Question
What is the main cause of Zener breakdown?
Solution
Zener diode is fabricated by heavily doping p-side and n-side. So, even for a small reverse bias voltage, the electric field of the junction is extremely high. The high electric field strength pull the valence electrons from the host atoms on the p-side which are accelerated to the n-side. The electrons emitted account for high current flow, causing a breakdown called zener breakdown.
