Electronic devices and integrated circuits have performance limits that are frequently set by the maximum allowable current density, voltage/electric field, and channel (or junction) temperature.
Self-heating of these devices is undesirable as it reduces performance and lifetime. The channel temperature Tc is correlated with the device lifetime through the Arrhenius equation and may be determined through simulations, theoretical models, or experimentally.
Channel temperature directly affects the bandgap, electron mobility, electron saturation speed, pinch-off voltage, breakdown voltage, transconductance, saturation current, output power, and noise performance. Transistor heating is a primary cause of memory effects which degrade linearity of power amplifiers, especially for modulated signals.
Conventional thermal management approaches such as increasing gate-pitch dimension, result in larger device size and performance degradation, especially at millimeter-wave frequencies.
To address heating issues in transistors, Army scientists and engineers have developed a distributed heating transistor with heat-generating regions separated into several active and inactive sections, thereby reducing self-heating. This novel design may be incorporated into field effector transistors (FETs), bipolar junction transistors (BJTs).
Simulations and experimental verification indicate a significant heat reduction as a result of these structures leading to improvements in device performance.
- Improved thermal characteristics leading to better performance
- The overall area of the device increases only slightly
- US patent 8,912,577 available for license