Si Atomic Layer Epitaxy Using Remote Plasma Assisted Hydrogen Desorption and Disilane as a Precursor.

摘要

We have demonstrated silicon Atomic Layer Epitaxy(ALE) using ions from an rf-excited helium plasma glow discharge which held remote from the substrate in a Remote Plasma Enhanced Chemical Vapor Deposition(RPCVD) system to minimize surface damage. The starting surface was a combination of dihydride and monohydride termination. The ALE experiment cycle consisted of bombarding the substrate with He ions from the plasma for 1-3 min. to desorb it followed by dosing the surface with disilane in a range of partial pressures(lO-7 Torr to 1.67 mToff), temperatures(250 deg C-400 deg C) and times(20 sec to 3 min.) without plasma excitation to adsorb Si2H6 on the bare surface Si atoms created by the bombardment as to silyl(SiH3) species in a self-limiting manner which results in a hydrogen terminated surface. The maximum growth obtained was 0.44 monolayers per cycle for a 3 minute bombardment cycle. The growth per cycle decreases as the bombardment cycle time is decreased, indicating that the percentage of hydrogen removed decreases with the bombardment time. Silicon, He plasma, Atomic layer epitaxy, Disilane.