A depletion type N -channel MOSFET is biased in its linear region for use as a voltage controlled resistor. Assume threshold voltage V_TH = -0.5 V, V_GS = 2.0 V, V_DS = 5 V, W/L=100, C_OX=10^-8 F/cm² and $${\mu _n}$$ = 800 cm²/V-s. The value of the resistance of the voltage controlled resistor (in $$\Omega $$ ) is _____.

The small-signal resistance (i.e., $${{d{V_B}} \over {d{I_D}}}$$ ) in $$k\Omega $$ offered by the n-channel MOSFET M shown in the figure below, at bias point of V_B = 2V is (device data for M: device transconductance parameter

k_N = $${\mu _n}{C_{ox}^{'}}$$ (W/L)= 40$$\mu {\rm A}/{V^2},$$ threshold voltage V_TN=1V, and neglect body effect and channel length modulation effects)

In the three dimensional view of a silicon n-channel MOS transistor shown below, $$\delta = 20$$ nm. The transistor is of width 1 $$\mu m$$. The depletion width formed at every p-n junction is 10 nm. The relative permittivities of Si and SiO₂, respectively, are 11.7 and 3.9, and $${\varepsilon _0}$$ = 8.9 $$ \times {10^{ - 12}}$$ F/m.

The gate-source overlap capacitance is approximately

The source of a silicon (n_i = 10¹⁰ per cm³) n - channel MOS transistor has an aewa of 1 sq $$\mu m$$ and a depth of 1 $$\mu m$$ . If the dopant density in the source is 10¹⁹/cm³, the number of holes in the source region with the above volume is approximately