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

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