Direct Growth of High-Quality InxGa1-xAs Strained Layers on Misoriented GaAs Substrates Grown by Metalorganic Chemical Vapor Deposition

Abstract

A new method to directly grow InxGa1-xAs strained layers, instead of using graded buffer layers, on misoriented GaAs (1 0 0) substrates by 10° towards (1 1 1)A while maintaining low interface dislocations, high crystal quality, and uniform and mirror like surfaces of the layers grown by metalorganic chemical vapor deposition (MOCVD) is presented. The large lattice defects existing between InxGa1-xAs and GaAs layers which lead to numerous interface dislocations and rough surface areas have been suppressed successfully by accurate control of growth temperature, growth rates, and the group III and V partial pressures with the V/III ratio of at least 91. The surface roughness is less than 1 nm as measured by atomic force microscopy (AFM). Lower interface dislocations can be observed by transmission electron microscopy (TEM). High crystal quality compared with that in previous studies is measured by an X-ray diffractometer (XRD). The mirror like surface is characterized by optical microscopy.