Properties of MODFET's grown on Si substrates at dc and microwave frequencies
Abstract
The first microwave characterization of 1-micron gate GaAs/AlGaAs modulation-doped field-effect transistors (MODFET's) grown on Si substrates by MBE is reported. Maximum transconductances of 170 mS/mm at room temperature were obtained in structures on Si, which compares to values of 200-250 mS/mm for this type of structure on GaAs. At 77 K, no collapse was observed in these structures, and transconductances of 270 mS/mm were obtained. From microwave S-parameter measurements at room temperature, current gain cutoff frequencies of 15 GHz were obtained from these GaAs/AlGaAs MODFETs on Si, which compares with 12-15 GHz obtained on GaAs substrates. From high-frequency equivalent circuit modeling, very little difference was observed in any of the parameters between growth on Si and on GaAs. This is significant in that it demonstrates the suitability of GaAs on Si for device applications.
- Publication:
-
IEEE Transactions on Electron Devices
- Pub Date:
- October 1986
- DOI:
- 10.1109/T-ED.1986.22687
- Bibcode:
- 1986ITED...33.1407F
- Keywords:
-
- Direct Current;
- Electrical Properties;
- Field Effect Transistors;
- Microwave Frequencies;
- Molecular Beam Epitaxy;
- Silicon;
- Electric Current;
- Equivalent Circuits;
- Gallium Arsenides;
- High Frequencies;
- Short Circuit Currents;
- Transconductance;
- Volt-Ampere Characteristics;
- Electronics and Electrical Engineering