JP2006015288A - Applicator and coating liquid applying method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an applicator with which a uniform organic film can be formed on a wafer having a large difference in level while removing air bubbles at an application step of applying a high-viscosity organic resin to the wafer and abnormal dry etching can be restrained, and to provide a coating liquid applying method. <P>SOLUTION: The applicator is provided with a vacuum pump for reducing the pressure in a vessel and a rotary stage integrated with a mechanism for heating a material to be coated. Since this applicator has such a characteristic that the material to be coated is heated, a coating liquid is spin-coated and the pressure in the vessel is reduced during the spin coating, air bubbles can be prevented perfectly from being mixed in the organic film on the wafer in the part having the large difference in level and abnormal dry etching can be restrained at the succeeding step of the application step. Air bubbles can be prevented from being mixed in a new film formed by degassing the wafer at a baking step after the application step. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor device manufacturing apparatus, and more specifically, in a process of applying a high viscosity thick film organic resin to a wafer having a high step, air bubbles in the organic film and in the step portion are completely eliminated to be uniform. The present invention relates to a coating machine and a coating method for forming an organic film.

In the application process of organic resin such as resist, polyimide, bisbenzocyclobutene, etc. in the conventional manufacturing process of semiconductor elements, the semiconductor wafer is rotated at an appropriate number of revolutions so as to have a desired thickness after being applied on the semiconductor wafer. Rotate with. Next, the coating material is cured by baking the wafer, and an organic resin film is formed on the surface of the semiconductor wafer. In addition, for the purpose of filling the slit, groove, and overhang with a liquid, there is a method of filling the stepped portion by applying the pressure under reduced pressure and then returning to atmospheric pressure by the pressure difference from the bubbles in the stepped portion. (See Patent Document 1).
JP-A-63-124524

  However, as described above, application is performed under reduced pressure, and after application, the pressure is returned to atmospheric pressure, and even when the stepped portion is filled, it is filled with a pressure difference. For example, as shown in FIG. A plated wiring 10 having a thickness of 5 μm is formed on the via hole 9 having a depth of about 140 μm, and a step portion on the wafer covered with the protective film 11 of an insulating film having a thickness of about 500 to 700 nm is shown in FIG. When the high-viscosity thick film organic film 12 having a viscosity of about 300 to 2700 cP is applied, bubbles 13 are generated in the stepped portion and the via hole. Next, when the pressure is returned to the atmospheric pressure, as shown in FIG. 2C, a dent 14 is generated in the coating material due to a pressure difference with the bubble 13 at the stepped portion. Therefore, as shown in FIG. 2D, abnormal dry etching 15 of the protective film 11 occurs in the dent portion 14 of the coating material generated due to the pressure difference by subsequent dry etching. Further, in the baking process after coating, bubbles are newly generated due to degassing from the wafer, and bubbles remain in the film. Or, it will bounce and remain in crater form on the organic film.

  The present invention relates to a coating machine and a coating method for forming a uniform organic film by completely eliminating bubbles in the organic film and in the stepped portion in the step of coating a high viscosity thick film organic resin on a semiconductor wafer having a high level difference. The purpose is to provide.

  The applicator of the present invention includes a rotary pump integrated with a vacuum pump for decompressing the inside of the container and a mechanism for heating the material to be coated.

  In the coating method of the present invention, the material to be coated is heated and then spin-coated, and the inside of the container is depressurized during coating. It is possible to suppress abnormal dry etching in the process. Further, by heating the wafer before coating, it is possible to prevent air bubbles from being mixed into the new film due to degassing from the wafer in the baking process after coating.

  As described above, the coating machine and the coating method of the present invention apply the spin coating after heating the material to be coated in the step of coating the high-viscosity thick film organic resin on the wafer having a high level difference. By depressurizing the inside, it is possible to completely prevent bubbles from being mixed in the high step portion and to suppress abnormal dry etching in the subsequent process.

  Next, the coating machine in the embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the coating machine which is embodiment of this invention has the nozzle 2 which discharges a coating material in the airtight container 1, and the rotation mechanism 4 integral with the chuck | zipper 3 with a heating mechanism under the nozzle. Is located. The hermetic container 1 can be depressurized by the vacuum pump 6, and the degree of vacuum can be controlled by operating the valve 7.

  Hereinafter, it demonstrates according to process order.

  First, the wafer 8 is fixed on the chuck 3 with a heating mechanism in the sealed container 1. Next, the heating mechanism is heated at 80 to 100 ° C. until the adhering gas on the wafer surface is eliminated. Next, the coating material is discharged onto the wafer 8 by the nozzle 2, and the wafer stage 5 is rotated to a film thickness at which the step portion is completely filled. Next, in the rotated state, the valve 7 is opened, and the inside of the sealed container 1 is decompressed to about .about.0.5 Pa. At this time, bubbles generated in the stepped portion are removed. Next, the valve 7 is closed, and spin coating is performed until the desired film thickness is obtained while maintaining the reduced pressure state. At this time, when spin coating is performed with the valve 7 open, bubbles in the coating material can be removed. Note that the heating mechanism may be a lamp heater mechanism capable of rapid heating. When the chuck is a vacuum chuck, the degree of vacuum needs to be higher than the reduced pressure state in the sealed container. Alternatively, an electrostatic chuck other than a vacuum chuck may be used. Further, the wafer may be structured to be chucked in a state close to the entire surface. As described above, by heating the wafer before coating and reducing the pressure during the coating, it is possible to completely eliminate bubbles in the stepped portion. Further, by heating the wafer before coating, it is possible to prevent air bubbles from being mixed into a new film due to degassing from the wafer in the baking process after coating.

  The coating machine and the coating method according to the present invention can completely prevent bubbles from being mixed in a high step portion, and can suppress abnormal dry etching in a post-process, and have a high viscosity thickness on a wafer having a high step. It is useful for the use of the manufacturing method of the semiconductor device used for the process of apply | coating film | membrane organic resin.

The figure which shows the coating device in embodiment of this invention Configuration diagram for explaining conventional technology

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Nozzle 3 Chuck with a heating mechanism 4 Rotation mechanism 5 Wafer stage 6 Vacuum pump 7 Valve 8 Wafer 9 Via hole 10 Plating wiring 11 Protective film 12 High-viscosity thick film organic film 13 Bubble 14 Depression 15 Abnormal dry etching

Claims (2)

An applicator comprising an airtight container, a vacuum pump for depressurizing the inside of the container, and a rotary stage integrated with a mechanism for heating the material to be coated. The coating method using the coating machine according to claim 1, wherein the coating material is heated and then spin-coated, and the inside of the container is decompressed during coating.

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