Stability of carbon and beryllium-doped base GaAs/AlGaAs heterojunction bipolar transistors

GaAs/AlGaAs heterojunction bipolar transitors (HBTs) utilizing highly Be-doped base layers display a rapid degradation of dc current gain and junction ideality factors during bias application at elevated temperature. For example, the gain of a 2×10 μm2 device with a 4×1019 cm−3 Be-doped base layer o...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Applied physics letters 1991-12, Vol.59 (27), p.3613-3615
Hauptverfasser: REN, F, FULLOWAN, T. R, LOTHIAN, J, WISK, P. W, ABERNATHY, C. R, KOPF, R. F, EMERSON, A. B, DOWNEY, S. W, PEARTON, S. J
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:GaAs/AlGaAs heterojunction bipolar transitors (HBTs) utilizing highly Be-doped base layers display a rapid degradation of dc current gain and junction ideality factors during bias application at elevated temperature. For example, the gain of a 2×10 μm2 device with a 4×1019 cm−3 Be-doped base layer operated at 200 °C with a collector current of 2.5×104 A cm−2 falls from 16 to 1.5 within 2 h. Both the base emitter and base collector junction ideality factors also rise rapidly during device operation, and this current-induced degradation is consistent with recombination-enhanced diffusion of Be interstitials producing graded junctions. By sharp contrast, devices with highly C-doped (p=7×1019 cm−3) base layers operated under the same conditions show no measurable degradation over much longer periods (12 h). This high degree of stability is most likely a result of the fact that C occupies the As sublattice, rather than the Ga sublattice as in the case of Be, and also has a higher solubility than Be. The effect of nearby implant isolated regions in promoting Be diffusion is also reported.
ISSN:0003-6951
1077-3118
DOI:10.1063/1.105623