$($Streetman $6$ th $5\mathrm{.}20)$ A Si n$+$

$-$p junction has an area of $5$ x $5$ m$.$ Calculate the total junction

capacitance associated with this junction at an applied reverse bias of $2$V$.$ Assume that the

n$+$ region is doped $1020$

$/$cm $3$ and the p doping is $1016$

$/$cm $3.$ If we forward bias this junction

$0\mathrm{.}5$V$,$ what is the electric field far from the junction on the p side, assuming a hole mobility

of $250$ cm $2$

$/$V$-$s$,$ an electron mobility of $100$ cm $2$

$/$V$-$s$,$ and a reverse saturation current density

of $1$ nA$/$cm $2$ for this ideal diode?