$(15$ points$)$ A one sided Si p$+-$n junction $102$ cm$2$ in area has ND $=1015$ cm$3$ doping on the n side and is very heavily doped $($but not degenerately$)$ on the p$-$side. T $=300$K$,$ ni $=1\mathrm{.}5$ x $1010$ cm$-3,$ Eg $=1\mathrm{.}12$ eV$,$Si $=12$ x $8\mathrm{.}85$ x $10-14$ F$/$cm$.(8$ points$)$ Calculate the junction capacitance with a reverse bias of $10$ V$.$ You can make reasonable assumptions for the p side based on given information. $(7$ points$)$ What is the depletion region thickness xd just prior to avalanche breakdown