Heteroepitaxial growth and characterization of GaAs on silicon-on-sapphire and sapphire substrates

A comparative study pertaining to the molecular beam epitaxial growth of GaAs directly on silicon-on-sapphire and (101̄2) sapphire substrates has been made. Thermal strain is significantly reduced in these heteroepitaxial GaAs films as compared with GaAs on silicon; however, the (111) GaAs epitaxy on nominal (101̄2) sapphire contains double-position boundaries. Hall effect measurements and current-voltage characteristics from metal-semiconductor contacts show that GaAs grown on silicon-on-sapphire is superior to GaAs grown on (101̄2) sapphire under the experimental conditions employed.