Low-frequency noise-reliability correlation and noise, power characteristics of gallium arsenide HBTs and high-speed integrated circuits.
Mohammadi, Saeed
2000
Abstract
AlGaAs/GaAs HBTs with similar DC and microwave performance and different low-frequency noise and reliability characteristics were studied. The low-frequency base noise was correlated to the HBT long term reliability, due to the fact that both base noise and degradation mechanisms had the same origin. The HBTs with high degree of reliability showed a record high lifetime of 10<super> 9</super> hours at 120°<italic>C</italic> junction temperature, while their base noise showed a minimum of 3 x 10<super>-20</super>A<super> 2</super>/Hz at 10Hz, which is the lowest reported value for AlGaAs/GaAs devices. Next, a general theory for low-frequency noise in semiconductor devices was developed, which can explain any measured noise characteristics that could not be explained with previous noise theories. This theory suggests that the low-frequency noise is an integral of many carrier trapping and de-trapping from a continuum of traps within the bandgap, of the semiconductor. The presented theory, unlike previous theories, does not require a specific lifetime probability function and can explain high lifetime values required for 1/f noise characteristics observed at very small frequencies. CBE grown GaInP/GaAs HBTs developed at the University of Michigan were characterized and modeled using a high-frequency noise model developed here. A minimum noise figure of 2.65dB with an associated gain of 12.5dB, at 8GHz was achieved for optimum geometry (2 x 30mum<super>2</super>) HBT. Analysis of the model showed the importance of base and emitter access resistances, shot noise sources and base-emitter incremental resistance on high-frequency noise. The same devices were also studied for their power and linearity characteristics, and showed the highest reported output power density of 3.48mW/mum<super> 2</super> for GaInP/GaAs HBTs. Furthermore, a 10 finger 2 x 20mum<super> 2</super> HBT achieved 1.08Watt CW output power at 8GHz. The GaInP/GaAs HBTs were also used in microwave monolithic amplifiers. A high-gain dual-feedback amplifier with a gain of 18.8dB and a bandwidth of 13.5GHz achieved the highest reported gain-bandwidth product among GaAs based HBT amplifiers. Moreover the design methodology of high gain HBT distributed amplifiers was investigated and showed the importance of base and collector resistances on amplifier gain. Based on the results, a 3-stage attenuation-compensated distributed amplifier with a gain of 12.7dB over a bandwidth of 27.5GHz was fabricated and tested.Subjects
Characteristics Frequency Gaas Gallium Arsenide Hbts Heterojunction Bipolar Transistors High Integrated Circuits Low Noise-reliability Correlation Power Semiconductor Speed
Types
Thesis
Metadata
Show full item recordCollections
Remediation of Harmful Language
The University of Michigan Library aims to describe library materials in a way that respects the people and communities who create, use, and are represented in our collections. Report harmful or offensive language in catalog records, finding aids, or elsewhere in our collections anonymously through our metadata feedback form. More information at Remediation of Harmful Language.
Accessibility
If you are unable to use this file in its current format, please select the Contact Us link and we can modify it to make it more accessible to you.