Difference between Wet and Dry Etching

 

Question: What is Etching? Write down the Difference between Wet and Dry Etching?

 

Solution:

Etching: Etching is a process that selectively removes unmasked portions of a layer. Simply etching is used to remove material from the wafer.

 

Difference between Wet and Dry Etching

	Wet Etching	Dry Etching
Method	Chemical Solutions	Ion Bombardment or chemical Reactive
Environment and Equipment	Atmosphere, Bath	Vacuum Chamber
Advantage	i) Low cost, easy to implement ii)High etching rate iii)Good selectivity for most materials	i)Capable of defining small feature size (<100nm)
Disadvantage	i)Inadequate for defining feature size <1um ii)Potential of chemical handling hazards iii)Wafer contamination issues	i)High cost, hard to implement ii)Low throughput iii)Poor selectivity iv)Potential radiation damage
Directionality	Isotropic (Except for etching crystalline materials)	Anisotropic