Bis(bis(trimethylsilyl)methyl)tin(IV) Chalcogenides as Possible Precursors for the Metal Organic Chemical Vapor Deposition of Tin(II) Selenide and Tin(II) Telluride Films

Abstract

Two air- and light-stable compounds, bis(bis(trimethylsilyl)methyl)tin(IV) selenide and telluride, [Sn{(SiMe3)2CH}2(μ-E)]2 (E = Se (1) and Te (2)), were investigated as possible precursors for metal organic chemical vapor deposition (MOCVD). Their sublimation rate was measured by thermal gravimetric analysis in the 190−260 °C range and was found to be as high as 2 mg/min at 260 °C at 14 mbar. MOCVD experiments were conducted using both compounds as precursors at 300−600 °C and 1 Torr under a flow of a 1:1 He/H2 mixture. Strong selectivity of the decomposition reaction was found toward the metallic surfaces (copper, silver, gold) with respect to nonmetallic surfaces (quartz, silicon with natural oxide layer). A thin layer (≈10 nm) of conducting seeding layer was used for the deposition of carbon-free film of SnTe, using 2 as a precursor. The films were examined by scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy analyses.