Heterojunction vertical FET's revisited - Potential for 225-GHz large-current operation
Abstract
High-speed operation of submicrometer Al(x)Ga(1-x)As/GaAs unipolar heterojunction transistors is examined using two-dimensional time-dependent self-consistent ensemble Monte Carlo simulation. Careful device design can significantly increase ballistic injection over the heterojunction in steady state by eliminating retarding gate-induced space-charge reversal there. Design for optimal large-signal transient operation must also avoid gate-voltage-dependent ballistic injection. General design principles for optimizing high-speed operation are proposed. The resulting VFET's show cutoff frequencies of 225 GHz at large drain currents at 300 K, with frequency-independent two-port y parameters.
- Publication:
-
IEEE Transactions on Electron Devices
- Pub Date:
- May 1992
- DOI:
- 10.1109/16.129081
- Bibcode:
- 1992ITED...39.1050W
- Keywords:
-
- Aluminum Gallium Arsenides;
- Field Effect Transistors;
- Heterojunction Devices;
- Carrier Injection;
- Monte Carlo Method;
- Optimization;
- Radio Frequencies;
- Transconductance;
- Electronics and Electrical Engineering