Thermal stability analysis of multiple emitter finger microwave AlGaAs/GaAs heterojunction bipolar transistors
- 30 December 2002
- conference paper
- Published by Institute of Electrical and Electronics Engineers (IEEE)
- No. 0149645X,p. 281-284
- https://doi.org/10.1109/mwsym.1993.276823
Abstract
A numerical electrothermal model for AlGaAs/GaAs heterojunction bipolar transistors (HBTs) has been developed, taking into account the nonuniform junction temperature rise due to self-heating. The model simulates both the DC current-voltage (I-V) characteristics and the microwave performance of multiemitter finger devices. The linear active region of the common-emitter I-V characteristics exhibits 'current crush', where the collector current rapidly decays with increasing collector voltage due to the formation of highly localized hot spots within the device. It is also shown that a rapid fall-off in the cut-off frequency and maximum frequency of oscillation occurs corresponding to the onset of this thermal instability. Methods of overcoming this instability using emitter ballast resistors and higher-thermal-conductivity substrates are discussed along with corresponding effects on the DC and microwave performance of the device.Keywords
This publication has 7 references indexed in Scilit:
- 12 W monolithic X-band HBT power amplifierPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2003
- Determination of junction temperature in AlGaAs/GaAs heterojunction bipolar transistors by electrical measurementIEEE Transactions on Electron Devices, 1992
- Numerical studies of thermal effects on heterojunction bipolar transistor current-voltage characteristics using one-dimensional simulationSolid-State Electronics, 1992
- A simplified model for the distributed base contact impedance in heterojunction bipolar transistorsSolid-State Electronics, 1992
- Thermal resistance measurements for AlGaAs/GaAs heterojunction bipolar transistorsIEEE Transactions on Electron Devices, 1991
- High power density pulsed X-band heterojunction bipolar transistorsElectronics Letters, 1991
- Thermal design studies of high-power heterojunction bipolar transistorsIEEE Transactions on Electron Devices, 1989