KR20070016446A - Exhaust apparatus of plasma processing equipment - Google Patents

Abstract

Provided is an exhaust device of a plasma processing facility. The exhaust device of the provided plasma processing apparatus includes a turbo pump, a foreline, a dry pump, and a thermocouple gauge provided with a filament and a thermocouple therein to measure the internal pressure of the foreline in order to evacuate the pressure inside the process chamber. And a pressure regulating member for preventing the filament provided inside the thermocouple gauge from being degraded and damaged by a sudden pressure change of the process chamber when the etching process is performed. Therefore, according to the exhaust device of the provided plasma processing equipment, even if the internal pressure of the process chamber is suddenly changed by the pressure regulating member and the internal pressure of the foreline is suddenly changed, it is possible to prevent the filament of the thermocouple gauge from being damaged. .

Description

Exhaust apparatus of plasma processing equipment

1 is a block diagram illustrating a plasma processing apparatus equipped with an exhaust device according to the present invention.

FIG. 2 is a cross-sectional view taken along line II of FIG. 1.

** Description of the symbols for the main parts of the drawings **

100: plasma processing equipment

110: process chamber

200: exhaust device

210: turbo pump

220: foreline

230: dry pump

240: branch line

250: thermocouple gauge

251 body

252 filament

253: thermocouple

260: control unit

270 fitting

280: pressure regulating member

The present invention relates to an apparatus for manufacturing a semiconductor device, and more particularly, to a plasma processing apparatus for etching a thin film formed on a wafer to manufacture a semiconductor device.

In general, a semiconductor device stacks at least one conductive layer, semiconductor layer, non-conductive layer, etc. by selectively repeating a process such as photolithography, etching, ashing, diffusion, chemical vapor deposition, ion implantation, and metal deposition on a wafer. To be combined.

In the semiconductor device manufacturing process, the etching process generates an electric field by applying a high frequency power source to the upper electrode and the lower electrode spaced a predetermined distance inside the closed process chamber to form a predetermined process gas supplied into the process chamber by the electric field. After activation to form a plasma state refers to a process of etching the wafer located on the lower electrode ions in the plasma state.

At this time, the process chamber of the plasma processing equipment where the etching process is performed is evacuated the unprocessed gas remaining without processing the predetermined process gas supplied into the process chamber to maintain the internal pressure of the process chamber at the predetermined pressure. The exhaust device is connected.

Here, the exhaust device includes a turbo pump provided in the lower portion of the process chamber, a foreline connected to one side of the turbo pump, through which untreated gas is evacuated through the turbo pump, and provided on the foreline to assist the turbopump. A scrubber is provided for collecting impurities contained in the dry pump, the turbo pump, and the untreated gas flowing through the foreline and the dry pump.

On the other hand, on the foreline connecting the turbopump and the dry pump, a pressure gauge for stopping the driving of the pump is provided when the pressure atmosphere of the unprocessed gas flowing in the foreline is measured to form a pressure atmosphere above a predetermined pressure. In this case, the pressure gauge may be a thermocouple gauge that is provided with a filament therein and measures a pressure by a temperature difference generated from the filament by applying a current to the filament.

However, in the process chamber provided in the conventional plasma processing equipment, a sudden pressure change occurs during the etching process. In addition, when a sudden pressure change occurs in the process chamber, a sudden pressure change occurs in an exhaust device for maintaining the internal pressure of the process chamber. Accordingly, the filament of the thermocouple gauge provided on one side of the exhaust device is a problem that is damaged because the temperature change occurs severely according to the pressure change.

Therefore, when the damage of the filament occurs due to a sudden pressure change in the exhaust system, the trouble of replacing the thermocouple gauge is generated, and the loss time for the etching process is generated.

Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide an exhaust device of a plasma processing apparatus for preventing the thermocouple gauge from being damaged when performing an etching process.

According to an aspect of the present invention for achieving the above object is provided on one side of the process chamber in which the etching process is performed, the turbo pump for evacuating the vacuum to maintain the pressure in the process chamber at a predetermined pressure, and is connected to one side of the turbo pump turbo It is combined with a foreline through which the gas discharged by the pump flows, a dry pump provided on the foreline to assist the turbopump, and a branching line branched on the foreline between the turbopump and the drypump and both ends of the filament and the filament therein. The thermocouple is connected to one side of the thermocouple gauge to measure the internal pressure of the foreline due to the temperature change of the filament, and the thermocouple gauge is connected to the other side of the thermocouple and is connected to the other side of the thermocouple gauge. Control unit and thermocouple to control the driving of the dry pump according to pressure A filament provided inside the page is degraded by a sudden change of pressure when performing a process chamber of the etching process provides an exhaust system of the plasma treatment equipment provided with a pressure adjusting member to be prevented from being damaged.

The pressure regulating member may be an orifice gasket provided at a portion where the thermocouple gauge and the branch line are coupled to each other.

