What is SiGe (silicon-germanium)?

An alloy of silicon and germanium with a larger lattice constant than silicon. Grown epitaxially, it is used to strain channels, as the base of HBTs and as the sacrificial layer in GAA transistors.

Field: Epitaxial growth

SiGe (silicon-germanium) in the explanations

Questions that mention SiGe (silicon-germanium) (25)

  1. Which is a characteristic of a SiGe HBT (heterojunction bipolar transistor)?
  2. How is silicon germanium (SiGe) classified?
  3. In manufacturing nanosheet GAA transistors, why is only the SiGe selectively removed from stacked alternating Si and SiGe layers?
  4. Why are SiGe and germanium considered or adopted instead of silicon as pMOS channel materials?
  5. When a thin silicon layer is grown epitaxially on a relaxed SiGe layer with a larger lattice constant, what strain develops in the silicon?
  6. Which technology is used to form the base layer of a SiGe HBT?
  7. In advanced CMOS processes, why is it necessary to lower the temperature of silicon and SiGe epitaxial growth?
  8. Which gas is used as the germanium source in SiGe epitaxial growth?
  9. Which correctly compares electron and hole mobility in silicon?
  10. Which value is closest to the band gap of germanium (Ge) at room temperature?
  11. Which value is closest to the lattice constant of crystalline silicon?
  12. What does the transition frequency fT of a bipolar transistor mean?
  13. Which pairing of a technology that integrates bipolar transistors and CMOS on the same chip with its purpose is correct?
  14. For nMOS and pMOS transistors of the same size, the nMOS generally has a larger drive current. What is the main reason?
  15. What is the main purpose of applying strain (stress) to a transistor's channel?

Related terms

Mobility Epitaxial growth CMOS GAA (gate-all-around) Effective mass HBT (heterojunction bipolar transistor) Nanosheet Heteroepitaxy Selectivity ALD

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