Accurate level doping can be confined by which of the following mechanisms ?

Accurate level doping can be confined by which of the following mechanisms ?

a) Wafer Cleaning
b) Epitaxial Deposition
c) Ion Implantation
d) Metalization

Correct Answer : c) Ion Implantation

Explanation :

Doping is only possible at ion implantation phase in an overall IC fabrication process.