Localized region of isolated silicon over dielectric mesa

Abstract

An integrated circuit is formed by forming an isolation mesa over a single crystal substrate which includes silicon, and forming a first epitaxial layer on the substrate by a selective epitaxial process so that a top surface of the first epitaxial layer is coplanar with the top surface of the isolation mesa. A non-selective epitaxial process forms single-crystalline silicon-based semiconductor material on the first epitaxial layer and non-crystalline silicon-based material on the isolation mesa. A cap layer is formed over the second epitaxial layer, and a radiantly-induced recrystallization process causes the non-crystalline silicon-based material to form single-crystalline semiconductor over the isolation mesa.

What is claimed is: 
     
         1 . A method of forming an integrated circuit, comprising the steps:
 providing a substrate comprising silicon-based single crystal semiconductor material extending to a top surface of the substrate;   forming an isolation mesa over the substrate;   forming a first epitaxial layer of single-crystalline silicon-based semiconductor material on exposed areas of the substrate adjacent to the isolation mesa by a selective epitaxial process, so that a top surface of the first epitaxial layer adjacent to the isolation mesa is substantially coplanar with the top surface of the isolation mesa;   forming an second epitaxial layer of silicon-based semiconductor material on the top surface of the first epitaxial layer and on the top surface of the isolation mesa so that the second epitaxial layer includes a single-crystalline region on the first epitaxial layer and a non-crystalline region on the isolation mesa laterally contacting the single-crystalline region; and   heating the second epitaxial layer by a radiantly-induced recrystallization process so that the non-crystalline region recrystallizes so as to extend the single-crystalline region over the isolation mesa.