JPH0480923A - Wafer cleaning device - Google Patents

Abstract

PURPOSE:To avoid the pollution of a wafer by the water content, oxygen gas, carbon dioxide gas, etc., contained in the atmosphere for augmenting the throughput by removing the dust in vacuum. CONSTITUTION:A wafer 4 with its surface to be cleaned up turning downward is held by a holding means 3 using the catches 31. Next, when a vacuum vessel 1 is pressure-reduced by an exhaust system 2, an electric dust collector 7 is impressed with power from a DC power supply 8 to oscillate an ultrasonic oscillator 5 by a high-frequency transmitter 6 for transmitting the oscillation to the wafer 4 to be oscillated so that the dust adhering to the wafer 4 may be released and removed, the dust drops due to the gravity to be arrested by the electric dust collector 7 provided on the lower part of the vacuum vessel 1. In such a constitution, the dust to be arrested by the static electricity shall not be blown up to adhere to the wafer 4 again.

Description

[Detailed Description of the Invention] [Summary] A wafer cleaning device that removes dust adhering to semiconductor wafers, particularly a wafer cleaning device that removes dust in a vacuum, cleans water, oxygen gas, and carbon dioxide contained in the atmosphere. The purpose of this device is to provide a wafer cleaning device that is not contaminated by gas, etc. and can improve throughput. a wafer support means having a restraint for restraining the wafer support means, an ultrasonic vibrator fixed to the wafer support means and vibrating the wafer support means, and a high frequency transmitting circuit supplying high frequency power to the ultrasonic vibrator. , an electrostatic precipitator provided at the bottom of the vacuum container facing the wafer support means and charged to either a positive or negative potential; The wafer cleaning device includes a DC power source that charges the wafer.

[Industrial Field of Application] The present invention relates to a wafer cleaning device that removes dust adhering to semiconductor wafers, and particularly to a wafer cleaning device that removes dust in a vacuum.

[Background Art] As the performance of semiconductor devices increases, semiconductor manufacturing processes are becoming increasingly finer. Therefore, if dust adheres to the wafer during the manufacturing process, it will cause serious defects such as pattern defects, so wafer cleaning techniques for removing dust are becoming increasingly important.

As a method for removing dust adhering to a wafer, a wet cleaning method is traditionally known in which wafers are cleaned using pure water in the atmosphere.

[Problem to be solved by the invention]

When performing wet cleaning, it is necessary to take the wafer out into the atmosphere from a vacuum processing apparatus such as a film forming apparatus or an etching apparatus.

If the wafer is cleaned in the atmosphere, the surface of the wafer will be contaminated again by moisture, oxygen gas, carbon dioxide gas, etc. contained in the atmosphere, so these contaminants should be removed before the cleaned wafer is sent to the vacuum processing equipment for the next process. An additional pretreatment step for removal using etching or other means is required, reducing throughput.

The purpose of the present invention is to eliminate this drawback, and to provide a wafer cleaning device that is not contaminated by moisture, oxygen gas, carbon dioxide gas, etc. contained in the atmosphere and can improve throughput and performance. It is about providing.

[Means for resolving issues]

The above purpose is to provide a vacuum container (1) with evacuation means (2)
, a wafer support means (3) which is fixed to the inner upper surface of the vacuum container (1) and has a restraint tool (31) on the lower surface for restraining the wafer (4); an ultrasonic vibrator (5) that vibrates the wafer support means (3), a high frequency transmitting circuit (6) that supplies high frequency power to the ultrasonic vibrator (5), and the vacuum container (1). An electrostatic precipitator (7) is provided at the bottom of the wafer supporting means (3) and is charged to either a positive or negative potential. This is achieved by a wafer cleaning apparatus having a DC type 5 (8) that is charged to either potential.

[Effect]

Floating fine dust is affected by both gravity and Brownian motion. However, in a high vacuum, Brownian motion no longer occurs, so dust is only affected by gravity. Therefore, if the wafer 4 to which dust is attached is vibrated by the van der Waals force using the ultrasonic vibrator 5 and the dust is peeled off from the wafer 4, the peeled dust will fall due to gravity.
The dust is collected and removed by an electrostatic precipitator 7 provided at the bottom of the wafer 4. As a result, the amount of dust sucked into the exhaust means 2 is reduced, and the performance deterioration of the exhaust means 2 due to the dust is reduced, and when the wafer 71 is taken out from the wafer cleaning device, the pressure inside the vacuum container 1 fluctuates. However, since the dust is collected by the electrostatic precipitator 7, it does not fly up and adhere to the wafer again.

[Embodiment] Hereinafter, a wafer cleaning apparatus according to an embodiment of the present invention will be described with reference to the drawings.

See Figure 1 FIG. 1 shows a block diagram of the wafer cleaning apparatus.

In the figure, reference numeral 1 denotes a vacuum container having exhaust means 2.

