JPH031530A - dry etching equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a polymeric organic film ashing device, particularly a dry etching device, used in the production of semiconductors and electronic components.

(Prior art) As a method of ashing a polymeric organic film, H2SO4/H20
There are two methods: a wet method according to No. 2, and a dry method using oxygen gas (02) plasma generated by a dry etching device.

Since the former method uses H2SO4, it has the disadvantage that it cannot be applied to metal films such as AI, so the latter method is exclusively used.

FIG. 2 shows an example of a barrel-type dry etching apparatus, which is currently widely used in the ashing of polymeric organic films.

In the apparatus shown in the figure, a workpiece 3 is placed on a mounting table 2 in a reaction chamber 1 made of a vacuum container, and oxygen gas is introduced into the reaction chamber 1 through a gas introduction pipe 4.

A high frequency voltage is applied from a high frequency power source 7 between the electrodes 5 and 6 placed above and below the reaction chamber 1 to excite the oxygen gas.
Generate plasma.

This 02 plasma reacts with carbon, which is the main component of the organic polymer film on the object 3 to be treated, to form carbon dioxide gas or -carbon oxide, and the organic polymer film is peeled off. The gas thus generated is exhausted through the gas exhaust pipe 8.

(Problem to be Solved by the Invention) In the conventional barrel-type dry etching apparatus described above, the temperature of the object to be processed rises during processing due to plasma, reaction heat, or heat from the heater, causing deterioration of the polymeric organic film. There is a risk that the organic polymer film may be hardened or hardened, and the polymeric organic film may not be completely removed and may remain as a residue 10 on the surface of the object 3 as shown in FIG.

In addition, in FIG. 3, 11 is a Si substrate, 12 is a 5i0
2 film, 13 shows a sputtered layer of Al-8i-Cu.

Furthermore, since the workpiece 3 is directly exposed to plasma, there is a drawback that contaminants are implanted into the workpiece 3, which tends to cause damage.

(Object of the Invention) The present invention has been made to solve the above-mentioned drawbacks in the prior art, and it prevents the workpiece from being directly exposed to plasma and reduces the temperature of the workpiece during processing by 12
The object of the present invention is to provide a dry etching apparatus which causes less damage and does not leave any residue of a polymeric organic film by controlling the temperature to 0° C. or lower.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the dry etching apparatus of the present invention is a polymer organic film ashing apparatus in which a plasma generator is separated from a reaction chamber. a to-be-treated object cooling device for cooling the to-be-treated object during oxidation; a temperature measuring means for measuring the temperature of the to-be-processed object; The present invention is characterized by comprising a temperature control device for controlling the temperature at 120° C. or lower during the oxidation.

(Function) As described above, in the dry etching apparatus of the present invention, the plasma generation device is provided separately from the reaction chamber, and the temperature of the object to be treated during ashing of the polymeric organic film is kept at 120°C.
Since the temperature is controlled to be below .degree. C., it is possible to completely incinerate the polymeric organic film with little damage to the object to be treated.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings. In addition,
The same parts as in FIG. 2 are given the same reference numerals.

FIG. 1 shows an example of a dry etching apparatus according to the present invention, in which a stage 2 on which a workpiece 3 to be processed is mounted is provided in a reaction chamber 1. As shown in FIG. The processing table 2 is equipped with an electrostatic chuck device 20, and when a high voltage is applied from a high voltage generator 21, the workpiece 3 is electrostatically attracted to the electrostatic chuck device 20 and brought into close contact with the workpiece 3.

A workpiece cooling device 22 such as a refrigerator is connected to the mounting table 2 and cools the workpiece 3 that is in close contact with the electrostatic adsorption device 20 on the mounting table 2 . Furthermore, a temperature measuring means (not shown) such as a thermocouple for measuring the temperature of the object 3 to be processed is attached to the mounting table 2 . A lead wire 23 drawn out from this temperature measuring means is connected to a temperature control device 24.

