LEED OBSERVATION OF 4X1-IN SUPERSTRUCTURE PREPARED ON SI(LLL)-QUASI-5X5-CU SURFACE

The surface structure of (Cu, In) binary system on Si(lll) has been st udied with the low energy electron diffraction (LEED) technique. First , the quasi- '5 X 5'-Cu structure can be prepared with the deposition of 1-2.5 ML of Cu on the clean surface of Si at temperatures of 300-55 0 degrees C. With the additional deposition of 0.5-1.6 ML of In, the s urface structure changes into a 4 X 1 structure at temperatures betwee n 400 and 500 degrees C. At 550 degrees C, however, the '5 X 5'-Cu str ucture does not disappear, despite of the supply of In vapor.