JP2009198750A - Method for manufacturing resin pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for improving productivity by reducing a developing time in the manufacture of a resin pattern formed from a photosensitive alkali aqueous solution developing type resin. <P>SOLUTION: A method for manufacturing a resin pattern includes at least steps in the following order: (1) applying a photosensitive alkali aqueous solution developing type resin on a substrate; (2) exposing the resin; (3) exposing the resin film after exposure to a high humidity environment; (4) developing and (5) drying the resin. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a resin pattern. More specifically, the present invention relates to a method for producing a resin pattern formed from a photosensitive alkaline aqueous solution developing resin that is suitably used for an interlayer insulating film, a surface protective film, and the like in the semiconductor field.

  Conventionally, resins such as polyimide and polybenzoxazole have been used as surface protective films and interlayer insulating films of semiconductor wafer substrates. These resins are generally developed with an organic solvent or an aqueous alkali solution. In recent years, a batch opening process has been introduced in which these resins are provided with the same high resolution as resists, and each process of resist and resin, which has been performed in the past, is performed once in resin processing. Contributes to improvement. However, there is a growing demand for further productivity improvement, and there is a need for a process that can shorten the development time.

  An object of the present invention is to provide a technique for improving productivity by shortening the development time in the production of a resin pattern formed from a photosensitive alkaline aqueous solution developable resin.

  The present invention includes at least (1) a step of applying a photosensitive alkaline aqueous developing resin on a substrate, (2) an exposure step, (3) a pre-development treatment step of exposing the exposed resin film to a high humidity atmosphere, (4) A method for producing a resin pattern having a developing step and (5) a drying step in this order.

  According to the present invention, the development time of the photosensitive alkaline aqueous solution developing resin can be shortened, so that the productivity of the resin pattern can be improved.

  The present invention will be described in detail below. The present invention is characterized by having a pre-development processing step of exposing the exposed resin film to a high humidity atmosphere. By providing such a pre-development processing step, the development time can be shortened. It is considered that the pre-development treatment step makes the resin film surface after the exposure easily compatible with the alkaline aqueous solution, and the development time is shortened. Hereinafter, each step will be described.

  (1) A photosensitive alkaline aqueous solution developing resin is applied on a substrate. When the composition containing the photosensitive alkaline aqueous solution developing resin and the solvent is applied on the substrate, a step of drying the substrate after application may be provided. By this step, a photosensitive alkaline aqueous solution developable resin film is obtained.

  As the substrate, a wafer made of silicon, ceramics, gallium arsenide, or the like is generally used, but is not limited thereto. Examples of the coating method include spin coating using a spinner, spray coating, roll coating, and the like. In general, the coating thickness is such that the thickness after drying is 0.1 to 30 μm.

  Examples of the photosensitive alkaline aqueous solution developing resin include acrylic resin, polyamic acid that is a precursor of polyimide, polyhydroxyamide that is a precursor of polybenzoxazole, and the like.

  Drying is preferably performed using an oven, a hot plate, infrared rays, or the like at 50 to 150 ° C. for 1 minute to several hours. If necessary, drying can be performed in two or more stages, such as 2 minutes at 80 ° C. and 2 minutes at 120 ° C.

  Next, (2) in the exposure step, the film obtained in the step (1) is irradiated with actinic radiation through a mask having a desired pattern. As the actinic radiation used for exposure, there are ultraviolet rays, visible rays, electron beams, X-rays and the like. In the present invention, i-ray (365 nm), h-ray (405 nm) or g-ray (436 nm) of a mercury lamp is used. preferable.

  Next, (3) in the pre-development treatment step, the exposed film obtained in the step (2) is exposed to a high humidity atmosphere. The humidity condition may be any condition that allows water molecules to be adsorbed on the surface of the resin film, and the humidity is preferably 75% or more.

  Next, (4) a developing step is performed. An appropriate developer can be selected in accordance with the structure of the photosensitive alkaline aqueous solution development resin. For example, ammonia, tetramethylammonium aqueous solution, diethanolamine, diethylaminoethanol, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, triethylamine, diethylamine, methylamine, dimethylamine, dimethylaminoethyl acetate, dimethylaminoethanol, dimethylamino Examples include aqueous solutions of alkaline compounds such as ethyl methacrylate, cyclohexylamine, ethylenediamine, and hexamethylenediamine.

