Question

In reverse bias the thickness of depletion layer increases.Then even if Zener diode is connected in reverse bias,its depletion layer is very thin i.e in the order of 10^-6.HOW?

Answer 1

An ordinary diode can not be used as a Zener diode. In reverse bias if you are able to overcome the breakdown voltage due to the huge amount of current flowing through the diode, it will burn itself. Zener diode is designed differently. It produces controlled avalanche. The Zener diode is constructed is such a way that it has a very small depletion region.