KR100251643B1 - Cutoff system for evaluating the impurities of process gas - Google Patents

Abstract

PURPOSE: A cut-off system for evaluating impurity within gas for manufacturing a semiconductor device is provided to evaluate the constituents of the gas easily and use a plurality of evaluation equipment by supplying the main constituents and the impurity of the gas being divided. CONSTITUTION: The first to the third column(14, 16, 18) divide sample gas into the main constituents and a plurality of impurity constituents. The first gas supplier divides the fuzzy gas and the sample gas from a gas source into a fuzzy mode and an evaluation mode by opening or closing a plurality of valves(24¯34) mounted on the closed circulation pipes(16, 22). Further, the first gas supplier outputs the fuzzy gas through the first column in the fuzzy mode, while collecting the sample gas. In the evaluation mode, the first supplier outputs the collected sample gas through the first column. The second gas supplier divides the gas through the first column by constituents, and supplies an evaluation apparatus through the third column.

Description

Cut-off System for Impurity Evaluation in Gas for Semiconductor Device Manufacturing

The present invention relates to a cut-off system for impurity evaluation in a gas for manufacturing a semiconductor device, and more particularly, in combination with various evaluation apparatuses for impurities included in an overall gas used in a process, A cut-off system for impurity evaluation in a gas for semiconductor device manufacturing to supply.

In general, many kinds of gases are used for various purposes in various processes such as oxidation, diffusion, deposition, ion implantation, and the like in the manufacturing process of semiconductor devices, and these gases must have a certain purity to be used in the process.

If the purity of the gas used in the manufacturing process of the semiconductor device is not guaranteed, the yield of the semiconductor device manufactured using the same decreases.

For this reason, the gas used in the semiconductor device manufacturing process is to evaluate the impurities contained in the gas, the evaluation of the impurity contained in the gas chromatography (Gas Chromatography Discharge Ionic Detector: 'GC-DID Gas Chromatography Thermal Conductivity Detector (hereinafter referred to as GC-TCD) Gas Chromatography Flammable Ionic Detector (hereinafter referred to as 'GC-FID') Devices such as Atmosphere Pressure Ionization Mass Spectrometer (hereafter referred to as 'API-MS') and Electronic Ionization Mass Spectrometer (hereafter referred to as 'EI-MS') It is done.

Chromatography refers to the difference in adsorption or partition coefficient between the mobile phase and the fixed phase of a sample by introducing a sample into the mobile phase while the various phases of the solid or liquid as a fixed phase and the gas or liquid as a mobile phase to allow the mobile phase to pass through the fixed phase. By using this method, the analysis method for separating a sample by component is collectively referred to.

Among the aforementioned devices, GC-DID is used to detect trace impurities contained in a gas such as nitrogen, oxygen, carbon monoxide or carbon dioxide, GC-FID is mainly used to detect methane (CH ₄ ), and GC -TCD is used to detect relatively high concentrations of impurities contained in gases such as nitrogen, oxygen, carbon monoxide, carbon dioxide or methane.

However, in order to evaluate the impurities contained in the gas using the apparatuses described above, a cut-off system for separating and supplying the main components and impurities of the gas to the apparatuses was needed. Without the development of the system, it was difficult to evaluate the effective gas, and accordingly there was a problem that the overall semiconductor device yield was lowered because the gas which was not accurately evaluated was used in the semiconductor device manufacturing process.

In particular, it is desired that the cut-off system be designed to be applicable to various evaluation apparatuses and to be evaluated throughout the gas rather than to be used for a specific evaluation apparatus or a specific gas.

An object of the present invention is to provide a cut-off for impurity evaluation in a semiconductor device manufacturing gas that can easily perform component evaluation on impurities contained in a gas, can be utilized for various evaluation devices, and can be used for evaluation of an overall gas. To provide a system.

1 is a block diagram showing an embodiment of a cutoff system for evaluating impurities in a gas for manufacturing a semiconductor device according to the present invention.

2 is a block diagram showing a configuration for driving a valve in an embodiment according to the present invention.

