Why is the amount of impurity added to a pure semiconductor closely controlled?

Asked by Topperlearning User | 4th Jun, 2014, 01:23: PM

Expert Answer:

Doping a pure semiconductor can have quite marked effect on the conductivity of the material. The addition of one impurity atom in one hundred million will increase the conductivity by 11 times at room temperature. Therefore the amount of impurity added has to be closely controlled during the preparation of the extrinsic semiconductor.

 

Answered by  | 4th Jun, 2014, 03:23: PM