STRUCTURAL-ANALYSIS OF AMORPHOUS THIN-FILMS BY TIME-OF-FLIGHT MASS-SPECTROMETRY

Laser desorption time of flight mass spectrometry (TOF-MS) was applied to the characterization of three kinds of silicon materials; single c rystalline silicon wafer (c-Si), hydrogenated amorphous silicon (a-Si: H) prepared by silane plasma chemical vapor deposited, and amorphous s ilicon (a-Si) deposited in vacuum by pulsed laser ablation of c-Si tar get. The peak with the largest amplitude appeared at m/z = 28 for ever y specimen. Other predominant fragments were differently distributed f rom one specimen to another; Si-2 and Si-3, Si-x (x = 2-6) clusters, a nd Si-5 cluster were for c-Si, a-Si:H and a-Si, respectively. The resu lts indicate the possibility of this technique capable of an analysis of medium range order in amorphous thin films.