GROWTH OF TERNARY SI1-X-YGEXCY THIN-FILMS FROM A SINGLE-SOURCE PRECURSOR, GE(SIME(3))(4)

Abstract

Ge(SiMe(3))(4) was used as a single-source precursor to deposit thin films of alloys of germanium, silicon, and carbon, Si1-x-yGexCy, by low-pressure chemical vapor deposition on silicon substrates at temperatures 873-973 K. X-ray diffraction studies indicated that the films grown above 898 K were cubic phase (a = 0.441-0.442 nm). Infrared spectra of the films showed a major absorption near 783 cm(-1). X-ray photoelectron spectra of a typical thin film showed binding energies of Ge-3d, Si-2p, and C-1s electrons at 30.0, 100.6, and 283.2 eV, respectively. As determined by wavelength dispersive spectroscopy, x was 0.07-0.15 and y was 0.43-0.50, indicating that the films contained 7-15% Ge, 38-43% Si, and 43-50% C. At 973 K, the C/(Si + Ge) ratio was 1. Based on these data, the films deposited above 898 K have a structure of beta-SiC with Ge atoms replacing some Si atoms in the lattice.