JPH0230132A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To form a coated film having no built-up part at its outer peripheral section without producing silica dust by forming the coated film having a uniform thickness on the entire surface of a wafer by dropping a coating liquid onto the wafer while an attracting plate holding the wafer on its surface by suction is rotated and removing the coated film on the outer peripheral section by etching after forming the coated film. CONSTITUTION:After a coated film having a uniform thickness is formed on the entire surface of a semiconductor substrate 8 by dropping a coating liquid onto the substrate 8 while an attracting plate 6 which holds the substrate 8 by suction is rotated, the film on the outer peripheral section of the substrate 8 is removed by etching. For example, the semiconductor wafer 8 is attracted by suction by means of a chuck 6 and a silica liquid is dropped. The number of revolution of the plate 6 is reduced to 300rpm after the number of revolution reaches 4000rpm and a mixed liquid produced by mixing 31% hydrogen peroxide and 29% aqueous ammonia 1:1 in volume is spouted from a nozzle 7 for 10 seconds. After spouting the liquid, the wafer 8 is again rotated at the 4000rpm for 3 seconds. Therefore, a silica film 2 which has no built-up parts and the outer peripheral part of which is removed by etching can be formed on a semiconductor wafer 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing a semiconductor device, and particularly to a method of forming an insulating film using a coating film.

[Conventional technology]

Generally, a high-quality insulating film is obtained by applying a silicon compound-containing solvent (silica film) on a semiconductor substrate (wafer) and then performing heat treatment, but the film before heat treatment is weak against physical forces, Immediately after, the groove of the wafer carrier that receives the wafer rubs against the outer periphery of the semiconductor wafer, causing the film to peel off and generate silica debris. On the other hand, as a conventional technique, after coating a silica film, the solvent of the coating liquid is flowed around the outer periphery of the semiconductor wafer to remove the silica film that causes silica debris on the outer periphery of the semiconductor wafer.

For example, there is a method using a coating device as shown in FIG. In this device, a wafer 8 is placed on a wafer chuck 6 provided at the center of a cylinder 4 for rotating the wafer, and a portion of the bottom of the cylinder 4 that is below the circumference of the wafer 8 is placed on a wafer chuck 6 for rotating the wafer. A nozzle γ for ejecting liquid is provided upward so as to face the back surface of the wafer 8, and is connected to the cylinder 4.
An exhaust port 5 is provided near the outer wall of the bottom surface. After applying the silica film coating liquid using this device, the silica film on the outer periphery of the wafer is removed by flowing only the solvent used in the silica film coating liquid from the nozzle 7 to the outer periphery of the back surface of the wafer. be. This results in
This is intended to prevent silica dust that tends to be generated from the outer periphery of the wafer.

[Problem to be solved by the invention]

However, in the conventional method described above, since the solvent of the coating solution is flowed onto the semiconductor wafer immediately after coating, most of the solute in the coating film is moved, and after the solvent evaporates, as shown in Figure 2, A bulge 3 of the coating film is formed on the outer periphery of the coating film on the semiconductor wafer. Therefore, it is not a perfect method, as it has the drawback that it cracks and peels off during the heat treatment in the post-process, which also causes the generation of silica debris.

[Means to solve the problem]

The method for manufacturing a semiconductor device of the present invention includes adsorbing a wafer on a suction plate, dropping a coating liquid onto a wafer, and rotating the suction plate to apply the coating liquid to a coating film with a uniform thickness over the entire surface of the wafer. The coating film on the outer periphery of the wafer is removed by etching.

[Example] Next, a first example of the present invention will be described with reference to the drawings. The coating device used is the same one shown in FIG. 3 as described above. A semiconductor wafer is adsorbed by a chuck 6, and silica liquid is dropped.

After that, the rotation speed was shaken off at 4000 revolutions per minute (rpm), and then the rotation speed was reduced to 300 rpm, and in that state, 31% hydrogen peroxide (H2O2) and 29% aqueous ammonia (NH, OH) were applied from nozzle 7 for 10 seconds. Spray up a 1:1 volume of the mixed solution and rotate again at 4000 rpm for 3 seconds. By this method, it is possible to form a silica film on the semiconductor wafer without any bulges and whose outer peripheral portion has been etched away, as shown in FIG. This can prevent the generation of silica dust when storing wafers in the wafer carrier. Thereafter, the semiconductor wafer is transferred to a carrier and heat-treated at about 600° C., thereby converting the silica film into a high-quality insulating film.

Next, a second embodiment of the present invention will be described.

Drop the silica film coating liquid in the same way as in the first example,
After that, the rotation speed is 400 rpm, then 300 rpm.
drop to rpm. A mixed solution of 10:1 volume of water (H2O) and 49% hydrofluoric acid (HF) was discharged from the nozzle 7 for 3 seconds and rotated again at 4000 rpm for 3 seconds. Then again 3
00 rpm, run pure water for 10 seconds from another nozzle, and rotate again at 4000 rpm for 3 seconds.

This method also makes it possible to form a coating film similar to that of the first embodiment.

〔Effect of the invention〕

As explained above, by adopting a method in which the coating film etching solution, which does not contain a coating solution, is introduced to the periphery of the semiconductor wafer, the solute components are etched away, and the periphery is removed without any swelling. It becomes possible to form a coating film of a state on a semiconductor wafer. Therefore, when a semiconductor wafer is placed on a carrier, no silica dust is generated, and cracks do not occur due to heat treatment, and the generation of silica dust can be suppressed.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the weno after coating according to the present invention, FIG. 2 is a sectional view of the weno coated by the conventional method, and FIG. 3 is a sectional view of the coating machine. 1... Semiconductor sea urchin...-12... Coating film, 3... Swelling of coating film, 4...
Cylinder, end...Exhaust port, 6...Wafer chuck, 7...Nozzle, 8...Semiconductor wafer representative Patent attorney Susumu Uchihara Semiconductor wafer request 4 - 1 cake, 7 pieces, y servings] = 9 Calligraphy and - mouthful) -tY soft nozzle stop guide) 1-

Claims (1)

[Claims] A semiconductor substrate is attracted to a suction plate, a coating liquid is dropped onto the semiconductor substrate, and the suction plate is rotated to apply the coating liquid to a uniform thickness over the entire surface of the semiconductor substrate. A method for manufacturing a semiconductor device, characterized in that the coating film on the outer periphery is removed by etching.