Substrate processing apparatus and control method of inert gas concentration
View Patent ↗Provided is a substrate processing apparatus capable of supplying pure water that is stabilized with respect to the concentration of nitrogen gas. First and second nitrogen concentration meters to measure the nitrogen gas concentration of pure water are respectively disposed before and after a concentration change part that can dissolve and degas nitrogen gas by using a hollow fiber type separation membrane. In order to maintain the nitrogen gas concentration of pure water at a target concentration value, the dissolution and degassing in the concentration change part are controlled by adjusting the degree to which a first valve on a nitrogen gas supply path and a second valve on a nitrogen gas degassing path are opened, based on a concentration difference between a target concentration and both of the first and second nitrogen concentration meters.
1. A substrate processing apparatus comprising:
(a) a processing part for performing a predetermined process of a substrate with a processing liquid;
(b) a processing liquid supply path for supplying a processing liquid to said processing part, said processing liquid supply path having:
(b-1) a first measuring element for obtaining a first measured concentration value by measuring a concentration of an inert gas of said processing liquid in a first state, said concentration of said inert gas of said processing liquid in said first state being not adjusted,
(b-2) a concentration change element comprising first and second groups of a plurality of hollow fiber type separation membranes housed in a single body for changing said processing liquid into a second state by changing said concentration of said inert gas of said processing liquid in said first state, and
(b-3) a second measuring element for obtaining a second measured concentration value by measuring said concentration of said inert gas of said processing liquid in said second state; and
(c) a controlling element for controlling said concentration of said inert gas of said processing liquid in said second state toward a predetermined target concentration by controlling said concentration change element, such that said concentration of said inert gas of said processing liquid is caused to be changed by both dissolving said inert gas in said processing liquid through said first group of said plurality of hollow fiber type separation membranes and degassing said inert gas from said processing liquid through said second group of said plurality of hollow fiber type separation membranes based on said first and second measured concentration values.
2. The substrate processing apparatus according to claim 1 , further comprising:
(d) a first flow adjusting element for adjusting the flow of said inert gas supplied to said concentration change element; and
(e) a second flow adjusting element for adjusting the flow of said inert gas degassed from said concentration change element, wherein
said controlling element controls dissolving through said first group of said plurality of hollow fiber type separation membranes by controlling said first flow adjusting element based on a difference between said first measured concentration value and said target concentration, and controls degassing through said second group of said plurality of hollow fiber type separation membranes by controlling said second flow adjusting element based on a difference between said second measured concentration value and said target concentration.
3. The substrate processing apparatus according to claim 1 wherein
said processing part and one part of said processing liquid supply path constitutes a first unit,
said first measuring element, said concentration change element, said second measuring element, said controlling element and the other part of said processing liquid supply path constitutes a second unit, and
said processing liquid supply path effects a processing liquid supply from said second unit to said first unit.
4. A substrate processing apparatus comprising:
(a) a processing part for performing a predetermined process of a substrate with a processing liquid;
(b) a processing liquid supply path for supplying a processing liquid to said processing part, said processing liquid supply path having:
(b-1) a first measuring element for obtaining a first measured concentration value by measuring a concentration of an inert gas of said processing liquid in a first state, said concentration of said inert gas of said processing liquid in said first state being not adjusted;
(b-2) a concentration change element for changing said processing liquid into a second state by changing said concentration of said inert gas of said processing liquid in said first state, comprising:
(b-2-1) a dissolving element for dissolving said inert gas in said processing liquid; and
(b-2-2) a degassing element for degassing said inert gas from said processing liquid; and
(b-3) a second measuring element for obtaining a second measured concentration value by measuring said concentration of said inert gas of said processing liquid in said second state; and
(c) a controlling element configured to control said concentration of said inert gas of said processing liquid in said second state toward a predetermined target concentration by controlling said dissolving element and said degassing element,
wherein said dissolving element and said degassing element are arranged in series on said processing liquid supply path with no branch therebetween, and
said concentration of said inert gas of said processing liquid in said second state is changed by either or both dissolving said inert gas in said processing liquid at said dissolving element and degassing said inert gas from said processing liquid at said degassing element, said controlling element deciding which of said either or both dissolving said inert gas in said processing liquid at said dissolving element and degassing said inert gas from said processing liquid at said degassing element is to be performed based on said first and second measured concentration values.
5. The substrate processing apparatus according to claim 4 , further comprising:
(d) a first flow adjusting element for adjusting the flow of said inert gas supplied to said dissolving element; and
(e) a second flow adjusting element for adjusting the flow of said inert gas degassed from said degassing element, wherein
said controlling element controls dissolving on said dissolving element by controlling said first flow adjusting element based on a difference between said first measured concentration value and said target concentration, and controls degassing on said degassing element by said second flow adjusting element based on a difference between said second measured concentration value and said target concentration.
6. The substrate processing apparatus according to claim 5 wherein
said degassing element is located upstream from said dissolving element on said processing liquid supply path.
7. The substrate processing apparatus according to claim 5 wherein
said dissolving element is located upstream from said degassing element on said processing liquid supply path.