The growth rates RSi of Si layers deposited on Si(011)"16×2" by gas-source molecular beam epitaxy from Si2H6 were determined as a function of temperature Ts (400-975 °C) and Si2H6 flux JSi2H6(5.0×1015-9.0×1016cm -2s-1). RSi ranges from 0.0015 μmh-1 at Ts=400°C to 0.415 μm h-1 at Ts=975 °C with JSi2H6=2.2×1016cm-2s-1. In the surface-reaction-limited regime at Ts <725 °C, RSi initially exhibits an exponential decrease with 1/Ts, then decreases at a slower rate at Ts≤550°C as an additional deposition pathway becomes operative. In the impingement-flux-limited regime. 725≤Ts≤900°C, RSi is independent of Ts but increases linearly with JSi2H6. At Ts>900°C, RSi(Ts) increases with Ts due to surface roughening. Overall, R·Si(JSi2H6,Ts) is well described at Ts≤900°C by a kinetic model incorporating two competing film growth mechanisms: (1) dissociative chemisorption of Si2H6 onto dangling bonds followed by fast surface dissociation steps and second-order H2 desorption from the surface monohydride phase; and (2) Si2H6 insertion into Si-H surface bonds followed by second-order desorption of SiH4.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)