Less Energetic Routes for the Production of SiOx Films from Tris(dimethylamino)silane by Plasma Enhanced Atomic Layer Deposition

Abstract

SiOx films, frequently derived from amino silane precursors, have found several applications with high added value. Although frequently used, the deposition of coatings from Tris(dimethyl amino) silane (TDMAS) has been reported to demand considerable amounts of energy, mainly due to the difficulty of oxidizing such compounds. As is well known, Plasma-enhanced atomic layer deposition (PEALD) is able to improve the oxidation efficiency, even under low processing temperatures. Owing to this, PEALD can be considered a very promising technique for the deposition of SiOx coatings. In this work, the deposition of silicon oxide films using TDMAS at 150 °C has been investigated. The effect of the plasma oxidation time (6 to 18 s) and atmosphere composition (pure O2 or O2 + Ar) on the chemical structure, elemental composition, and chemical bonding state of the films has also been evaluated. Increasing the plasma oxidation time in pure O2 resulted in a larger proportion of retained C (Si-CH3), whereas N was preserved in the structure (Si-N). On the other hand, the formation of SiOx films from TDMAS is favored in shorter oxidation times and O2 + Ar plasmas.