The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 14, 1997
Filed:
Aug. 22, 1996
Li-Ming Wang, Pingtung, TW;
Gwo-Yuh Shiau, Hsinchu, TW;
Vanguard International Semiconductor Corporation, Hsin-Chu, TW;
Abstract
A method is proposed where striation-free coating of photoresist on a wafer is possible. This is accomplished by first prewetting the wafer with a particular agent, or solution, at a particular rate while the wafer is being accelerated to a predetermined rotational speed. Then the prewetting solution is cut off, after which the wafer is accelerated to a second rotational speed. Next, a photoresist of relatively high viscosity is dispensed concurrently with the wafer being accelerated to a third rotational speed, In order to achieve much reduced thickness variations than found in prior art, the third speed and the dispense rate are set at an unexpectedly lower value than that would be expected with a high viscosity photoresist. It is shown that with the disclosed method, critical dimensions of linewidths are preserved and product yield is improved.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile