KR20070066325A - System for cleaning single type silicon wafer using ozone - Google Patents

Abstract

A single-type silicon wafer cleaning apparatus using ozone is provided to effectively remove contaminants and obtain cleaning effect of a high uniformity without causing reverse contamination of metal by simultaneously performing the cleaning and dry processes in conventional equipment while using only one sealed cleaning stage. A cleaning stage(11) is sealed by a chamber(17). A wafer support unit(12) supports a rotating silicon wafer(14), installed over the cleaning stage. Ozone water is supplied to the silicon wafer by a first nozzle(15). A chemical solution is supplied to the silicon wafer by a second nozzle(16) installed at a side of the first nozzle. An ozone generating apparatus(19) generates ozone gas of a high density. A gas-liquid contact(25) of the ozone gas generated from the ozone generating apparatus and deionized water occurs in a gas-liquid contactor for fabricating ozone water of a high density. A bubble removing unit removes unnecessary gas before the ozone water is supplied to the cleaning stage. An ozone density measuring unit measures the ozone density of the gas phase and liquid phase of the ozone gas and ozone water. A nitrogen tank(23) and a vacuum apparatus(24) perform a nitrogen purge process and makes vacuum to remove the impurities in the chamber. A heating member(13) is installed to dry the silicon wafer. A supersonic oscillator can be installed in the wafer support unit, the first nozzle and the second nozzle.

Description

Single wafer silicon wafer cleaning device using ozone {SYSTEM FOR CLEANING SINGLE TYPE SILICON WAFER USING OZONE}

1 is a view schematically showing the configuration of a single wafer type silicon wafer cleaning apparatus using ozone according to the present invention.

FIG. 2 is a detailed view showing the nozzle of FIG. 1 in detail. FIG.

<Description of the symbols for the main parts of the drawings>

11. Cleaning stage

12. Vacuum Chuck

13. Heating element

14. Wafer

15. Nozzle 1

16. Second nozzle

17. Chamber

18. Chemical supply tank

19. Ozone Generator

20. Ultrapure Water Supply Tank

23. Nitrogen Tank

24. Vacuum

25. Gas-Liquid Contactor

26. Bubble Remover

28. Dissolved ozone concentration meter

29. Ozone gas concentration meter

The present invention relates to a single wafer type silicon wafer cleaning apparatus using ozone, and more specifically, all cleaning processes and drying processes can be performed simultaneously, and ozone for supplying various kinds of chemical liquids to be cleaned. It is related with the single wafer type silicon wafer cleaning apparatus used.

RCA cleaning, which is widely used in the semiconductor field to date, is a wet cleaning using high concentration strong acid and strong base chemicals as a high temperature process.

In addition, the batch bath type wafer cleaning apparatus has a problem that the cleaning efficiency is low while the production efficiency is high because the wafers are cleaned several times at a time.

In addition, in recent years, the number of unit cleaning processes and the amount of chemical liquids are required due to the large diameter of semiconductor wafers and the miniaturization of patterns.

In order to solve such a problem, a single wafer cleaning apparatus has been proposed as an apparatus capable of further improving cleaning performance such as particle removal and etching uniformity improvement.

This single wafer cleaning is generally used as a metal contaminant and particle removal cleaning of the inside surface of a silicon wafer.

Chemicals used for cleaning are classified into basic and acidic cleaning solutions based on hydrogen peroxide. Among them, basic cleaning solutions show excellent effects in removing particles, and acidic cleaning solutions are used to remove transitional metal contaminants.

Hydrogen peroxide, which is commonly added in the present washing solution, serves as an oxidizing agent, and a dehydrogen peroxide process is essential for treating wastewater containing hydrogen peroxide.

In order to solve this problem, the wafer cleaning apparatus of the present invention described below is intended to introduce a single wafer type wafer cleaning apparatus using ozone, which uses an ozone known as an oxidizing agent more powerful than hydrogen peroxide in an environmentally friendly process.

In recent years, practical use is performed as a high performance wafer surface cleaning with the novel cleaning process combined with the cleaning liquid. The cleaning method combined with HF and ozone water with the concept of room temperature treatment is required to develop a new technology of the cleaning process for removing metal contaminants and organic matter.

