CVD of metal chalcogenide films

The preparation of SnE, Ag2E and Cu2E (E = Se, Te) thin films by Chemical Vapor Deposition (CVD) and Vapor Phase Transport (VPT) has been studied. The precursors, [Sn{(SiMe3)(2)CH}(2)(mu-E)](2) (E = Te, Se), have been studied for the deposition of SnE films. Deposition experiments have been performed on nonmetallic substrates, Si, and SiO2, as well as on Cu and on M/Si and M/SiO2 substrates (M = Cu, Ag and Au). Depositions were carried out at temperatures ranging between 300 - 600 degrees C: and pressures ranging between 0.5 - 40 mbar in either pure H-2 atmosphere or H-2/He mixture in a cold wall vertical CVD reactor. The film deposition was very selective with respect to the metal substrates, where phases of M2E and MSn were found. Thin metal film was employed as a seeding layer to obtain SnTe films. Thin films of chalcogenides M2E (M = Ag, Cu and E = Se, Te) were prepared by vapor transport and electron beam evaporation techniques. The magnetoresistivity (MR) of Ag2-deltaTe showed markedly different temperature dependencies for oriented and non-oriented films. Furthermore, in contrast to the bulk samples, a large anisotropy and a sign reversal effect of MR, were found in these films.