JPS60171728A - Dry etching unit - Google Patents

Abstract

PURPOSE:To enable a wafer to be etched at a uniform speed for improving the pattern precision, by arranging a parallel-plate electrode consisting of upper and lower electrodes within a chamber while burying a plurality of ring-shaped temperature control pipes in the lower electrode, any by circulating temperature controlled liquids independently in each of the pipes. CONSTITUTION:A chamber 1 is mounted on a stage 3 while it is hermatically sealed by means of an O ring 2. A parallel-plate electrode consisting of an upper electrode 4 and a lower electrode 5 is arranged within the chamber 1. The upper and lower electrodes 4 and 5 are grounded. A plurality of ring-shaped temperature control pipes 7 are buried in the lower electrode 5, and temperature controlled liquids 8a, 8b, 8c and 8d which are constantly temperature controlled by a temperature control unit (not shown) are independently circulated in each of the pipes. The temperature controlled liquids 8a-8d are independently controlled so as to have different temperatures from one another. Further, the temperature control pipes 7 are surrounded by a heat insulating material 9 so that the temperature precision of each pipe 7 is maintained by preventing the pipes from dissipating heat to or receiving it from the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a dry etching apparatus for etching semiconductor wafers in a semiconductor manufacturing process.

[Background of the invention]

In semiconductor wafer manufacturing technology, improving etching accuracy is an important issue that greatly affects the improvement of pattern accuracy formed on wafers or the pattern formation yield. One important parameter that influences etching accuracy and affects etching uniformity is wafer temperature.

It has been known for a long time that wafer temperature has a large effect on etching speed, and various techniques have been used to control wafer temperature.

One such method is to control the temperature of the entire electrode on the side where the wafer is adsorbed or placed at a constant temperature using a heater or a temperature control liquid. However, since this method can only control the entire wafer at the same temperature, there is a problem in that the etching rate differs between the center and the periphery of the wafer, making it impossible to completely eliminate variations in the amount of etching.

[Purpose of the invention]

The purpose of the present invention is to utilize the fact that the etching rate depends on the wafer temperature to eliminate variations in etching between the center and the periphery of the wafer to ensure etching uniformity and to improve the precision of the putter 7. It is an object of the present invention to provide a dry etching apparatus that can realize the improvement in yield and yield.

[Summary of the invention]

In order to achieve the above object, the present invention disposes a parallel plate zh consisting of an upper electrode and a lower electrode in a chamber, and embeds a plurality of temperature control pipes in a ring shape in the lower electrode. It is characterized by a configuration in which temperature control liquid is circulated through each pipe independently.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

A chamber is mounted on a stage 3 in a state where it is hermetically sealed via an O-ring 2, and parallel plate electrodes consisting of an upper electrode 4 and a lower electrode 5 are disposed inside the chamber. A high frequency power source 6 is connected between the upper electrode 4 and the lower electrode 5, and the lower electrode 5 side is grounded. Further, a plurality of ring-shaped temperature control pipes 7 are embedded in the lower electrode 5, and each has an independent temperature control device l (not shown).
Temperature regulating liquids 8a, 8b, 8C18 whose temperature is constantly controlled by this
d is beginning to circulate. The temperature control liquids 8a to 8d are independently controlled to have different temperatures, and the temperature control pipes 7 are covered with a heat insulating material 9 to prevent heat transfer to the outside and maintain the temperature of each pipe 7. It is designed to maintain accuracy. With the above configuration, the temperature of the wafer 10 on the fi4i5 can be controlled to have a concentric distribution.

Next, the operation will be explained. When etching the semiconductor wafer 10, as shown in the figure, the wafer 10 is transferred onto the lower electrode 5 in the etching processing chamber, and the etching process is carried out in the chamber 1.
After covering the processing chamber with stage 3 exhaust port 3,a
Then, use a vacuum pump to evacuate until a constant pressure is reached. After supplying etching gas from the gas supply 1a of the chamber under constant pressure, wait until the etching pressure becomes stable and apply a high frequency voltage from the high frequency power supply 6 to generate plasma discharge between the upper electrode 4 and the lower electrode 5. The film on the wafer 10 is etched by chemical and physical reactions.

In this case, depending on the etching gas and the material of the film, the etching tends to proceed in a circular manner from the center of the wafer 10 to the periphery, or vice versa.

However, by lowering the temperature of the portion where etching progresses faster than the temperature control pipe 71, and increasing the temperature of the portion where etching progresses slowly.

The etching speed of the film on the wafer 1o is controlled, and the etching on the wafer 1o is uniformized and killed.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a parallel plate 1 consisting of an upper electrode, a lower part w, and a pole is disposed in a chamber, and a plurality of heating pipes are connected to the lower electrode as a ring. Since the temperature control liquid is configured to be embedded in the wafer and circulated independently through the temperature control pipes, the etching speed within the wafer is made uniform, improving the pattern irradiance and improving the yield of pattern formation. can be done.

[Brief explanation of drawings]

The figure is a sectional view showing an example of the dry etching device 4 according to the present invention. I...Chamber, 3゛...Stage, 4...Upper electrode, 5...Lower electrode, 6...High frequency power supply,
7...Temperature control pipe, 8a-8d...Temperature control liquid, 9.
...Insulation material, 1o...Wafer X-+, No

Claims (1)

[Claims] In a dry etching device in which a parallel plate electrode consisting of an upper electrode and a lower electrode is arranged in a chamber, a plurality of ring-shaped temperature control pipes are embedded in the lower electrode, and each temperature control pipe can independently control the temperature. A dry etching device characterized by being configured to circulate a liquid.