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:
Oct. 28, 2014
Filed:
Sep. 10, 2009
Gopal Prabhu, San Jose, CA (US);
Kathy J. Jackson, Felton, CA (US);
Orion Leland, Fremont, CA (US);
Aditya Agarwal, Sunnyvale, CA (US);
Gopal Prabhu, San Jose, CA (US);
Kathy J. Jackson, Felton, CA (US);
Orion Leland, Fremont, CA (US);
Aditya Agarwal, Sunnyvale, CA (US);
GTAT Corporation, Merrimack, NH (US);
Abstract
A donor wafer, for example of silicon, has an irregular surface following cleaving of a lamina from the surface, for example by exfoliation following implant of hydrogen and/or helium ions to define a cleave plane. Pinholes in the lamina leave column asperities at the exfoliated surface of the donor wafer, and the beveled edge may leave an edge asperity which fails to exfoliate. To prepare the surface of the donor wafer for reuse, mechanical grinding removes the column and edge asperities, and minimal additional thickness. Following cleaning, growth and removal of an oxide layer at the surface rounds remaining peaks. The smoothed surface is well adapted to bonding to a receiver element and exfoliation of a new lamina. A variety of devices may be fabricated from the lamina, for example a photovoltaic cell.