Remote plasma deposition of aluminum nitride

Abstract

Aluminum nitride thin films have been deposited from the addition of trimethyl aluminum in the afterglow of N2, N2:H2 microwave plasmas over a pressure range of 0.01–0.3 Torr. With N2 as the plasma gas at 0.3 Torr, strongly chemiluminescent reactions of N with CH3 lead to CN incorporation and resulting films are poor insulators. With N2:H2 as the plasma gas or for deposition at low pressures, chemiluminescence is extinguished and films with resistivities ≳1015 Ω cm can be deposited. It is proposed that the improvement results because the fast gas phase reactions between N and CH3 are avoided.