JPH08327551A - Atmosphere contamination evaluating device - Google Patents

Abstract

PURPOSE: To enable the control of the contamination of an in-process atmosphere to be evaluated in-line and in real time. CONSTITUTION: This atmosphere contamination evaluating device consisting of a measuring part 2 and an analysis/output part 3 has the measuring part 2 consisting of a leak sample introducing part 9 into which an outside atmosphere is sampled, a discharge tube 7 inside which a vacuum discharge is caused by introducing the outside atmosphere from the leak sample introducing part 9 and applying voltage thereto, a spectrometer 4 which makes spectrometry by receiving light produced by the vacuum discharge, and a vacuum pump 6 for evacuating the leak sample introducing part 9 and the discharge tube 7. Therefore, the outside atmosphere can be directly introduced into the device and analysed in gas form, so the device can be fixed at a measuring site, on-site measurement and analysis can be performed, and control of the contamination of the in-process atmosphere can be evaluated in-line and in real time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is effective for measuring and evaluating atmospheric pollution when manufacturing products requiring atmospheric pollution control during manufacturing, such as semiconductor integrated circuits and other precision equipment. Is.

[0002]

2. Description of the Related Art In order to maintain high reliability and high yield in the production of semiconductor integrated circuits (hereinafter referred to as "LSI"), dust countermeasures are important, and they have been actively tackled. However, with further high integration,
Not only dust but also molecular contaminants have to be targeted for removal.

Regarding the atmosphere pollution evaluation technique in the LSI manufacturing process, for example, "Monthly Semiconductor Wo
rld 1989.11 ”pp. 198 to 205, and as a chemical evaluation method, argon high frequency inductively coupled plasma optical emission spectrometry (hereinafter, IPC method), graphite fannes atomic absorption spectrometry (hereinafter, GFAAS method). ), And that the ion chromatography method (hereinafter, ICG method) is mainly used. Among them, IC
The P method is diversified as an automatic micro-evaluation apparatus that has been advanced to a microcomputer. When evaluating molecular contaminants using the ICP method, a quartz impinger and a handy suction pump sampler shown in Fig. 6 are used, and the atmosphere is bubbled in pure water in the impinger at a flow rate of 1 l / min to vaporize the vapor. The impurities are dissolved in pure water, and then evaluated by the ICP method. A schematic view of the plasma emission spectrometer is shown in FIG. First, the sample 27 in which vapor impurities are dissolved in pure water is put into the nebulizer 35, and the plasma flame 24 is generated by the high frequency inductively coupled plasma using the argon gas 29. The light of the plasma flame 24 is dispersed by the spectroscope 23, the result is evaluated by the microcomputer 31, and the evaluation result is output by the CRT display 32 and the printer 33.

[0004] In addition, as for the evaluation technology of atmospheric pollution in the LSI manufacturing process, for example, "Clean Technology", August 1991, pp. 11-12.
Page.

[0005]

The impinger method described in the ICP method is effective for evaluating impurities in the atmosphere and gas, but there are some problems with this method. That is, (1) Since the measurement cannot be performed in-line, the contamination is likely to occur during the measurement.

(2) In the production line, it is necessary to quickly find the result, but since the above method requires batch sampling, it takes time to find the result, and real-time control of atmospheric pollution in the process is required. It is impossible.

The present inventor has identified the following as factors that take time to determine the result. The collected sample must be bubbled into an aqueous solution, b. The point is that argon gas must be supplied to generate a plasma flame.

Therefore, an object of the present invention is to provide an evaluation technique capable of in-line and real-time evaluation of pollution control of an atmosphere in a process.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0010]

The outline of the representative one of the inventions disclosed in the present application will be briefly described as follows. That is, the external atmosphere is introduced into the discharge tube as it is, and the light emitted by vacuum discharge is spectroscopically measured, and the measured data is evaluated by a computer.

[0011]

[Function] Since the external atmosphere introduced into the equipment is analyzed as it is as a gas, the equipment can be fixed at the measurement location and measurement / analysis can be performed on the spot, and in-process contamination control can be evaluated in-line and in real time. Becomes

[0012]

