Electron Spin Resonance Analysis of Lattice Defects in Polycrystalline Aluminum Nitride

Abstract

Electron spin resonance was used in the present study to detect lattice defects in an aluminum nitride lattice. The ESR spectra were obtained from polycrystalline AlN with various thermal conductivities. Measurement of the AlN g values clearly indicated that the obtained ESR signals arose from electrons trapped by nitrogen vacancies. The ESR study revealed that thermal conductivity increases with an increase in the number of electrons trapped by nitrogen vacancies. The explanation for that phenomenon is that the thermal conductivity of AlN increases with a decreasing concentration of oxygen impurities incorporated into the AlN lattice, and the concentration of nitrogen vacancies changes inversely with the concentration of oxygen impurities.