Factors influencing the interfacial roughness of InGaAs/GaAs heterostructures: A scanning tunneling microscopy study

Using cross-sectional scanning tunneling microscopy, we have investigated f actors which influence interfacial roughness in InGaAs/GaAs heterostructure s and have found that the roughness of the growth front and In segregation are two major factors influencing the interfacial roughness. In addition, w e noticed no preferential clustering of indium atoms along the [001] growth direction as previously reported by others. Furthermore, a growth procedur e which combines substrate temperature ramping with a growth interruption r esults in an atomically smooth interface. (C) 1999 American Institute of Ph ysics. [S0003-6951(99)01238-3].