title: Electron-beam-induced-current investigation of GaN/AlGaN/Si heterostructures using scanning transmission electron microscopy.
abstract: An electron-beam-induced-current technique has been applied to scanning transmission electron microscopy to characterize GaN/AlGaN/n-Si heterostructures. The structure was formed by metalorganic vapor phase epitaxy using AlGaN as an intermediate layer. Two samples with nominal intermediate layer thicknesses of 60 and 120 nm were studied. It was found that there is a junction in the n-type Si region underneath the nitride/Si interface irrespective of the intermediate layer thickness, whereas induced current occurred neither in the nitride region nor at the nitride/Si interface. The junction formed was found to be undulated. The sample with the thin intermediate layer had undulations of a shorter periodicity than that with the thick intermediate layer. The formation of the junction is attributed to the diffusion of Al during the nitride growth.
authors.affiliation: EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan. s-tanaka@esi.nagoya-u.ac.jp
authors.forename: Shigeyasu
authors.initials: S
authors.lastname: Tanaka
authors.forename: Kentaro
authors.initials: K
authors.lastname: Aoyama
authors.forename: Mikio
authors.initials: M
authors.lastname: Ichihashi
authors.forename: Shigeo
authors.initials: S
authors.lastname: Arai
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Honda
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Sawaki