Bias dependence and light sensitivity of (Al, Ga)As/GaAs MODFET's at 77 K
Abstract
Modulation doped field-effect transistors typically show a threshold-voltage shift of about 0.2 V at 77 K with respect to room temperature. An investigation of the characteristics of Al(0.33)Ga(0.67)As/GaAs and Al(0.24)Ga(0.76)As/GaAs MODFETs confirms that the low temperature performance of these devices is affected by the presence of persistent photoconductive traps in the bulk (Al, Ga)As and the properties of the surface, both of which depend strongly on the Al mole fraction and the growth conditions. Al(0.33)Ga(0.67)As/GaAs MODFETs grown at 610 C show a threshold voltage shift of less than 0.05 V at 77 K with respect to room temperature, and little sensitivity of the current-voltage characteristics on illumination and on bias condition, indicating that by proper control of the growth parameters it is possible to obtain high quality (Al, Ga)As/GaAs MODFETs suitable for operation 77 K.
- Publication:
-
IEEE Transactions on Electron Devices
- Pub Date:
- December 1983
- DOI:
- 10.1109/T-ED.1983.21449
- Bibcode:
- 1983ITED...30.1806D
- Keywords:
-
- Field Effect Transistors;
- Gallium Arsenides;
- Heterojunction Devices;
- Photosensitivity;
- Volt-Ampere Characteristics;
- Aluminum Gallium Arsenides;
- Bias;
- Crystal Growth;
- Doped Crystals;
- Energy Bands;
- Fabrication;
- Modulation;
- Room Temperature;
- Threshold Voltage;
- Thresholds;
- Electronics and Electrical Engineering