High quality silicon carbide crystals and method of making the same

US10793972B1 · kind B1 · utility

Assignee

• II-VI DELAWARE, INC. · US

Inventors

• Xueping Xu · Vernon, US
• Avinash Gupta · Gainesville, US
• Mark Spiridonovich Ramm · Saint Petersburg, RU
• Ilya Zwieback · Township of Washington, US
• Varatharajan Rengarajan · Flanders, US
• Gary E. Ruland · Morristown, US

Key dates

• Filing date: Jul 10, 2018
• Grant date: Oct 6, 2020
• Expiry date: Nov 24, 2038

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C30B23/06
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A physical vapor transport (PVT) apparatus suitable for growing SiC boules comprises a crystal growth chamber (with a defined central vertical axis), a sealed crucible containing sublimation source material and including a seed fixture disposed in an offset position with respect to the central vertical axis of the apparatus, and a heat source disposed to surround the crystal growth chamber. The heat source is configured to raise the temperature within the sealed crucible such that the source material vaporizes and deposits on the seed wafer. The offset position of the seed fixture creates a radial temperature gradient across an exposed surface of the seed as the crystal boule is grown.