Characterization of defect levels in undoped n-BaSi2 epitaxial films on Si(111) by deep-level transient spectroscopy

Electrically active defect levels in 650-nm-thick undoped n-BaSi2 epitaxial layers grown by molecular beam epitaxy were investigated by deep-level transient spectroscopy (DLTS) using undoped n-BaSi2/p-Si heterojunction diodes. The layer structure was designed so that the depletion region extended toward the n-BaSi2 layers under reverse bias conditions. DLTS revealed the presence of majority-carrier (electron) traps located at approximately 0.1 and 0.2 eV below the bottom of the conduction band. The densities of these trap levels were approximately 1 x 10(15) cm(-3). Photoresponse spectra are also discussed in relation to these trap levels. Minority-carrier traps were not detected in this work. (C) 2015 The Japan Society of Applied Physics