Title :
Slow transients in polyimide-passivated InP-InGaAs HBTs: effects of UV irradiation, thermal annealing and electrical stress
Author :
Ng, Chai-Wah ; Wang, Hong
Author_Institution :
Microelectron. Centre, Nanyang Technol. Univ., Singapore, Singapore
Abstract :
The effects of UV irradiation, thermal annealing and electrical bias on the base current instability in polyimide (PI)-passivated InP-based heterojunction bipolar transistors (HBTs) have been studied. The base current transient could be effectively suppressed by UV irradiation. The suppression of current transient by UV irradiation can be attributed to the reduction of the near interface trap density in the PI, which has long-term stability at room temperature. However, baking the device at a temperature higher than 100 °C may induce a significant increase in PI trap density as well as the broadening of spatial electron trap distribution causing the enhancement of current transient, and the current transient induced by electrical stress could be directly related to the device self-heating through thermal annealing effect.
Keywords :
III-V semiconductors; annealing; heterojunction bipolar transistors; indium compounds; stress effects; transients; ultraviolet radiation effects; InP-InGaAs; PI trap density; UV irradiation effects; base current instability; base current transient; charge carrier process; current transient enhancement; current transient suppression; electrical stress effects; heterojunction bipolar transistors; near interface trap density; polyimide-passivated InP-lnGaAs HBT; slow transients; spatial electron trap distribution; thermal annealing effects; trap density reduction; Annealing; Electron traps; Heterojunction bipolar transistors; Indium gallium arsenide; Indium phosphide; Passivation; Plasma temperature; Polyimides; Stability; Thermal stresses; Charge carrier process; HBTs; InP; heterojunction bipolar transistors; indium phosphide; interface trap; passivation; polyimide PI;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2004.832866
