Tris(dimethylamido)aluminum(III) and N2H4: Ideal precursors for the low-temperature deposition of large grain, oriented c-axis AlN on Si via atomic layer annealing

Abstract

The low-temperature (≤400 oC) deposition of polycrystalline AlN films on silicon is demonstrated by atomic layer annealing (ALA) using either trimethyl aluminum (TMA) and anhydrous hydrazine (N2H4) or tris(dimethylamido) aluminum (TDMAA) and anhydrous N2H4 with an argon plasma treatment utilizing a DC bias to tune the ion energy. Using TDMAA and N2H4, high-quality AlN films are deposited with large grain size and low oxygen/carbon contamination which can be used as a templating layer for further high-speed AlN film growth via sputtering. The deposition of high-quality AlN films deposited by ALA are successfully used as templates for sputtered AlN resulting in a >2x improvement in average grain size when compared to an analogous amorphous template layer.