Design and Development of MBE Grown AlGaN/GaN HEMT Devices on SiC Substrates for RF Applications
- PDF / 201,213 Bytes
- 10 Pages / 612 x 792 pts (letter) Page_size
- 33 Downloads / 242 Views
0892-FF13-12.1
Design and Development of MBE Grown AlGaN/ GaN HEMT Devices on SiC substrates for RF Applications Ashok K. Sood, Rajwinder Singh1 and Yash R. Puri2 Magnolia Optical Technologies, Inc. 52-B Cummings Park, Woburn, MA 01801 Frederick W. Clarke US Army Space and Missile Defense Command, Huntsville, AL, 35807 Amir Dabiran and Peter Chow SVT Associates, Inc. 7620 Executive drive, Eden Prairie, MN, 55344 Jie Deng and James C. M. Hwang Department of Electrical Engineering Lehigh University, 5 East Packer Avenue, Bethlehem, PA 18015 ABSTRACT GaN /AlGaN transistors are being developed for a variety of RF electronic and high temperature electronics applications that will replace GaAs and Silicon based devices and amplifiers for commercial and military applications. In this paper, we present GaN/AlGaN based HEMT device architecture with simulation and modeling results that includes AlN buffer layer followed by AlGaN layers on semi-insulating SiC substrates. The HEMT epitaxial layers were grown using RF Plasma Assisted MBE Technique. This approach has demonstrated very uniform epitaxial layers. Key to high quality HEMT structures is the ability to grow high quality AlN Buffer layer and AlGaN layers. Details of the electrical and optical characteristics of the HEMT epitaxial layers are presented. INTRODUCTION Al1-xGaxN-based hetero-structures have demonstrated versatility in RF electronic applications which is practically unmatched by any other material system. There are many device structures under consideration for RF and Power amplifiers (1). These include HEMT (High Electron Mobility Transistor), HFET (Hetero-structure Field Effect Transistor), MOSHFET (Metal Oxide Semiconductor Hetero-structure Field Effect Transistor) and MESFET (Metal Semiconductor Field Effect Transistors) ( 1,2,3,4). In this paper, we will discuss HEMT device design, modeling and growth and characterization of GaN/AlGaN based HEMT structures grown on SiC substrates by Molecular Beam Epitaxy (MBE). These devices offer significant advantages at the material technology level. The high saturation velocity of electrons in GaN, and low density of lattice defects in AlGaN/GaN epitaxial layers allows higher working voltages than any other material system. This, in turn, results in reduced transistor capacitance per watt of output power. The AlGaN/GaN HEMT structures also offer impedance much 1 2
Present Address: Intel Corporation, 2200 Mission College Blvd, Santa Clara, CA 95052 Also of COM, University of Massachusetts, Lowell, MA 01854
0892-FF13-12.2
closer to the industry-standard 50 Ω level, and consequently require much smaller additional effort at impedance matching. This, in turn, results in higher power added efficiency (PAE). EXPERIMENTAL DETAILS HEMT DEVICE DESIGN The HEMT device design shown in Figure 1 has the potential of significant improvements over the current device performance. Our approach takes advantage of growth of GaN and AlGaN layers using MBE technique on semi-insulating SiC substrates. Use of the SiC substrates and th
Data Loading...
