Semiconductor Device Modeling and Characterization EE5342, Lecture 7-Spring 2002. Professor Ronald L. Carter email@example.com http://www.uta.edu/ronc/. Ideal Junction Theory. Assumptions E x = 0 in the chg neutral reg. (CNR) MB statistics are applicable Neglect gen/rec in depl reg (DR)
Professor Ronald L. Carter
Ideal JunctionTheory (cont.)
Apply the Continuity Eqn in CNR
Forward Bias Energy Bands
Evaluating thediode current
Special cases forthe diode current
Js,p = qni2Dp coth(Wn/Lp)/(NdLp) = qni2Dp/(NdWn), Wn << Lp, “short” = qni2Dp/(NdLp), Wn >> Lp, “long”
Js,n = qni2Dn coth(Wp/Ln)/(NaLn) = qni2Dn/(NaWp), Wp << Ln, “short” = qni2Dn/(NaLn), Wp >> Ln, “long”
Js,n << Js,p when Na >> Nd
Diffnt’l, one-sided diode conductance
Static (steady-state) diode I-V characteristic
Charge distr in a (1-sided) short diode
Wn = xnc- xn
Charge distr in a 1-sided short diode
* Semiconductor Physics and Devices, 2nd ed., by Neamen, Irwin, Boston, 1997.
**Device Electronics for Integrated Circuits, 2nd ed., by Muller and Kamins, John Wiley, New York, 1986.
***Physics of Semiconductor Devices, Shur, Prentice-Hall, 1990.