MBE

• Atomic resolution, no dopant diffusion
• Ultrahigh vacuum - 10-10 Torr
• A beam is produced by a source, which can be:
  • Knudsen cell - effusion cell - solid sources are evaporated
  • Electron- beam
  • Gas source

RTVPE

• Combine RTP and VPE - for limiting diffusion
• The wafer is heated by lamps
• Problems with temperature uniformity (tthe wafer is cooler at the edges) -
• solution: can deposit in mass limited regime but it is not possile tilting the wafers for uniform stagnant layers (as is the case for simple VPE), due to the heating method

UHV/CVD

• CVD wafer tilted to for a uniform stagnant layer
• Similar to LPCVD
• For low deposition growth at low temperatures - low flows are used
• in order to have a clean surface ( important for epitaxy), high vacuum is used