Hewlett-packard Company

California Institute of Technology

Silvanus S Lau

James W Mayer

Marc A Nicolet

Thomas W Sigmon

A method is provided for producing a low-defect layer of silicon on a sapphire substrate. A silicon-on-sapphire (SOS) wafer is formed by initially epitaxially depositing silicon on the sapphire substrate to form a monocrystalline layer which is substantially free of lattice defects near its surface, but which exhibits a high defect density near the sapphire substrate. The wafer is subsequently subjected to an ion implantation to form an amorphous region in the silicon near the silicon-sapphire interface. The implanted ions are preferably 'channeled' through the silicon layer to insure that the amorphous region will be localized in the imperfect region near the substrate, leaving the upper region of the silicon layer undamaged. During a subsequent high temperature anneal cycle, monocrystalline silicon is regrown from the residual upper regions of the silicon down to the silicon-sapphire interface, producing a silicon layer having a greatly reduced defect density throughout the layer.

Method for producing a low defect layer of silicon-on-sapphire wafer

A solid phase epitaxially grown semi-conductor is described wherein a thin film of a semi-conductor material together with a thin film dopant are transported through a metal film onto a substrate, using a temperature below the eutectic temperature for the material.

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Pasadena, CA, United States of America

Silvanus S Lau