The present invention was created in order to solve the above problems, and it is possible to simultaneously perform all the cleaning processes and drying processes possible in the conventional equipment by using only one sealed cleaning stage, and to provide various kinds of chemical liquids. It is an object of the present invention to provide a single wafer silicon wafer cleaning apparatus using ozone which is supplied and cleaned.

Single wafer silicon wafer cleaning apparatus using ozone of the present invention for achieving the above object, the chamber; A cleaning stage sealed by the chamber; A wafer support installed on the cleaning stage to support the rotating silicon wafer; A first nozzle installed to supply ozone water to the silicon wafer; A second nozzle installed at one side of the first nozzle to supply chemical liquid to the silicon wafer; An ozone generator for generating a high concentration of ozone gas; A contactor for producing high concentration ozone water by gas-liquid contact between ozone gas generated by the ozone generator and ultrapure water; A bubble remover installed to remove unnecessary gas before the ozone water is introduced into the cleaning stage; An ozone concentration measuring instrument installed to measure the ozone concentrations of the gaseous and liquid phases of the ozone gas and the ozone water; A nitrogen device for vacuum purging and vacuum for removing impurities in the chamber, a vacuum device; And a heating member installed to dry the silicon wafer.

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

Figure 1 is a schematic diagram showing the configuration of a single wafer type silicon wafer cleaning apparatus using ozone according to the present invention.

Referring to the drawings, the single wafer type silicon wafer cleaning apparatus using ozone according to the present invention is provided with a cleaning stage 11 sealed in the chamber 17 to prevent contamination from external contaminant particles. (11) In order to increase the cleaning efficiency, an ultrasonic oscillator (Megasonic transducer) 31 is provided.

The ultrasonic oscillator 31 not only transmits a physical force to the silicon wafer 14 but also promotes decomposition of organic matter by OH radicals generated by promoting decomposition of ozone.

In addition, the single wafer type silicon wafer cleaning apparatus using ozone according to the present invention includes an ozone generator 19 installed to generate high concentration ozone gas, and an ozone gas and ultrapure water supply tank 20 generated from the ozone generator 19. Gas-liquid contactor with ultra-pure water of) to produce a high concentration of ozone water, and a gas-liquid contactor 25 installed to remove undissolved ozone gas and unnecessary gas from the gas-liquid contactor 25 The bubble remover 26 and the dissolved ozone concentration measuring instrument 28 are installed to measure the concentration of ozone water introduced into the cleaning stage 11.

In addition, ozone gas was used in the drying process in order to improve the drying process.

At this time, the inside of the cleaning device is a high temperature atmosphere by the heating member (Heater) 13, which is effective to dry the silicon wafer 14, and has the advantage of promoting the decomposition of ozone used as a dry gas.

In addition, the ozone gas is decomposed to generate OH radicals, which hydrophilize the surface of the silicon wafer 14 to protect the surface of the silicon wafer 14 from contaminant particles.

An ozone gas measuring instrument (29) for measuring the concentration of ozone gas introduced into the cleaning stage (11) is attached, and ozone at a constant concentration is always supplied and dried.

2 shows a detailed view of the nozzle of FIG. 1.

As shown, the nozzles 15 and 16 to which ozone water and chemical liquid are injected are attached to the ultrasonic oscillator 32, and branched back into several injection nozzles 32a to transfer the force to the large-diameter wafer as a whole. It is composed.

In addition, the chemical liquid supply tank 18 for supplying the chemical liquid to the cleaning stage 11 is connected to the cleaning stage 11 through the second nozzle 16 to which the ultrasonic oscillator 32 is attached. Is supplied.

In the single wafer type silicon wafer cleaning apparatus using ozone according to the present invention, a nitrogen tank 23 for vacuum purging and vacuum for removing impurities and a vacuum apparatus 24 are installed in the chamber 17. A filter 27 is installed between the dissolved ozone concentration meter 28 and the bubble remover 16.

Referring to the operation of the single wafer silicon wafer cleaning apparatus using ozone according to the present invention having the configuration as described above are as follows.

Referring again to the drawings, the single wafer type silicon wafer cleaning apparatus using ozone according to the present invention is sealed with a chamber 17 to improve cleaning efficiency and prevent recontamination of the silicon wafer 14 from external contaminant particles. The cleaning stage 11 was constructed, and the silicon wafer 14 was fixed to the wafer support 12 by vacuum, and the ozone water and the chemical liquid were simultaneously sprayed onto the silicon wafer 14 rotating at high speed. This is done.

