Electrical and structural characterizations of BGaN thin films grown by metal-organic vapor-phase epitaxy

In this report, the electrical and structural properties of BGaN thin films, with boron composition up to 2%, have been investigated. The resistivity, Hall mobility and carrier concentration were measured by the van der Pauw/Hall Effect technique, using annealed indium ohmic contacts. The current‐voltage measurements between two planar gold and titanium/aluminum electrodes were performed. To analyze the structural properties, the polarized Raman spectra were measured with a micro‐Raman spectrometer. The resistivity displays a strong increase with respect to the boron composition in BGaN alloy, directly related to the decrease of the n‐type carrier concentration, while the mobility increases with boron content, well correlated to the structural measurements showing a good crystalline quality of the BGaN layers. This boron‐controlled resistivity is very promising for using the BGaN based materials in microelectronic and optoelectronic devices. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)