KR20060095640A - Method and apparatus for liquid mixing supply - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical liquid mixing supply apparatus and method for a semiconductor manufacturing process capable of adding a small amount of hydrofluoric acid (HF) to a sulfuric acid, hydrogen peroxide, and ultrapure water mixture. The chemical liquid mixing supply apparatus of the present invention comprises a mixing tank in which at least two chemical liquids and ultrapure water are mixed at a predetermined ratio; And a minute amount supply unit for supplying a specific chemical liquid to the mixing tank in units of PPM; The micro-quantity supply unit is a first fixed quantity tank filled with a specific chemical liquid; A first metering pump for pumping a predetermined amount of a specific chemical liquid stored in the first metering tank; A second fixed quantity tank filled with ultrapure water by a predetermined capacity and wherein the specific chemical liquid is added through the first fixed pump to dilute the specific chemical liquid in a predetermined ratio in the ultrapure water; And a second fixed pump pumping a predetermined amount of the diluent stored in the second fixed tank to the mixing tank. According to such an apparatus, it is possible to quantitatively supply a small amount of a specific chemical liquid to a mixed liquid mixed with two or more chemical liquids.

Description

METHOD AND APPARATUS FOR LIQUID MIXING SUPPLY}

1 is a block diagram of a chemical liquid mixing supply device 100 according to a preferred embodiment of the present invention;

2 is a table showing a chemical liquid mixing ratio according to a preferred embodiment of the present invention;

3 is a flow chart showing a chemical liquid mixing process in the chemical liquid mixing supply apparatus according to a preferred embodiment of the present invention;

4 is a configuration diagram schematically showing a chemical liquid mixing supply device of a semiconductor spin-etcher process.

* Explanation of symbols for the main parts of the drawings

110: mixing tank

130: micro amount supply unit

132: 1st fixed tank

134: 1st fixed pump

136: 2nd fixed tank

138: 2nd fixed pump

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical liquid mixing supply apparatus of a semiconductor manufacturing process, and more particularly, to a chemical liquid mixing supply apparatus and a method of a semiconductor manufacturing process capable of adding a small amount of hydrofluoric acid (HF) to a sulfuric acid, hydrogen peroxide, and ultrapure water mixture.

In the semiconductor manufacturing process, the importance of the etching and cleaning process is accelerating with increasing integration of semiconductor devices. The current trend is that particle management standards become more stringent, and the minimum high cleaning process for micro-contamination such as organic, inorganic and metal contamination is urgently required. Currently, various chemical solutions (chemical solutions) used in etching and cleaning processes are used, and various chemical solutions are mixed and used for an efficient and optimized process.

Therefore, the semiconductor device manufacturing equipment requires specific conditions and management according to the supply of the respective chemical liquids. In particular, in the chemical liquid mixing supply device for mixing and supplying various chemical liquids, the respective chemical liquids are mixed at a predetermined ratio and these mixtures are mixed. The precise control of the concentration relationship and the supply amount is required.

4 is a configuration diagram schematically showing a chemical liquid mixing supply device of a semiconductor spin-etcher process.

FIG. 4 schematically shows an apparatus for supplying sulfuric acid, hydrogen peroxide, ultrapure water, and hydrofluoric acid at a constant ratio (sulfuric acid: hydrogen peroxide: ultrapure water: hydrofluoric acid = 3: 7: 50: 85 PPM) in a semiconductor spin-etch process to be supplied to a treatment unit. . The chemical liquid supply device 10 includes a respective flow rate adjusting means 18 (consisting of a flow sensor, a valve, and the like) provided on the supply pipe 16 between each of the chemical liquid supply parts 12a-12d and the mixing tank 14. By controlling the mixing tank 14, ultrapure water, sulfuric acid, hydrogen peroxide and hydrofluoric acid are quantitatively supplied.

Such a conventional chemical liquid mixing and supplying device 10 can be quantitatively supplied through general flow rate control means to supply a large flow rate such as ultrapure water, sulfuric acid and hydrogen peroxide. However, in the case of hydrofluoric acid, the supply amount is very small at 85 PPM (1.7 cc in flow rate), which makes it difficult to supply a precise fixed amount with a general flow rate adjusting means.

As such, the existing chemical liquid supply device has a problem in accuracy and reproducibility in adding a small amount of the specific chemical liquid to the mixed liquid mixed with at least two or more chemical liquids.

