The effect of growth condition on the structure of 2H-AlN films deposited on Si(111) by plasma-assisted molecular beam epitaxy

摘要

The effects of substrate cleaning, nitridation time, and substrate temperature in the range 800- l000 deg C on the microstructure of AlN/Si(l l1) films grown by simultaneous plasma-assisted molecular beam epitaxy have been investigated. It has been demonstrated, using a combination of conventional and high-resolution transmission electron microscopy, that the interface structure, the film defect structure, and the film surface roughness are strongly related. The formation of single crystal 2H--AlN films with atomically flat surfaces occurs at 800 deg. C for conditions of 2.5 nm/min growth rate on very pure, atomically flat Si substrates.