A high-dielectric constant (high-k) TiOx thin layer was fabricated on hydrogen-terminated diamond (H-diamond) surface by low temperature oxidation of a thin titanium layer in ambient air. The metallic titanium layer was deposited by sputter deposition. The dielectric constant of the resultant TiOx was calculated to be around 12. The capacitance density of the metal-oxide-semiconductor (MOS) based on the TiOx/H-diamond was as high as 0.75 µF/cm2 contributed from the high-k value and the very thin thickness of the TiOx layer. The leakage current was lower than 10-13 A at reverse biases and 10-7A at the forward bias of -2 V. The MOS field-effect transistor based on the high-k TiOx/H-diamond was demonstrated. The utilization of the high-k TiOx with a very thin thickness brought forward the features of an ideally low subthreshold swing slope of 65 mV per decade and improved drain current at low gate voltages. The advantages of the utilization high-k dielectric for diamond MOSFETs are anticipated.
Bibliographical noteCopyright 201.5 Acoustical Society of America. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the Acoustical Society of America.
The following article appeared in Zhao, J., Liu, J., Sang, L., Liao, M., Coathup, D., Imura, M., ... Ye, H. (2016). Assembly of a high-dielectric constant thin TiOX layer directly on H-terminated semiconductor diamond. Applied Physics Letters, 108(1), . The following article appeared in http://link.aip.org/link/?APL/108/012105/
Funding: EC FP7 Marie Curie Action (project No 300193 and 295208); EPSRC (EP/K003070/1); Nanotechnology Platform projects sponsored by MEXT in Japan KAKENHI (15H03999), Green Network of Excellence (GRENE), Low-Carbon Research Network (LCnet); and National Natural Science Foundation of China (Grant Nos.1272278，61390503, and 91323304)