A wafer support means 3 is fixed to the upper surface of the vacuum chamber 1 via an elastic member 32 such as a spring, and has a restraining device 31 such as a link type stopper on the lower surface, and the wafer 4 is surrounded by the above-mentioned restraint. The wafer 4 is supported by holding it with the tool 31. Reference numeral 5 denotes an ultrasonic vibrator for vibrating the wafer support means 3, and electrodes are formed on both sides of a zinc oxide plate. Reference numeral 6 denotes a high frequency transmitting device that generates high frequency power to be applied to the ultrasonic transducer 5. Reference numeral 7 denotes an electrostatic precipitator fixed to the lower part of the vacuum chamber 1 facing the wafer support means 3 via an insulator 71. Reference numeral 8 denotes an electrostatic precipitator 7 which is applied with a DC voltage to make it positive or negative. It is a DC power source that charges electricity.

First, the wafer 4 is held on the wafer support means 3 by holding the retainer 31 so that the surface to be cleaned faces downward.
support. Next, the pressure inside the vacuum container 1 is reduced to 10-'' Torr or less using the evacuation means 2 consisting of a vacuum pump, etc., and a DC voltage of about 10 to 100 V is applied to the electrostatic precipitator 7 from the DC power supply 8. Next, high frequency power of about 10 to 100 MHz generated by the high frequency transmitter 6 is applied to the ultrasonic vibrator 5 to vibrate it, and the vibration is supported by the wafer support means 3 via the wafer support means 3. The wafer 4 is vibrated, and the dust adhering to the surface of the wafer 4 is peeled off and removed.The peeled off dust undergoes Brownian motion due to the high vacuum inside the vacuum chamber 1. The dust falls linearly according to the force of gravity and is collected by electrostatic force in the electrostatic precipitator 7 provided at the bottom of the vacuum container 1.The dust is collected in the electrostatic precipitator 7 by the electrostatic force. Therefore, even if the pressure inside the vacuum chamber 1 fluctuates, the dust will not fly up and adhere to the wafer 4 again.

A processing device such as a film forming device or an etching device used in the manufacture of semiconductor devices is configured with the wafer cleaning device according to the present invention, and these wafer cleaning devices are connected to a gate pulp 9 as shown in FIG. The wafer cleaning devices described above are connected to the vacuum transfer path 90 via the transfer holder 11, and the wafer 4 is transferred using the transfer holder 11.
If you transport the wafers between each wafer cleaning device,
It is possible to configure a semiconductor device manufacturing system using a continuous vacuum processing method, which can continuously perform various processes entirely in a vacuum without exposing the wafer 4 to the atmosphere. In this case, it goes without saying that the manufacturing system is configured so that processes that may generate dust are performed in the wafer cleaning apparatus according to the present invention. In such a system, all steps, including wafer cleaning, can be performed in vacuum.

〔Effect of the invention〕

As explained above, in the wafer cleaning apparatus according to the present invention, contamination of the wafer by moisture, oxygen gas, carbon dioxide gas, etc. in the atmosphere is prevented by removing dust in a vacuum. Pretreatment steps to remove these contaminants before sending to the process are no longer necessary, simplifying the manufacturing process and increasing throughput.

In addition, various vacuum processing equipment for manufacturing semiconductor devices are interconnected through vacuum conveyance paths to form a semiconductor device manufacturing system using a continuous vacuum processing method in which all manufacturing processing steps for semiconductor device manufacturing are performed in vacuum. In this case, by configuring a vacuum processing device that generates dust with the wafer cleaning device according to the present invention, all semiconductor device manufacturing processing steps including dust removal can be continuously performed in a vacuum. becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a wafer cleaning apparatus according to an embodiment of the present invention. FIG. 2 is a schematic diagram of a manufacturing system in which various vacuum processing apparatuses for manufacturing semiconductor devices each including a wafer cleaning apparatus according to the present invention are interconnected through a vacuum transfer path. Vacuum container, evacuation means, wafer support means, restraints such as link-type stoppers, elastic members such as springs, wafers, ultrasonic vibrators, high frequency transmitters, electrostatic precipitators, ・DC power supply, ・Gate valves, ・Vacuum conveyance path, ・Transfer holder.

Claims (1)

[Claims] A vacuum container (1) having an evacuation means (2), a wafer (4) fixed to the inner upper surface of the vacuum container (1), and a wafer (4) on the lower surface.
wafer support means (
3), an ultrasonic vibrator (5) fixed to the wafer support means (3) and vibrating the wafer support means (3), and a high frequency transmitter for supplying high frequency power to the ultrasonic vibrator (5). a circuit (6), and the wafer support means (3) at the bottom of the vacuum container (1).
), the electrostatic precipitator (7) is charged to either a positive or negative potential, and the DC power source (7) is provided to charge the electrostatic precipitator (7) to a positive or negative potential. 8) A wafer cleaning apparatus comprising: