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:
Jun. 23, 2015
Filed:
Oct. 12, 2009
Melissa Archer, Mountain View, CA (US);
Melissa Archer, Mountain View, CA (US);
Alta Devices, Inc., Santa Clara, CA (US);
Abstract
Embodiments of the invention generally relate to compositions of mesa etch solutions and methods for mesa etching materials on a wafer during an epitaxial lift off (ELO) process. The wafer usually contains an etch stop layer disposed thereon and a laminated epitaxial material disposed on the etch stop layer. In one embodiment, an etch process includes exposing the wafer to a non-selective etch solution and subsequently exposing the wafer to a selective etch solution while peeling the laminated epitaxial material from the wafer. The selective etch solution may contain succinic acid, an ammonium hydroxide compound, and an oxidizing agent, such as hydrogen peroxide. The selective etch solution may have a GaAs/AlAs selectivity of about 600, about 1,000, about 1,400, or greater. The non-selective etch solution may be an aqueous solution containing sulfuric acid and hydrogen peroxide.