Abstract
The impact of mechanical uniaxial stress on the characteristics of SiGe heterojunction bipolar transistors is reported. A four-point bending apparatus was used to apply a uniaxial stress in the range of . Due to the strain-induced modulation of carrier mobility and energy bandgap, the changes in the collector current , base current , current gain , and breakdown voltage are related to the strain-polarity. The strain-polarity dependence of the collector current was found to oppose that of the breakdown voltage , revealing a trade-off between uniaxial compressive and tensile stress. The response of the cutoff frequency under uniaxial stress was also investigated. Unlike the obvious changes of dc characteristics, a minor change in the maximum could be found for uniaxial stress levels below . Finally, various components of the transit time are analyzed to assess their contribution to the frequency response.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call