Effects of growth temperature and metamorphic buffer on electron mobility of InAs film grown on Si substrate by molecular beam epitaxy

The growth of the InAs film directly on the Si substrate deflected from the plane (100) at 4° towards (110) has been performed using a two-step procedure. The effect of the growth and annealing temperature on the electron mobility and surface topography has been investigated for a set of samples. The results show that the highest electron mobility is 4640 cm²/V·in the sample, in which the 10-nm InAs nucleation layer is grown at a low temperature of 320℃ followed by ramping up to 560℃, and the nucleation layer was annealed for 15 min and the second layer of InAs is grown at 520℃. The influence of different buffer layers on the electron mobility of the samples has also been investigated, which shows that the highest electron mobility of 9222 cm²/V·at 300 K is obtained in the sample grown on a thick and linearly graded InGaAlAs metamorphic buffer layer deposited at 420℃.