Reactive force-field molecular dynamics simulation for the surface reaction of SiH_x (x = 2–4) species on Si(1 0 0)-(2 × 1):H surfaces in chemical vapor deposition processes

Reactive force-field molecular dynamics simulation of Si thin film deposition in order to prove the availability of the simulation model including both chemical reactions and physical dynamics for a plasma-enhanced chemical vapor deposition process was performed. We simulated surface reactions of SiH_x (x = 2–4) formed in the plasma on a Si(1 0 0)-(2 × 1) surface covered with H atoms and evaluated the surface reactions with different substrate temperature and H coverage. The existing potential parameter set was modified to fit the dissociation energies in the gaseous species. The gaseous species collided with the surface one by one, and then the surface reactions were classified into four events: reflection, desorption, chemisorption, and physisorption. Our results show that an increase in substrate temperature affects both the bond dissociation in the gaseous species and the desorption of gaseous species on the surface. The H atoms inhibit the chemisorption by terminating dangling bonds on the surface and promote reflection and desorption by thermal movement. This method should facilitate the simulation of much more complex systems such as SiC and SiGe.