Showing papers on "Schottky barrier published in 1998"
TL;DR: In this article, the authors describe the fabrication and characterization of vertical geometry transparent Schottky barrier ultraviolet detectors based on n- /n+ -GaN and AlGaN structures grown over sapphire substrates.
Abstract: The invention concerns the fabrication and characterization of vertical geometry transparent Schottky barrier ultraviolet detectors based on n- /n+ -GaN and AlGaN structures grown over sapphire substrates. Mesa geometry devices of different active areas were fabricated and characterized for spectral responsitivity, speed and noise characteristics. The invention also concerns the fabrication and characterization of an 8×8 Schottky barrier photodiode array on GaN with a pixel size of 200 μm by 200 μm.
339 citations
TL;DR: In this paper, the authors review the metal-GaN contact technology to shed light on some of the critical issues such as GaN surface cleaning for metallization, Schottky barrier formation to GaN, thermal stability of contacts, low contact-resistance ohmic contacts to n −GaN and to Ga n/AlGaN heterostructures, and ohmic contact to p -GaN.
Abstract: In this paper, we review the metal–GaN contact technology to shed light on some of the critical issues such as GaN surface cleaning for metallization, Schottky barrier formation to GaN, thermal stability of contacts, low contact-resistance ohmic contacts to n-GaN and to GaN/AlGaN heterostructures, and ohmic contacts to p-GaN. Some general conclusions are drawn on the electrical behavior of metal contacts on n-GaN for further advances in this exciting field of GaN-based devices and materials.
314 citations
TL;DR: In this paper, a new method of refrigeration is proposed by thermionic emission of electrons over Schottky barriers between metals and semiconductors, which can have only a small temperature difference.
Abstract: A new method of refrigeration is proposed. Efficient cooling is obtained by thermionic emission of electrons over Schottky barriers between metals and semiconductors. Since the barriers have to be thin, each barrier can have only a small temperature difference $(\ensuremath{\sim}1\mathrm{K})$. Macroscopic cooling is obtained with a multilayer device. The same device is also an efficient generator of electrical power. A complete analytic theory is provided.
310 citations
TL;DR: In this paper, the reverse leakage current is observed to depend on device area, Schottky barrier height, electric field at the metal-semiconductor interface, and temperature (a decreasing temperature dependence with increasing reverse bias).
Abstract: Practical design of high-voltage SiC Schottky rectifiers requires an understanding of the device physics that affect the key performance parameters. Forward characteristics of SiC Schottky rectifiers follow thermionic emission theory and are relatively well understood. However, the reverse characteristics are not well understood and have not been experimentally investigated in-depth. In this paper we report the analysis and experimental results of both the forward and reverse characteristics of high-voltage SiC Schottky rectifiers. Ti and Ni Schottky rectifiers with boron implant edge termination were fabricated on n-type 4H SiC samples. Ni Schottky rectifiers fabricated on a 13-/spl mu/m thick 3.5/spl times/10/sup 15/ cm/sup -3/ epilayer have a current density of 100 A/cm/sup 2/ at approximately 2 V forward bias and a reverse leakage current density of less than 0.1 A/cm/sup 2/ at a reverse bias of 1720 V. The reverse leakage current is observed to depend on device area, Schottky barrier height, electric field at the metal-semiconductor interface, and temperature (a decreasing temperature dependence with increasing reverse bias). In addition. the reverse leakage current magnitude is larger and the electric field dependence is stronger than predicted by thermionic emission and image-force barrier height lowering. This suggests the reverse leakage current is due to a combination of thermionic field emission and field emission.
219 citations
TL;DR: In this paper, a method for enhancing effective Schottky barrier heights in III-V nitride heterostructures based on the piezoelectric effect is proposed, demonstrated, and analyzed.
Abstract: A method for enhancing effective Schottky barrier heights in III–V nitride heterostructures based on the piezoelectric effect is proposed, demonstrated, and analyzed. Two-layer GaN/AlxGa1−xN barriers within heterostructure field-effect transistor epitaxial layer structures are shown to possess significantly larger effective barrier heights than those for AlxGa1−xN, and the influence of composition, doping, and layer thicknesses is assessed. A GaN/Al0.25Ga0.75N barrier structure optimized for heterojunction field-effect transistors is shown to yield a barrier height enhancement of 0.37 V over that for Al0.25Ga0.75N. Corresponding reductions in forward-bias current and reverse-bias leakage are observed in current–voltage measurements performed on Schottky diodes.
