What is Step coverage?
A measure of how uniformly a film covers the sidewalls and bottoms of steps and holes compared with flat areas. ALD gives excellent step coverage.
Field: Deposition (CVD and PVD)
Step coverage in the explanations
Step coverage expresses how much film lands on the sidewalls and bottoms of trenches and holes relative to flat areas, e.g., bottom thickness ÷ top thickness as a percentage.
Which correctly describes step coverage in deposition?Faster gas diffusion makes deposition surface-reaction-limited, so more than 100 wafers stood a few mm apart can be coated uniformly, with good step coverage.
Which is a characteristic of low-pressure CVD (LPCVD)?The equipment is relatively simple and films are pure, but line-of-sight travel gives poor step coverage and alloy compositions drift, so sputtering dominates LSI wiring.
Which correctly describes vacuum evaporation?
Questions that mention Step coverage (8)
- Which correctly describes step coverage in deposition?
- Under what condition does CVD give good step coverage (conformality)?
- Which is a characteristic of low-pressure CVD (LPCVD)?
- Which correctly describes vacuum evaporation?
- Which liquid organosilicon compound is widely used as a source for CVD of silicon oxide?
- Which gas is used as the source for tungsten CVD?
- What is an advantage of vacuum evaporation that heats material with an electron beam?
- In PVD such as sputtering and evaporation, why is it hard to coat the sidewalls and bottoms of deep trenches?
Related terms
CVD Sputtering Precursor ALD TEOS Vacuum evaporation Silane (SiH4) LPCVD (low-pressure CVD) Plasma 3D NAND