※ Explanation of symbols for main parts of drawing

10: GC-DID 12: GC-TCD

14, 18, 20, 46, 48: column 16, 22: closed circulation piping

24 to 34, 38 to 44, 50 to 68: valve 36: sampling unit

70: controller

Cut-off system for impurity evaluation in the semiconductor device manufacturing gas according to the present invention for achieving the above object, at least one gas supply source for supplying the purge gas and the sample gas and at least one to perform the evaluation of the gas contained in the gas In the cut-off system for impurity evaluation in the semiconductor device manufacturing gas comprised between evaluation apparatuses, The first to 3rd column which isolate | separates the main component and the some impurity component of the said sample gas, The said purge gas supplied from the said gas supply source And the sample gas are divided into a purge mode and an evaluation mode by opening / closing control of a plurality of valves installed in a first closed circulation pipe, and in the purge mode, the sample is disposed at a predetermined portion while discharging the purge gas to the first column. Gas The purge gas is supplied through the first gas supply means and the second column which push the sample gas collected in the predetermined portion into the purge gas and discharge the sample gas into the first column in the evaluation mode. And a second gas supply means for classifying the gas supplied separately from each component through the first column and supplying the gas to the evaluation apparatus through the third column by controlling opening and closing of a plurality of valves installed in a circulation pipe. Is done.

The first gas supply means includes a first sampling part for collecting a predetermined amount of the sample gas to collect sample gas in the purge mode, and collect the sample gas in the evaluation mode in the valve of the first closed circulation pipe. Preferably it is configured to discharge to the first column through a predetermined path determined in accordance with the opening and closing of the.

The first gas supply means may include a first valve through which purge gas is introduced, a second valve connected to discharge gas to the first column, and a third sampling part configured to collect a predetermined amount of the sample gas. And a fourth valve, a fifth valve through which the sample gas is introduced, and a sixth valve through which the sample gas therein is discharged, wherein the first, third, fifth, sixth, fourth, and second valves are in this order. As it may be installed in the first closed circulation pipe.

If the first closed circulation pipe is in the purge mode, purge gas is discharged to the first column through a path between the first valve and the second valve, and the fifth valve, the third valve, the sampling unit, and the fourth valve. The sample may be configured to be discharged through the valve and the sixth valve, and the first closed circulation pipe may be configured to sample the purge gas flowing from the first valve according to opening / closing of the valves in the evaluation mode. It may be configured to discharge through the path formed in the order of the secondary, fourth valve and second valve.

The second gas supply means may include a seventh valve connected to receive gas from the first column, an eighth valve connected to receive purge gas from the second column, and the first and second columns. Preferably, a ninth valve connected to alternatively supply the gas flowing from the column is installed in the second closed circulation pipe.

Further, a tenth valve may be further installed in the second closed circulation pipe of the second gas supply means to perform an alternative supply of gas for sample or purge to an additional evaluation device.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring to Fig. 1, an embodiment according to the present invention is configured to supply helium (He) gas to a purge gas, and a GC-DID 10 and a GC-TCD 12 are provided as evaluation apparatuses. A closed circulation pipe 16 is configured to circulate the helium gas and the sample gas to supply the column 14, and circulate the helium gas supplied through the column 18 and the gas introduced from the column 14. The closed circulation pipe 22 is configured to discharge to the column 20.

Valves 24 to 34 are installed in series along the closed path in the above-described closed circulation pipe 16, and a sampling unit 36 for collecting a predetermined amount of sample gas is connected between the valves 28 and 30. . In addition, valves 38 to 44 are provided in series in the closed circulation pipe 22 along the closed path.

The specific structure of each closed circulation pipe 16 and 22 is demonstrated.

The valve 24 of the closed circulation pipe 16 is configured to supply the helium gas for purging, the valve 26 is configured to supply the gas circulated and exhausted to the column 14, and the valve 28 and As described above, a sampling unit 36 for collecting a predetermined amount of sample gas is connected between the valves 30, and the valve 32 is configured such that a sample gas supplied from the outside flows in, and the valve 34 ) Is configured to discharge the internal sample gas passed through the sampling unit 36 and the valve 30 to the outside.

In addition, the valve 38 of the closed circulation pipe 22 is configured to allow gas to flow from the column 14, and the valve 40 separates the gas to be supplied to the GC-DID 10 by component 20. Valve 42 is configured to discharge the gas to be supplied to the GC-TCD 12 to the column 46 for separating the components by component, the valve 44 through the column 18 It is connected so that helium gas which is purge gas flows in.

