A CHEMICAL AND STRUCTURAL STUDY OF THE AIN-Si INTERFACE

Samples of AIN grown on silicon [111] substrates were examined using electron energy loss spectroscopy (EELS) and selected area diffraction (SAD) with high-resolution transmission electron microscopy (TEM) to determine the source of out-of-plane tilts and in-plane rotations of the AIN crystallite at the Si interface. SAD results indicate that the interracial crystallite are sheared along vertical planes, with random, intercrystallirw rotation. The interracial phenomena are believed to be the result of Si-Al-N interaction. Analytical experiments show no evidence of silicon nitride formation, witnessed by nitrogen-K peak shape, up to the Si interface. No evidence of substrate-epilayer interdiffusicm was observed. Chemical interaction within one monolayer of the interface is therefore suspected as the cause of the epilayer tilts and rotations.