Advanced transistors (FinFET and GAA)

What is the main reason for using high-k (high-dielectric-constant) materials for the gate insulator?

  1. AA material with a high dielectric constant gives large gate capacitance with a thicker physical film, suppressing tunneling current
  2. BTo reduce wiring resistance
  3. CTo eliminate the gate insulator itself
Show answer and explanation

Answer: A. A material with a high dielectric constant gives large gate capacitance with a thicker physical film, suppressing tunneling current

If SiO2 is made too thin, gate leakage from tunneling increases sharply. Using hafnium-based oxides or other materials with high permittivity allows a thicker physical film for the same gate capacitance, suppressing leakage. Because high-k films are not compatible with polysilicon gates, they are combined with metal gate electrodes.

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More Advanced transistors (FinFET and GAA) questions

  1. What is the main purpose of applying strain (stress) to a transistor's channel?
  2. Which correctly describes EOT (equivalent oxide thickness)?
  3. Which correctly describes the SOI (silicon on insulator) structure?
  4. Which correctly describes DIBL (drain-induced barrier lowering)?
  5. How is the effective channel width of a FinFET adjusted?