Design an ideal silicon n-channel depletion mode MOSFET with a polysilicon gate to have a threshold voltage of V_T = -0.65 V. Assume an oxide thickness of t_ox = 300 A, a channel length of L = 1.25 mu m., and a nominal value of Q'_ss = 1.5 times 10^11 cm^-2. It is desired to have a drain current of I_D = 50 mu A at V_GS = 2.5 V and V_DS = 0.1 V. Determine the type of gate, substrate doping concentration, and channel width required