Title :
An analysis of small-signal and large-signal base resistances for submicrometer BJT´s
Author :
Fuse, Tsuneaki ; Sasaki, Yoko
Author_Institution :
ULSI Res. Center, Toshiba Corp., Kawasaki, Japan
fDate :
3/1/1995 12:00:00 AM
Abstract :
Small-signal and large-signal base resistances for submicrometer BJT´s have been analyzed in detail by using a two-dimensional device simulator. It has been clarified that the small-signal base resistance cannot be obtained from the input impedance semicircle in the complex plane accurately due to the effect of the emitter resistance at low frequencies, and also due to the reduction of the base-emitter junction resistance and the diffusion capacitance at high frequencies. A new method for extracting an accurate value of the small-signal base resistance is proposed. The extracted small-signal base resistance not only differed from the large-signal base resistance extracted from the dc characteristics of a BJT, but also agreed with the differential resistance. It has been shown that, for a 0.6 μm emitter-width BJT, the measured value of the small-signal base resistance is less than half that of the large-signal base resistance in the bias region in which actual BJT circuits operate
Keywords :
bipolar transistors; semiconductor device models; 0.6 micron; DC characteristics; base-emitter junction resistance; complex plane; differential resistance; diffusion capacitance; emitter resistance; input impedance semicircle; large-signal base resistances; small-signal base resistances; submicrometer BJTs; two-dimensional device simulator; Analytical models; Bipolar transistor circuits; Capacitance; Data mining; Electrical resistance measurement; Frequency; Fuses; Helium; Impedance; Voltage;
Journal_Title :
Electron Devices, IEEE Transactions on
