FORMATION OF POLYSILICON FILMS BY CATALYTIC CHEMICAL VAPOR-DEPOSITION (CAT-CVD) METHOD

Silicon films are deposited by a new plasma-free and low-temperature deposition technique, the catalytic chemical vapor deposition (cat-CVD) method, in which deposition gases are decomposed by reactions with a heated catalyzer placed near substrates. It is found that polysilicon films of a grain size of around 0.1-mu-m can be easily obtained at substrate temperatures lower than 450-degrees-C by this cat-CVD method when gas pressure P(g) is below a certain critical value, although films are amorphous even for substrate temperatures higher than 450-degrees-C when P(g) is larger than such a critical gas pressure.