-gate material is p+ polycrystalline-silicon (work function O-5.2 eV); -substrate is n-type Si, with doping concentration 3x10¹7 cm²; -oxide thickness x,-2 nm. (a) What is the flat-band voltage, VB, of this capacitor? (b) What is the threshold voltage, VT, of the MOS capacitor? (c) What is the maximum width of the depletion region, WT? (d) how your answers to part (a) ( give quantitative answer) would change if the substrate doping No were to be decreased to 5x100 cm³. (e) how your answers to part (a) would change (give quantitative answer) if the oxide thickness x, were to be increased to 3 nm.