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:
Nov. 28, 1995
Filed:
Jul. 05, 1994
Soon E Neoh, Singapore, SG;
Chartered Semiconductor Manufacturing Pte Ltd., Singapore, SG;
Abstract
A station for coating a semiconductor wafer with a photoresist is provided with a detector for bubbles that may occur in the resist that is supplied to the wafer. The resist is carried to the coating apparatus by a plastic tube. A commercially available capacitance detector is positioned to detect the dielectric constant of the combination of the tube, the resist, and any bubbles in the resist. The dielectric constant of the bubbles is lower than the dielectric constant of the resist, but the difference is not sufficient for detecting the bubbles with the capacitance detector alone. A metal backing plate is located on the side of the tube opposite the detector and enhances the operation of the detector sufficiently to detect bubbles of various sizes.