CVD of A1N and SiC Using Cyclic Organometallic Precursors

The use of cyclic organometallic molecules as single-source MOCVD precursors is illustrated by means of examples taken from our recent work on AIN and SiC deposition, with particular focus on SiC. Molecules containing (AIN) 3 and (SIC) 2 rings as the 'core structure' were employed as the source materials for these studies. The organoaluminum amide, (Me 2 AINH 2) 3' was used as the AlN source and has been studied in a molecular beam sampling apparatus in order to determine the gas phase species present in a hot-wall CVD reactor environment. In the case of SiC CVD, a series of disilacyclobutanes,(Si(XX')CH 2) 2(with X and X' - H, CH 3' and CH 2 SIH 2 CH 3), were examined in a cold- wall, hot-stage CVD reactor in order to compare their relative reactivities and prospective utility as single-source CVD precursors. The parent compound, disilacyclobutane, (SiH 2 CH 2) 2' was found to exhibit the lowest deposition temperature (ca. 670 C) and to yield the highest purity SiC films. This precursor gave a highly textured, polycrystalline film on the Si(100) substrates (70% with a SiClll orientation).