CHEN/PHGN  435/535 - Interdisciplinary Silicon Processing Lab
Spring 2001

Prelab IB: Etching

Name: __________________________

Read plasma etching procedures and Campbell p. 252 - 265

  1. What is the purpose of the NH4F in the Buffered Oxide Etch (BOE)?

    2.  

     

  2. Define etch selectivity?

    3.  

     

  3. List 3 advantages of plasma etching over wet etching.

    4. i.)

    ii.)

    iii.)

     

  4. Define anisotropy:

    5.  

     

  5. Using Figure 11-11b estimate the selectivity of a CF4/H2 plasma for SiO2 over polysilicon at 0, 20, and 40% H2.