Chemisorption of CHCl on Si(001) surface under UHV condition

Imanaka, Soichi*; Okada, Michio*; Kasai, Toshio*; Teraoka, Yuden; Yoshigoe, Akitaka 

The reactions of organic molecules with a Si(001) surface play important roles in many applied fields such as LSI, molecular device, sensor, non-liner optical materials, catalysis, coating, preservation from decay, and so on. Especially, the dissociative adsorption of CHCl is an important initial process in the production of diamond and silicon carbide thin films. However, it is required to control the orientation of CHCl for the elucidation of the detailed mechanism of the dissociative adsorption. In the present experiments, we studied the dissociative adsorption of CHCl on a clean Si(001) surface under ultra-high vacuum using Scanning Tunneling Microscopy (STM). We found, for the first time, that there are two reaction passes of CHCl(g) to CH(a)+Cl(a) and CHCl(g) to CH(a)+Cl(g) in the dissociative adsorption of CHCl on the Si surface.