Infrared attenuated-total-reflection spectroscopy of microcrystalline silicon growth

in situ Fourier transform infrared attenuated-total-reflection (FT-IR-ATR) spectroscopy has been applied to study the growth of mu c-Si:H from an rf glow discharge decomposition of H-2-diluted SiH4 and from a layer-by-layer (LbL) process in which 3 nm-thick Si:H deposition and H-2-plasma annealing are alternately repeated. The results indicate that the FT-LR-ATR technique enables us to measure the nucleation and the grain growth with a submonolayer sensitivity. During the mu c-Si:H growth, the time evolution of the absorption intensity of the stretching modes due to interior silicon hydrides is suppressed and distinct absorption peaks due to surface hydrides emerge, which an not observable in the case for a-Si:H him growth. Temporal changes in the ATR spectrum during the LbL process at 250 degrees C have shown that the hydrogen desorption from a near surface region, especially the grain boundary and amorphous phase, caused by H-2-plasma exposure affects the crystalline nucleation and the grain growth. (C) 2000 Elsevier Science B.V. All rights reserved.