Chemical vapor deposition of aluminum from methylpyrrolidine alane complex

Chemical vapor deposition of aluminum from a recently developed precursor, methylpyrrolidine alane complex, has been studied. Aluminum films deposited on conducting surfaces (titanium nitride, copper, gold), but not on insulating surfaces (silicon, silicon dioxide, glass) at low substrate temperatures, showing deposition selectivity, while the deposition selectivity was lost at high substrate temperatures (> 210 °C). Al deposition rates on TiN and Cu were very close, but much higher than on Au. Deposition rates on all conducting substrates increased with the temperature and reached maximum at ∼180 °C. Al films deposited on as-sputtered TiN or Cu have no preferred orientations. Al–Au alloys and intermetallics were observed in the films deposited on Au. Surface morphology observation revealed that the film growth on TiN or Cu is different from that on Au. The surface roughness of Al films increased with the deposition time or the film thickness.