A combinatorial study of materials in transition from amorphous to microcrystalline silicon

A technique to grow a number of materials on a single substrate using a physical mask in a hot wire chemical vapor deposition (HWCVD) system is developed. Using this technique, we examine materials continuously varying from amorphous to microcrystalline silicon as we vary the hydrogen-to-silane gas ratio from 0 to 20 at a substrate temperature of about 250°C. Raman and reflectance spectra clearly show that the material structure changes rapidly at a ratio of 2 to 4. The results indicate that the near-transition materials still retain optoelectronic properties similar to amorphous silicon.