Large dimension silicon carbide single crystalline materials with reduced crystallographic stress

US12125701B2 · kind B2 · utility

Assignee

• Wolfspeed, Inc. · US

Inventors

• Yuri Khlebnikov · Raleigh, US
• Varad R. Sakhalkar · Morrisville, US
• Caleb A. Kent · Durham, US
• Valeri F. Tsvetkov · Durham, US
• Michael James Paisley · Garner, US
• Oleksandr Kramarenko · Durham, US
• Matthew David Conrad · Durham, US
• Eugene Deyneka · Raleigh, US
• Steven Griffiths · Ellicott City, US
• Simon Bubel · Carrboro, US
• Adrian Powell · Apex, US
• Robert Tyler Leonard · Raleigh, US
• Elif Balkas · Cary, US
• Curt Progl · Raleigh, US
• Michael Fusco · Wake Forest, US
• Alexander K. Shveyd · Chapel Hill, US
• Kathy Doverspike · Cary, US
• Lukas Nattermann · Chapel Hill, US

Key dates

• Filing date: Dec 15, 2020
• Grant date: Oct 22, 2024
• Expiry date: Mar 25, 2043

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C30B23/005
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

Silicon carbide (SiC) materials including SiC wafers and SiC boules and related methods are disclosed that provide large dimension SiC wafers with reduced crystallographic stress. Growth conditions for SiC materials include maintaining a generally convex growth surface of SiC crystals, adjusting differences in front-side to back-side thermal profiles of growing SiC crystals, supplying sufficient source flux to allow commercially viable growth rates for SiC crystals, and reducing the inclusion of contaminants or non-SiC particles in SiC source materials and corresponding SiC crystals. By forming larger dimension SiC crystals that exhibit lower crystallographic stress, overall dislocation densities that are associated with missing or additional planes of atoms may be reduced, thereby improving crystal quality and usable SiC crystal growth heights.