CVD of metal chalcogenide films

The preparation of SnE, Ag2E and Cu2E (E = Se, Te) thin films by Chemical V apor 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 performe d 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 tem peratures ranging between 300 - 600 degrees C: and pressures ranging betwee n 0.5 - 40 mbar in either pure H-2 atmosphere or H-2/He mixture in a cold w all vertical CVD reactor. The film deposition was very selective with respe ct 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 vap or transport and electron beam evaporation techniques. The magnetoresistivi ty (MR) of Ag2-deltaTe showed markedly different temperature dependencies f or oriented and non-oriented films. Furthermore, in contrast to the bulk sa mples, a large anisotropy and a sign reversal effect of MR, were found in t hese films.