midterm BJT

# Midterm BJT - p = 10 cm 2/s ± Excess minority carrier lifetime τ n0 = τ p0 = τ = 1 × 10-7 s ± Dielectric constant ε = 12 Problem 2 Find N A

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ESE 512 Midterm exam 03/10/2008 Prof. Gorfinkel Student's Name_______________________ ID #____________________________ 10 3 2 2 16 3 ( ), 1.5 10 / cm , 0.1 / , 0.03 / , Na=5x10 / cm , 7 cm. np i n p qn p n m Vs m Vs σμ μ ρ =+ = × = = = Ω Problem 1 Consider a Silicon pn junction at T = 300K under the reverse bias of 5V. Calculate following: 1. The built-in potential (plot as function of x) 2. The depletion region width W 3. The saturation current J S Assume that the pn junction has the following parameters: ± The cross-sectional area A = 2x10 -3 cm 2 ± Acceptor concentration in the p-type region N a = 10 16 cm -3 ± Donor concentration in the n-type region N d = 3 × 10 16 cm -3 ± Diffusion coefficient for electrons D n = 20 cm 2 /s ± Diffusion coefficient for holes D
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Unformatted text preview: p = 10 cm 2 /s ± Excess minority carrier lifetime τ n0 = τ p0 = τ = 1 × 10-7 s ± Dielectric constant ε = 12 Problem 2 Find N A in Si at T=300K if: Problem 3 Si sample in thermal equilibrium, T=300K, n i =10 10 cm-3 . Problem 4 Consider a Si p+-n-n+ diode. The measured dependence of 1/C 2 versus applied voltage is shown in the figure. Find the built-in voltage, the concentrations in the p+ and n regions and the width W of the n region. The diode area is 10-3 cm 2 . -3-3 3 Plot and as function of cm < < cm for =5x cm 14 17 15 10 10 10 / . n p Nd Na 2 4 6 -6 -5 -4 -3 -2 -1 0 1 2 p+ n n+ W 1/C 2 , x10 29 F-2...
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## This note was uploaded on 04/11/2008 for the course EE 571,558, taught by Professor Jacob,rao,chi during the Spring '08 term at SUNY Stony Brook.

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