JPH0637080A - Supplying method for chemical - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a supply system for materials, particularly a chemical liquid, by reviewing a normal supply method of directly piping a chemical itself and utilizing an existing high-purity gas supply system. The purpose is to obtain a high-purity chemical solution supply method by removing the influence of impurity ions contained in the chemical solution. [Structure] A high-purity gas 1 in a gas cylinder 9 serving as a chemical liquid material is introduced by bubbling through a high-purity gas supply line 2 into a chemical liquid treatment tank 4 for a semiconductor substrate containing ultrapure water 3 to obtain a required amount. The chemical solution 5 consisting of an aqueous solution of high-purity gas 1 whose concentration has been adjusted is prepared. In addition, the chemical solution 5 contains a densitometer or a measuring probe 7 of a PH meter 6 in ultrapure water 3, Alternatively, the solenoid valve 8 of the high-purity gas supply line 2 is opened and closed in conjunction with the PH meter 6 to adjust the bubbling amount of the high-purity gas 1 with respect to the ultrapure water 3 to obtain the chemical solution 5 of the required concentration. To do.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for supplying a semiconductor substrate processing material, especially a chemical solution. In the recent supply of chemicals in semiconductor factories, automatic supply by pipes is performed, and in order to manufacture semiconductor devices with higher integration, it is necessary to supply clean, highly polluted chemicals of high purity. .

Therefore, it is necessary to completely remove particles such as minute dust and the like and impurity ions contained in the chemical as much as possible.

[0003]

2. Description of the Related Art FIG. 4 is an explanatory view of a conventional example. In the figure, 32 is a chemical solution tank, 33 is a compressed gas inlet, 34 is a chemical solution supply pipe, 35 is a chemical solution valve, 36 is a chemical solution treatment tank, 37 is an etching station, 38 is a draft, 39 is a semiconductor substrate, 40 is a substrate holder. Is.

As the conventional high-purity chemicals for the electronic industry, only those which satisfy the delivery specifications of particles, impurity ions, chemical concentrations, etc. have been accepted and used from the chemical supplier.

However, the chemical itself or the prepared chemical solution is stored in a chemical solution tank and is supplied to a plurality of drafts which are user points or a chemical solution processing tank of a semiconductor substrate in an etching station through a chemical solution supply line by a pressure system. ing.

The chemical liquid supply line, mainly Teflon pipes for acids and alkalis, and stainless steel pipes for organic solvents are used, but dust and impurities are generated from the pipes themselves and pipe joints during the supply of the chemical liquids. Ions are mixed with chemicals,
At the actual point of use, a highly contaminated chemical liquid will be supplied as a high-purity chemical.

As a measure for reducing particles, particles are removed by passing through filters provided in several stages. However, impurity ions in the chemical solution are removed because an effective ion exchange membrane does not exist. Since the development of perfect removal technology has not been reached, it has been extremely difficult to completely remove impurity ions in reality.

[0008]

Therefore, there is a problem that the impurity ions in the chemical solution cannot be completely removed at the point of use, and the quality of the semiconductor device is greatly affected in the manufacture of the semiconductor device.

In view of the above points, the present invention has reviewed the normal supply method of directly piping the chemical itself and utilizes the existing high-purity gas supply system to remove the impurity ions contained in the chemical solution. It is provided for the purpose of removing the influence and obtaining a high-purity chemical solution supply method.

[0010]

FIG. 1 is a diagram for explaining the principle of the present invention. In FIG. 1, 1 is a high-purity gas, 2 is a high-purity gas supply line, 3 is ultrapure water, 4 is a chemical solution treatment tank, 5 is a chemical solution, 6 is a concentration meter or PH meter, 7 is a measurement probe, and 8 is An electromagnetic valve, 9 is a gas cylinder, and 10 is a pure water valve.

The above-mentioned problems are caused by using a high-purity gas as a chemical material source and delivering it to a chemical treatment tank in a draft or a wet station at a use point through a high-purity gas supply line to obtain ultrapure water in the chemical treatment tank. High-purity gas is bubbled inside, and the solenoid valve of the high-purity gas supply line is required for semiconductor substrate processing in conjunction with the measurement value of the concentration probe or PH meter measurement probe installed in advance in the chemical treatment tank. This can be solved by adopting a chemical solution supply method of preparing a chemical solution adjusted to a different concentration.

That is, as shown in FIG. 1, the object of the present invention is to provide a semiconductor substrate in which ultrapure water 3 in which a high purity gas 1 in a gas cylinder 9 which is a chemical liquid material is supplied through a high purity gas supply line 2 is introduced. The chemical solution 5 is introduced into the chemical solution treatment tank 4 for use by bubbling, and the chemical solution 5 composed of an aqueous solution of the high-purity gas 1 adjusted to the required concentration is prepared. Alternatively, the measuring probe 7 of the PH meter 6 is inserted, and the solenoid valve 8 of the high-purity gas supply line 2 is opened / closed in conjunction with the concentration meter or the PH meter 6, and the bubbling amount of the high-purity gas 1 with respect to the ultrapure water 3 is bubbled. Is adjusted to obtain the chemical solution 5 having a required concentration.

