Line growth on the H/Si(100)-2 × 1 surface: Density functional study of allylic mercaptan reaction mechanisms

The growth of molecular lines on the Si(100)-2 × 1 surface is an area of intense interest due to its possible application to the microelectronics industry. While many molecules have been found to grow along dimer rows of the Si(100)-2 × 1 surface, only allylic mercaptan (ALM) has been shown to grow exclusively across dimer rows. In this work, we compare several possible mechanisms for line growth across silicon dimer rows. We conclude that a reaction mechanism starting from a branched carbon radical adsorbed on the surface and ending with an interdimer bridged structure is the most probable mechanism for initial ALM reactivity.