It is an object of the present invention to provide a novel chemical liquid mixing supply device and a method for supplying a quantitative supply of a specific amount of a specific chemical liquid to a mixed liquid of at least two or more chemical liquids.

The chemical liquid mixing supply device of the present invention for achieving the above technical problem is a mixing tank in which at least two chemical liquids and ultrapure water is mixed in a predetermined ratio; And a minute amount supply unit for supplying a specific chemical liquid to the mixing tank in units of PPM; The micro-quantity supply unit is a first fixed quantity tank filled with a specific chemical liquid; A first fixed-quantity pump for pumping a specific chemical liquid stored in the first fixed-quantity tank daily; A second fixed quantity tank filled with ultrapure water by a predetermined capacity and wherein the specific chemical liquid is added through the first fixed pump to dilute the specific chemical liquid in a predetermined ratio in the ultrapure water; And a second fixed pump pumping a predetermined amount of the diluent stored in the second fixed tank to the mixing tank.

According to an embodiment of the present invention, the chemical liquid supply apparatus sets the flow rate of the diluent to be supplied to the mixing tank according to the ratio of the specific chemical liquid diluted in the ultrapure water (the specific chemical liquid concentration of the dilution liquid) to the second quantitative amount. It further comprises a control unit for controlling the pump.

According to an embodiment of the present invention, the specific chemical solution is hydrofluoric acid, and the chemical solutions include hydrogen peroxide and sulfuric acid.

In accordance with another aspect of the present invention, there is provided a method of mixing and supplying a chemical liquid in a mixing tank at a ratio of at least two chemical liquids and ultrapure water; Including a small amount of a specific chemical liquid in the mixing tank; The minute amount mixing step may include diluting the specific drug solution in ultrapure water; And supplying ultrapure water (the diluent) in which the specific chemical liquid is diluted to the mixing tank.

According to an embodiment of the present invention, the step of supplying the ultrapure water in which the specific chemical liquid is diluted to the mixing tank may include setting a flow rate of the diluent to be supplied to the mixing tank according to the ratio of the specific chemical liquid diluted in the ultrapure water; ; Supplying a diluent to the mixing tank through a flow control means by the set flow rate.

According to an embodiment of the invention, the flow control means is a metering pump.

In accordance with another aspect of the present invention, there is provided a method of mixing and supplying a chemical liquid in a mixing tank at a ratio of at least two chemical liquids and ultrapure water; Including a small amount of a specific chemical liquid in the mixing tank; The minute amount mixing step includes storing the specific chemical liquid in a first metering tank; Storing ultrapure water in a second metering tank by a predetermined capacity; Supplying the specific chemical liquid stored in the first fixed tank to the second fixed tank to dilute the specific chemical liquid in the ultrapure water at a ratio of 10: 1 or more; And pumping a predetermined amount of the diluent stored in the second fixed tank to the mixing tank.

According to an embodiment of the present invention, the specific chemical liquid supplied from the first fixed tank to the second fixed tank is supplied by a predetermined volume through the first fixed pump.

According to an embodiment of the present invention, the step of supplying the diluent to the mixing tank sets the flow rate of the diluent to be supplied to the mixing tank according to the ratio of the specific chemical liquid diluted in the ultrapure water, and the second flow rate by the set flow rate It is supplied via a metering pump.

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 and 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. Portions denoted by like reference numerals denote like elements throughout the specification.

Referring to FIG. 1, the chemical liquid mixing and supplying apparatus 100 according to the present invention includes a treatment liquid in which pure water and chemical liquids are mixed at a predetermined ratio in an etching (spin etcher, spin etcher) or wet station process. It is to supply.

The chemical liquid supply device 100 includes a mixing tank 110 and a minute amount supply unit 130.

Sulfuric acid, hydrogen peroxide, ultrapure water and hydrofluoric acid are mixed in the mixing tank 110 at a constant ratio. In the present embodiment, the chemical liquids may be mixed in the mixing ratio as shown in the table of FIG. 2.

The sulfuric acid, hydrogen peroxide and ultrapure water are supplied to the mixing tank 110 through a supply pipe 114 connected to the respective source portions 112a, 112b, 112c. Flow rate control of the chemical liquids (sulfuric acid, peroxide, ultrapure water) supplied to the mixing tank 110 is made through a flow control valve 116a and a flow meter 116b installed in each supply pipe 114. Reference numeral 118 denotes a circulation line, 118a denotes a circulation pump, and 118b denotes a chemical liquid concentration meter.

