In reverse-biasing, a very small current flows due to the minority charge carriers. The current is termed leakage saturation current (Is).
If reverse voltage is further increased, a large current flows suddenly at a certain reverse-bias voltage. This mechanism of producing a large reverse current is called breakdown.
There are two breakdown mechanisms:
i. Zener breakdown
ii. Avalanche breakdown.
The main difference between the Zener breakdown and Avalanche breakdown are as follows:
If reverse voltage is further increased, a large current flows suddenly at a certain reverse-bias voltage. This mechanism of producing a large reverse current is called breakdown.
There are two breakdown mechanisms:
i. Zener breakdown
ii. Avalanche breakdown.
The main difference between the Zener breakdown and Avalanche breakdown are as follows:
- Zener breakdown occurs due to a high electric field intensity across the junction.
Avalanche breakdown occurs due to a collision of charge carriers with other atoms.
2. Zener breakdown occurs normally at a low-reverse voltage.
Avalanche breakdown occurs at a high-reverse voltage.
3. Zener breakdown occurs in a heavily-doped diode.
Avalanche breakdown occurs at a high-reverse voltage.
4. Zener breakdown voltage decrease with a rise of temperature.
Avalanche breakdown voltage increase with an increase of temperature.