MOS Capacitor

• One of the key components of analogue MOS circuits
  
• Dielectric almost always SiO₂ ... very stable insulator
  
• If a higher permittivity and breakdown voltage is needed,
                 additional layer of Si₃N₄ can be used
• Several ways of electrodes realization ... depending on the technology available:

• Metal-or Polysilicon-over-Diffusion Structure

 

 

• Polysilicon-over-Polysilicon Structure

 

 

• Metal-over-Polysilicon Structure