A Zener diode is fabricated by heavily doping both p- and n-sides of the junctions. Explain, why ? Briefly explain the use of zener diode as a dc voltage regulator with the help of a circuit diagram.

Explanation

### Step-by-Step Solution

**Step 1: Understanding the Fabrication of Zener Diodes**
A Zener diode is fabricated by heavily doping both the P-type and N-type semiconductor materials. This heavy doping has two primary effects:

1. **Narrower Depletion Region**: The heavy doping reduces the width of the depletion region at the junction. A narrower depletion region allows for easier movement of charge carriers (electrons and holes), which is crucial for the diode’s operation, especially in reverse bias.

2. **Lower Resistance**: Heavily doped regions have a higher concentration of charge carriers, resulting in lower resistance. This allows the Zener diode to conduct a large current with a small voltage drop across it when it is in breakdown.
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