Thermally stable ZrN/Zr/n-GaN ohmic contacts

Thermally stable ZrN(200 nm)/Zr (5nm)/n-GaN ohmic contacts are reported. Sp ecific contact resistances as low as 2 x 10(-5) Omega cm(2) are obtained af ter annealing in Ar at 1100 degrees C for 1 min. Compared to previously rep orted TiN(200 nm)/Ti (5 nm)/n-GaN contacts, higher annealing temperatures a re required to achieve ohmic behavior. This observation is attributed to sl ower reaction kinetics between Zr and GaN compared to Ti and GaN, as reveal ed by X-ray photoelectron spectroscopy depth profiles of annealed Zr/n-GaN and Ti/n-GaN contacts. The ZrN/Zr/n-GaN contacts exhibit excellent thermal stability during aging in evacuated quartz tubes at 600 degrees C for 1000 h. (C) 1999 The Electrochemical Society. S1099-0062(98)10-095-0. All rights reserved.