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:
Jul. 09, 1991
Filed:
Jan. 08, 1990
Applicant:
Inventors:
Assignee:
Fujitsu Limited, Kawasaki, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; B44C / ; C03C / ; C03C / ;
U.S. Cl.
CPC ...
156626 ; 156643 ; 156646 ; 156653 ; 156657 ; 1566591 ; 156662 ; 156663 ; 20419237 ; 20419233 ;
Abstract
A trench etching process comprises the steps of: preparing a substrate, forming a mask pattern for the trench etching having a material different from that of the substrate, on the substrate, and detecting changes in results of emission spectroanalyses generated by etching the mask pattern and the substrate while using the etching ratios of the mask pattern and the silicon substrate to determine that the trench etching is completed.