Question

Problem 1: Schottky Diode Small-Signal Capacitance Consider the measured reverse-bias capacitance data in Figure 14.8b of Pierret, reproduced below 1/c2 4 103 3. Pp2 -12 10 8 6 4 VA (volts) Illustrate with simple quantitative sketches how the measured curve would change if a) the Schottky barrier Dn decreases to 0.5 eV (but the semiconductor doping concentration remains N-1x1016 em) b) the semiconductor doping concentration Np increases to 1x1017 cm3 (but the Schottky barrier remains 0.8 eV)

Answer 1

The schottky diode( Barrier) is a very important device which have many application like Photodetector, High speed rectifier etc.

be expreund The barsies Lan as N Ec - Ep whr a Ver 4 -8 12 -6 -10 4- -2 VA

consequences of Barrier hight of Schottky diode-

1-Pinning of surface Fermi level at the neurtal level imclude-

  $\phi$_B=E_g-E_N

_{the value given in above equation does not agree all the time.}

All the results for N type diode is implies for P type also.

2-The influence of doping concentration on semiconductor on the pintchoff effect and the apparent parameter of Schottky diodewith small amount of low barrier hight defects is given below:

Influence of the pintchoff effect on silicon schottky diodes parameters is max for an n type doping concentration of about 10¹⁶cm^-3 and it will decreases for both higher and lower doping concentration.