text: The semiconductor is a collective term for a series of devices. It mainly includes three categories：two-terminal devices, three-terminal devices, and four-terminal devices. The combination of the semiconductors is called an integrated circuit. 
  The relationship between Ficks law and semiconductors: the principle of the semiconductor is transferring chemicals or dopants from a layer to a layer. Ficks law can be used to control and predict the diffusion by knowing how much the concentration of the dopants or chemicals move per meter and second through mathematics. 
  Therefore, different types and levels of semiconductors can be fabricated.
  Integrated circuit fabrication technologies, model processes like CVD, thermal oxidation, wet oxidation, doping, etc. use diffusion equations obtained from Fick's law.