INTERFACIAL INTERACTION BETWEEN AL-1-PERCENT-SI AND PHOSPHORUS-DOPED HYDROGENATED AMORPHOUS SI ALLOY AT LOW-TEMPERATURE

The interfacial interaction between phosphorus-doped amorphous silicon hydrogen alloy ((n(+))a-Si:H) and thermal evaporated Al-1%Si layer af ter furnace annealing in the temperature range from 150 to 250 degrees C has been investigated in detail. The scanning electron microscope p hotographs show that many dendrites were formed on the original(n(+))a -Si:H surface at annealing temperature higher than 170 degrees C. Rama n spectroscopy and transmission electron diffraction show that the ori ginal (n(+))a-Si:H film has been converted to polycrystalline Si with the crystalline Si dendrites on top. The drastic increase (similar to 4 orders of magnitude) of electrical conductivity of the 200 degrees C annealed (n(+))a-Si:H films with the Al-1%Si removed is caused by the formation of polycrystalline silicon percolation channel in the backg round area between dendrites. Auger spectroscopy also provides evidenc e that no aluminum is incorporated into the converted film during sili con recrystallization and thus no SiAl alloy is formed. (C) 1997 Ameri can Institute of Physics.