Question

2(a) Qualitatively hand-sketch log(I) vs. V for a Schottky diode and a PN diode in the same figure. Comment on the similarity and difference.

2(b) Calculate the IS of a 1 mm2 metal on N-type Si Schottky diode with A*=100A/cm2-K2, T=300K, ?Bn=0.55eV. Compare it with the IS of a 1 mm2 P+N diode with ND = 1018 cm–3, T=300K and, Dp =4cm2/s, ?p=1?s.

(c) Compare the forward voltage of the two diodes in (b) at a forward current of 50A.

(d) Besides increasing the diode area (cost), what can one do to reduce the forward voltage drop of the Schottky diode?

(e) What prevents one from using a Schottky diode having a much smaller ?Bn?

Answer 1