Gate Current Modeling for Insulating Gate III-N Heterostructure Field-Effect Transistors
- PDF / 214,466 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 92 Downloads / 189 Views
L9.10.1
Gate Current Modeling for Insulating Gate III-N Heterostructure Field-Effect Transistors Frederick W. Clarke 1, Fat Duen Ho2, M. Asif Khan3, Grigory Simin3, J. Yang3, Remis Gaska4, Michael S. Shur5, Jianyu Deng4, S. Karmalkar6 1
U.S. Army Space and Missile Defense Command Technical Center, Huntsville, AL. Department of Electrical and Computer Engineering, University of Alabama in Huntsville 3 Department of Electrical Engineering, University of South Carolina 4 Sensor Electronic Technology Inc., Columbia, SC 29209 5 Broadband Center and ECSE Department, Rensselaer Polytechnic Institute, Troy, NY 12180 6 Department of Electrical Engineering, Indian Institute of Technology, Madras, India 2
Index Terms—Modeling, AlGaN, FET, GaN, HFET, MOSHFET, MISHFET, leakage, gate current Abstract: Gate current plays an important role in determining the characteristics and limiting performance of GaN-based field effect transistors. In GaN-based HFETs, the gate current limits the gate voltage swing and, hence, the maximum device current. Since the electron transport across the wide band gap barrier layer involves trapping, under certain bias conditions, the gate current leads to the threshold voltage shifts and causes reliability problems. Under reverse bias, the gate leakage in GaN-based HFET dominates the minimum (pinch-off) drain current. Insulating gate HFETs (i.e. Metal Oxide Heterostructure Field Effect Transistors – MOSHFETs) have the gate leakage currents 4 – 6 orders of magnitude lower than HFETs, even at elevated temperatures up to 300 °C. In this paper, we report on the gate current characteristics in these devices at room and elevated temperatures. We propose a semi-empirical model for the currentvoltage characteristics in these devices, which is in good agreement with experimental data. Our data also show that both tunneling and temperature activation are important factors in MOSHFETs. These results are important for possible applications of GaN MOSHFETs in high power amplifiers and power switches as well as in non-volatile memory devices and integrated circuits that will operate in a much wider temperature range than conventional silicon and GaAs devices.
L9.10.2
Introduction: With the successful growth of high quality insulators such as SiO2 and Si3N4 over AlGaN barrier, MISHFETs and MOSHFETs have emerged as a beneficial addition to modern GaNbased transistor technology1. The low interface charge density at insulator/semiconductor interface makes these devices operate using the same principle as AlGaN/GaN HFETs while enjoying higher dynamic range and much lower gate current, which come from better gate isolation. The gate current is a good indicator of the insulator quality and interface surface charge density. Gate leakage current determines the dynamic operation regime for microwave power transistors. MOSHFETs have larger dynamic range than conventional HFET and often can operate at large forward gate bias (>+5V) with a drain-source current increase up to fifty percent. 2 Lower gate leakage current also p
Data Loading...
