Title :
RF-Enhanced Contacts to Wide-Bandgap Devices
Author :
Simin, G. ; Yang, Z.-J.
Author_Institution :
Dept. of Electr. Eng., South Carolina Univ., Columbia, SC
Abstract :
This letter proposes a novel approach to fabricate high-performance heterostructure microwave devices with nonohmic contacts. The contact can be as-deposited or made by "shallow" low-temperature annealing to form a low-height Schottky barrier while preserving the two-dimensional electron-gas layer (2DEG) at the heterointerface. Coupling between the metal and the 2DEG occurs via two paths: dc current injects through the barrier leakage current and ac-current component injects through capacitive coupling. Contacts with resistive/capacitive coupling have low microwave impedance and enhance the heterostructure field-effect transistor\´s maximum oscillation frequency, output power, and power-added efficiency as compared to resistive ohmic contacts
Keywords :
high electron mobility transistors; microwave devices; ohmic contacts; wide band gap semiconductors; 2D electron-gas layer; RF-enhanced contacts; barrier leakage current; capacitive coupling; heterostructure field-effect transistor; high-performance heterostructure microwave devices; low microwave impedance; low-height Schottky barrier; nonohmic contacts; shallow low-temperature annealing; wide bandgap devices; Annealing; Contact resistance; Electrodes; HEMTs; Impedance; Leakage current; MODFETs; Microwave devices; Schottky barriers; Temperature; Contacts; HEMT; heterostructure field-effect transistor (HFET); heterostructures; microwave; wide bandgap;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2006.887627
