JPH09289200A - Substrate temperature control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make processing results uniform through all the surface of the substrate, by a method wherein the substrate is divided into two regions, a first region and a second region, and the regions are so controlled as to be different from each other in temperature. SOLUTION: A lower electrode 16 is formed like a disc whose upside is slightly larger in diameter than a wafer 1. The lower electrode 16 is composed of a center electrode 16A whose diameter is nearly 2/3 as large as the overall diameter of the electrode 16 and a peripheral electrode 16B. Warm water is supplied to the electrodes 16A and 16B from temperature controls 18 and 20 to keep them at 30 deg.C and 20 deg.C, respectively, to cause a temperature difference of 10 deg.C between the center 21 and the periphery 22 of the wafer 1. By this setup, all the surface of a wafer 1 is uniformly processed, so that the substrate can be set uniform in processing result through all its surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate temperature control device, and can be applied to, for example, an etching device for etching a wafer with a predetermined gas.

[0002]

2. Description of the Related Art Conventionally, an etching apparatus of this type includes a so-called microwave plasma etcher for etching a gas in a plasma state generated by being excited by microwaves by applying a magnetic field. Some etching gases introduced into the etching chamber of the microwave plasma etcher have etching properties and deposition properties at the same time. When a wafer is etched by this etching gas, the wafer is etched in a direction orthogonal to the plane of the wafer to form a step portion, and a reaction product of plasma and etching gas is deposited on the side wall of the step portion. Thus, it is possible to prevent the sidewall from being excessively etched by the etching gas.

[0003]

However, in the above-described microwave plasma etcher, the etching gas is exhausted from the periphery of the wafer, and it is difficult to exhaust this etching gas uniformly when exhausting. The lower electrode on which the wafer is placed controls the temperature of the entire surface of the wafer to be the same.

Therefore, when etching is performed on, for example, polysilicon on the wafer surface using an etching gas having etching properties and deposition properties in the microwave plasma etcher described above, the residence time of the etching gas is the center of the wafer. It was shorter in the peripheral part than in the part. Therefore, the shape of the side wall at the end of etching is not uniform in the wafer surface.

That is, as shown in FIG. 3, in the central portion of the wafer 1, reaction products 2 of the gas in the plasma state and the etching gas are deposited more in the lower portion than in the upper portion of the side wall of the step portion 3, The sidewall was etched into a shape inclined with respect to the in-plane direction of the wafer 1. On the other hand, in the peripheral portion of the wafer 1, the reaction products 2 were deposited almost uniformly above and below the side wall, and the side wall was etched into a shape orthogonal to the in-plane direction of the wafer 1.

The present invention has been made in consideration of the above points, and an object thereof is to propose a substrate temperature control device capable of uniformizing the processing result on the substrate surface over the entire surface of the substrate.

[0007]

In order to solve such a problem, according to the present invention, in a substrate temperature control device for controlling the temperature of a substrate, the first region is set by dividing the substrate into a plurality of regions, and It is controlled so as to give an arbitrary temperature difference to the second region set by dividing into regions.

By giving an arbitrary temperature difference between the first region and the second region, which are set by dividing the substrate surface into a plurality of regions having different processing results at the same temperature, almost the entire surface of the substrate is By uniformly processing, the processing result on the substrate surface can be made uniform over the entire surface of the substrate.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a microwave plasma etcher 10 as a temperature control device as a whole, which uniformly etches the entire surface of a silicon semiconductor wafer as a substrate. The microwave plasma etcher 10 excites hydrogen gas or nitrogen gas introduced into the plasma chamber 11 by microwaves introduced from the magnetron 12 above the plasma chamber 11 to generate plasma discharge. Microwave plasma etcher 1
0 introduces hydrogen plasma or nitrogen plasma into the etching chamber 14 arranged in the lower part of the plasma chamber 11 by the magnetic field generated by the coil 13 arranged around the plasma chamber 11.

In the microwave plasma etcher 10, a lower electrode 16 is arranged below the etching chamber 14, and the lower electrode 16 is biased to a predetermined potential by a DC bias power supply 17. Microwave plasma etcher 10
Irradiates one substantially disk-shaped silicon semiconductor wafer 1 mounted on the lower electrode 16 with hydrogen plasma or nitrogen plasma.

At this time, the microwave plasma etcher 1
At 0, an etching gas having an etching property and a deposition property is supplied into the etching chamber 14. This causes the microwave plasma etcher 10 to move the surface of the wafer 1 to the wafer 1
Etching is performed in a direction orthogonal to the in-plane direction to form a step portion 3 such as a contact hole on the surface of the wafer 1. Further, the microwave plasma etcher 10 causes the reaction product 2 of the hydrogen plasma or nitrogen plasma and the etching gas to pass through the step portion 3.
Is deposited on the side wall of the substrate and prevents the side wall from being excessively etched by the etching gas.

As shown in FIG. 2, the lower electrode 16 is formed in a disc shape whose upper surface has a diameter slightly larger than that of the wafer 1. Further, the lower electrode 16 is composed of a central electrode portion 16A and a peripheral electrode portion 16B having a diameter of approximately 2/3 of the entire diameter. The peripheral electrode portion 16B is the center electrode portion 16
It is formed in a donut shape sharing the center with A, and the inner peripheral wall is fitted into the outer peripheral wall of the center electrode portion 16A.

