JPH04321216A - Spin coater - Google Patents

Abstract

PURPOSE:To circulatively use a small amount of cleaning organic solvent by providing a three-way valve on the way of a chemical supply line from a chemical pressure tank to a dispenser, and providing a circulation cleaning line of cleaning chemical in a separate system from the chemical supply line connected to the valve. CONSTITUTION:In the case of a normal chemical coating, chemical to be coated is charged in a chemical pressure tank 2, and the chemical is fed under pressure. The fed chemical is discharged from a dispenser 12 through a three-way valve 9 and a chemical supply line 11. When the line is cleaned, cleaning solvent 1 is sucked by a solvent circulation pump 7 through a three-way valve 5 and a filter 6. The sucked solvent is introduced to the line 11 through a three-way valve 8 and the valve 9. In this case, the stop valve of the dispenser 12 is so controlled as to be opened at a timing for discharging of the pump 7 to discharge the solvent from the dispenser 12.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spin coater for discharging a chemical onto a semiconductor wafer, and more particularly to a spin coater that has a circulation cleaning mechanism in its chemical supply piping system and is capable of cleaning the piping system.

0002

2. Description of the Related Art FIG. 2 shows the layout of a chemical liquid piping system in a conventional pressurized pressure-feeding spin coater. As shown in the figure, there is a pressurized chemical tank 21 containing a chemical such as photoresist, a nitrogen gas pressurizing line 22 for pushing out the chemical, a chemical supply line 23, and a dispenser 24 for adjusting the discharge of the chemical.
(including a stop valve and a suckback valve).

0003

[Problems to be Solved by the Invention] In conventional spin coaters, when cleaning chemical piping used for coating polyimide or photoresist, the chemical supply source is loaded with an organic solvent that dissolves the polyimide or photoresist, and The method of cleaning by flowing the organic solvent is common, but in order to increase the cleanliness level in the pipes with this method,
It was necessary to use large amounts of organic solvents. In particular, polyimide has a high viscosity, changes quickly over time, and tends to harden in piping due to the nature of the liquid, so it has been impossible to improve the cleanliness without using a larger amount of organic solvent. Also,
There was a problem in that it was necessary to use an organic solvent with high solubility, and the cost was quite high.

0004

[Means for Solving the Problems] The spin coater of the present invention is provided with a three-way valve in the middle of the chemical liquid supply line from the chemical liquid pressurized tank to the dispenser, and connected to the three-way valve and provided in a separate system from the chemical liquid supply line. Equipped with a cleaning line that circulates cleaning chemicals.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a layout diagram of an embodiment of the present invention. This has a configuration in which a circulating cleaning mechanism is added to a dispensing system that uses a pressurized nitrogen gas feeding system. When applying a normal chemical solution, the chemical solution to be applied is loaded into the chemical solution pressure tank 2, nitrogen gas is introduced from the nitrogen gas pressurization line 3, and the chemical solution is fed under pressure. The pressure-fed chemical liquid passes through the three-way valve 9 and the chemical liquid supply line 11, and then is delivered to the dispenser 12.
more discharged.

Next, when cleaning the chemical supply line,
A cleaning organic solvent 1 is sucked up by a solvent circulation pump 7 through a three-way valve 5 and a filter 6. This sucked up solvent is passed through a three-way valve 8 and a three-way valve 9 to a chemical solution supply line 11.
lead to. At this time, by controlling the stop valve of the dispenser 12 to open in synchronization with the timing at which the circulation pump 7 discharges, the solvent is released from the dispenser 12.
It is discharged from. The discharged solvent is led to the original supply source of the cleaning organic solvent 1 through the solvent drainage line 10. By repeating this process several times,
The chemical supply line 11 and dispenser 12 are cleaned.

Next, the case of cleaning the line from the chemical liquid pressure tank 2 to the three-way valve 9 will be explained. First, the cleaning organic solvent 1 is sucked up by the solvent circulation pump 7 through the three-way valve 5 and the filter 6. The sucked up solvent is introduced into the chemical liquid pressurized tank 2 through a three-way valve 8 and a three-way valve 9. At this time, the nitrogen gas pressurization line 3 is controlled to close in synchronization with the timing of discharge of the circulation pump 7, so that the solvent is discharged into the pressurization tank 2. Next, this discharged solvent is sent under pressure from the pressurized tank 2 through the three-way valve 9, the three-way valve 8, the bypass line 4, and the three-way valve 5 by opening the nitrogen gas pressurizing line 3. The user is guided to the source of the cleaning organic solvent 1. By repeating this process several times, the line of the chemical liquid pressure tank 2 is cleaned.

[0009]

[Effects of the Invention] As explained above, the present invention adds a chemical circulation cleaning mechanism to the chemical supply piping system of the spin coater, so that a small amount of cleaning organic solvent can be circulated and used. can be washed. This method is especially effective when cleaning pipes that have been coated with polyimide because organic solvents for cleaning are expensive.

[Brief explanation of the drawing]

FIG. 1 is a layout diagram of an embodiment of the present invention.

FIG. 2 is a layout diagram of a conventional spin coater.

[Explanation of symbols]

1 Organic solvent for cleaning 2 Chemical liquid pressurized tank 3 Nitrogen gas pressurization line 4 Bypass line 5, 8, 9 Three-way valve 6 Filter 7 Solvent circulation pump 10 Solvent drain line 11 Chemical supply line 12 Dispenser 21 Chemical liquid pressurized tank 22 Nitrogen gas pressurization line 23 Chemical supply line 24 Dispenser

Claims (1)

[Claims] Claim 1: In a spin coater that discharges a chemical liquid onto a semiconductor wafer, a three-way valve is provided in the middle of a chemical liquid supply line from a chemical liquid pressure tank to a dispenser, and the three-way valve is provided in a separate system from the chemical liquid supply line. A spin coater characterized in that a cleaning line for circulating cleaning chemicals is connected.