What is STI (shallow trench isolation)?

Isolating devices by etching shallow trenches in silicon, filling them with insulator and planarizing by CMP. It has no bird's beak like LOCOS and is the standard isolation for fine-pitch LSIs.

Field: Oxidation and diffusion

STI (shallow trench isolation) in the explanations

Questions that mention STI (shallow trench isolation) (13)

  1. Which abrasive particles are often used in STI CMP to achieve high polishing selectivity of oxide to silicon nitride?
  2. Which method is mainly used for device isolation in scaled LSIs?
  3. Which method reacts hydrogen and oxygen near the wafer surface to form a high-quality thin oxide in a short time?
  4. In LOCOS (local oxidation), what is the phenomenon called in which oxide encroaches like a bird's beak under the edge of the nitride mask?
  5. Which is a typical use of thermally grown silicon oxide?
  6. Why does the compressive stress in thermally grown oxide become smaller when oxidation is done above about 950 °C?
  7. Why has high-density plasma CVD (HDP-CVD) been used to fill narrow trenches with insulator?
  8. Which correctly describes uses of silicon nitride (Si3N4) films?
  9. Which deposition method fills very narrow, deep trenches from the bottom with a flowable film and then solidifies it?
  10. Which solution is commonly used for wet etching of silicon nitride?
  11. In dry etching, what is the profile defect called in which the bottom of a trench is etched deeper near the sidewalls than in the center, creating narrow grooves?
  12. Which combination correctly lists processes in which CMP is used?
  13. Which CMP method fixes the abrasive particles in the polishing pad instead of putting them in the slurry?

Related terms

CMP LOCOS CVD Selectivity Ceria (cerium oxide) FinFET Slurry Crystal orientation Bird's beak HDP-CVD (high-density plasma CVD)

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