High-resolution electron microscopy of growth interruption effect on AlAs/GaAs interfacial structure during molecular beam epitaxy

Abstract

Step structures at an AlAs/GaAs interface grown by molecular beam epitaxy (MBE) and the effects of growth interruption were investigated by high-resolution transmission electron microscopy (HRTEM) of the interface in the [11̄0] imaging orientation. In order to accomplish this, we developed a new TEM specimen preparation technique and determined an observation condition for HRTEM of the interface. Atomic steps were clearly observed at the AlAs-on-GaAs interface grown by conventional MBE, and the step intervals ranged from a few nm to several tens of nm. When 120 s growth interruption was employed, the interfacial steps were smoothed out and the step intervals become larger than several tens of nm.