ELECTROPHYSICAL PROPERTIES OF SURFACE PHASES OF IN ON SI (111)

We report the results of measurements of the temperature dependence (4 .2K less-than-or-equal-to T less-than-or-equal-to 300K) of the sheet r esistance R(T) and the magnetoresistance tensor components R(xx)(T) an d R(xy)(T) in a magnetic field (0 less-than-or-equal-to H less-than-or -equal-to 10T) for surface phases Si(111)-In(1x1)R30-degrees coated wi th an amorphous Si film (45 angstrom). The formation of surface struct ures upon metal deposition was investigated by LEED, Auger and LEELS. It is found that the d.c. and a.c. conductivity for IML of In atoms sh ows semiconductor behaviour with electron mobility -6.10(4) cm2/v.sec at T=50K (which is 4 times higher than that for the Si substrate itsel f). It is also found that the sheet electron concentration is about 1. 10(12) cm-2 at 80K and strongly decreases at low temperatures.