Etching

Which is a characteristic of atomic layer etching (ALE)?

  1. AIt etches several µm quickly in one step
  2. BIt alternates surface modification and removal, controlling the etched amount at the atomic-layer level
  3. CIt is isotropic wet etching using chemical solutions
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Answer: B. It alternates surface modification and removal, controlling the etched amount at the atomic-layer level

ALE repeats a self-limiting cycle: first only the top layer of the surface is reacted and modified, then only that layer is removed. Because the amount removed per cycle is fixed, etching can be controlled precisely at the atomic-layer level with little surface damage. It is essentially the etching counterpart of ALD.

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More Etching questions

  1. Which correctly describes one mechanism by which dry etching achieves anisotropy?
  2. Which solution is commonly used for wet etching of silicon nitride?
  3. During plasma etching, what is the phenomenon called in which conductors acting as antennas, such as long wires, collect charge and damage the gate oxide they connect to?
  4. Which is a characteristic of wet etching of silicon with potassium hydroxide (KOH) solution?
  5. Which is a characteristic of inductively coupled plasma (ICP) etching equipment?