A fitting for fixing the thermocouple gauge and the branch line is provided at the combined portion of the thermocouple gauge and the branch line provided with the orifice gasket.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed subject matter is thorough and complete, and that the spirit of the present invention to those skilled in the art will fully convey. Like numbers refer to like elements throughout.

1 is a block diagram showing a plasma processing apparatus equipped with an exhaust device according to the present invention, Figure 2 is a cross-sectional view taken along the line II 'of FIG.

First, referring to FIG. 1, a plasma processing apparatus 100 is provided with a process chamber 110 in which an etching process is performed. In this case, the lower region of the process chamber 110 is provided with an electrostatic chuck 120 on which the wafer W transferred into the process chamber 110 is seated by a wafer transfer device (not shown). In addition, a lower electrode 123 to which an external high frequency power source 129 is applied is provided below the electrostatic chuck 120, and a plasma generated from the upper portion of the electrostatic chuck 120 is disposed on the outer circumference of the electrostatic chuck 120. A focus ring 126 is provided to concentrate on the wafer W.

In addition, inside the electrostatic chuck 120 and the lower electrode 123, the wafer W transferred to the upper portion of the electrostatic chuck 120 by a wafer transfer device (not shown) is mounted on the electrostatic chuck 120. The lift pin 105 is provided to pass through.

In this case, the upper region of the process chamber 110 is disposed to be spaced apart from the electrostatic chuck 120 by a predetermined distance so as to face the above-described electrostatic chuck 120, and to the inside of the process chamber 110 to perform an etching process. A shower head 130 for supplying a predetermined process gas is provided.

Here, the shower head 130 serves as an upper electrode by applying an external high frequency power source 139, and each high frequency power source is provided to the shower electrode 130 serving as the lower electrode 123 and the upper electrode. When 129 and 139 are applied, an electric field is formed inside the process chamber 110 to generate plasma.

On the other hand, one side of the process chamber 110 to exhaust the unprocessed gas remaining without the process gas supplied through the shower head 130 and the exhaust device for maintaining the internal pressure of the process chamber 110 at a predetermined pressure ( 200).

In this case, the exhaust device 200 includes a turbo pump 210 provided at a lower portion of the process chamber 110, a fore line 220 connected to one side of the turbo pump 210, and the foreline ( The dry pump 230 provided on the 220 is provided.

Here, the turbo pump 210 provided in the lower portion of the process chamber 110 serves as a high vacuum pump to evacuate the unprocessed gas inside the process chamber 110. In addition, the dry pump 230 provided on the foreline 220 connected to the turbo pump 210 serves to assist the above-described turbo pump 210 as a low vacuum pump. Although not shown in the drawing on the foreline 220 at this time, an isolation valve may be provided to automatically adjust the pressure of the untreated gas flowing on the foreline 220.

Meanwhile, as illustrated in FIG. 1, a branch line 240 branched on the foreline 220 between the turbo pump 210 and the dry pump 230 is provided. At this time, the end of the branch line 240 is a pressure gauge that measures the pressure of the untreated gas flowing in the foreline 220 to determine the operation of the dry pump 230 according to the measured pressure value, that is, the thermocouple gauge 250 Is prepared.

At this time, referring to Figure 2, the thermocouple gauge 250 is provided with a main body 251 to form an appearance. A filament 252 is provided at an inner side of the main body 251, and one side of the thermocouples 253 is connected to both ends of the filament 252, respectively.

And, one side of the body 251 described above, that is, as shown in the upper portion of the body 251, the control unit 260 for controlling the thermocouple gauge 250 as a whole is coupled, the control unit 260 at this time The other side of the thermocouples 253 connected to both ends of the filament 252 is connected to.

In addition, the other side of the body 251 described above, that is, the lower portion of the body 251 is screwed with the branch line 240 branched from the foreline 220.

In addition, when the pressure inside the foreline 220 suddenly changes between the main body 251 of the thermocouple gauge 250 and the branch line 240, the pressure of the foreline 220 that is rapidly changed is the thermocouple gauge. A pressure regulating member 280 is provided to slowly flow into the body 251 of the 250.

Meanwhile, the pressure regulating member 280 described above may be an orifice gasket. At this time, the orifice gasket is formed in the center of the hole smaller than the diameter of the thermocouple gauge 250 and the branch line 240 to prevent the pressure of the foreline 220 is rapidly introduced into the inside of the thermocouple gauge 250 Will be. The orifice gasket also serves to prevent untreated gas from leaking at the connection portion between the thermocouple gauge 250 and the branch line 240.

In this case, a fitting 270 is provided at a connection portion of the thermocouple gauge 250 and the branch line 240, that is, an orifice gasket is interposed, and the fitting 270 of the thermocouple gauge 250 is described above. The connecting portion of the main body 251 and the branch line 240 is fixed.

On the other hand, although not shown in the drawings as another embodiment of the above-described pressure adjusting member 280 may be provided between the venturi tube between the main body 251 and the branch line 240 of the thermocouple gauge 250.

