integration, phosphorography technology using electron beams, X-rays, etc. is attracting attention, and high-sensitivity and high-resolution radiation resists for use therein are being developed.

However, none of these methods is sufficient on a practical level, and they also have some drawbacks in terms of process.

It has been reported that fluoroalkyl α-chloroacrylate polymers, such as polytrifluoroethyl α-chloroacrylate, are highly sensitive positive radiation resists (T-Tada, J.Electroc.
hem, Sac, 1261829 (1979)
).

When this resist was developed with a relatively highly soluble developer and subjected to normal IPA rinsing, resist residues tended to be formed in some areas. In particular, the larger the area of the substrate used, the more remarkable this tendency was.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and provides a specific method for a positive radiation resist made of polytrifluoroethyl α-chloroacrylate or a copolymer of trifluoroethyl α-chloroacrylate and other vinyl monomers. The present invention aims to provide a method for forming a resist image that is clear and has no resist residue by performing a two-step rinsing process using a rinsing liquid of 100%, which is therefore highly practical.

[Summary of the Invention] In other words, 1 the present invention is to coat at least one kind of a homopolymer of a monomer represented by the following formula or a copolymer of this and another vinyl monomer onto a substrate, and to form a desired The area is irradiated with radiation,
The above objective is achieved by performing the following two-stage rinsing process in the process of rinsing after the development process.

First stage: Rinse treatment with an IPA-MIBK mixed solution in which the concentration of MIBK is 50% (volume ratio) or less.

Second stage: Rinse treatment with IPA alone.

〔Effect of the invention〕

High sensitivity positive radiation resist polytrifluoroethyl α
- When performing a conventional one-step rinse treatment using IPA on chloroacrylate, resist residues were frequently generated, especially when irradiated with a low dose and using a highly soluble developer. According to the present invention, the rinsing process is divided into two stages, and as the first stage rinsing, the rinsing process is performed using an MIBK-IPA mixed solution with an MIBK concentration of 50% (volume ratio) or less, and as the second stage rinsing, It was confirmed that by performing the rinsing treatment with IPA, a clear resist pattern without any resist residue was obtained.

Examples of positive radiation resists targeted by the present invention include polytrifluoroethyl α-chloroacrylate, trifluoroethyl α-chloroacrylate-methacrylic acid copolymer, and trifluoroethyl α-chloroacrylate-methyl methacrylate. copolymer, trifluorony f-fivα-chloroacrylate-1-butyl methacrylate copolymer, trifluoroethyl α-chloroacrylate-trifluoroisopropyl α-chloroac! 21 j”-to, trifluoroethyl 71z
Examples include α-chloroacrylate-phenyl α-chloroacrylate-14 polymer, trifluoroethyl α-chloroacrylate-α-methylsgurun copolymer, trifluoroethyl α-chloroacrylate-benzyl α-chloroacrylate copolymer, and the like. Possible 1. The composition of the rinsing liquid used in the first stage rinsing in the rinsing process used in the present invention varies depending on the developer used, but the MIBK concentration is 50% or less, preferably 1 to 5%.

[Embodiments of the invention]

Example 1 Polytrifluoroethyl α-chloroacrylate (molecular weight: 600,000) was spin-coated onto 6-inch Cr.
After coating the mask substrate to a thickness of 0.5 μm, a prebaking process was performed in air at 200C for 1 hour.

Then, a desired portion of the prebaked resist film is accelerated 4.
After irradiating the electron beam with a pressure of 20KV at an irradiation density of 4μC/cm2, go! After developing with a developer consisting of IIBK-IPA (8:2), rinsing with a mixed solution of IPA-MIBK (99:1) is performed as a first rinse, and then rinsing with IPA as a second rinse. I did it. As a comparative example, a sunflu was also produced in which a conventional IPAI stage rinse was performed after the development process.

As a result of preparing 10 samples each of the two-step rinsing process according to the present invention and the conventional one-step rinsing process, it was found that 3 of the 10 1-step rinsing samples had partial resist residual liquid. However, it was confirmed that no resist residue was generated in the two-stage rinsed sample, and a clear resist pattern was obtained.

Example 2 Trifluoroethyl α-chloroacrylate-7zyl α-chloroacrylate copolymer (composition ratio 90:1
0, molecular weight 800,000) by spin coating.
After coating to a thickness of 0.5μ on a 2-inch Cr mask substrate
0I:' Prebaking treatment was performed in air for 1 hour. Next, a desired portion of the prebaked resist film was irradiated with an electron beam at an acceleration voltage of 20 KV at an irradiation density of 4 μC/cIrL2, and then developed with a developer consisting of MIBK-IPA (8:2). A rinsing process using an IPA-MIBK (99:1) mixed solution was performed as a stage rinsing, and then a rinsing process using IPA was performed as a second stage rinsing. In addition, as a comparative example, after development processing,
Samples were also prepared that underwent a conventional IPAI stage rinse.

As a result of producing 10 samples each of sandals subjected to the two-step rinsing process according to the present invention and the conventional one-step rinsing process, partial occurrence of resist residue was observed in 4 out of 10 samples subjected to the 1-step rinsing process. However, it was confirmed that no resist residue was generated in the two-stage rinsed sample, and a clear resist pattern was obtained.

As described in detail above, by performing the rinsing process of the present invention on a specific positive radiation resist, it is possible to form a resist pattern that is clearer than before without any residual resist liquid, and thereby improves the quality of semiconductor substrates.

It is possible to provide a highly practical resist image forming method that can be effectively used for microfabrication of mask substrates and the like.

Procedural amendment (formality) 1 Display of incident Anwa 57th year special application No. 208471 2 Name of the invention Resist image forming method 3 Person making the amendment Related to the case: Patent applicant (307) Tokyo Shibaura Electric Co., Ltd. 4 agents 〒100 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo -1・

Claims (1)

[Claims] (1) At least one homopolymer of the monomer represented by the formula, or a copolymer of this and other vinyl thread yarn
Resist image formation characterized by applying the following two-stage rinsing treatment on a substrate, irradiating desired areas with radiation, developing, and rinsing. Law.