Atomic Layer Deposition of SnTe Thin Film Using Sn(N(CH₃)₂)₄ and Te(Si(CH₃)₃)₂ with Ammonia Coinjection

Abstract

This study introduces the synthesis of conformal crystalline SnTe films through atomic layer deposition (ALD) using the sequential injection of Sn­(N­(CH3)2)4 and Te­(Si­(CH3)3)2 with NH3 coinjection. The one to one stoichiometry of the deposited SnTe films indicates the conversion of Sn­(IV) to Sn­(II) and the removal of Te(0) during the deposition process as a result of the redox reaction between Sn­(IV) and Te2–. NH3 coinjection with Te­(Si­(CH3)3)2 facilitated the uniform growth of SnTe films even at high temperatures (>130 °C), where the growth was severely retarded in the absence of NH3 due to the desorption of the precursors from the substrates. The self-limiting growth rates of 93 and 150 ng·cm–2·cycle–1 (1.5 and 2.4 Å·cycle–1) were obtained at 90 and 130 °C, respectively. The process produced high-purity, crystalline-as-deposited SnTe films with a face-centered cubic structure.

Physicochemical Properties of SnTe Thin Films Dependent on Compositional Ratios

“…This information indicates that the reduction–oxidation reaction occurred between Sn and Te in STX TFs. [ 11 ] The peaks of Sn 4+ and Te 4+ were associated with SnO 2 and TeO 2 on the TF surface. [ 47 ] The ratio of Sn 4+ species decreased and the ratio of Te 4+ species increased as the Te composition of the STX TFs increased.…”

“…Thin films (TFs) are one class of nanomaterials in which the morphology, crystallinity, and oxidation state can be controlled with relative ease. [ 9,10 ] There is a wide spectrum of methods to fabricate TFs including but not limited to chemical vapor deposition, [ 9 ] thermal evaporation, [ 10 ] atomic layer deposition, [ 11 ] molecular beam epitaxy, [ 12 ] pulsed laser deposition, [ 13 ] electrodeposition, [ 14 ] and radio frequency (RF) magnetron cosputtering. [ 15–17 ] Among them, RF magnetron cosputtering has advantages such as great adhesion, low degree of contamination, uniformity over large areas on the substrate, and high deposition rate.…”

Tailoring the surface properties of molybdenum oxytelluride thin films by its compositional ratio

“…Thin films (TFs) are considered a type of nanomaterial in which the resulting crystallinity and morphology can be fine‐tuned relatively easily 12,13 . There are many methods to fabricate TFs, for example, thermal evaporation, 14 chemical bath deposition, 15 spray pyrolysis, 16 atomic layer deposition, 17 and radio frequency (RF) magnetron co‐sputtering 18–20 . Among them, RF magnetron co‐sputtering has striking advantage of obtaining uniform TFs at a high deposition rate with precisely controlled elemental compositions 21,22 …”