192 citations
TL;DR: Functional integration between semiconductors and ferromagnets was demonstrated with the spin-valve transistor and the vacuum bonding technique allows the realization of many ideas for vertical transport devices and forms a permanent link that is useful in demanding adhesion applications.
Abstract: Functional integration between semiconductors and ferromagnets was demonstrated with the spin-valve transistor. A ferromagnetic multilayer was sandwiched between two device-quality silicon substrates by means of vacuum bonding. The emitter Schottky barrier injected hot electrons into the spin-valve base. The collector Schottky barrier accepts only ballistic electrons, which makes the collector current very sensitive to magnetic fields. Room temperature operation was accomplished by preparing Si-Pt-Co-Cu-Co-Si devices. The vacuum bonding technique allows the realization of many ideas for vertical transport devices and forms a permanent link that is useful in demanding adhesion applications.
186 citations
IBM1
TL;DR: In this article, the authors presented a physical contact tunneling model that is critical for studying the increasingly important contact behavior in future scaled CMOS. And they compared the performance of raised S/D and Schottky S/d MOSFETs.
Abstract: We present, for the first time, a physical contact tunneling model that is critical for studying the increasingly important contact behaviour in future scaled CMOS. The tunneling processes are self-consistently treated with all current transport in the semiconductor. With this new model, we compared the performance of raised S/D and Schottky S/D MOSFETs. Both raised S/D and Schottky S/D MOSFETs can be designed to give good short-channel characteristics. Our analyses show that despite the lower sheet resistance of the Schottky S/D MOSFETs, contact resistance could be large due to finite Schottky barrier height. A lower barrier height contact material should be used to minimize the contact resistance.
185 citations
TL;DR: In this article, the temperature dependence of the current-voltage characteristics of Ni-GaN Schottky barriers has been measured and analyzed and it was found that the enhanced tunneling component in the transport current of metal GaN-Schottky barrier contacts is a likely explanation for the large scatter in the measured Richardson constant.
Abstract: The temperature dependence of the current–voltage characteristics of Ni–GaN Schottky barriers have been measured and analyzed. It was found that the enhanced tunneling component in the transport current of metal-GaN Schottky barrier contacts is a likely explanation for the large scatter in the measured Richardson constant.
185 citations
TL;DR: In this paper, the self-polarization effect of Pb(Zr,Ti)O3 (PZT) thin films deposited by sol-gel and magnetron sputtering techniques was investigated.
Abstract: The self-polarization effect is investigated in Pb(Zr,Ti)O3 (PZT) thin films deposited by sol-gel and magnetron sputtering techniques. The effective piezoelectric coefficient of as-grown films, which is proportional to their initial polarization (self-polarization), is measured by a sensitive interferometric technique as a function of the annealing temperature, PZT composition, film thickness and bottom electrode material. The results indicate that the films are self-polarized by an internal bias field upon cooling through the phase transition temperature. It is suggested that a built-in field of a Schottky barrier between the PZT film and the bottom electrode is responsible for the observed effect. Self-polarization of the films is found to be very stable and in some cases to be as high as 90% of that produced by the subsequent room temperature poling. This property is very useful for piezoelectric and pyroelectric applications of PZT films since the poling procedure can be avoided. The properti...
158 citations
TL;DR: In this paper, the thermal stability of indium tin oxide (ITO) on n-type GaN was investigated by annealing the samples at various temperatures, and currentvoltage measurements were taken to deduce the Schottky barrier heights.
Abstract: In this work indium tin oxide (ITO) films were prepared using electron beam evaporation to form Schottky contacts on n-type GaN films. The thermal stability of ITO on n-type GaN was also investigated by annealing the samples at various temperatures. In addition, current–voltage (I–V) measurements were taken to deduce the Schottky barrier heights. Owing to the large series resistance, the Norde method was used to plot the F(V)–V curves and the effective Schottky barrier heights were determined as well. The effective Schottky barrier heights were 0.68, 0.88, 0.94, and 0.95 eV for nonannealed, 400, 500, and 600 °C annealed samples, respectively. Results presented herein indicate that an increase of the barrier heights may be attributed to the formation of an interfacial layer at the ITO/GaN interface after annealing.
151 citations
TL;DR: In this article, the authors report solar-blind AlxGa1−xN photovoltaic detectors with cutoff wavelengths as short as 290 nm, with spectral responsivity of the devices near the cutoff wavelength is 0.07 A/W.
