What is ALD?
Atomic layer deposition. A deposition method that repeats self-limiting surface reactions of precursor gases to control film thickness one atomic layer at a time.
Field: Deposition (CVD and PVD)
ALD in the explanations
ALD repeats a cycle: dose a precursor gas that adsorbs only one layer on the surface, purge the excess, then supply a reactant gas to complete the reaction.
Which is a characteristic of ALD (atomic layer deposition)?ALD offers atomic-level thickness control and excellent conformality, so it deposits high-k hafnium oxide gate dielectrics, titanium nitride for metal gates and barriers, zirconium oxide in DRAM capacitors, films around 3D NAND charge-trap layers, and spacers for multiple patterning—wherever thin, uniform films are needed.
Which is an example of a typical material deposited by ALD?PEALD uses plasma during the reactant step to create highly reactive oxygen, nitrogen or hydrogen radicals, depositing at lower temperatures (room temperature to a few hundred °C) than thermal ALD and enabling chemistries that react poorly thermally, such as SiN and TiN.
What is an advantage of plasma-enhanced ALD (PEALD)?
Questions that mention ALD (17)
- Which is a characteristic of ALD (atomic layer deposition)?
- Which is an example of a typical material deposited by ALD?
- What is an advantage of plasma-enhanced ALD (PEALD)?
- What is the approximate film thickness deposited in one ALD cycle?
- In ALD, what is the temperature range called in which self-limiting surface reactions keep the thickness per cycle constant?
- Which is an example of the precursors used to deposit HfO2 gate dielectrics by ALD?
- Why are high-k materials such as zirconium oxide used for the dielectric film of DRAM capacitors?
- Which ferroelectric material, compatible with CMOS processes, has recently attracted attention for FeRAM and ferroelectric transistors (FeFETs)?
- Which technique, used to make the thin fins of FinFETs, uses sidewall spacers to create patterns finer than the lithography limit?
- In manufacturing nanosheet GAA transistors, why is only the SiGe selectively removed from stacked alternating Si and SiGe layers?
- How does the thermal oxidation rate of silicon depend on crystal orientation?
- Which correctly describes step coverage in deposition?
- Which pair of source gases is used to deposit silicon nitride (Si3N4) by thermal CVD?
- What is the most appropriate range for the thickness of thin films handled in semiconductor manufacturing?
- In PVD such as sputtering and evaporation, why is it hard to coat the sidewalls and bottoms of deep trenches?
Related terms
Precursor CVD Multiple patterning Plasma GAA (gate-all-around) Step coverage Sputtering 3D NAND Photoresist CMOS