Reference no: EM13864411

1. MOS Band Diagrams. Consider four simple cases of the MOS capacitor, all combinations of low gate metal work function (e.g. Al qΦ_M ≈ 4.05 eV), high gate metal work function (e.g. Pt qΦ_M ≈ 5.15 eV), n+type silicon and p+type silicon substrate. Assume the substrate is highly doped, such that E_F coincides with E_C (n+) and E_V (p+) respectively. ThConsider four simple cases of the MOS capacitor, all combinations of low gate metal work function (e.g. Al qΦ_M ≈ 4.05 eV), high gate metal work function (e.g. Pt qΦ_M ≈ 5.15 eV), n+type silicon and p+type silicon substrate. e SiO₂ thickness is 2 nm. Please assume silicon electron affinity is qX_S = 4.05 eV and band gap is E_G = 1.1 eV.

(a) Sketch the four band diagrams across all MOS structures in equilibrium (V_G = 0 V).

(b) Sketch the four band diagrams exactly at threshold (V_G = V_T), as the surface is inverted. Is the threshold voltage V_T >0 or <0 in each case?