In the ozone water, ozone gas generated by the ozone generating device 19 is produced by the gas-liquid contact with the ultrapure water in the gas-liquid contactor 25, thereby producing ozone water having a high concentration of 100 ppm or more. Here, as shown in Figure 1, the ozone gas is generated by the discharge of high purity oxygen by the ozone generator, using a carbon dioxide to increase the half-life of ozone.

In addition, the residual gas generated in the process of dissolving ozone in ultrapure water in the gas-liquid contactor 25 is removed from the bubble remover 16, and the ultrasonic oscillator 32 is attached to the ozone water only filter 27. The first and second nozzles 15 and 16 are sprayed onto the silicon wafer 14.

In addition, the ultrasonic oscillator 31 is attached to the lower portion of the wafer support 12 to maximize the cleaning efficiency.

In the single wafer type silicon wafer cleaning apparatus using ozone according to the present invention, the silicon wafer 14 is dried using ozone gas. That is, ozone gas generated in the ozone generator 19 is supplied from the chamber 17 to the cleaning stage 11, and the sealed cleaning stage 11 becomes an ozone atmosphere. At this time, the inside of the cleaning apparatus is maintained in a warm atmosphere by the heating member 13, which is not only effective for drying the silicon wafer 14, but also promotes decomposition of ozone used as a drying gas. The ozone gas is decomposed to generate OH radicals, which hydrophilize the surface of the silicon wafer 14 to protect the surface of the silicon wafer 14 from contaminating particles.

At this time, in order to optimize the concentration of ozone water used as the cleaning liquid, it is measured in real time by the dissolved ozone concentration meter 28, and constant ozone water is always supplied.

And the single wafer type silicon wafer cleaning apparatus using ozone according to the present invention undergoes the following steps before cleaning in order to increase the cleaning efficiency. Nitrogen gas is supplied to the cleaning stage 11 sealed by the chamber 17, and the contaminant suspended by nitrogen is removed by the vacuum device 24. In addition, contaminants removed from the silicon wafer 14 during cleaning are discharged directly to the drain, thereby preventing recontamination of the contaminants and the metal.

As described above, the sheet type silicon wafer cleaning apparatus using ozone according to the present invention has the following effects.

By using only one sealed cleaning stage, all the cleaning processes and drying processes possible in the conventional equipment can be simultaneously performed, and cleaning can be performed by supplying various kinds of chemical liquids.

In addition to effectively removing contaminants, there is a high uniformity cleaning effect without back contamination of metals.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent embodiments are possible. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

Claims (6)

A chamber; A cleaning stage sealed by the chamber; A wafer support installed on the cleaning stage to support the rotating silicon wafer; A first nozzle installed to supply ozone water to the silicon wafer; A second nozzle installed at one side of the first nozzle to supply chemical liquid to the silicon wafer; An ozone generator for generating a high concentration of ozone gas; A gas-liquid contactor which produces gas-liquid contact with ozone gas generated by the ozone generator and ultrapure water to produce a high concentration of ozone water; A bubble remover installed to remove unnecessary gas before the ozone water is introduced into the cleaning stage; An ozone concentration measuring instrument installed to measure the ozone concentrations of the gaseous and liquid phases of the ozone gas and the ozone water; A nitrogen tank for vacuum purging and vacuum for removing impurities in the chamber, and a vacuum apparatus; Single wafer type silicon wafer cleaning apparatus using ozone, characterized in that it comprises a heating member installed to dry the silicon wafer. The method of claim 1, Single wafer type silicon wafer cleaning apparatus using ozone, characterized in that the ultrasonic wave oscillator is installed on the wafer support and the first and second nozzles. The method of claim 1, The silicon wafer cleaning device using ozone, characterized in that the silicon wafer is provided to be dried by the ozone gas. The method of claim 1, Single wafer type silicon wafer cleaning apparatus using ozone, characterized in that it is provided to be measured in real time by the dissolved ozone concentration meter in order to optimize the concentration of the ozone water. The method of claim 1, The first and second nozzles are single wafer type silicon wafer cleaning apparatus using ozone, characterized in that a plurality of injection nozzles are provided. The method of claim 1, The heating member is a single wafer type silicon wafer cleaning apparatus using ozone, characterized in that provided as a catalyst for promoting decomposition of the ozone gas.

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