ELECTRICAL-PROPERTIES OF AU CAF2/N-SI[111] STRUCTURES GROWN BY MOLECULAR-BEAM EPITAXY WITH ULTRATHIN (LESS-THAN 20NM) CAF2 LAYERS/

Au/CaF2/n-Si(111) structures with CaF2 film thickness d from 1.9 to 20 .9 nm are obtained by molecular-beam epitaxy. The dielectric strength of the fluoride layers that were grown is (4-5)X10(6) V/cm for d<6 nm and of the order of 1.5X10(6) V/cm for 10 nm <d<20 nm. The decrease in strength with increasing thickness is attributed to the partial ''rel axation'' of the CaF2 layer. The current-voltage characteristics of th e Au/CaF2/n-Si[111] structures are presented. It is shown that the cur rent in these structures consists only of an electronic component. The absence of photosensitivity in the experimental structures for low ph oton energy (less than 3 eV) is explained. (C) 1996 American Institute of Physics.