Preparation of aluminum nitride films by low pressure organometallic chemical vapor deposition

Abstract

The low pressure chemical vapor deposition of aluminum nitride films from hexakisdimethylamido-dialuminum (Al2(N(CH3)2)6) and ammonia has been studied. The deposition conditions were varied in order to establish the influence of deposition parameters on final film composition. The grown films were characterized by Fourier transform IR spectroscopy, showing an absorption peak at 680 cm−1. Only at low temperatures or for depositions without ammonia, are an absorption peak at 810 cm−1 and peaks at higher frequencies (3000–3500 cm−1) found. These contributions are due to a strong carbon incorporation as a result of precursor decomposition. The lowest temperature to obtain a film without ammonia was determined to be 473 K. Film compositions were found to be near stoichiometric for almost any deposition conditions, with N-to-Al ratios ranging between 0.9 and 1.