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:
Apr. 22, 2003
Filed:
Jun. 22, 2001
John Pohl, Leicester, GB;
Nirmal Chaudhary, Poughkeepsie, NY (US);
Veit Klee, Pleasant Valley, NY (US);
Tobias Mono, Poughkeepsie, NY (US);
Paul Schroeder, Dresden-Langerbrueck, DE;
Infineon Technologies, AG, Munich, DE;
Abstract
A nitride hard mask ( ) is used to isolate active areas of a DRAM cell. The shallow trench isolation (STI) method includes forming memory cells comprising deep trenches ( ) on a semiconductor wafer ( ). The memory cell deep trenches ( ) are separated from active areas ( ) by a region of substrate ( ). A nitride hard mask ( ) is formed over the semiconductor wafer ( ). The wafer ( ) is patterned with the nitride hard mask ( ), and the wafer ( ) is etched to remove the region of substrate ( ) between the deep trenches and active areas to provide shallow trench isolation. An etch chemistry selective to the nitride hard mask ( ) is used.