Improved empirical interatomic potential for C-Si-H systems

The Brenner hydrocarbon potential was extended recently to include interactions with silicon. This extended Brenner potential has now been improved by the fitting of bond order correction terms, and the introduction of an adjustable parameter into the angular function. The new potential gives an excellent description of small SimHn molecules and radicals. Its treatment of the low index surfaces of silicon and beta-SiC is also significantly improved, although the recently proposed non-dimerized structure for the silicon terminated (001) surface of beta-SiC is not described properly. Calculations of the chemisorption of C2H2 and CH3 onto the (001) surfaces of silicon and beta-SiC using this improved potential are reported. Also presented are some initial results of molecular dynamics simulations of the: Si(111) 7 x 7:CH3 and hydrogenated Si(001) 2 x 1:C2H2 chemisorption systems.