AVS 51st International Symposium
    Semiconductors Monday Sessions
       Session SC+MI-MoM

Paper SC+MI-MoM4
Thermal Stability of GaCrN Epitaxial Layers

Monday, November 15, 2004, 9:20 am, Room 304B

Session: Dilute Magnetic and Ferromagnetic Semiconductors
Presenter: G.T. Thaler, University of Florida
Authors: G.T. Thaler, University of Florida
R.M. Frazier, University of Florida
C.R. Abernathy, University of Florida
S.J. Pearton, University of Florida
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A number of recent studies have reported the observation of room temperature ferromagnetism in GaMnN. However, this material appears to be thermally unstable during processing at temperatures as low as 500°C unless co-doped with oxygen. For the development of spintronics devices based on GaN, thermal annealing at or above ~700°C is necessary to improve contact resistances and for p-dopant activation. An alternative material that has received some interest of late is GaCrN, which has also been reported to be ferromagnetic at room temperature. However, little is known as yet about the thermal stability of this material and its suitability for integration with GaN device processing technology. In this talk we will discuss the thermal stability of GaCrN and the effect of Cr concentration on both the as-grown magnetic behavior and the magnetic properties as a function of annealing. Epitaxial growth was performed using Gas Source Molecular Beam Epitaxy. Films with magnetic transition temperatures above room temperature were produced for a variety of Cr concentrations, though the signal appeared to maximize around 2-3% Cr, as is the case for GaMnN. Unlike GaMnN, the addition of Cr to GaN produced material that was thermally stable after annealing up to 700°C with little change observed in the magnetic behavior of the GaCrN films. The implications of this stability for device processing and performance will also be discussed. This work was supported by the Army Research office under: ARO-DAAD19-01-1-0701 and by NSF under: ECS-0224203.