Title :
Measurement of base and collector transit times in thin-base InGaAs/InP HBT
Author :
Kahn, M. ; Blayac, S. ; Riet, M. ; Berdaguer, Ph ; Dhalluin, V. ; Alexandre, F. ; Godin, J.
Author_Institution :
R&I/Opto+, Alcatel, Marcoussis, France
fDate :
7/1/2003 12:00:00 AM
Abstract :
The influence of base thickness reduction on performances of heterojunction bipolar transistors (HBTs) is examined. HBT structures are grown, with a base thickness in the range 25-65 nm and doping concentration from 3/spl times/10/sup 19/ to 6/spl times/10/sup 19/ at/cm/sup 3/. Base transit time is accurately extracted from total base-collector transit time, and described using a simple drift-diffusion approach. This model, however basic, shows very good agreement with measurements when usual parameter values are used. A 0.13-ps transit time reduction is measured when thinning the base from 65 to 25 nm. The thinnest base structure presents a 0.08 ps transit time, allowing a 250 GHz f/sub t/ operation at 270 kA/cm/sup 2/ emitter current density.
Keywords :
III-V semiconductors; gallium arsenide; heterojunction bipolar transistors; indium compounds; 25 to 65 nm; 250 GHz; InGaAs-InP; InGaAs/InP HBT; base transit time; collector transit time; current density; doping concentration; drift-diffusion model; thin-base heterojunction bipolar transistor; Current density; Doping; Electrical resistance measurement; Heterojunction bipolar transistors; Indium gallium arsenide; Indium phosphide; Molecular beam epitaxial growth; Semiconductor process modeling; Time measurement; Transmission line measurements;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2003.815005
