What is the built in voltage for the source and drain

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Unformatted text preview: , J x B 0.762 ⋅ 0.25 from which the density and mobility may be found as n= 3. 1 1 = = 7.94 × 10 21 / m 3 = 7.94 × 1015 / cm 3 −4 −19 RH e 7.87 × 10 ⋅ 1.6 × 10 R 7.87 × 10 −4 µ = σ RH = H = = 0.75 m 2 / Vs = 7500 cm 2 / Vs ρ 10.5 × 10 −4 . The drain contact of a MOSFET at 300 K is doped with ND = NE = 7x1019 cm- 3 and the channel/body of the device is doped with NA = 5 x 1017 cm- 3. What is the built- in voltage for the source and drain p- n junctions? What is the width of this junction? The built- in voltage is determined by the doping and the intrinsic concentration as ⎛ 7 × 1019 ⋅ 5 × 1017 ⎞ kBT ⎛ N D N A ⎞ Vbi = ln ⎜ = 0.0259 ln ⎜ = 1.025 e ⎝ (1.5 × 1010 )2 ⎟ ⎠ ⎝ ni2 ⎟ ⎠ We find the width from 4. W= 2ε sVbi ⎛ N a + N d ⎞ = 52 nm . e ⎜ Na Nd ⎟ ⎝ ⎠ In the MOSFET of problem 3, the oxide thickness is 1.5 nm, oxide d...
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This document was uploaded on 01/28/2014.

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