Si Atomic Layer Epitaxy Based on Si2H6 and Remote He Plasma Bombardment
TEXAS UNIV AT AUSTIN MICROELECTRONICS RESEARCH CENTER
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Atomic layer Epitaxy ALE of Si has been demonstrated by using remote He plasma low energy ion bombardment to desorb H from a H-passivated Si100 surface at low temperatures and subsequently chemisorbing Si2H6 on the surface in a self-limiting fashion. Si substrates were prepared using an RCA clean followed by a dilute HF dip to provide a clean, dihydride-terminated 1 x 1 surface, and were loaded into a Remote Plasma Chemical Vapor Deposition RPCVD system in which the substrate is downstream from an r-f noble gasHe or Ar glow discharge in order to minimize plasma damage. An in situ remote H plasma clean at 250 deg C for 45 min. was used to remove surface 0 and C and provide an alternating monohydride and dihydride termination, as evidenced by a 3 x 1 RHEED pattern. It was found necessary to desorb the H from the Si surface to create adsorption sites for Si bearing species such as Si2H6. Remote He plasma bombardment for 1-3 min. was investigated over a range of temperatures 250 deg C-410 deg C, pressures 50-400 mTorr and r-f powers 6-30 W in order to desorb the H and convert the 3 x 1 RHEED pattern to a 2 x 1 pattern which is characteristic of either a monohydride termination or a bare Si surface.
- Inorganic Chemistry
- Physical Chemistry
- Plasma Physics and Magnetohydrodynamics