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Direct observation of inversion capacitance in p-type diamond MOS capacitors with an electron injection layer

MetadataDetails
Publication Date2018-02-16
JournalJapanese Journal of Applied Physics
AuthorsTsubasa Matsumoto, Hiromitsu Kato, Toshiharu Makino, Masahiko Ogura, Daisuke Takeuchi
InstitutionsNational Institute for Materials Science, National Institute of Advanced Industrial Science and Technology
Citations14

The electrical properties of Al2O3/p-type diamond (111) MOS capacitors were studied with the goal of furthering diamond-based semiconductor research. To confirm the formation of an inversion layer in the p-type diamond body, an n-type layer for use as a minority carrier injection layer was selectively deposited onto p-type diamond. To form the diamond MOS capacitors, Al2O3 was deposited onto OH-terminated diamond using atomic layer deposition. The MOS capacitor showed clear inversion capacitance at 10 Hz. The minority carrier injection from the n-type layer reached the inversion n-channel diamond MOS field-effect transistor (MOSFET). Using the high-low frequency capacitance method, the interface state density, Dit, within an energy range of 0.1-0.5 eV from the valence band edge energy, Ev, was estimated at (4-9) Ɨ 1012 cmāˆ’2 eVāˆ’1. However, the high Dit near Ev remains an obstacle to improving the field effect mobility for the inversion p-channel diamond MOSFET.