The New Equations of p-n Junction Carrier Injection Level

A Baskys,M Sapurov,R Zubavicius

doi:10.5755/j01.eee.19.2.3467

Abstract

The new equations of minority carrier hole and electron injection levels kp and kn valid at high-level injection have been derived. They relate the kp and kn and the voltage drop across the p-n junction depletion region Ud. At low Ud, i.e. at low-level injection the obtained equations coincide with well known exponential equations of injection level. However, at high-level injection when Ud becomes high and is close to the potential barrier of junction, the derived equations give increased steepness of kp and kn dependence on Ud as compared with the exponential law. The dependences of kp and kn of concrete silicon p-n junctions with different impurity concentrations have been analyzed using derived equations of injection level.DOI: http://dx.doi.org/10.5755/j01.eee.19.2.3467

Highlights

The p-n junction is still the basic building block of many semiconductor devices
If injection level is low the voltage drop across the quasi-neutral regions of the p-n junction can be neglected and exponential (Shockley) equation-based models can be used for simulation
If injection level is high, the operating conditions of p-n junction are changed greatly and more complex models should be used for adequate simulation of such devices

Summary

INTRODUCTION

The p-n junction is still the basic building block of many semiconductor devices. The parameter, which indicates the operating conditions of forward biased p-n junction, is injection level of minority carriers. If injection level is high, the operating conditions of p-n junction are changed greatly and more complex models should be used for adequate simulation of such devices. Equilibrium majority carrier concentration of real pn junctions is very close to concentration of impurity, the injection level of holes and electrons kp and kn can be presented as follows:. The junctions of the semiconductor devices especially those used in the integrated circuits and power semiconductor devices operate at high-level injection of minority carriers. Because of this it is of interest to relate the injection level of minority carriers with Ud for case of highlevel injection

THE EQUATIONS OF INJECTION LEVEL VALID AT ARBITRARY INJECTION

ANALYSIS OF CONCRETE P-N JUNCTIONS

CONCLUSIONS