Characterization of GaAs regrowth interfaces grown by metal‐organic vapor phase epitaxy

Abstract

Abstract If epitaxial growth is interrupted to incorporate processes followed by epitaxial regrowth, the degree of freedom in device designing increases. This paper characterizes the GaAs epitaxial regrowth interface grown by metal‐organic vapor phase epitaxy (MOVPE). Three basic regrowth processes were evaluated by C‐V carrier profiling, DLTS analysis and I‐V measurements, and the following results have been obtained: (1) when regrowth is carried out after growth is interrupted in the furnace, carrier accumulation at the interface is observed. This is due to the transitional change of the V/III ratio and can be eliminated by proper control of the gas flow; (2) when regrowth occurs after exposure to air for a long period of time, carrier depletion/accumulation or carrier accumulation alone is observed. This can be explained by a formation of interface energy levels which are energy‐wise continuous. The cause of the interface energy levels can be explained by our model DIGS (disorder induced gap state); (3) when regrowth is carried out after the sample is soaked in acetone, a depletion profile due to carbon adsorption is observed.