Displacement current of Aup-diamond Schottky contacts.pdfVIP

Materials Science in Semiconductor Processing (xxxx) xxxx–xxxx Contents lists available at ScienceDirect Materials Science in Semiconductor Processing journal homepage: /locate/mssp Si:iscsi-vii/istdm2016 Displacement current of Au/p-diamond Schottky contacts Toshichika Aokia,?, Tokuyuki Terajib, Yasuo Koideb, Kenji Shiojimaa a Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507, Japan b National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan ARTICLE INFO Keywords: p‐diamond p‐GaN Schottky contact I–V characteristic AC operation ABSTRACT In this study, the displacement current of Au/p-diamond Schottky contacts was studied by comparing them with low-Mg-doped p-GaN Schottky contacts. In the current–voltage (I–V) characteristics, the current was proportional to the voltage sweep speed at V ?1.5 V. The di?erential output waveform was obtained through AC operation. Therefore, the displacement current was dominant in the low voltage region where in the true current was extremely small due to the large Schottky barrier height of 1.57 eV. The memory e?ect, due to the charge and discharge of localized acceptor-type deep-level defects, was negligible in the I–V curve. A clear AC di?erential signal was con?rmed. This suggested that the interface defect density of the p-diamond contacts was very small compared to the p-GaN contacts. Hence, p-diamond Schottky contacts were expected to be a good candidate for a key device such as a phase modulator in a wireless transmitter. 1. Introduction Wide bandgap materials such as GaN and SiC are readily used in commercially available products such as GaN/InGaN blue light-emitting diodes, laser diodes [1], radio-frequency AlGaN/GaN high electron mobility transistors [2–4], SiC power Schottky diodes, and MOSFETs [5,6]. These materials are of interest for developing the next-generation of high-power switching applications for GaN devices and mass production of SiC devices. In addit