JP2748664B2 - Chemical treatment equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical processing apparatus such as a resist coating apparatus or a developing apparatus used in a lithography process which is one of semiconductor device manufacturing processes, and in particular, to a chemical solution. Regarding the supply unit.

[Conventional technology]

In general, this type of chemical processing apparatus includes a chemical processing section for processing a semiconductor substrate one by one, a chemical supply section having a supply system line including a buffer tank and an opening / closing valve for supplying a chemical to the chemical processing section, There is a chemical storage source that replenishes the buffer with a chemical so that a constant chemical is always stored in the buffer tank of the chemical supply unit.

In addition, the chemical solution supply unit may be responsible for a plurality of chemical solution processing units. In this case, a supply system line having a plurality of buffer tanks is activated and corresponds to each of the chemical solution processing units.

FIG. 2 is a system diagram showing an example of a chemical supply section in a conventional chemical treatment apparatus. As shown in the drawing, the chemical solution supply unit includes two buffer tanks 1 and 2 for replenishing and storing a chemical solution from an external chemical solution storage source, a regulator 12 for adjusting the pressure of the chemical solution supplied to the chemical solution processing unit, and The pressure gauge 13, the float sensors 4, 5, 6, and 7 for detecting the upper and lower limits of the liquid level of the chemical in the buffer tanks 1 and 2, and the supply and stop of the chemical from the chemical storage source to the buffer tanks 1 and 2 are provided. Control valves 8 and 9; valves 10 and 11 for supplying and stopping the chemical solution to the chemical solution processing unit; a four-way valve 14 for switching between pressurizing and depressurizing the buffer tanks 1 and 2 with nitrogen; In response to the signal, a four-way valve and a chemical supply control circuit 16 for controlling switching of the valves 8, 9, 10, and 11 were provided.

Next, the operation of the chemical supply unit will be described. now,
It is assumed that the buffer tank 1 is in a pressurized state and the buffer tank 2 is in a depressurized state by the operation of the four-way valve 14. As a result, the valve 8 is closed, the valve 10 is opened, and the chemical is supplied from the buffer tank 1 to the chemical processing section. In the buffer tank 2, the valve 9 is opened and the valve 11 is closed, so that the liquid medicine is replenished due to storage loss.

This state continues, the liquid level of the buffer tank 2 rises,
When the flow sensor 5 detects the upper limit, the valve 9 closes,
Stop refilling the drug solution. On the other hand, in the buffer tank 1,
The liquid level drops, the flow sensor 6 detects the lower limit, and the valve
Close 10 and stop supplying the chemical to the chemical processing section. Next, simultaneously with the switching of the valve, the four-way valve 14 operates,
The buffer tank is depressurized, the buffer tank 2 is pressurized, and the valves 8 and 11 are opened. Conversely, the buffer tank 1 is in the replenishing state and the buffer tank 2 is in the chemical supplying state. In this way, this operation is always repeated to supply a constant chemical to the chemical processing section.

[Problems to be solved by the invention]

However, in the chemical solution supply unit in the above-described conventional chemical solution treatment device, the cycle of supply from the two buffer tanks differs between the case of supplying to a plurality of chemical solution treatment units and the case of supplying to one chemical solution treatment unit. . Further, the supply cycle of the two buffer tanks differs depending on the operation of the chemical processing section. For this reason, the time during which the chemical solution stays in the buffer tank or the pipe is different, and the contamination degree and purity of the chemical solution vary. This causes a problem of lowering the yield in processing the semiconductor substrate. Further, the fact that there are two supply systems centered on the buffer tank not only increases the equipment cost but also increases the failure rate.

An object of the present invention is to provide a chemical solution processing apparatus having a chemical solution supply unit that solves such a drawback.

[Means for solving the problem]

A feature of the present invention is that a chemical solution is supplied from a chemical solution supply source via a first valve to a chemical solution processing unit that stores the chemical solution and processes the semiconductor substrates one by one through the second valve. One buffer tank, a float sensor for detecting an upper limit and a lower limit of the liquid level of the chemical solution in the buffer tank, and a nitrogen gas at a predetermined pressure for pumping the chemical solution to the chemical solution processing unit. Means for supplying the chemical solution level to the upper limit, the second valve is opened when the chemical solution level exceeds the upper limit, the chemical solution is pressure-fed to the chemical solution processing unit, and the first valve is opened when the processing in the chemical solution processing unit is completed. A chemical liquid processing apparatus including a chemical liquid supply control circuit for supplying the chemical liquid to the buffer tank from a chemical liquid supply source.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a system diagram showing one embodiment of a chemical solution supply section in the chemical solution treatment apparatus of the present invention. As shown in the figure, the chemical supply section of the chemical processing apparatus has a supply system line for supplying the chemical to the chemical processing section as one system line, and a chemical for transmitting the operation status of the chemical processing section to the chemical supply control circuit 16a. That is, the processing control circuit 15 is provided.

