AlGaN/GaN High Electron Mobility Transistors on Si/SiO 2 /poly-SiC Substrates
- PDF / 1,636,000 Bytes
- 9 Pages / 612 x 792 pts (letter) Page_size
- 62 Downloads / 225 Views
0955-I16-02
AlGaN/GaN High Electron Mobility Transistors on Si/SiO2/poly-SiC Substrates Travis Anderson1, Fan Ren1, Lars Voss2, Mark Hlad2, Brent P Gila2, Stephen Pearton2, Lance Covert3, Jenshan Lin3, Julien Thuret4, H Lahreche4, and P Bove4 1 Chemical Engineering, University of Florida, PO Box 116005, Gainesville, FL, 32611 2 Materials Science and Engineering, University of Florida, PO Box 116400, Gainesville, FL, 32611 3 Electrical and Computer Engineering, University of Florida, PO Box 116130, Gainesville, FL, 32611 4 Picogiga International SAS, Place Marcel Rebuffat, Parc de Villejust, 91971, Courtaboeuf, France
ABSTRACT The dc and rf performance of AlGaN/GaN High Electron Mobility Transistors (HEMTs) grown by Molecular Beam Epitaxy on Si-on-poly (SopSiC) substrates is reported. The HEMT structure incorporated a 7 period GaN/AlN superlattice between the AlGaN barrier and GaN channel for improved carrier confinement. The knee voltage of devices with 2 µm gatedrain spacing was 2.12 V and increased to 3 V at 8 µm spacing. The maximum frequency of oscillation, fMAX, was ~40 GHz for devices with 0.5 µm gate length and 2 µm gate-drain spacing. Parameter extraction from the measured rf characteristics showed a maximum intrinsic transconductance of 143 mS.mm-1. INTRODUCTION GaN and related alloys are typically grown on either sapphire or SiC substrates. The GaN has a significant lattice mismatch with both types of substrates, leading to a high density of threading dislocations in the nitride layer. The use of SiC substrates is preferred for electronic devices such as High Electron Mobility Transistors (HEMTs) because of the superior thermal conductivity, leading to less device self-heating and improved reliability and operating stability. AlGaN/GaN high electron mobility transistors (HEMTs) grown on SiC substrates are very promising for high power, high temperature commercial applications in telecommunications, hybrid electric vehicles, power flow control and remote sensing. GaN-based electronics is in the initial stages of commercialization for power amplifiers dedicated to next generation wireless infrastructures, including World Interoperability for Microwave Access (WiMAX) base stations, and also for hybrid electric vehicles, power flow control and defense applications (1-10). In particular, the WiMAX market requires demanding combinations of power, efficiency, frequency (typically 2.3-2.9 GHz and 3.3-3.8 GHz) and bandwidth that are beyond the specifications of existing GaAs and Si devices. GaN-on-silicon field-effect transistor technology enables base station equipment manufacturers to optimize bandwidth, power and efficiency at attractive sizes and costs (9,11-15). The use of 100mm silicon wafers allows scaling to produce statistically significant reliability data, to use proven packages from the silicon industry and to quickly scale-up volume production. However, SiC substrates
would be preferred because of their superior thermal conductivity but the cost of large area single-crystal SiC is prohibitive. The
Data Loading...
