抄録
Using predeposited thin amorphous Si layers, less than 40 Å thick, before chemical vapor deposition (CVD), Si (100) films of high quality were grown successfully on sapphire substrates. This growth method consists of two processes: (1) a sapphire surface is covered in the begging with a amorphous Si layer and (2) Si CVD is carried out on the substrate covered with the amorphous layer. The most remarkable feature of this method is that films with a smooth surface and a high crystalline quality grow even at a slow growth rate, less than 0.1 μm/min and a high growth temperature of about 1000℃. The interface region between the film and the substrate has an abrupt concentration gradient of constituent atoms. In order to investigate the growth features and properties of the films, various physical analyses (RHEED, SIMS, AES and XPS) were used, and electrical properties of MOS FETs were measured. A model to understand this growth method is proposed.
