Chemical and semiconducting properties of NO2-activated H-terminated diamond
TL;DR: In this paper, the surface conductance and the surface H atoms are stable in dry nitrogen, with or without NO2-activation, but the surfaces conductance, the concentrations of H atoms both with and without activation and NO3− decrease when exposed to laboratory air over a period of hours to days.
About: This article is published in Diamond and Related Materials.The article was published on 2018-04-01. It has received 20 citations till now. The article focuses on the topics: Diamond & Surface conductivity.
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TL;DR: A review of surface transfer doping of diamond can be found in this paper, where the authors present a history and current outlook of this highly exploitable attribute, as well as a review of the current state-of-the-art.
59 citations
52 citations
Journal Article•
TL;DR: In this paper, hole doping was observed when using NO2 molecules on a H-diamond surface, and hole activation energy was measured as 0.006 eV, and holes were fully activated at room temperature.
Abstract: Diamond possesses a combination of exceptional physical properties and is expected to be used as a semiconductor material in high-efficiency and high-power electronic devices. In this study, hole doping was observed when using NO2 molecules on a H-diamond surface. The activation energy of hole concentration in NO2/H-diamond was measured as 0.006 eV, and holes were fully activated at room temperature. A thermal stabilization of the hole channel was realized by passivation with an atomic-layer-deposited Al2O3 layer. The passivation method enabled the realization of a thermally stable high-performance diamond field-effect transistor (FET), which exhibited high-performance DC and RF characteristics. NO2 hole-doping and Al2O3-passivation technologies enabled reproducible measurements of MOS structure electric properties. Such technologies also facilitated observations of two-dimensional holes at the MOS interface and type-II band alignment of Al2O3/NO2/H-diamond. Additionally, the band diagram under various gate bias conditions was proposed on the basis of capacitance–voltage measurements and analysis using Poisson's equations.
25 citations
TL;DR: In this article, the effect of NO2 p-type doping at the Al2O3/H-diamond interface was investigated by measuring the conductance as a function of frequency and applied voltage.
25 citations
TL;DR: In this paper, the authors investigated diamond metal oxide semiconductor field effect transistors (MOSFETs) with NO2 p-type doping and Al2O3 passivation layer fabricated on a high-quality heteroepitaxial single crystal (001) diamond substrate called Kenzan diamond®.
Abstract: In this study, we investigated diamond metal oxide semiconductor field effect transistors (MOSFETs) with NO2 p-type doping and Al2O3 passivation layer fabricated on a high-quality heteroepitaxial single crystal (001) diamond substrate called Kenzan diamond®. MOSFETs with a gate length of 1.4 $\mu \text{m}$ and nearly zero source-gate spacing exhibited a high drain current density of −776 mA/mm with a negligible gate leakage current ( $ /mm). MOSFETs with a gate-to-drain length of 4.8 $\mu \text{m}$ delivered a high off-state breakdown voltage (−618 V) at an average breakdown field of 1.2 MV/cm and a specific on-resistance of 2.63 $\text{m}\Omega \cdot $ cm2. Baliga’s Figure-Of-Merits was calculated as 145 MW/cm2 and the anticipated maximum power density was 12 W/mm. The diamond MOSFET was improved with high crystal quality.
23 citations
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24,580 citations
TL;DR: Experimental evidence is given that hydrogen is only a necessary requirement for SC; exposure to air is also essential and a mechanism in which a redox reaction in an adsorbed water layer provides the electron sink for the subsurface hole accumulation layer is proposed.
Abstract: Hydrogen-terminated diamond exhibits a high surface conductivity (SC) that is commonly attributed to the direct action of hydrogen-related acceptors. We give experimental evidence that hydrogen is only a necessary requirement for SC; exposure to air is also essential. We propose a mechanism in which a redox reaction in an adsorbed water layer provides the electron sink for the subsurface hole accumulation layer. The model explains the experimental findings including the fact that hydrogenated diamond is unique among all semiconductors in this respect.
