Q7Micro and Smart System Technology
Question
2 marks
Q.7. Write down the difference between wet and dry etching. [2]
Answer
Wet etching uses liquid chemical reagents to dissolve exposed material and is generally isotropic (etches equally in all directions, causing undercutting), simple, and inexpensive but offers poorer feature-size control. Dry etching (plasma or reactive-ion etching) uses ionized gas species and can be made highly anisotropic (etching predominantly in the vertical direction), giving much better control of fine feature dimensions and sidewall profile, though at higher equipment cost and complexity.