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:
May. 11, 1999
Filed:
Feb. 24, 1997
Alfred Yi Cho, Summit, NJ (US);
Minghwei Hong, Watchung, NJ (US);
James Robert Lothian, Bethlehem, PA (US);
Joseph Petrus Mannaerts, Summit, NJ (US);
Fan Ren, Warren, NJ (US);
Lucent Technologies Inc., Murray Hill, NJ (US);
Abstract
It has been found that a Ga-oxide-containing layer is substantially not etched in HF solution if the layer is a Ga-Gd-oxide with Gd:Ga atomic ratio of more than about 1:7.5, preferably more than 1:4 or even 1:2. This facilitates removal of a protective dielectric (typically SiO.sub.2) layer after an ohmic contact anneal, with the Ga-Gd-oxide gate oxide layer serving as etch stop and not being adversely affected by contact with the HF etchant. Gd-Ge-oxide also exhibits a composition-dependent etch rate in HCl:H.sub.2 O.