Nonuniformly doped gallium arsenide microwave power MESFETs
Abstract
Nonuniform doping profile GaAS microwave power metallized semiconductor field effect transistors (MESFET) structures were investigated to explore the effects of various doping profiles on device charcteristics. Using molecular beam epitaxial materials, microwave power MESFETs with exponential, impulse, delta function as well as uniform doping profiles were fabricated. Device characteristics were examined at DC as well as at microwave frequencies. The nonuniformly doped MESFETs were found to have inferior field distribution which lead to smaller drain current capability. The drain-source burnout voltage was not affected, however, provided the full channel current was properly chosen. Burnout voltage of 45 volts was routinely obtained independent of the doping profile. graded doping profiles were found to be most effective in improving a MESFET's linearlity when the operating power level was well below the saturated power of the device. At large signal application, the advantage was significantly smaller. Hence the graded doping profile FETs are most useful for very linear operation but less so for the applications where larger power is more important than the linearity.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1981
- Bibcode:
- 1981PhDT........19J
- Keywords:
-
- Doped Crystals;
- Electrical Properties;
- Field Effect Transistors;
- Gallium Arsenides;
- Microwave Frequencies;
- Delta Function;
- Intermodulation;
- Linearity;
- Metallizing;
- Molecular Beam Epitaxy;
- Electronics and Electrical Engineering