Center electrode portion 16A and peripheral electrode portion 16B
The temperature is controlled by, for example, supplying hot water by the temperature controllers 18 and 20, respectively. As a result, in the wafer 1, the temperatures of the central portion 21 as the first region and the peripheral portion 22 as the second region, which are respectively placed on the central electrode portion 16A and the peripheral electrode portion 16B, are centered. It is controlled separately by the electrode portion 16A and the peripheral electrode portion 16B.

In the above structure, the central electrode portion 16A and the peripheral electrode portion 16B have a temperature of, for example, 30 [° C.].
And 20 [° C.] so that a temperature difference of 10 [° C.] is generated between the central portion 21 and the peripheral portion 22 of the wafer 1. As a result, the deposition rate of the reaction product 13 in the central portion 21 of the wafer 1 is reduced as compared with the peripheral portion 22 by the temperature difference, and the stepped portions 3 formed in the central portion 21 and the peripheral portion 22 respectively. The reaction product 2 during etching on the side wall is deposited to a substantially uniform thickness.

Accordingly, the side walls of the step portions 3 of the central portion 21 and the peripheral portion 22 are etched into a shape orthogonal to the in-plane direction of the wafer 1. As a result, it is possible to etch the side wall of the step portion 3 into the same uniform shape over the entire surface of the wafer 1.

According to the above configuration, the central electrode portion 16A and the peripheral electrode portion 16B are provided between the central portion 21 and the peripheral portion 22 of the wafer 1 in which the deposition state of the reaction product 2 at the same temperature is different. The reaction product 2 during etching is deposited over the entire surface of the wafer 1 to a uniform thickness on the side wall of the step portion 3 on the surface of the wafer 1 by controlling so as to give an arbitrary temperature difference. The side wall shape of the step portion 3 formed by etching the surface can be made uniform over the entire surface of the wafer 1.

In the above-described embodiment, the case where the wafer 1 is divided into the two regions consisting of the central portion 21 and the peripheral portion 22 to control the temperature has been described, but the present invention is not limited to this, and for example, It can also be applied to the case where the temperature is controlled by concentrically dividing into three or more regions. In this case, the same effect as described above can be obtained.

Further, in the above-described embodiment, the case where the present invention is applied to the microwave plasma etcher 10 for etching the surface of the wafer 1 is described, but the present invention is not limited to this, and the CVD process for performing the CVD process on the wafer The present invention can be widely applied to the case where the temperature is controlled so as to give an arbitrary temperature difference between a plurality of regions set on an arbitrary substrate, such as an apparatus, and arbitrary treatment is performed.

Further, in the above-described embodiment, the case where a temperature difference between the central portion 21 and the peripheral portion 22 of the wafer 1 is given by the temperature controllers 18 and 20 has been described. Not limited to this, for example, by increasing the density of the heaters in the central portion and decreasing the density of the heaters in the peripheral portion, it can be applied to a case where an arbitrary temperature difference is provided between the central portion and the peripheral portion.

[0021]

As described above, according to the present invention, the substrate surface is divided into a plurality of regions having different processing results at the same temperature, and the region is set between the first region and the second region. It is possible to realize a substrate temperature control device in which the entire surface of the substrate is processed substantially uniformly by providing the temperature difference of 1, and the processing result for the surface of the substrate can be made uniform over the entire surface of the substrate.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a microwave plasma etcher according to an embodiment of a substrate temperature control device of the present invention.

FIG. 2 is a schematic side view and a schematic top view for explaining a lower electrode.

FIG. 3 is a schematic diagram showing a deposition state of reaction products on a wall surface of a step portion.

[Explanation of symbols]

1 ... Wafer, 2 ... Reaction product, 3 ... Step portion, 10
…… Microwave plasma etcher, 11 …… Plasma chamber, 12 …… Magnetron, 13 …… Coil, 14 ……
Etching chamber, 16 ... Lower electrode, 16A ... Center electrode part, 16B ... Peripheral electrode part, 17 ... DC bias power supply, 18, 20 ... Temperature controller, 21 ... Wafer center part, 22 ... Wafer Peripheral area.

Claims (5)

[Claims] 1. A substrate temperature control device for controlling the temperature of a substrate, wherein the substrate is divided into a plurality of regions and set between a first region and a second region set by dividing the region. A substrate temperature control device characterized in that the temperature is controlled so as to give an arbitrary temperature difference. 2. A first temperature control means for controlling the first area to a first temperature, and a second temperature control means for controlling the second area to a second temperature. The first and second
2. The substrate temperature control device according to claim 1, wherein the arbitrary temperature difference is given by the temperature of. 3. The substrate temperature control device according to claim 1, wherein the substrate temperature control device is a substrate processing device that arbitrarily processes the substrate surface. 4. The substrate according to claim 3, wherein the process is an etching process in which the substrate is housed in a processing chamber and the substrate is etched by a predetermined gas introduced into the processing chamber. Temperature control device. 5. The first region is a central portion of the substrate, the second region is a peripheral portion of the substrate set so as to surround the central portion, and the temperature of the central portion is controlled. The substrate temperature control device according to claim 1, wherein the temperature is controlled to be higher than the temperature of the peripheral portion by the arbitrary temperature difference.