823 citations
TL;DR: In this article, inelastic mean free paths (IMFPs) for 41 elemental solids (Li, Be, graphite, diamond, glassy C, Na, Mg, Al, Si, K, Sc, Ti, V, Cr, Fe, Co, Ni, Cu, Ge, Y, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Cs, Gd, Tb, Dy, Hf, Ta, W, Re, Os, Ir, Pt, Au and Bi) were calculated from experimental
Abstract: We have calculated inelastic mean free paths (IMFPs) for 41 elemental solids (Li, Be, graphite, diamond, glassy C, Na, Mg, Al, Si, K, Sc, Ti, V, Cr, Fe, Co, Ni, Cu, Ge, Y, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Cs, Gd, Tb, Dy, Hf, Ta, W, Re, Os, Ir, Pt, Au and Bi) for electron energies from 50 eV to 30 keV. The IMFPs were calculated from experimental optical data using the full Penn algorithm for energies up to 300 eV and the simpler single-pole approximation for higher energies. The calculated IMFPs could be fitted to a modified form of the Bethe equation for inelastic scattering of electrons in matter for energies from 50 eV to 30 keV. The average root-mean-square (RMS) deviation in these fits was 0.48%. The new IMFPs were also compared with IMFPs from the predictive TPP-2M equation; in these comparisons, the average RMS deviation was 12.3% for energies between 50 eV and 30 keV. This RMS deviation is almost the same as that found previously in a similar comparison for the 50 eV–2 keV range. Relatively large RMS deviations were found for diamond, graphite and cesium. If these three elements were excluded in the comparison, the average RMS deviation was 9.2% between 50 eV and 30 keV. We found satisfactory agreement of our calculated IMFPs with IMFPs from recent calculations and from elastic-peak electron-spectroscopy experiments. Copyright © 2010 John Wiley & Sons, Ltd.
741 citations
TL;DR: In this paper, a mechanism for the low resistivity of the as-grown diamond films is postulated to be due to hydrogen passivation of traps in the films, which is confirmed by an observed reduction of the resistivity when they are subjected to a plasma hydrogen treatment.
Abstract: Diamond films grown by plasma chemical vapor deposition techniques display a fairly low resistivity (∼106 Ω cm). Heat treating the films causes an increase in the resistivity by up to six orders of magnitude. The low resistivity of the as‐grown films is postulated to be due to hydrogen passivation of traps in the films. Annealing causes dehydrogenation resulting in the electrical activation of deep traps with an attendant increase in the resistivity. This mechanism has been confirmed by an observed reduction of the resistivity of the heat‐treated films when they are subjected to a plasma hydrogen treatment.
470 citations
TL;DR: Clean, ordered GaN(0001)−(1×1) surfaces are prepared by sputtering with nitrogen ions followed by annealing in ultrahigh vacuum as mentioned in this paper and the surfaces are subsequently exposed at room temperature to O2 and the chemisorption process studied using Auger, valence and core-level photoemission and electron energy loss spectroscopies, low-energy electron diffraction, and work function measurements.
Abstract: Clean, ordered GaN(0001)‐(1×1) surfaces are prepared by sputtering with nitrogen ions followed by annealing in ultrahigh vacuum. The surfaces are subsequently exposed at room temperature to O2 and the chemisorption process studied using Auger, valence and core‐level photoemission and electron energy loss spectroscopies, low‐energy electron diffraction, and work function measurements. Saturation occurs at a coverage of Θox=0.4 ML and is accompanied by the removal of surface states near the band edges. The continued presence of a clear (1×1) diffraction pattern, together with other data, indicates a well‐defined adsorption site, but the relative importance of Ga–O and N–O bonding remains undetermined. The realization that surface states exist near the valence‐band maximum has led to a more accurate determination of the surface Fermi‐level pinning position, and of dependent quantities, than given previously. Clean‐surface data are also compared with those for surfaces prepared by in situ deposition of Ga metal followed by thermal desorption. No significant differences are seen, which suggests that nitrogen‐ion sputtering and annealing is suitable for preparing clean, ordered GaN(0001)‐(1×1) surfaces. The results for O chemisorption on atomically clean surfaces have been applied to evaluating the passivation of surfaces prepared by ex situ wet‐chemical cleaning. The band bending is found to be ∼0.5 eV less than on atomically clean surfaces.
264 citations