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 diagram showing the outline of the pollution evaluation device of the present invention, and FIG. 2 is a diagram showing the main part of the measuring unit 2. The contamination evaluation apparatus 1 collects an external atmosphere and performs a spectroscopic analysis on the spot, and a computer 10 for displaying the analysis result.
It is configured by an analysis / output unit 3 which analyzes and evaluates by using, and displays the evaluation result on a display means such as a CRT display 11 or outputs to a printer 12. A discharge electrode 7a is built in the center of the measuring unit 2 and a glass discharge tube 7 elongated in the electrode direction is provided. This discharge tube 7
Is to generate a measurement light by introducing an external atmosphere, which is a measurement sample, as it is into a gas, and discharging the gas. Further, a vacuum degree meter 17 for measuring the degree of vacuum inside the discharge tube 7 is provided adjacent to the discharge tube 7. A vacuum pump 6 for exhausting the inside of the discharge tube 7 and the inside of the leak sample introducing portion 9 is provided below the discharge tube 7, and the vacuum pump 6 includes a rotary pump, a mechanical booster pump, a turbo molecular pump, or the like. They are used in combination. In particular, a combination of a turbo molecular pump that does not generate oil mist due to backflow and an auxiliary pump for ensuring a back pressure of the turbo molecular pump, for example, a rotary pump is preferable. A valve 8c and a leak valve are provided between the discharge tube 7 and the vacuum pump 6 so that the degree of vacuum inside the discharge tube 7 during discharge can be maintained. A voltage is applied to the discharge electrode 7 a of the discharge tube 7 from the high voltage power supply device 5. The applied voltage can be controlled by the computer 10.

The discharge tube 7 is connected to a leak sample introducing section 9 for collecting an external atmosphere, and valves 8a and 8b are provided.
The external atmosphere is introduced into the discharge tube 7 by opening.
The leak sample introduction part 9 takes in the external atmosphere 18 to be measured by the pressure difference between the outside and the inside. The pressure inside the leak sample introducing section 9 is adjusted by the vacuum pump 6 and the valve 8a.

A spectroscopic measurement device 4 is provided around the discharge tube 7, and the discharge tube 7 is introduced with an atmosphere serving as a measurement sample.
Measure the wavelength, energy, or quantity of light from the discharge. In this method, when the atmosphere introduced into the discharge tube 7 is discharged, the substances constituting the atmosphere emit light having individual wavelengths and energy. Spectroscopic measurement device 4 whose light entrance is directed to the discharge tube 7
Receives the discharge light 7 of the discharge tube 7 introduced with the external atmosphere from the leak sample introduction part 9 and measures the wavelength peak and energy of the discharge light 7.

The spectroscopic measurement device 4 is connected to the computer 10 and transfers the measurement data of the discharge light 16 measured by the spectroscopic measurement device 4 to the computer 10. The computer 10 analyzes the measurement data of the discharge light 16 and analyzes / evaluates the substances constituting the measured atmosphere. The evaluation result is displayed on the CRT display 11 or output by the printer 12.

FIG. 3 is a diagram showing an installation example of the pollution evaluation device 1 of the present invention. In this embodiment, the computer 10 analyzes and outputs the spectroscopic measurement data, and sets one analysis / control chamber 20 for controlling the operation of the measurement unit 2. For example, an impurity introduction step 21a, an oxidation / diffusion step 21b, and a dry etching step. 21c, CVD process 21d, ashing process 21e
The analysis / control room 20 can be used for multiple processes that require pollution control.
Measurement units 2a to 2e connected to the analysis / output unit installed in the above are respectively installed. This gives you one place
The contamination evaluation in each step can be performed in real time.

Next, the contamination evaluation method of the present invention will be described step by step.

(A) The vacuum pump 6 of the measuring unit 2 installed in the process of measuring the atmosphere is driven to evacuate the gas inside the discharge tube 7, and the pressure inside the discharge tube 7 is adjusted to 0.2 Torr to 0. .
Set the vacuum to about 7 Torr. Before exhausting, the inside of the leak sample introducing portion 9 and the inside of the discharge tube 7 may be washed with air.

(B) Valve 8 on the side of the leak sample introducing section 9
A and 8b are opened, and the sample is introduced into the discharge tube 7 from the leak sample introduction part 9.

(C) A voltage is applied to the discharge tube 7 by the high-voltage power supply device 5 to cause a vacuum discharge in the discharge tube 7. (E) Operate the valve 5c on the vacuum pump 3 side to stabilize the degree of vacuum in the discharge tube 7. (V) The spectroscopic measurement device 4 is operated to measure the wavelength, energy, or light amount of the discharge light generated in the discharge tube 7, and the measurement data is transferred to the analysis / output unit 3.

(G) The computer 7 calculates the measurement result to obtain the contamination degree. The obtained result is displayed on the CRT display or printed out by the printer 12. The effects of the present invention will be described below.

