Patent ID: 6291252
Filing Date: 2001-09-18
Classification: H01L

Abstract:
A method of manufacturing semiconductor wafers in a processing tool, the method comprising:(a) placing at least one cassette with product wafers into the processing tool;(b) loading wafers from the cassette to product slots in an elevator, wherein the elevator also contains phantom slots holding conditioning wafers;(c) loading a processing recipe containing conditioning steps and product steps into the processing tool;(d) determining if the processing tool has been on idle longer than a predetermined period of time;(e) loading a product wafer from the elevator into a processing chamber if the time period in step (d) does not exceed tile predetermined period of time;(f) processing tile product wafer;(g) loading a conditioning wafer from a phantom slot in the elevator into the processing chamber if the time period in step (d) exceeds the predetermined period of time; and(h) processing the conditioning wafer.