EQUIPMENT

• Diffusion tubes (horizontal) using
  • O₂/N₂
  • Dopants
    • Gaseous: AsH₃, PH₃, BH₃
      • Doping concentration controlled by ratio of partial pressures
    • Liquid source
      • Doping concentration in case of liquid dopants controlled by:
        • temperature of the bath
        • pressure of the gas above the liquid
        • flow ratio (bubbler/reactor)
    • Solid source
      • A doped material is deposited on a substrate, when exposed at high temperature the dopans will diffuse in the substrate
• Difficult to control shallow junction, small features
  • Ion implantation is usead instead