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:
Sep. 09, 1997
Filed:
Apr. 28, 1995
Young Hoon Lee, Somers, NY (US);
Keith Raymond Milkove, Beacon, NY (US);
John William Stiebritz, Jr, Somers, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method for etching silicon is described incorporating first and second steps of reactive ion etching through a patterned oxide layer in respective atmospheres of HBr, Cl.sub.2 and O.sub.2 and then HBr and O.sub.2 in situ by terminating the first etching step and removing substantially all Cl.sub.2 before continuing with the second step of etching. The invention overcomes the problem of uneven etching of n+ and p+ silicon gates for CMOS transistor logic during the step of simultaneously etching silicon to form sub 0.25 micron gate lengths and vertical sidewalls while stopping on the gate oxide.