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US 5,395,803 AGranted
Method of spiral resist deposition
AssigneeAT&T Corp.
InventorThomas E. Adams
Life of this patent
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Abstract
A method of depositing a material upon a substrate is disclosed. A material, such as photoresist, is deposited upon a substrate such as a semiconductor wafer by spinning the substrate and commencing deposition at the edge of the wafer and moving inward in a spiral pattern. The method produces a more uniform coating than hitherto available.
Claims7
A method of semiconductor integrated circuit fabrication comprising:
- spinning a wafer at a speed r.sub.1 ;
- commencing deposition of a resist material at the edge of said wafer;
- continuously depositing said resist in a spiral pattern extending toward the center of said wafer;
- and then
- continuously depositing said resist in a spiral pattern extending from the said center of said wafer to the edge of said wafer;
- terminating said deposition;
- spinning said wafer at a faster speed, r.sub.3, for a period of time and further including the step of reducing the spinning speed of said wafer from r.sub.3 to speed r.sub.2 where r.sub.3 >r.sub.2 >r.sub.1, and continuing to spin said wafer for a period of time.
4 more elements
Dependencies are inferred from the claim text.