Formation of amorphous silicon by the low-temperature tunneling reaction of H atoms with solid thin film of SiH4 at 10 K

The reaction of H atoms with SiH4 molecules deposited on the silicon substrate at 10 K led to the formation Of Si2H6 as an intermediate and a thin solid product. The yields of reaction products increased with decrease of temperature from 50 to 10K. The film thickness of about 10-20 monolayers; of SiH4 gave the highest yield of the solid product at 10 K. When the solid product formed at 10 K was further reacted with H atoms at 200 K, the growth of Si-Si bond network was observed. Analysis of the solid product by FT-IR and spectroscopic ellipsometry revealed that it has the structure similar to amorphous silicon (a-Si:H) formed by the plasma chemical vapor deposition.