JPH05243191A - Dry etching device - Google Patents

Abstract

PURPOSE:To control a semiconductor substrate in shape when temperature control as it is important that arm etched object is controlled in etching shape at dry etching. CONSTITUTION:Coolant feed paths 22, 23, and 24 are provided inside an electrode 31 where a semiconductor substrate 32 is installed, and the temperature of the semiconductor substrate 32 is controlled by the use of controllers 1, 2, and 3, coolant tanks 10, 11, and 12, and temperature monitors 28, 29, and 30. By this setup, a through-hole can be controlled in depth and direction when it is formed by etching.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus, and more particularly to a temperature control system for controlling the temperature of an electrode on which a semiconductor substrate is placed in a dry etching apparatus.

[0002]

2. Description of the Related Art FIG. 3 is a diagram showing a temperature control system of a conventional dry etching apparatus. The controller 1 controls the refrigerant tank 10 via the signal cable 7 so that the monitoring temperature from the temperature monitor 28 sent via the signal cable 4 becomes the same as the set temperature.

The refrigerant tank 10 controls the temperature of the refrigerant in the refrigerant tank 10 according to the set temperature sent from the controller 1 via the signal cable 7.

The coolant in the coolant tank 10 is sent into the electrode 31 via the coolant supply path 22 and the valve 16 by the pump 13, and the monitoring temperature output from the temperature monitor 28 to the controller 1 via the signal cable 4 is detected. Change the temperature so that the set temperatures of the controller 1 match,
It returns to the refrigerant tank 10 via the refrigerant supply path 25 and the valve 19.

As described above, since the conventional temperature control system of this type of dry etching apparatus has only one coolant tank 10, coolant supply paths 22 and 25, and a temperature monitor 28,
The temperature control of the electrode 31 on which the semiconductor substrate 32 is installed focuses only on one place. Reference numeral 33 is an upper electrode, and 34 is a vacuum processing chamber.

[0006]

Since the dry etching apparatus of this type has only one coolant tank and one temperature monitor in the temperature control system, it is necessary to keep the temperature on the semiconductor substrate 32 within a certain temperature range. Is not much of a problem,
If it is attempted to keep the temperature difference on the semiconductor substrate 32 within 1 to 2 degrees in the plane, sufficient temperature control cannot be performed.

On the other hand, the etching shape of the object to be etched on the semiconductor substrate 32 depends on the in-plane temperature distribution of the semiconductor substrate 32. There is a problem that it will vary.

FIG. 4 is a cross-sectional view of a Si oxide film on a semiconductor substrate etched by using a dry etching apparatus having a conventional temperature control system. The set temperature of the electrode is −
It is 20 degrees. FIG. 4A is a sectional view of the central portion of the semiconductor substrate, and FIG. 4B is a sectional view of the peripheral portion. 40 is a semiconductor substrate, 41 is a Si oxide film, 42 is a photoresist, 4
3 is a reaction product.

Since the semiconductor substrate is exposed to plasma during etching, the semiconductor substrate is heated above the set temperature of the electrodes. In particular, the peripheral portion of the semiconductor substrate has a lower cooling efficiency than the central portion, and is therefore heated to a higher temperature. Therefore, if the temperature is controlled so that the peripheral portion is cooled as much as necessary, the central portion tends to be excessively cooled. FIG. 2B shows the temperature distribution on the semiconductor substrate. When the peripheral portion is 70 degrees, the central portion is lowered by about 10 to 30 degrees.

Taking the formation of contact holes as shown in FIG. 4 as an example, excessive reaction products are attached to the excessively cooled central portion as compared with the peripheral portion. This reaction product hinders the progress of etching, and as a result, etching stops halfway, resulting in insufficient etching compared with the peripheral portion. In particular, this problem becomes important when forming a fine contact hole of 0.5 μm or less of a VLSI.

It is an object of the present invention to provide a dry etching apparatus capable of controlling the etching shape by controlling the temperature of a semiconductor substrate.

