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:
Feb. 27, 2001
Filed:
Aug. 28, 1998
Jong Hyeob Baek, Daejon-Shi, KR;
Bun Lee, Daejon-Shi, KR;
Electronics and Telecommunications Research Institute, Daejon-shi, KR;
Abstract
A method for sensing the etch of distributed Bragg reflector (called DBR below) in a real time is provided. More particularly, a method for searching informations of etch speed and etch stop step by monitoring the etching procedure in the wet etching method which is a post-process in the semiconductor device manufacturing process. A laser beam is irradiated on the sample sunk in the etching solution during the etching process is on the way. Then, computer measures the intensity of laser beam reflected on the sample, analyzes the periodic signals occurred by its interference and obtains the etching speed of the sample in a real time. The laser provides thermal energy on the sample during wet etching and occurs irregular etching speed on a beam contacting part of sample and non contacting part. Uniform etching speed can be obtained in the entire sample using a convex lens having a suitable focal distance.