Amorphous Si/insulator multilayers grown by vacuum deposition and electroncyclotron resonance plasma treatment

a-Si/insulator multilayers have been deposited on (0 0 1) Si by electron gu n Si evaporation and periodic electron cyclotron resonance plasma oxidation or nitridation. Exposure to an O or N plasma resulted in the formation of a thin SiO2 and SiNx layer whose thickness was self-limited and controlled by process parameters. For thin-layer( similar to 2 nm) Si/SiO2 and Si/SiNx multilayers no visible photoluminescence (PL) was observed in most samples , although all exhibited weak "blue" PL. For the nitride multilayers, annea ling at 750 degrees C or 850 degrees C induced visible PL that varied in pe ak energy with Si layer thickness. Depth profiling of a-Si caps on thin ins ulating layers revealed no detectable contamination for the SiNx layers, bu t substantial O contamination for the SiO2 films. (C) 1999 Elsevier Science B.V. All rights reserved.