On the other hand, the hydrofluoric acid is supplied to the mixing tank 110 through the minute amount supply unit 130.

The minute amount supply unit 130 is for quantitatively supplying a small amount of hydrofluoric acid (PPM unit) to the mixing tank 110, the first metering tank 132, the second metering tank 136, the first metering pump 134, a second metering pump 138, and a controller 140.

The first fixed tank 132 is filled with the hydrofluoric acid provided from the hydrofluoric acid source part 112d. The hydrofluoric acid provided from the hydrofluoric acid source part 112d contains 50% of the stock solution. The second fixed tank 136 is filled with ultrapure water by a predetermined capacity. The first metering pump 134 pumps a predetermined amount of hydrofluoric acid from the first metering tank 132 and supplies it to the second metering tank 136. The second fixed tank 136 is made of a diluent in which a small amount of hydrofluoric acid is mixed with ultrapure water. A circulation line 137 is connected to the second fixed tank 136 for mixing the ultrapure water with the hydrofluoric acid. The second metering pump 138 pumps a predetermined amount of the diluent stored in the second metering tank 136 and supplies it to the mixing tank 110. Here, the control unit 140 sets the flow rate of the diluent to be supplied to the mixing tank 110 according to the ratio of hydrofluoric acid diluted in the ultrapure water (concentration of the hydrofluoric acid of the diluent) to the second fixed pump 138 Will be controlled.

The chemical liquid mixing supply device 100 having such a configuration is capable of precisely supplying hydrofluoric acid to the mixing tank 110 in units of PPM.

The chemical liquid mixture supply method using the chemical liquid mixture supply device of the present invention described above is as follows.

Referring to Figures 1 to 3, the chemical liquid mixing method (a) mixing sulfuric acid, hydrogen peroxide and ultrapure water in the mixing tank 110 in a predetermined ratio (see the table in Figure 2) (s10) and (b) It includes a step (s20) of mixing a small amount of hydrofluoric acid in the mixing tank (110). Steps (a) and (b) may be reversed.

In step (a), the sulfuric acid, hydrogen peroxide, and ultrapure water are supplied to the mixing tank 110 through supply pipes 114 connected to the respective source parts 112a, 112b, and 112c by a flow rate corresponding to a predetermined ratio. do. The mixing tank 110 has a 20L quantity. Therefore, the mixing tank 110 is supplied with 1000cc sulfuric acid, 2333,3cc hydrogen peroxide and 16,665cc ultrapure water. The flow rate of the chemical liquids (sulfuric acid, peroxide, ultrapure water) supplied to the mixing tank 110 is controlled through a flow control valve 116a and a flow meter 116b installed in each supply pipe 114.

Step (b) (s20), as shown in the table of FIG. 2 is to further mix 85PPM of hydrofluoric acid (calculated as the flow rate 1.7cc) in a 20L mixing tank, the hydrofluoric acid is the minute amount supply unit 130 It is supplied to the mixing tank 110 through. Step (b) is as follows. First, (c) the first fixed tank 132 is filled with hydrofluoric acid having a concentration of 50% (s22). (d) The second quantitative tank 136 is filled with 850cc of ultrapure water and the quantitative confirmation is set by the level sensor 136a (s24). (e) supplying 17 cc of hydrofluoric acid (the hydrofluoric acid concentration is 8.5cc due to the hydrofluoric acid concentration of 50%) of the first fixed tank 132 to the second fixed tank 136 through the first fixed pump 134. The hydrofluoric acid and the ultrapure water ratio of the second quantitative tank 136 are mixed at 1: 100 (s26). (f) The diluent (hydrofluoric acid and ultrapure water ratio 1: 100) mixed in the second fixed tank 136 is supplied to the mixing tank 110 by using the second fixed pump 138 (s28). The controller 140 sets the flow rate of the diluent to be supplied to the mixing tank 110 according to the ratio of hydrofluoric acid diluted in the ultrapure water, and supplies the flow rate through the second fixed pump 138 by the set flow rate. At this time, the flow rate of the diluent supplied to the mixing tank 110 is 170cc, 1.7cc of hydrofluoric acid is supplied to the mixing tank 110. If the mixing ratio of hydrofluoric acid and ultrapure water in the second quantitative tank 136 is 1:50, 85 cc of diluent will be supplied to the mixing tank. Through this process, the hydrofluoric acid may be supplied to the mixing tank 16 in a ratio measured by the minute amount supply unit.

