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:
Jan. 06, 1987
Filed:
Jul. 29, 1985
Applicant:
Inventors:
Assignee:
Ricoh Company, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B44C / ; C03C / ; C03C / ;
U.S. Cl.
CPC ...
156628 ; 156644 ; 156653 ; 156657 ; 1566591 ; 156663 ;
Abstract
The etch rate of phosphosilicate glass becomes lowered as boron ions are implanted therein. In accordance with the principle of the present invention, boron ions are implanted into a phosphosilicate glass film selectively in location or concentration and the thus boron-implanted phosphosilicate glass film is etched by an etchant, for example buffered hydrofluoric acid solution, to etch an intended portion of the phosphosilcate glass film preferentially thereby defining a hole, such as a contact hole, or substantially flat surface.