GROWTH MECHANISMS OF ALUMINUM DOTS DEPOSITED BY LASER-INDUCED DECOMPOSITION OF TRIMETHYLAMINE ALANE

Aluminum dots have been deposited by thermal decomposition of trimethy lamine alane (TMAA) on silicon substrates irradiated with a tightly fo cused argon ion laser beam (lambda = 514 nm), Carbon free Al deposits containing less than 5 at.% of impurities (mainly oxygen) detected by Auger Electron Spectroscopy were grown. The growth kinetics of Al dots was investigated as a function of TMAA pressure and laser-induced tem perature. The deposition of dots occurred at a laser-induced temperatu re as low as 210 degrees C. The TMAA decomposition was thermally activ ated (activation energy of 18 kcal/mole) and the deposition rate at 30 0 degrees C was equal to 2 mu m/s. The effects of Hz or He (used as bu ffer gases) in the gas phase on the growth kinetics of dots was also s tudied. The growth mechanisms of dots are discussed and proposed on th e basis of the results of this kinetic study.