Liquid encapsulated crystal growth

US4824520A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventor

• Andrew Morrison · Altadena, US

Key dates

• Filing date: Mar 19, 1987
• Grant date: Apr 25, 1989
• Expiry date: Mar 19, 2007

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C30B29/48
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

Low-defect crystals are grown in a closed ampoule under a layer of encapsulant. After crystal growth, the crystal is separated from the melt and moved into the layer of encapsulant and cooled to a first temperature at which crystal growth stops. The crystal is then moved into the inert gas ambient in the ampoule and further cooled. The crystal can be separated from the melt by decanting the melt into an adjacent reservoir or by rotating the ampoule to rotate the crystal into the encapsulant layer.