Browse Prior Art Database

Variable Rate Chemical Processor

IP.com Disclosure Number: IPCOM000080155D
Original Publication Date: 1973-Nov-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Harding, WE: AUTHOR

Abstract

Where different rates of reactivity are desired between a wafer and a processing fluid, it has been proposed as in U. S. Patent 3,419,956 to maintain two solutions of the processing fluid at different concentrations in each of the tanks. In this manner, processing, such as etching or development, may be carried out quickly in the more concentrated of the solutions with subsequent transfer of the wafer to a solution of lower concentration, so that the final portion of the processing may be carried out at a reduced rate to permit precision control of the process.

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Variable Rate Chemical Processor

Where different rates of reactivity are desired between a wafer and a processing fluid, it has been proposed as in U. S. Patent 3,419,956 to maintain two solutions of the processing fluid at different concentrations in each of the tanks. In this manner, processing, such as etching or development, may be carried out quickly in the more concentrated of the solutions with subsequent transfer of the wafer to a solution of lower concentration, so that the final portion of the processing may be carried out at a reduced rate to permit precision control of the process.

It has been found that a variable-rate processing can be effected in a single processing station, by varying the concentration and/or temperature of the chemical solution as the process nears completion. This can be accomplished by temperature (coolant or heater) changes, or by injecting solvent to dilute the processing fluid.

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