(1) The measuring unit of the atmosphere pollution evaluation apparatus includes a sample introducing unit for collecting an external atmosphere, a discharge tube for introducing an external atmosphere from the sample introducing unit and applying a voltage to discharge the inside in a vacuum, and a vacuum. By configuring a spectroscopic measurement device that receives the light from the discharge and performs spectroscopic measurement, and a vacuum pump that exhausts the sample collection unit and the discharge tube, it is possible to introduce the external atmosphere directly into the device and analyze it as a gas. ,
By fixing the device at the measurement location, you can measure and analyze on the spot.
It is possible to evaluate in-line and real-time control of pollution in the process atmosphere.

(2) By using a turbo molecular pump as the vacuum pump, it is possible to prevent the sample collection part and the inside of the discharge tube from being contaminated by oil mist or the like caused by the reverse flow of the pump. Therefore, the atmosphere pollution can be evaluated accurately. In addition, maintenance of the sample collection unit and the discharge tube can be made free.

(3) Atmosphere pollution at each location can be controlled centrally and in real time by providing measurement units at multiple locations to be measured and connecting to the analysis / output unit. it can.

Although the present invention has been concretely described based on the embodiments by the present inventor, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say. For example, in the above-described embodiment, an example has been described in which the analysis / output unit is provided in one place and the measurement units are respectively provided in a plurality of processes subject to atmospheric pollution, but as shown in FIG. You may provide the pollution evaluation apparatus which consists of an output part in each process.

[0027]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

That is, the measuring unit of the atmosphere pollution evaluation apparatus comprises a sample introducing unit for collecting the external atmosphere, a discharge tube for introducing the external atmosphere from the sample introducing unit and applying a voltage to discharge the inside, and a vacuum discharge. By configuring the spectroscopic measurement device that receives the light by and performs spectroscopic measurement and the vacuum pump that exhausts the sample collection unit and the discharge tube, it is possible to introduce the external atmosphere directly into the device and analyze the gas as it is. The equipment can be fixed at the measurement location and measurement / analysis can be performed on the spot, and contamination control of the atmosphere in the process can be evaluated in-line and in real time.

[0029]

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of an atmosphere pollution evaluation device of the present invention.

FIG. 2 is a diagram showing a main part of a measuring unit of the atmosphere pollution evaluation device of the present invention.

FIG. 3 is a diagram showing an example of installation of an atmosphere pollution evaluation device of the present invention.

FIG. 4 is a diagram showing another example of installation of the atmosphere pollution evaluation device of the present invention.

FIG. 5 is a schematic diagram of a conventional plasma emission analyzer used for evaluation of atmospheric pollution.

FIG. 6 is a view showing a quartz impinger used for atmosphere sampling in the conventional atmosphere pollution evaluation.

[Explanation of symbols]

1 ... Contamination evaluation device, 2, 2a, 2b, 2c, 2d, 2
e ... Measuring unit, 3 ... Analysis / output unit, 4 ... Spectroscopic measurement device, 5 ... High-voltage power supply device, 6 ... Vacuum pump, 7 ... Discharge tube, 8a, 8b, 8c ... Vacuum valve, 9 ... Leak sample introduction part, 10 ... Computer, 11 ... CRT display, 12 ... Printer, 13 ... Measurement data signal, 14 ... Power control signal, 15 ... Printer cable, 16 ... Discharge light, 17 ... Vacuum meter, 18 ... External atmosphere, 19 ... Sample introduction tube, 20 ... Analysis / control room,
21 ... Production line, 21a ... Impurity introduction line, 2
1b ... Oxidation / diffusion line, 21c ... Etching line, 21d ... CVD line, 21e ... Ashing line, 22 ... Plasma emission analyzer, 23 ... Spectrometer, 24 ... Plasma light, 25 ... Torch , 26 …… Nebulizer, 27 …… Sample, 28 …… High frequency power supply, 2
9 ... Argon gas, 30 ... Photomultiplier tube, 31 ...
Microcomputer, 32 ... CRT display,
33 ... Printer, 34 ... Floppy disk

Claims (3)

[Claims] 1. An atmosphere comprising a measuring unit for collecting gas and analyzing the gas by using optical means, and an analysis / output unit capable of evaluating the analysis result and outputting the evaluation result to a display unit or a printer. A contamination evaluation apparatus, wherein the measurement unit includes a sample introduction unit that collects an external atmosphere, a discharge tube that introduces the external atmosphere from the sample introduction unit and applies a voltage to cause a vacuum discharge inside, and a vacuum discharge unit. An atmospheric pollution evaluation device comprising: a spectroscopic measurement device that receives light from the device and performs spectroscopic measurement; and a vacuum pump that exhausts the sample introduction unit and the discharge tube. 2. The atmosphere pollution evaluation device according to claim 1, wherein the vacuum pump is a turbo molecular pump. 3. The atmosphere pollution device according to claim 1, wherein the measurement units are provided at a plurality of places to be measured and are connected to the analysis / output unit.