$3.($Sedra P$5\mathrm{.}10)$ Consider a CMOS process for which Lmin $=0\mathrm{.}18$ m$,$tox $=4$ nm$,$n $=450$ cm$2/$V$$ s$,$ and Vt $=0\mathrm{.}5$ V$.$

$($a$)$ Find Cox and k$\text{'}$n$..$

$($b$)$ For an NMOS transistor with W$/$L $=2\mathrm{.}4$m$/0\mathrm{.}18$m$,$ calculate the values of vOV $,$vGS$,$ and vDSmin needed to operate the transistor in the saturation region with a current iD $=0\mathrm{.}1$ mA$.$

$($c$)$ For the device in $($b$),$ find the values of vOV and vGS required to cause the device to operate as a $500$ resistor for very small vDS$.$