Mass spectrometric study of laser induced pyrolytic decomposition of TIBA and TMAA

The composition of the gaseous phases during pyrolytic laser-induced chemical vapor deposition (LCVD) of aluminium from triisobutylaluminium (TIBA) and trimethylamine alane (TMAA) (aluminium trihydride trimethylamine) was determined. The analysis was carried out by means of quadrupole mass spectrometer (QMS) in closed reaction cell. The developed arrangement for sampling allowed in situ analyses during the LCVD process. The decomposition of the aluminium precursors was induced by copper bromide vapor laser on the surface of (111) silicon monocrystalline wafer at different process parameters (partial pressure, laser power and scanning speed). The analyses showed usual gaseous products for the pyrolysis of TIBA and TMAA and additional species. The occurred pyrolysis products were probably dueto different ways of decomposition of the precursors caused by pulsed laser irradiation. The results from this study combined with surface analysis of the deposit could help for better understanding of LCVD and for obtaining of high purity aluminium layers