Cat-CVD (hot-wire CVD): how different from PECVD in preparing amorphous silicon

Catalytic chemical vapor deposition (Cat-CVD), often called hot-wire CVD, is a new method to prepare device quality thin films at low substrate temperatures. In this method, deposition species are generated by the catalytic cracking reaction of source gases on the heated catalyzer, instead of the collision between energetic electrons and molecules of source gases in the conventional plasma-enhanced CVD (PECVD). The difference between Cat-CVD and PECVD in generating deposition species causes the differences in both deposition mechanism and the properties of thin films such as amorphous silicon (a-Si). In this review paper, at first, recent understandings on deposition mechanism of Cat-CVD are introduced. Secondly, based on such understandings, unique properties of Cat-CVD a-Si films are explained, and finally their device applications are demonstrated to show the feasibility of Cat-CVD technology.