CMOS Process Integration: FEOL & BEOL

The CMOS process integration is often divided into two major parts: the front end of the line (FEOL) and the back end of the line (BEOL).

Front End of the Line (FEOL) CMOS Fabrication Process Steps

• Wafer Preparation(P substrate) #
• Well Formation
  • Twin-Well Process
  • Triple-Well process
• Isolation Process
  • Shallow trench isolation (STI) process
  • Local Oxidation of Silicon (LOCOS)
• Threshold voltage adjustment
• Polysilicon gate structure process
• Lightly-doped drain (LDD) extension implant process
• Source/drain implant process

Back End of the Line (BEOL) CMOS Fabrication Process Steps

• Contact (silicide and salicide) formation  #
• Metal1 interconnect formation
• Via1 and plug1 formation
• Metal2 interconnect formation
• Via2 and plug2 formation
• Metal3 interconnect formation
• Passivation and Bonding pad