System and method for supplying and dispensing bubble-free photolithography chemical solutions
A method of supplying a chemical solution to a photolithography system. The chemical solution is pumped from a variable-volume buffer tank. The pumped chemical solution is dispensed in a spin-coater. The variable-volume buffer tank is refilled by emptying a storage container filled with the chemical solution into the variable-volume buffer tank.
1 . A method of supplying a dispensing system with a chemical solution, the method comprising:
providing a buffer tank, wherein the buffer tank has an inlet port, an outlet port, a piston and a cylinder, wherein the piston and the cylinder define a container space and the container space increases and decreases according to movements of the piston within the cylinder;
supplying the buffer tank with the chemical solution via an inflow of the chemical solution from a storage container through the inlet port;
supplying the dispensing system with the chemical solution via an outflow of the chemical solution from the buffer tank through the outlet port; and
moving the piston, or allowing the piston to move, in response to differences between the inflow and the outflow so as to prevent headspace from forming within the container space.
2 . The method of claim 1 , wherein the container space is within the cylinder.
3 . The method of claim 1 , further comprising eliminating gas from the container space by expelling the gas through a port in the piston.
4 . The method of claim 1 , further comprising eliminating gas from the container space by expelling the gas through a port in an uppermost part of the container space, wherein the port is in the cylinder.
5 . A method of supplying a dispensing system with a chemical solution, the method comprising:
providing a buffer tank, wherein the buffer tank has an inlet port, an outlet port, a piston, and a chamber, wherein the piston and the chamber define a container space and the container space increases and decreases according to movements of the piston within the chamber;
supplying the buffer tank with the chemical solution from the inlet port while moving the piston to expand the container space; and
supplying the dispensing system from the buffer tank while moving the piston to prevent headspace from forming within the container space.
6 . The method of claim 5 , wherein supplying the dispensing system from the buffer tank comprises operating a pump external to the buffer tank.
7 . The method of claim 5 , wherein the inlet port and the outlet port are below the piston.
8 . The method of claim 5 , further comprising releasing bubbles from the container space through a port.
9 . The method of claim 5 , wherein the dispensing system comprises a positive displacement pump operative to diminish a volume of the container space with each displacement cycle.
10 . The method of claim 9 , wherein the chemical solution is a photolithography chemical solution.
11 . The method of claim 5 , wherein supplying the buffer tank with the chemical solution from the inlet port comprises:
connecting the buffer tank to a storage container;
initiating a flow of the chemical solution from the storage container to the buffer tank; and
maintaining the flow until the storage container is empty.
12 . The method of claim 5 , wherein supplying the buffer tank with the chemical solution from the inlet port comprises:
connecting the buffer tank to a storage container; and
increasing the container space by approximately a storage capacity of the storage container.
13 . The method of claim 5 , wherein supplying the buffer tank with the chemical solution from the inlet port comprises:
connecting a storage container to the inlet port with the storage container having an initial amount of the chemical solution; and
draining the initial amount of the chemical solution from the storage container into the buffer tank.
14 . The method of claim 13 , wherein the container space expands by a volume equal to that of the initial amount of the chemical solution.
15 . The method of claim 13 , wherein the storage container is drained within a period of five minutes or less.
16 . The method of claim 13 , wherein the storage container has a bottom, and the storage container is drained from the bottom.
17 . The method of claim 13 , further comprising detaching the storage container from the inlet port prior to draining the buffer tank of the chemical solution transferred to the buffer tank from the storage container.
18 . The method of claim 13 , wherein draining the initial amount of the chemical solution from the storage container into the buffer tank comprises maintaining positive pressure in the storage container.
19 . The method of claim 18 , wherein maintaining positive pressure in the storage container comprises connecting the storage container to a bottled gas source.
20 . A method of supplying a dispensing system with a chemical solution, the method comprising:
providing a buffer tank, wherein the buffer tank has an inlet port, an outlet port, a piston and a chamber, wherein the piston and the chamber define a container space and the container space increases and decreases according to movements of the piston within the chamber;
connecting a storage container having the chemical solution to the inlet port, wherein the buffer tank has a larger capacity than the storage container;
transferring the chemical solution from the storage container into the buffer tank, wherein the piston moves to expand the container space as the chemical solution enters the buffer tank;
after transferring the chemical solution from the storage container into the buffer tank, preventing backflow out of the inlet port using a valve; and
after transferring the chemical solution from the storage container into the buffer tank, supplying the dispensing system with the chemical solution via an outflow of the chemical solution from the buffer tank through the outlet port, wherein the piston moves to contract the container space and prevent headspace from forming in the buffer tank as the chemical solution flows out of the buffer tank.