ROOM-TEMPERATURE EPITAXIAL-GROWTH OF AG ON LOW-INDEX SI SURFACES BY A PARTIALLY IONIZED BEAM

The room temperature growth of 1000-1500 angstrom Ag films on HF-dipped Si substrates is studied as a function of self-ion (Ag+) energy during deposition. In all cases the films contained a mixture of epitaxial grains and randomly oriented (111) grains. The orientations observed were Ag(111)/Si(111) with both type A (Ag[110]//Si[110]) and type B (Ag[110]//Si[114]) twins; Ag(110)/Si(110) with Ag[001]//Si[001]; and Ag(100)/Si(100) with Ag[011]//si[011]. All three constructions match three Si atomic rows with four Ag rows. As judged by the ratio of epitaxial to nonepitaxial grains, the strength of the epitaxy was seen to decrease in the order (111) > (110) > (100). Increasing the Ag+ ion energy during the deposition was generally seen to decrease this ratio. Annealing of the Ag/Si (100) films induced preferential (100) grain growth.