  Examples of the developing method include a method in which the above developing solution is radiated on the surface of the resin film on the substrate as it is or in the form of a mist to pour liquid. Moreover, the method of immersing a board | substrate during image development can also be mentioned. Further, ultrasonic treatment may be performed while dipping. The temperature of the developer is usually about 23 ° C. ± 2 ° C., but is not particularly limited.

  Next, a step of washing the relief pattern formed by development with a rinse solution may be provided. As the rinse liquid, water is preferable. Further, rinsing treatment may be performed by adding an ester such as ethanol, isopropyl alcohol or propylene glycol monomethyl ether acetate, an acid such as carbon dioxide, hydrochloric acid or acetic acid to water.

  Next, (5) it is necessary to remove the rinse liquid by a drying process. When the rinse liquid remains on the electrode portion of the substrate, a slight amount of the photosensitive component or additive may be dissolved from the resin film, which may change the characteristics of the electrode. In addition, when a polyimide precursor or polybenzoxazole precursor is used as the photosensitive alkaline aqueous solution developing resin, it may be converted into a resin having an imide ring or an oxazole ring by heating in the drying step, and a separate heat treatment step may be performed. It may be provided.

  In order to convert a polyimide precursor or a polybenzoxazole precursor into a resin, it is common to apply a temperature of 200 to 500 ° C., and the temperature may be raised stepwise or continuously. May be. The heat treatment time is generally 5 minutes to 5 hours. As an example, a method of performing heat treatment at 130 ° C., 200 ° C., and 350 ° C. for 30 minutes each, or a method of linearly raising the temperature from room temperature to 400 ° C. over 2 hours may be mentioned.

  The resin pattern thus obtained is preferably used for a semiconductor device as a surface protective film or an interlayer insulating film.

  Hereinafter, in order to describe the present invention in detail, examples will be described.

Example 1
Using a coater developer ACT-8 manufactured by Tokyo Electron, a positive photosensitive polyimide PW-1001 manufactured by Toray Industries, Inc. was applied on an 8-inch silicon substrate, baked on a hot plate at 120 ° C. for 6 minutes, and a film thickness of 7 μm. A resin film was prepared. The obtained resin film was exposed for 1400 msec through a mask having a pattern of 5 μm line using Nikon i-line stepper NSR2005 i9C. The silicon substrate having the exposed resin film was left in a place at a temperature of 23 ° C. and a relative humidity of 75% for 1 minute. Next, the film was immersed in a 2.38% tetramethylammonium aqueous solution at 23 ° C. for 60 seconds, rinsed with water at 23 ° C. for 60 seconds, then blown off with an air gun and dried. The film thickness of the obtained resin pattern after development was measured, and the amount of film reduction (initial film thickness before development (7 μm) −film thickness after development) was determined to be 0.6 μm. The line width of the 5 μm pattern was 5.0 μm (75%).

Example 2
A resin pattern was formed in the same manner as in Example 1 except that the humidity during the pre-development treatment was changed from 75% to 100%. The amount of film reduction was 0.6 μm, and the line width of the 5 μm pattern was 5.0 μm.

Comparative Example 1
A resin pattern was formed in the same manner as in Example 1 except that the humidity of the pretreatment for development was changed from 75% to 45%. The amount of film reduction was 0.5 μm, the line width of the 5 μm pattern was 4.5 μm, and the desired 5.0 μm opening was not achieved.

Comparative Example 2
A resin pattern was formed in the same manner as in Comparative Example 1 except that the immersion time (development time) in the tetramethylammonium aqueous solution was changed from 60 seconds to 80 seconds. The amount of film reduction was 0.6 μm, and the line width of the 5 μm pattern was 5.0 μm.

Claims (2)

At least (1) a step of applying a photosensitive alkaline aqueous development resin on a substrate, (2) an exposure step, (3) a pre-development treatment step in which the exposed resin film is exposed to a high humidity atmosphere, and (4) development. (5) A method for producing a resin pattern having a drying step in this order. The method for producing a resin pattern according to claim 1, wherein the humidity in the (3) pre-development treatment step is 75% or more.