Question

For a Zener diode

• A. both $p$ and $n$ regions are heavily doped
• B. $p$ region is heavily doped but $n$ region is lightly doped
• C. $n$ region is heavily doped but $p$ region is lightly doped
• D. both $p$ and $n$ regions are lightly doped
• E. depletion region is very thick

Hint:

Zener diode has heavy doping $\Rightarrow$ sharp breakdown at low voltage.

Answer 1

The Correct Option is A

Concept:
Zener diode characteristics:
• Heavily doped $p$ and $n$ regions
• Thin depletion layer

Step 1: Doping effect.
Heavy doping reduces depletion width.

Step 2: Conclusion.
\[ \text{Both regions are heavily doped} \]