INSITU INTERFACE CONTROL OF PSEUDOMORPHIC INAS/INP QUANTUM-WELL STRUCTURE GROWTH BY SURFACE PHOTOABSORPTION

The exchange reaction of group V atoms was monitored in situ by surface photo-absorption on a submonolayer scale during metalorganic vapor phase epitaxial growth of pseudomorphic InAs/InP heterostructure on (001) InP substrates. About a 0.4-monolayer As/P exchange reaction was observed after arsine was supplied at 0.2 mumol/s onto the In surface of InP at a substrate temperature (T(s)) of 400-degrees-C. At a T(s) of 350-degrees-C, this As/P exchange reaction was suppressed to less than 0.1 monolayer. In contrast, the P/As exchange reaction was less than 0.1 monolayer below 400-degrees-C. The benefits of in situ control were shown by growing pseudomorphic InAs/InP single and multiple quantum wells with 1-12 InAs well layers at T(s)=350-degrees-C and characterizing them by cross sectional transmission electron microscopy, photoluminescence, and double crystal X-ray diffraction. Metallurgically abrupt and atomically flat heterostructures without dislocations were grown to 10 monolayer (ML) of InAs well, which corresponds to the critical layer thickness.