Finally, 1.7cc of hydrofluoric acid, 1000cc of sulfuric acid, 2333.3cc of hydrogen peroxide and 16,665cc + 168.3cc of ultrapure water are mixed in the mixing tank. The supply amount of the ultrapure water may be added or subtracted by the flow rate of the ultrapure water added in the process of supplying the diluent.

On the other hand, the present invention is a chemical liquid mixing supply device and the method consisting of the above configuration can be variously modified and can take various forms. It is to be understood that the invention is not to be limited to the specific forms referred to in the foregoing description, but rather includes all modifications, equivalents and substitutions that fall within the spirit and scope of the invention as defined by the appended claims. It must be understood.

In the above, the chemical liquid mixture supplying apparatus and method thereof according to the present invention have been shown in accordance with the above-described description and drawings, but this is merely described for example, and various changes and modifications are made within the scope of the present invention. Of course, change is possible.

As described above, the present invention can accurately supply a small amount of a specific chemical liquid to a mixed liquid of at least two or more chemical liquids, and can always maintain a constant (reproducible) supply of a fixed amount.

Claims (10)

In the chemical liquid supply device: A mixing tank in which at least two chemical liquids and ultrapure water are mixed at a predetermined ratio; And It includes a minute amount supply for supplying a specific chemical liquid to the mixing tank in units of PPM; The minute amount supply unit A first fixed-quantity tank filled with a specific chemical liquid; A first metering pump for pumping a predetermined amount of a specific chemical liquid stored in the first metering tank; A second fixed quantity tank filled with ultrapure water by a predetermined capacity and wherein the specific chemical liquid is added through the first fixed pump to dilute the specific chemical liquid in a predetermined ratio in the ultrapure water; And a second fixed pump pumping a predetermined amount of the diluent stored in the second fixed tank to the mixing tank. The method of claim 1, The chemical liquid supply device And a controller configured to control the second fixed pump by setting a flow rate of the diluent to be supplied to the mixing tank according to the ratio of the specific chemical liquid diluted in the ultrapure water (the specific chemical concentration of the diluent). Mixed feeder. The method of claim 1, The specific drug solution is hydrofluoric acid, The chemical liquid mixture supplying device characterized in that the hydrogen peroxide and sulfuric acid. In the chemical liquid feeding method: Mixing at least two chemical liquids and ultrapure water in a mixing tank at a predetermined ratio; Including a small amount of a specific chemical liquid in the mixing tank; The minute amount mixing step Diluting the specific drug solution in ultrapure water; And supplying the ultrapure water (the dilution liquid) in which the specific chemical liquid is diluted to the mixing tank. The method of claim 4, wherein Supplying ultrapure water diluted with the specific chemical liquid to the mixing tank Setting a flow rate of the diluent to be supplied to the mixing tank according to the ratio of the specific chemical liquid diluted in the ultrapure water; And supplying a diluent to the mixing tank through a flow rate control means by the set flow rate. The method of claim 5, The flow rate control means is a chemical liquid mixing supply method, characterized in that the metering pump. The method of claim 4, wherein The specific drug solution is hydrofluoric acid, The chemical solution is a mixed solution supplying method characterized in that it comprises hydrogen peroxide and sulfuric acid. In the chemical liquid feeding method: Mixing at least two chemical liquids and ultrapure water in a mixing tank at a predetermined ratio; Including a small amount of a specific chemical liquid in the mixing tank; The minute amount mixing step Storing the specific chemical liquid in a first metering tank; Storing ultrapure water in a second metering tank by a predetermined capacity; Supplying the specific chemical liquid stored in the first fixed tank to the second fixed tank to dilute the specific chemical liquid in the ultrapure water at a ratio of 10: 1 or more; And supplying the dilution liquid stored in the second fixed tank to the mixing tank by pumping a predetermined amount. The method of claim 8, The chemical liquid supplying method characterized in that the specific chemical liquid supplied from the first fixed tank to the second fixed tank is supplied by a predetermined volume through the first fixed pump. The method of claim 8, Supplying the diluent to the mixing tank And setting a flow rate of the diluent to be supplied to the mixing tank according to the ratio of the specific chemical liquid diluted in the ultrapure water, and supplying the chemical liquid through the second fixed pump by the set flow rate.

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