The temperature control device 24 controls the processing object cooling device 22 based on the temperature signal measured by the temperature measuring means, and provides feedback so that the temperature of the processing object 3 is always below 120° C. during the processing time. Control.

A gas introduction pipe 4 is connected to the upper part of the reaction chamber 1, and a plasma generator 25 is inserted in the middle of this gas introduction pipe.

The plasma generator 25 is composed of a discharge tube 26 made of quartz and a waveguide 27 installed outside the discharge tube 26. By applying microwaves through the waveguide 27, the inside of the discharge tube 26 is The reactive gas flowing through is activated, becomes O2 plasma, flows into the reaction chamber 1, and chemically etches the object to be processed 3.

A gas exhaust pipe 8 for discharging gas after etching is connected to the bottom wall of the reaction chamber 1, and a vacuum pump (not shown) is connected to this gas exhaust pipe.

FIG. 4 shows an example of the object to be processed 3, in which a 5i02 film 12 is formed on a Si substrate 11 by a thermal oxidation method, and a sputtered layer 13 of A I -S i -Cu is formed thereon. is provided. This sputtered layer 13 is formed by a positive resist (polymer organic film) 1 with a mask formed thereon.
4 and etched into a predetermined pattern.

An electrostatic adsorption device 20 in the reaction chamber 1 of a dry etching apparatus according to the present invention shown in FIG.
A reactive gas was sent into the reaction chamber 1 from the plasma generator 26 to incinerate the polymeric organic film. In this case, a mixed gas of CF4+02 was used as the reactive gas, and the temperature control device 24 feedback-controlled the object cooling device 22 to maintain the temperature of the object 3 at 120° C. or lower. As a result, as shown in FIG. 5, in the obtained object 3, the positive resist 14 was completely removed by ashing, and neither deterioration nor hardening of the resist 14 occurred.

Next, as another application example of the present invention, a 5i02 film is formed on a Si substrate by a thermal oxidation method, a polycrystalline St layer is deposited thereon by a vapor phase epitaxy method, and after masking with a positive resist, I did etching.

Figure 6 shows its performance in terms of pressure resistance characteristics, where curve (■) is for the case using the apparatus of the present invention, curve (2) is for the case using the barrel type apparatus in Figure 2, and curve (■) is for wet etching using H2SO4/H202. The case is shown below.

As is clear from this figure, in the case of the device of the present invention shown by curve (2), the bare foil defect rate is significantly lower in the low electric field region than in the case of the conventional barrel-type device shown by curve (2). Furthermore, as is clear from a comparison of curves (2) and (2), the defective rate in the case of the present invention is almost as low as in the case of wet etching.

In addition, although the above-mentioned example described the example which used a thermocouple as a temperature measurement means, this invention is not limited to this, For example, an infrared thermometer or a fluorescence thermometer may be used.

〔Effect of the invention〕

As explained above, according to the present invention, there is less damage and
Moreover, it is possible to obtain a dry etching apparatus that does not leave any residue of the polymeric organic film.

Processed object cooling device, 23... Lead wire, 24... Temperature control device, 25... Plasma generation device, 26...
Discharge tube, 27... waveguide.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating a dry etching apparatus of the present invention, FIG. 2 is a schematic diagram illustrating a conventional dry etching apparatus, and FIG. 3 is a sectional view illustrating a workpiece etched by a conventional method. , FIG. 4 is a cross-sectional view illustrating a workpiece to which the method of the present invention is applied, and FIG. 5 is a cross-sectional view illustrating a workpiece etched by the apparatus of the present invention.
FIG. 6 is a graph explaining the effects of the present invention and the conventional device.

Claims (1)

[Claims] In a polymer organic film ashing device in which a plasma generator is installed separately from a reaction chamber, a processing object cooling device is used to cool the processing object during polymer organic membrane ashing, and the temperature of the processing object is measured. and temperature measuring means to set the temperature at the time of incineration of the polymeric organic film of the object to be treated to 1 based on the output from the temperature measuring means.
A dry etching apparatus comprising: a temperature control device for controlling the temperature to 20°C or less.