In the above-described configuration, helium gas is configured to be directly supplied to the GC-TCD 12 through the column 48 for additional purging.

In addition, the valves 24 to 34 and 38 to 44 of the closed circulation pipes 16 and 22 are hydraulic valves whose opening and closing are switched according to the supply state of nitrogen (N ₂ ) gas. Nitrogen gas is supplied through 50 to 68, and each of the valves 50 to 68 is configured to be operated by a control signal applied according to the state programmed in the controller 70 and the operation of the process operator.

The embodiment according to the present invention configured as described above is operated by being divided into a purge mode and an evaluation mode, and the sample gas is supplied to the GC-DID 10 or the GC-TCD 12 as shown in FIG. Will be described.

In the purge mode, the closed circulation pipe 16 has a path through which gas flows into the sections between the valves 24 and 26, the sections between the valves 32 and 28, and the sections between the valves 34 and 30. In the evaluation mode, the closed circulation pipe 16 has gas in the sections between the valves 24 and 28, the sections between the valves 32 and 34 and the sections between the valves 30 and 26. A flowing path is formed.

In addition, the valves 38 to 44 of the closed circulation pipe 22 supply gas separated by components through the column 20 when the impurities included in the sample gas are separated and supplied while passing through the column 14. And to discharge to the DID 10 or to the GC-TCD 12 through the column 46.

First, in the purge mode, helium gas is supplied to the column 14 through a path between the valves 24 and 26 of the closed circulation pipe 16, and the helium gas passing through the column 14 is the closed circulation pipe 22. ) Is introduced into column 20 via a path comprising valves 38, 40, and helium gas is supplied from column 20 to GC-DID 10.

At this time, the gas remaining in the pipe or the columns 14 and 20 is removed by the helium gas flowing along the aforementioned path.

At this time, the sample gas is supplied to the sampling unit 36 via a path between the valve 32 and the valve 28, and after collecting a predetermined amount from the sampling unit 36, the sample gas passes through the path between the valve 30 and the valve 34. It is discharged through.

In the evaluation mode, the valves 24 to 34 of the closed circulation pipe 16 are switched in the open / closed state. The predetermined amount of samples collected in the sampling section 36 is supplied to the column 14 by the conversion of the open / close state.

Specifically, since helium gas is supplied to the sampling unit 36 through a path between the valve 24 and the valve 28 of the closed circulation pipe 16, the sample collected in the sampling unit 36 is pushed to the closed circulation pipe 16. It is introduced into the column 14 through the path between the valve 30 and the valve 26, the sample gas introduced into the column 14 is separated because the moving speed of the main component and impurities differ by the difference in molecular weight.

When mono-silane (SiH ₄ ) gas is used as a sample, the internal impurities (H ₂ ), oxygen (O ₂ ), nitrogen (N ₂ ), carbon monoxide (CO), and carbon dioxide (CO) ₂ ) are separated in the order described above according to their molecular weight.

Then, in the column 14, impurities such as hydrogen, oxygen, nitrogen, carbon monoxide, and carbon dioxide are sequentially introduced into the valve 38 of the closed circulation pipe 22, and hydrogen is introduced first among the impurities, and then a predetermined time thereafter. At intervals, impurities such as oxygen, nitrogen, carbon monoxide, and carbon dioxide are sequentially introduced at predetermined intervals.

Accordingly, the closed circulation pipe 22 sends hydrogen to the column 20 through the path between the valve 38 and the valve 40 for a predetermined time, and the switching state of the valves 38 to 44 is changed after a predetermined time. The helium gas for purging the column 18 while being varied is supplied to the column 20 through a path between the valve 44 and the valve 40. At this time, impurities containing hydrogen in the pipe or column 20 are removed by the helium gas for purging.

Then, the switching states of the valves 38 to 44 of the closed circulation pipe 22 are changed again, followed by hydrogen and oxygen to the GC-DID 10 in the above-described manner. After the purge is performed, nitrogen is sent to the GC-DID 10 again.

That is, in the closed circulation pipe 22 in the state in which the closed circulation pipe 16 is switched to the evaluation mode, the opening and closing states of the valves 38 to 44 are varied in accordance with the passage time of each component separated from the sample gas. The GC-DID 10 alternately supplies and purges a specific impurity component of the sample gas.

