Radiant energy – Photocells; circuits and apparatus – Optical or pre-photocell system
Patent
1987-12-17
1989-08-15
Nelms, Davis C.
Radiant energy
Photocells; circuits and apparatus
Optical or pre-photocell system
250373, 356442, 354298, G01N 1506, G01J 142
Patent
active
048577502
ABSTRACT:
An optical analyzer and a developer recirculation system is used to determine the amount of photoresist polymer dissolved in a quantity of developer solution and the sensor output signal is utilized by a control computer to control the admission of fresh developer solution to replace used developer and maintain a fixed level of dissolved photoresist polymer to keep the developer bath at a fixed level of chemical activity.
REFERENCES:
patent: 3712203 (1973-01-01), Kishi et al.
patent: 3722559 (1973-03-01), Hoffman
patent: 3990088 (1976-11-01), Takita
patent: 4021832 (1977-05-01), Krehbiel et al.
patent: 4166702 (1979-09-01), Okamoto et al.
patent: 4469424 (1984-09-01), Matsui et al.
patent: 4669847 (1987-06-01), Taniguchi et al.
patent: 4671309 (1987-06-01), Iemura et al.
patent: 4796590 (1989-01-01), Degobert et al.
Millis Edwin G.
Wood, Jr. Samuel J.
Honeycutt Gary C.
Merrett Rhys
Messinger Michael
Nelms Davis C.
Sharp Melvin
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