0x211 Semiconductor

Electrical conductivity of Semiconductor is between medal and insulator

Properties

  • amplification
  • switch
  • energy transformation

Material

  • Group 14: Silicon, Germanium

Band

  • Conduction band: electrons distributed here for medals
  • Valence band: electrons distributed here for insulators

Doping

  • N type: redundent electron
  • P type: electron hole

Diode

p-n junction

  • forward bias: electron moves when voltage > 0.7V
  • reverse bias: reverse voltage will widen energy of depletion layer

Transistor

Bipolar junction transistor

Invented by Shockley, Bardeen, Brattain at Bell Labs in 1947. (Nobel Prize awarded in 1956)

NPN or PNP

Component

  • Base
  • Emitter
  • Collector

MOSFET

Feature

  • Little energy waste compared with Bipolar
  • Building blocks of SRAM and CPU
  • Scalable

Component

  • Gate
  • Source
  • Drain

Reference

Fabrication

photolithography