Lecture Notes_20-22_MOS_2014

this slide is a slightly different variation of

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Unformatted text preview: is negative in our example, we reach flat band. For simplicity, we consider only a sheet of fixed positive oxide charges, Qo in the top diagrams (equivalent to our Qss’ above). Because of the large positive oxide charges, the metal gate bias has to be negative in this example. Then the electric field profile is shown in the bottom. Note that the electric field direction is from positive to negative charge. The discontinuity of the electric field at the oxide- semiconductor interface is because it is the displacement field (dielectric constant Κεo times the electric field ε). Since the dielectric constant of the oxide is smaller than that of the semiconductor, the electric field in the oxide is larger than that in the semiconductor. Ks = 11.8 for Si and Kox = 3.9 for SiO2. εo i...
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