[0012]

In order to achieve the above object, a dry etching apparatus according to the present invention converts a process gas introduced into a vacuum processing chamber into plasma by applying high frequency power, and the plasma is used to form a semiconductor substrate on a semiconductor substrate. In a dry etching apparatus for etching an object to be etched, a plurality of coolant supply paths provided inside an electrode on which a semiconductor substrate is installed, a plurality of coolant tanks for supplying coolant to the coolant supply paths, and a coolant tank are individually provided. And a temperature control device for controlling the temperature.

[0013]

A plurality of coolant supply paths are provided inside the electrode on which the semiconductor substrate is installed, and the temperature-controlled coolant is supplied to the coolant supply paths.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention.

In FIG. 1, the electrode 31 on which the semiconductor substrate 32 is installed has the coolant supply passages 22, 23, 24, 25, 26, 27 concentrically from the center of the semiconductor substrate 32 therein.
Have.

The controller 1 controls the refrigerant tank 10 via the signal cable 7 so that the monitoring temperature sent from the temperature monitor 28 via the signal cable 4 becomes the same as the set temperature.

The refrigerant tank 10 controls the temperature of the refrigerant in the refrigerant tank 10 according to the set temperature sent from the controller 1 via the signal cable 7.

The coolant in the coolant tank 10 is sent into the electrode 31 by the pump 13 via the coolant supply path 22 and the valve 16, and the monitoring temperature output from the temperature monitor 28 to the controller 1 via the signal cable 4 is detected. Change the temperature so that the set temperatures of the controller 1 match,
It returns to the refrigerant tank 10 via the refrigerant supply path 25 and the valve 19.

This means that the controllers 2 and 3, the signal cables 8 and 9, the refrigerant tanks 11 and 12, the pumps 14 and 15,
Valves 17, 18, 20, 21, refrigerant supply paths 23, 2
The same applies to 4, 26, 27 and temperature monitors 29, 30.

As shown in FIG. 2A, when the temperature is controlled according to this embodiment, the temperature distribution on the semiconductor substrate becomes uniform.

[0021]

As described above, the present invention has a plurality of coolant supply paths inside the electrode on which the semiconductor substrate is installed, and a plurality of coolant tanks for supplying the coolant to the coolant supply paths, and By having a temperature control device for individually controlling the temperature of each coolant tank, it is possible to control the temperature distribution in the semiconductor substrate to be uniform.

Therefore, it is possible to uniformly control the etching shape distribution of the object to be etched on the semiconductor substrate depending on the temperature.

In particular, when forming a contact hole of a VLSI, a large effect can be found by forming a contact hole in a portion having a small diameter and a small margin such as a deep margin.
In fact, it has been confirmed that if the temperature distribution of the semiconductor substrate is suppressed within the temperature range of 5%, the 0.5 μm contact hole can be etched with good in-plane distribution.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

2A is a diagram showing a temperature distribution on a semiconductor substrate when a temperature control system of the present invention is used, and FIG. 2B is a diagram showing a temperature distribution on a semiconductor substrate when a conventional temperature control system is used. Is.

FIG. 3 is a diagram showing a conventional example.

FIG. 4 shows an object to be etched on a semiconductor substrate that has been etched using a conventional temperature control system.
Is a cross-sectional view of the central portion of the semiconductor substrate, and (b) is a cross-sectional view of the peripheral portion.

[Explanation of symbols]

 1,2,3 Controller 4,5,6 Signal cable 7,8,9 Signal cable 10,11,12 Cooling tank 13,14,15 Pump 16,17,18 Valve 19,20,21 Valve 22,23,24 Refrigerant supply path 25, 26, 27 Refrigerant supply path 28, 29, 30 Temperature monitor 31 Electrode 32 Semiconductor substrate 33 Upper electrode 34 Vacuum processing chamber 40 Semiconductor substrate 41 Si oxide film 42 Photoresist 43 Reaction product

Claims (1)

[Claims] 1. A dry etching apparatus for converting a process gas introduced into a vacuum processing chamber into plasma by applying high-frequency power, and etching an object to be etched on a semiconductor substrate using the plasma, inside a electrode on which the semiconductor substrate is set. A dry etching apparatus comprising: a plurality of coolant supply paths provided; a plurality of coolant tanks for supplying a coolant to the coolant supply paths; and a temperature control device for individually controlling the temperature of the coolant tanks.