ELECTRONIC TRANSPORT IN HIGHLY DOPED RELAXED Si/Si1-xGex QUANTUM HETEROSTRUCTURES

The low-temperature electrical and magnetotransport characteristics of partially relaxed Si/Si1-xGex heterostructures with two-dimensional electron channel (ne. 1012 cm(-2)) in an elastically strained silicon layer of nanometer thickness have been considered. The detailed calculation of the potential and the electrons distribution in the layers of the structure was carried out to understand the observed patterns. The dependence of the tunneling transparency of the barrier between 2D and 3D transport channels from the doping level, the degree of blurring boundaries, layer thickness, degree of relaxation of elastic stresses in the layers of the structure was studied. Tunnel characteristics of the barrier between the layers were manifested by the appearance of a tunneling component in the current-voltage characteristics of real structures. Instabilities manifested during the magnetotransport measurements using both weak and strong magnetic fields are explained by the transitions of charge carriers from the two-dimensional into three-dimensional state, due to interlayer tunneling transitions of electrons.