That is, the chemical solution supply unit includes one buffer tank 1a for replenishing and storing a chemical solution from an external chemical solution storage source, a regulator 12 and a pressure gauge 13 for adjusting the pressure of the chemical solution supplied to the chemical solution processing unit, and a buffer tank 1a. Float sensors 4a and 6a that detect the upper and lower limits of the liquid level of the chemical solution, a valve 8a that controls supply and stop of the chemical solution from the chemical storage source to the buffer tank 1a, and supply and stop of the chemical solution to the chemical solution processing unit. A three-way valve 3 for switching between pressurization and depressurization of the buffer tank 1a with nitrogen, and a chemical supply control circuit 16a for controlling the switching between the three-way valve 3 and the valves 8a, 10a in response to a signal from the float sensor. And a chemical processing control circuit 15 for transmitting an operation signal to the chemical supply control circuit 16a.

Next, the operation of the chemical supply unit will be described. First, when a wafer is prepared in the chemical processing section and the operating state is reached, the chemical processing control circuit 15 transmits a liquid sending request signal to the chemical supply control circuit 16a. As a result, the chemical liquid supply control circuit 16a checks whether one of the float sensors 4a and 6a is detecting. If the upper limit float sensor 4a
When the is detected, the liquid supply enable signal is transmitted to the chemical processing control circuit, and at the same time, the valve 10a is opened to supply the chemical to the chemical processing section. Also, if the buffer tank 1a has insufficient storage of the chemical solution and the float sensor 6a is operating, the three-way valve 3 is switched, and the buffer tank 1a is depressurized,
Open the valve 8a and replenish the chemical from the storage decrease. Then, the buffer tank 1a becomes full and the float sensor
If 4a detects, the three-way valve 3 switches and the buffer tank
The valve 8a is closed at the same time when the pressure of 1a is set to the pressurized state, the signal for allowing liquid supply is transmitted to the chemical liquid processing control circuit 15, the valve 10a is opened, and the chemical liquid is supplied to the chemical liquid processing section.

When the processing of the wafer is completed by the chemical processing section, a chemical sending control signal is sent from the chemical processing control circuit 15, and the chemical supply control circuit 16a closes the valve 10a, switches the three-way valve 3, and depressurizes the buffer tank 1a. In this state, the valve 8a is opened, and the chemical is replenished from the decrease in the chemical storage. And the float sensor 4a
Detects that the buffer tank 1a is full, closes the valve 8a, and stops supplying the chemical solution. In this way, the chemical supply unit automatically replenishes and supplies the chemical by the operation of the chemical processing unit.

〔The invention's effect〕

As described above, the present invention unifies a chemical supply system including a reservoir tank, an opening / closing valve, and a sensor for detecting a chemical liquid level in the tank, and controls the chemical liquid processing unit to transmit operation to the chemical liquid processing unit. By providing the circuit, the supply rate of the chemical solution is increased, the amount of the chemical solution remaining in the chemical solution processing unit is reduced, and the supply system line can be reduced to one line. Accordingly, there is an effect that a chemical processing apparatus having a low failure rate can be obtained at a low equipment cost while maintaining the purity of the chemical.

[Brief description of the drawings]

FIG. 1 is a system diagram showing one embodiment of a chemical solution supply unit in a chemical solution treatment device of the present invention, and FIG. 2 is a system diagram showing one example of a chemical solution supply unit in a conventional chemical solution treatment device. 1, 1a, 2 ... buffer tank, 3 ... three-way valve, 4, 4
a, 5, 6, 6a, 7: Float sensor, 8, 8a, 9, 1
0, 10a, 11 ... valve, 12 ... regulator, 13 ... pressure gauge, 14 ... four-way valve, 15 ... chemical solution processing control circuit, 16, 16
a ... Chemical liquid supply control circuit.

Claims (1)

(57) [Claims] 1. A chemical liquid supply section supplies a chemical liquid via a second valve to a chemical liquid processing section for replenishing a chemical liquid from a chemical liquid supply source via a first valve, storing the chemical liquid, and processing the semiconductor substrate one by one. One buffer tank, a float sensor for detecting an upper limit and a lower limit of the liquid level of the chemical solution in the buffer tank, and a nitrogen gas at a predetermined pressure for pumping the chemical solution to the chemical solution processing unit to the buffer tank. Means for supplying, when the chemical level exceeds the upper limit, the second valve is opened and the chemical is pressure-fed to the chemical processing unit, and when the processing in the chemical processing unit is completed, the first valve is opened. A chemical liquid processing apparatus, comprising: a chemical liquid supply control circuit for supplying the chemical liquid from the supply source to the buffer tank.