Bsc CSIT Semester 1 – Physics – Unit 6: Semiconductor and Semiconductor devices (8 Hrs.)

What do you mean by the contact potential? Give band scheme of a p-n Junction by illustrating:
$\quad$(a) Potential difference Vc resulting from the positive donor ions in the n-side of the depletion layer and the negative acceptor ions in the n-side of the depletion layer.
$\quad$(b) Potential energy barrier faced by the majority charge carriers (electrons) in the n-side of the diode as they attempt to cross the junction.
$\quad$(c) Potential energy barrier faced by the majority side of the diode as they attempt to cross the junction.

Discuss effective mass of electrons and holes.

Discuss electrical conductivity of semiconductors. Derive expression for conductivity in terms of impurity ionization energy. Give a plot to dicuss 'Theoretical temperature dependence of the electrical conductivity of an impurity semiconductor'.

Derive expression for electrical conductivity of semiconductor in terms of impurity ionization energy.

Describe the following process of IC production:

$\quad$ (a) Oxidation and

$\quad$(b) Doping.

Explain photolithography in brief.

Explain the construction and working of bipolar junction transistor (BJT)

Explain the process of semiconductor purification by describing the terms zone refining, single crystal growth, and scheme of IC production. Give an account of electronic component fabrication on a chip.

Explain the construction and working of bipolar junction transistor (BJT)

Explain equilibrium current across the PN junction? Use Fermi-Dirac statistics and Maxwell Boltzmann distribution to show the flow n to p is equal to the flow from p to n .How electron current from p to n (that is , associated with minority carries) is not affected by the height of the potential energy barrier? Explain

Discuss effective’s mass of electrons and holes.

Describes electrical conductivity of semiconductors.