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:
Dec. 11, 2001
Filed:
Dec. 11, 1998
Yu-Hwa Lo, Ithaca, NY (US);
Felix Ejeckam, Ithaca, NY (US);
Nova Crystals, Inc., San Jose, CA (US);
Abstract
A method for producing a stress-engineered substrate includes selecting first and second materials for forming the substrate. An epitaxial material for forming a heteroepitaxial layer is then selected. If the lattice constant of the heteroepitaxial layer (a,) is greater than that (a,) of the immediate substrate layer the epitaxial layer is deposited on, then the epitaxial layer is kept under “compressive stress” (negative stress) at all temperatures of concern. On the other hand, if the lattice constant of the heteroepitaxial layer (a,) is less than that (a,) of the immediate substrate layer the epitaxial layer is deposited on, then the epitaxial layer is kept under “tensile stress” (positive stress). The temperatures of concern range from the annealing temperature to the lowest temperature where dislocations are still mobile.