New low-temperature process for growth of GaAs on Si with metalorganic molecular beam epitaxy assisted by a hydrogen plasma

Abstract

A new low-temperature cleaning as well as a growth method using a hydrogen (H) plasma was successfully applied to the growth of GaAs on Si. The H plasma is expected to play several roles, such as cleaning the Si surface just prior to growth, decomposition of the metalorganic sources introduced without thermal cracking for the GaAs growth, supplying H radicals to terminate the organic-alkyl radicals, and enhancement of the mobilities for the surface migration. The almost atomically flat Si clean surface was prepared at a temperature as low as 300 °C using the H plasma. A single-domain GaAs epilayer was successfully realized at 400 °C after growth of 100 nm on a two-domain (001) Si surface using triethylgallium and triethylarsenic introduced without thermal cracking. The films were grown just after surface cleaning with the H plasma in the same chamber. Therefore, the reduction of the temperature for the whole growth process is possible with this new method.