Suppose in a p'n diode the n region and the p region thickness are 20 μm and 5 μm, respectively.

step 1 In this problem, the breakdown diode is given by ID which is equal to minus 10 to the power 6 by

Suppose in a p'n diode the n region and the p region...

Suppose in a p'n diode the $\mathrm{n}$ region and the $\mathrm{p}$ region thickness are $20 \mu \mathrm{m}$ and $5 \mu \mathrm{m}$, respectively. What will be the $\mathrm{RB}$ applied to obtain a breakdown for this diode? [Given: $\left.\in=11.8, N d=10^{15} / \mathrm{cm}^{3}\right]$

Key Concepts

pn Junction Diode

A pn junction diode is a semiconductor device formed by joining p-type and n-type materials, creating a junction with a built-in potential. This junction establishes a depletion region where mobile charge carriers are depleted, and its behavior under applied bias forms the foundation for understanding diode operation including conduction and breakdown phenomena.

Depletion Region

The depletion region is the zone around the pn junction that is void of free carriers due to recombination, leaving behind immobile ions. Its width is influenced by the doping concentrations of the p-type and n-type regions and changes with applied voltage, playing a critical role in determining the electric field distribution across the junction.

Breakdown Voltage

Breakdown voltage is the reverse bias voltage at which a pn junction diode starts to conduct large currents due to breakdown mechanisms. It is determined by the critical electric field strength that the depletion region can withstand before mechanisms such as avalanche multiplication set in, and is essential for designing devices with desired voltage ratings.

Reverse Bias Operation

Under reverse bias, the pn junction is subjected to a voltage that widens the depletion region and increases the electric field across it. This condition is used to study breakdown phenomena, where the increasing electric field eventually initiates carrier avalanche multiplication leading to breakdown.

Avalanche Breakdown

Avalanche breakdown is a mechanism by which a strong electric field accelerates carriers to energies high enough to ionize lattice atoms, creating additional electron-hole pairs. This self-sustaining process leads to a rapid increase in current once a critical field is reached, marking the breakdown point of the diode.

Impact of Doping Concentration

The doping concentration in the semiconductor influences the depletion width and the maximum electric field in the diode. A lower doping concentration typically results in a wider depletion region and lower peak electric field, thereby affecting the breakdown voltage and overall device performance.

Permittivity in Semiconductors

The permittivity of a semiconductor material determines how electric fields interact with the material by scaling the capacitance and influencing the depletion region. It is a critical parameter in the calculation of the electric field distribution and breakdown voltage in devices like pn junction diodes.

Please give Ace some feedback