Electrical characterization of wurtzite (Al,B)N thin films

Wurtzite aluminum nitride (w-AlN) thin films are of great interest for electro-acoustic applications and their material properties have in recent years been extensively studied. One way to tailor material properties is to vary the composition by adding other elements. Boron is an element that can take the place of aluminum in the crystal lattice of w-AlN. In the present study, polycrystalline w-(AI,B)N thin films were grown on p-Si(100) and Al/p-Si(100) substrates by pulsed DC reactive magnetron sputtering from a single Al/B target. MIS and MIM structures were fabricated to investigate the electrical properties of w-(AI,B)N thin films. Important dielectric thin film properties for microelectronics applications are the breakdown field, the permittivity (K) and leakage current through the film. The (AI,B)N thin film is found to have a dielectric strength of similar to 3 x 10(6) V cm(-1) and a kappa close to 12. The measured leakage current through the film is assumed to be mainly due to Frenkel-Poole emission with a trap energy at 0.71 eV below the conduction band edge. (C) 2011 Elsevier Ltd. All rights reserved.