Solid-State Electronics Vol. 35, No. 6, pp. 821-827, 1992 0038-1101/'92 $5.00 + 0.00 Printed in Great Britain. All rights reserved Copyright © 1992 Pergamon Press Ltd ANALYTICAL MODEL FOR GaAs PIN DIODES FOR A WIDE RANGE OF CURRENTS AND TEMPERATURES S. BELLONE, l G. COCORULLO, 2 F. G. DELLA CORTE, 2 H. L. HARTNAGEL 3 and G. SCHWL~GEg 3 )Department of Electronic Engineering, University of Naples, Italy 2CNR-IRECE, Naples, Italy 3Institut ffir Hochfrequenztechnik, TH Darmstadt, Fed. Rep. Germany (Received 25 March 1991; in revised form 2 July 1991) Abstract--An analytical model is proposed which can describe the I-V characteristics of a GaAs pin diode in a wide range of currents from room temperature up to 220°C and above. Be + implanted test diodes with low leakage current have been produced. Good agreement was found between experimental and theoretical I-V plots over the full range of currents and temperatures. It is shown for good-quality diodes which current components are dominant for different operating conditions. NOTATION D^ ambipolar diffusion constant in the base (cm2 s-~) D. electron diffusion constant in the base (cm 2 s -z) D,~ electron diffusion constant in p+ (cm2 s-z) Dp hole diffusion constant in the base (cm2 s-~) D~ hole diffusion constant in n + (cm 2 s-i) E electric field (Vcm -z) Ev Fermi level (eV) E i Fermi level in intrinsic material (eV) Er recombination centre energy level (eV) J total current density (Acm -2) J~ recombination current density into the neutral re- gion of the base (Acm -2) Jn electron current density (Acm -2) J~ electron current density into the p + region (A cm-2) Jp hole current density (A cm -2) J~ recombination current density into p +-n depletion layer (A cm -2) "/sub hole current density into the n + region (Acm -2) L ambipolar diffusion length in the base (#m) L~ electron diffusion length in the p + region (#m) Lp, hole diffusion length in the n + region (#m) N~ acceptor concentration in the p + region (cm -3) Nd donor concentration in the base (cm -3) Nd~ donor concentration in the n + region (cm -3) n electron concentration (cm -3) n~ electron concentration in the conduction band, when ET = EF (cm -3) n~ intrinsic carrier concentration (cm -3) q electron charge (A.s) p hole concentration (cm -3) p~ hole concentration in the valence band, when Fir = EF (cm -3) P~0 equilibrium hole concentration in the base (cm -3) SN recombination velocity of the n + region (cms -z) Se recombination velocity of the p + region (cm s -~) Urn, maximum recombination rate in the p +-n depletion region (s -I cm -3) U, SHR generation-recombination rate (s -~ cm -3) V applied voltage (V) V0 built-in voltage of the p +-n junction (V) V b voltage drop across the neutral region of the base (V) V~, voltage drop across the n-n + junction (V) voltage drop across the p +-n junction (V) I~t thermal voltage (V) w base width (#m) we p+ region width (#m) w~c p+--n depletion region width Cum) A Vg effective bandgap narrowing (eV) A V n effective bandgap narrowing in the n + region (eV) A Vp effective bandgap narrowing in the p + region (eV) E dielectric constant (F cm-~) ~0 vacuum dielectric constant (F cm-~) ~r specific dielectric constant ~A ambipolar lifetime in the base (s) % electron lifetime (s) ~o electron lifetime in the base (s) ~p hole lifetime (s) Tpo hole lifetime in the base (s) /~, electron mobility in the base (cn'I2'V -I s -I) #r hole mobility in the base (cm2.V -z s -z) i. INTRODUCTION Pin diode structures are widely used in all fields of electronics, for low- as well as high-frequency appli- cations both in the low- and high-power regimes. Most of the pin devices produced today are Si-made devices, but high-frequency applications call more and more for GaAs devices. Moreover, increasing interest towards high-temperature applications re- quires extensive use of suitable III-V compound semiconductors showing an intrinsic carrier concen- tration several orders of magnitude smaller than the one of Si. From this point of view, an accurate though simple analytical description of the GaAs pin diode I-V characteristics, valid at any injection level and over a wide temperature range as required for high- temperature applications could be of great interest. As far as we know, such kind of thermal analysis for GaAs pin diodes has not been published until now. Recently published papers[l,2] fail in describing pin diode characteristics over a wider range of cur- rents because, in one case only, phenomena in the high-injection regime are discussed, while in the other case experimental structures showed an anomalously 821