JPH01289119A - Semiconductor manufacturing device - Google Patents

Abstract

PURPOSE:To enhance the etching evenness in wafers by a method wherein the etching process is performed by turning an electrode holding a wafer centered on the position deflected from the center of the wafer. CONSTITUTION:A rotary axle 4 is provided on a position distant from the center of an electrode 2 holding a wafer 3 in a parallel flat plate type dry etching device while the rotary axle 4 driven by a driving motor 7 provided outside an etching chamber 1. Then, both of the lower electrode 4 and an opposite electrode 2 are impressed with high-frequency to make gas plasmic for performing the etching process. Through these procedures, the etching evenness in wafers can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to semiconductor manufacturing equipment, particularly dry etching equipment.

[Prior Art] In the conventional dry etching method, for example, when etching polycrystalline silicon, etching is performed using a parallel plate type dry etching apparatus as shown in FIG. 2 without rotating the wafer. CF as gas, 1100
5 CC, a pressure of 250 mTorr, and a high frequency of 250 W are applied, but the uniformity is only 8%, and even if the above conditions are changed, the uniformity does not improve any further, and hardware changes are required.

[Problem to be solved by the invention] In the case of a parallel plate type dry etching device, the plasma distribution may not be uniform due to the electrodes not being accurately parallel or the positional relationship of the gas inlet and exhaust port. Therefore, there was a problem that uniformity was not improved.

Therefore, the present invention solves these problems, and when the center of rotation is shifted from the center of the wafer,
The present invention provides a semiconductor manufacturing apparatus and a semiconductor device manufacturing method that improve etching uniformity within a wafer by performing etching while rotating the wafer.

[Means to solve the problem]

The semiconductor manufacturing apparatus of the present invention includes a dry etching apparatus which has an electrode for holding a wafer and an electrode facing the same, and performs etching by applying a high frequency between the electrodes to turn gas into plasma, and an electrode for holding the wafer. , a dry etching apparatus that performs etching by applying microwaves to turn gas into plasma, and is characterized by rotating an electrode that holds a wafer about a point offset from the center of the wafer.

Further, the method for manufacturing a semiconductor device according to the present invention is characterized in that etching is performed using the semiconductor manufacturing apparatus.

[Function] According to the present invention, since etching is performed while rotating the wafer at a location where the center of rotation is shifted from the center of the wafer, every location within the wafer comes into contact with plasma of various densities. This ensures uniform etching at all locations, improving uniformity.

[Example 1] Hereinafter, the present invention will be described in detail based on Examples.

The dry etching device was a parallel plate type device as shown in FIG. The device is not limited to this type, and may be a microwave type or a magnetron type (and the results will be the same regardless of the type).

A rotating shaft 4 is provided 2 cm away from the center of the electrode 2 on which the wafer 3 is placed, and is rotated by a drive motor 7 provided outside the etching chamber 1. As a result, the electrode 2 rotates, and the wafer 3 also rotates at the same time.The position of the zero rotation axis is not limited to this, but may be any position. The rotation method is not limited to this, for example, the electrode may be directly rotated by a drive motor.

In this case, since high frequency is applied to the rotating electrode 2,
The gear 6 is made of an insulating material so that no voltage is applied to the drive motor 7.
For example, it needs to be made of ceramic, but the material is not limited to this.

Furthermore, since the high frequency is applied to the rotating electrode 2 or the rotating shaft 4, a mechanism is required in which a roller 8 made of a conductive material is attached to the side of the rotating shaft 4 and the high frequency is applied from there. The method is not limited to this, and contact may be made using a brush made of a conductive material.

When etching polycrystalline silicon using a dry etching apparatus with the above mechanism, CF4 is used as a gas at 110%
05CC, pressure 250mTorr, high frequency 250W
When etching is performed while rotating the wafer 3 at a rotational speed of 4 revolutions per minute, the etching speed distribution as shown in Fig. 4 is obtained, and Fig. 3 shows the results obtained using the conventional technique as shown in Fig. 2. (Compared to this, the uniformity within the wafer was significantly improved, and the uniformity within the wafer was about 3%.The material to be etched is not limited to this, but for example, a resist or an oxide film may be used. The conditions and rotational speed are not limited to these.

By performing etching while rotating the wafer at a position offset from the center in this manner, it has been found that the uniformity of etching within the wafer is improved by more than twice as much as in the conventional technique.

[Effect of the invention 1 As described above, according to the present invention, by performing etching while rotating the wafer at a position offset from the center, the uniformity, which conventionally improved to only about 8%, has been improved to 3%.
It has the effect of being improved to a certain degree.

[Brief explanation of the drawing]

FIG. 1 is a diagram of a dry etching apparatus according to an embodiment of the invention. FIG. 2 is a diagram of a conventional dry etching apparatus. FIG. 3 is a speed distribution diagram of etching performed using the conventional technique. FIG. 4 is an etching rate distribution diagram based on an embodiment of the present invention. l... Etching chamber 2... Electrode 3... Wafer 4... Rotating shaft 5... High frequency power source 6... Gear 7... Drive motor 8... Conductive roller 9... Gas inlet port 10...Gas exhaust port and above Applicant: Seiko Epson Co., Ltd. Agent Patent attorney Masatoshi Kamiyanagi (1 person) Figure 1 Figure 2

Claims (1)

[Claims] (1) There is a dry etching device that has an electrode that holds the wafer and an electrode that faces it, and applies high frequency between the electrodes to turn gas into plasma for etching, and there is an electrode that holds the wafer and applies microwaves. What is claimed is: 1. A semiconductor manufacturing device that performs etching by converting gas into plasma, the semiconductor manufacturing device being characterized in that an electrode that holds a wafer is rotated about a point offset from the center of the wafer as a center of rotation.