Also, when the GC-TCD 12 evaluates the sample gas, the operation of the closed circulation pipe 16 is the same, and as the opening and closing states of the valves 38 to 44 in the closed circulation pipe 22 are changed, Components and purge helium gas are fed to the GC-TCD 12 through column 46. In addition, the embodiment may be adjusted so that the helium gas is supplied through the column 48 when the GC-TCD 12 additionally needs to purge using the helium gas for purging.

The embodiment according to the present invention constitutes the GC-DID and the GC-TCD as the evaluation device, but is not limited thereto, and another evaluation device may be installed in the valve further configured by additionally installing a valve in the closed circulation pipe 22. have.

Therefore, the embodiment according to the present invention can perform impurity analysis on various gases used in the process of manufacturing a semiconductor device, and the evaluation method may be variously made according to the selective installation of the evaluation device.

Therefore, it is possible to evaluate the entire gas for semiconductor processing using the same cut-off system as in the embodiment according to the present invention, so that the accurately evaluated gas can be used in the process, so that the overall yield of the semiconductor manufacturing process Can be improved.

Therefore, according to the present invention, the evaluation of various gases used in the semiconductor manufacturing process can be performed by using one facility, so that the configuration of the evaluation system can be simplified, and the evaluation work can be made efficient and simplified. In addition, as a result, the yield of the semiconductor process is maximized.

Although the present invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, and such modifications and modifications are within the scope of the appended claims.

Claims (7)

A cut-off system for impurity evaluation in a semiconductor device manufacturing gas configured between a gas supply source for supplying a purge gas and a sample gas and at least one evaluation device for evaluating the gas contained in the gas, wherein the sample gas First to third columns to separate the main component of the and a plurality of impurity components; The purge gas and the sample gas supplied from the gas supply source are divided into a purge mode and an evaluation mode by opening and closing a plurality of valves installed in a first closed circulation pipe, and the purge gas is supplied to the first column in the purge mode. First gas supply means for collecting the sample gas in a predetermined portion while discharging the gas, and pushing the sample gas collected in the predetermined portion into the purge gas and discharging the sample gas into the first column in an evaluation mode; And The gas supplied for the purge is supplied through the second column, and the gas supplied by the component is separated by the component through the first column by the opening / closing control of a plurality of valves installed in the second closed circulation pipe. Second gas supply means for supplying the evaluation apparatus through a column; And a cutoff system for impurity evaluation in a gas for manufacturing a semiconductor device. The method of claim 1, wherein the first gas supply means, A first sampling part for collecting a predetermined amount of the sample gas to collect the sample gas in the purge mode, and through the predetermined path determined in accordance with the opening and closing of the valves of the first closed circulation pipe in the evaluation mode. And cut off the impurity in the gas for manufacturing the semiconductor device. The gas supply system of claim 1, wherein the first gas supply means comprises: a first valve through which a purge gas is introduced; A second valve connected to exhaust gas to the first column; Third and fourth valves connected between a second sampling unit configured to collect a predetermined amount of the sample gas; A fifth valve through which the sample gas is introduced; And A sixth valve through which the sample gas therein is discharged; And a first, third, fifth, sixth, fourth, and second valve are installed in said first closed circulation pipe in said order. The method of claim 3, wherein the first closed circulation pipe; In the purge mode, purge gas is discharged to the first column through a path between the first valve and the second valve, and the sample is passed through the fifth and third valves, the sampling unit, and the fourth and sixth valves. And a cutoff system for evaluating impurities in said semiconductor device manufacturing gas. The method of claim 3, wherein the first closed circulation pipe; In the evaluation mode, the semiconductor is configured to discharge purge gas flowing from the first valve through a path formed in the order of a third valve, a sampling unit, a fourth valve, and a second valve according to opening and closing of the valves. Cut-off system for impurity evaluation in gas for device manufacturing. The method of claim 1, wherein the second gas supply means, A seventh valve connected to receive gas from the first column, an eighth valve connected to receive purge gas from the second column, and the third column to alternatively supply gas introduced from the first and second columns; A cutoff system for evaluating impurities in gas for manufacturing a semiconductor device, wherein a connected ninth valve is installed in a second closed circulation pipe. The method of claim 6, And a tenth valve is further provided in the second closed circulation pipe of the second gas supply means so as to perform an alternative supply of a sample or purge gas to an additional evaluation device. Cut-off system for impurity evaluation.

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