Large area seed crystal for ammonothermal crystal growth and method of making

US9650723B1 · kind B1 · utility

Assignee

• SORAA, INC. · US

Inventors

• Mark P. D'Evelyn · Fremont, US
• Wenkan Jiang · Corona, US
• Derrick S. Kamber · Goleta, US
• Rajeev Pakalapati · Kanchinakote, IN
• Michael R. Krames · Los Altos, US

Key dates

• Filing date: Apr 10, 2014
• Grant date: May 16, 2017
• Expiry date: Sep 5, 2035

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/2007
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

Large area seed crystals for ammonothermal GaN growth are fabricated by deposition or layer transfer of a GaN layer on a CTE-matched handle substrate. The sides and back of the handle substrate are protected from the ammonothermal growth environment by a coating comprising an adhesion layer, a diffusion barrier layer, and an inert layer. A patterned mask, also comprising an adhesion layer, a diffusion barrier layer, and an inert layer, may be provided over the GaN layer to allow for reduction of the dislocation density by lateral epitaxial growth.