[0013]

In the present invention, by bubbling high-purity gas into ultrapure water in a chemical treatment tank, a high-purity chemical with less contamination can be obtained. The concentration of the chemical liquid is adjusted by using a concentration meter installed in the chemical liquid treatment tank or an opening / closing valve linked with a PH meter.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is an explanatory view of an embodiment of the present invention. In the figure, 11 is hydrogen chloride gas, 12 is a high purity gas supply line, 13 is ultrapure water, 14 is a chemical treatment tank, 15 is hydrochloric acid, 16
Is a concentration meter, 17 is a measuring probe, 18 is a solenoid valve, 19 is a gas cylinder, 20 is a cylinder cabinet, 21 is an etching station, 22 is a draft, 23 is a chemical pressure pump, 24 is a chemical treatment tank, 25 is a chemical valve, 26 is hydrogen peroxide gas, 27
Is a gas cylinder, 28 is a high-purity gas supply system, 29 is a solenoid valve, 30 is a concentration meter, 31 is a measuring probe, 41 is sulfuric acid, and 42 is a chemical liquid tank.

As shown in FIG. 2, in the first embodiment of the present invention, from the gas cylinder 19 which is the supply source of high purity gas,
Hydrogen chloride gas through the existing high-purity gas supply line 12
11 is supplied to the draft station 22 or the wet station 21 which performs the wet processing of the semiconductor substrate in the semiconductor factory.

The chemical solution treatment tank 14 is filled with ultrapure water 13, and hydrogen chloride gas 11 is bubbled into the chemical solution treatment tank 14 to prepare 10% concentration of hydrochloric acid 15 required for processing semiconductor substrates. To adjust the concentration of hydrochloric acid 15, the concentration of hydrochloric acid 11 should be kept at 10% by opening and closing the solenoid valve 18 that works in conjunction with the measuring probe 17 of the concentration meter 16 incorporated in the chemical treatment tank 14. To

In the above embodiment, the hydrogen chloride gas 11 is bubbled by itself in the chemical treatment tank 14 filled with the ultrapure water 13. However, when the pH of the chemical is adjusted or mixed acid is mixed, Is the chemical treatment tank containing the chemicals already prepared.
Alternatively, a high-purity gas, which is a material of the chemical liquid to be directly mixed, may be bubbled.

A chemical liquid supply system according to the second embodiment of the present invention is shown in FIG. Sulfuric acid 41 of 90% concentration is introduced from the chemical solution tank 42 into the chemical solution treatment tank 24 by the chemical solution pressure pump 23 made of Teflon.
Hydrogen peroxide gas 26 is bubbled from a gas cylinder 27 through a high-purity gas supply system 28 into a chemical treatment tank 24 to prepare a 75% persulfuric acid solution. The density adjustment is performed in the same manner as in the first embodiment.

[0019]

As described above, according to the present invention,
In addition to the reduction of particles and impurity ions, the stable supply of basic semiconductor materials becomes possible with the reduction of chemicals, which greatly contributes to the quality improvement of semiconductor devices.

[Brief description of drawings]

FIG. 1 is an explanatory view of the principle of the present invention.

FIG. 2 is an explanatory diagram of a first embodiment of the present invention.

FIG. 3 is an explanatory diagram of a second embodiment of the present invention.

FIG. 4 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 1 High-purity gas 2 High-purity gas supply line 3 Ultrapure water 4 Chemical solution treatment tank 5 Chemical solution 6 Concentration meter or PH meter 7 Measuring probe 8 Solenoid valve 9 Gas cylinder 10 Pure water valve 11 Hydrogen chloride gas 12 High-purity gas supply line 13 Ultra pure water 14 Chemical solution treatment tank 15 Hydrochloric acid 16 Concentration meter 17 Measuring probe 18 Solenoid valve 19 Gas cylinder 20 Cylinder cabinet 21 Etching station 22 Draft 23 Chemical solution pressure pump 24 Chemical solution treatment tank 25 Chemical solution valve 26 Hydrogen peroxide gas 27 Gas Cylinder 28 High-purity gas supply system 29 Solenoid valve 30 Concentration meter 31 Measuring probe 41 Sulfuric acid 42 Chemical solution tank

Claims (2)

[Claims] 1. A high-purity gas supply line for supplying a high-purity gas (1)
(2) was introduced into the chemical treatment tank (4) of the semiconductor substrate containing ultrapure water (3) by bubbling, and the chemical solution (5) consisting of an aqueous solution of the high-purity gas (1) adjusted to the required concentration ) Is mixed, and the chemical solution supply method characterized by the above-mentioned. 2. The chemical liquid (5) is provided with a concentration meter or a measuring probe (7) of a PH meter (6) in the ultrapure water (3), and is linked with the concentration meter or PH meter. The solenoid valve (8) of the high-purity gas supply line (2) is opened and closed to adjust the bubbling amount of the high-purity gas (1) with respect to the ultrapure water (3) so that the chemical solution (5 ) Is obtained, the chemical solution supply method according to claim 1.