At this time, the venturi tube is smaller in diameter from one side to the center and larger in diameter from the other side to the other side, and the pressure of the untreated gas flowing through the foreline 220 rapidly increases inside the thermocouple gauge 250, like the orifice gasket. It is prevented from flowing in.

In addition, fittings are provided on the outer circumferential surfaces of the main body 251 of the thermocouple gauge 250 and the connection portion of one side of the venturi tube and the branch line 240, and the connection portion of the other side of the venturi tube, and the main body 251 and the branch line 240. To fix the venturi tube.

Hereinafter, with reference to the drawings will be described the operation and effect of the exhaust device of the plasma processing equipment according to the present invention.

First, in order to perform the etching process, the wafer W is seated on the electrostatic chuck 120 and a predetermined process gas is supplied into the process chamber 110 through the shower head 130. Then, when the high frequency power sources 129 and 139 are applied to the lower electrode 123 and the upper electrode, that is, the shower head 130 provided under the electrostatic chuck 120, an electric field is generated in the process chamber 110. At this time, the electric field changes the process gas into plasma to etch the thin film formed on the wafer (W).

At the same time, the process gas supplied into the process chamber 110 is not changed into a plasma state, and the remaining unprocessed gas is evacuated to the outside of the process chamber 110 through the exhaust device 200 to evacuate the inside of the process chamber 110. Maintain the pressure at a preset pressure.

At this time, in order to perform the etching process, a sudden change in the internal pressure is frequently generated during the vacuum exhaust process of the unprocessed gas inside the process chamber 110.

In addition, in order to evacuate the unprocessed gas inside the process chamber 110 as described above, the turbo pump 210 provided in the lower portion of the process chamber 110 is operated first, and the unprocessed gas is evacuated, and the turbo pump 210 is operated. Gas exhausted by the vacuum flows to the foreline (220). In addition, the untreated gas flows into the dry pump 230 assisting the turbo pump 210 along the foreline 220, and the turbo pump 210 and the dry pump 230 operate to operate the interior of the process chamber 110. The pressure is maintained at a preset pressure.

Meanwhile, in the thermocouple gauge 250 coupled with the branch line 240 branched from the foreline 220 between the turbo pump 210 and the dry pump 230, the untreated gas flowing in the foreline 220 may be formed. The pressure will be measured. As such, the thermocouple gauge 250 that measures the pressure of the unprocessed gas flowing through the foreline 220 is operated when the pressure of the unprocessed gas flowing on the foreline 220 flows above a predetermined pressure. Will stop.

At this time, when a sudden pressure change occurs in the process chamber 110 as described above in the process of stopping the operation of the dry pump 230 by the thermocouple gauge 250, the thermocouple gauge is conventionally due to this sudden pressure change. The filament of the 250 is damaged, but in the exhaust apparatus 200 of the plasma processing apparatus 100 according to the present invention, the pressure regulating member 280 provided between the thermocouple gauge 250 and the branch line 240, for example, an orifice gasket. Alternatively, the pressure of the untreated gas flowing in the foreline 220, that is, the branch line 240, is gradually introduced into the thermocouple gauge 250 by the venturi tube, thereby preventing damage to the filament 252.

On the other hand, the present invention has been described with reference to the illustrated drawings, which are merely exemplary, those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the scope of the present invention should be defined by the appended claims and their equivalents.

As described above, in the exhaust device of the plasma processing apparatus according to the present invention, even if a sudden pressure change occurs on the foreline due to a pressure change inside the process chamber, a pressure regulating member is provided between the branch line and the thermocouple gauge. This prevents damage to the couple gauge.

In addition, the exhaust device of the plasma processing apparatus according to the present invention has an effect of extending the life of the thermocouple gauge by preventing damage to the thermocouple gauge by the pressure regulating member.

Claims (4)

A turbo pump provided at one side of a process chamber in which an etching process is performed, and a vacuum pump to maintain a pressure inside the process chamber at a predetermined pressure; A foreline connected to one side of the turbo pump, through which gas exhausted by the turbo pump flows; A dry pump provided on the foreline to assist the turbopump; It is coupled to the branch line branched on the foreline between the turbopump and the dry pump, there is provided a thermocouple connected to both ends of the filament and the filament therein, the internal pressure of the foreline by the temperature change of the filament Thermocouple gauge to measure the; And And a pressure regulating member for preventing the filament from being damaged due to a sudden pressure change of the process chamber when performing the etching process. The method of claim 1, The pressure regulating member is an exhaust system of the plasma processing equipment, characterized in that the orifice gasket interposed in the portion coupled to the thermocouple gauge and the branch line. The method of claim 2, And a fitting for fixing the thermocouple gauge and the branch line to a combined portion of the thermocouple gauge and the branch line. The method of claim 1, And a control unit coupled to the thermocouple gauge and connected to the other side of the thermocouple to control driving of the dry pump according to the pressure of the foreline measured at the filament of the thermocouple gauge. Exhaust system of plasma processing equipment.

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