Abstract: We report solar-blind AlxGa1−xN photovoltaic detectors with cutoff wavelengths as short as 290 nm. Mesa geometry devices of different active areas are fabricated and characterized for spectral responsitivity, speed, and noise performance. The responsivity of the devices near the cutoff wavelength is 0.07 A/W. The detector noise is found to be 1/f limited, with a noise equivalent power of 6.6×10−9 W over the total response bandwidth of 100 kHz.
TL;DR: In this paper, Wurtzite structure epitaxial GaN exhibits room-temperature photoluminescence with a band-edge-related emission width as narrow as 7 nm and intensities comparable to high quality layers grown on sapphire by metalorganic chemical vapor deposition.
Abstract: We report novel GaN detectors grown by molecular beam epitaxy on Si(111) substrates. Wurtzite structure epitaxial GaN exhibits room-temperature photoluminescence with a band-edge-related emission width as narrow as 7 nm and intensities comparable to high quality layers grown on sapphire by metalorganic chemical vapor deposition. Spectral response of lateral geometry Schottky detectors shows a sharp cutoff at 365 nm with peak responsivities of ∼0.05 A/W at 0 V, and ∼0.1 A/W with a −4 V bias. The dark current is ∼60 nA at −2 V bias. The noise equivalent power is estimated to be 3.7×10−9 W over the response bandwidth of 2.2 MHz.
TL;DR: In this paper, a static induction transistors (SITs) using copper phthalocyanine films and Al Schottky gate electrode are fabricated and the basic electrical characteristics are investigated.
TL;DR: In this article, the formation of Schottky barriers between n- and p-GaN(0001)−(1×1) grown by metalorganic chemical vapor deposition and a series of high and low work function metals (Mg, Al, Ti, Au, and Pt).
Abstract: We present a systematic investigation of the formation of Schottky barriers between n- and p-GaN(0001)−(1×1) grown by metalorganic chemical vapor deposition and a series of high and low work function metals (Mg, Al, Ti, Au, and Pt). Al, Ti, and Mg react at room temperature with nitrogen, whereas Au and Pt form abrupt, unreacted interfaces. We find that the Fermi level movement on both n- and p-GaN is consistent with variations in metal work functions, but limited by surface or interface states. Upon annealing, the incorporation of Mg increases the density of acceptors as seen on both n- and p-GaN. In spite of similar work functions and chemical reaction with nitrogen, Ti and Al show drastic differences in Schottky barrier formation due to differences in the nature of the products of reaction. AlN is a wide band gap semiconductor whereas TiN is a metallic compound.
TL;DR: In this paper, electron beam induced current and currentvoltage (I-V) measurements on Schottky diodes on p-type doped GaN layers grown by metal organic chemical vapor deposition were reported.
Abstract: We report on electron beam induced current and current–voltage (I–V) measurements on Schottky diodes on p-type doped GaN layers grown by metal organic chemical vapor deposition. A Schottky barrier height of 0.9 eV was measured for the Ti/Au Schottky contact from the I–V data. A minority carrier diffusion length for electrons of (0.2 ± 0.05) µm was measured for the first time in GaN. This diffusion length corresponds to an electron lifetime of approximately 0.1 ns. We attempted to correlate the measured electron diffusion length and lifetime with several possible recombination mechanisms in GaN and establish connection with electronic and structural properties of GaN.
TL;DR: In this paper, the Schottky energy barrier to charge injection from one contact was modeled as a function of the energy barrier and the current flow was assumed to be space-charge limited.
Abstract: We present device model calculations of the current–voltage (I–V) characteristics of organic diodes and compare them with measurements of structures fabricated using MEH-PPV. The structures are designed so that all of the current is injected from one contact. The I–V characteristics are considered as a function of the Schottky energy barrier to charge injection from the contact. Experimentally, the Schottky barrier is varied from essentially zero to more than 1 eV by using different metal contacts. A consistent description of the device I–V characteristics is obtained as the Schottky barrier is varied from small values, less than about 0.4 eV, where the current flow is space-charge limited to larger values where it is contact limited.
TL;DR: In this article, the electron emission properties of metal-diamond interfaces were characterized by means of UV photoemission spectroscopy (UPS) and field-emission measurements.
Abstract: The electron emission properties of metal–diamond (100), (111), and (110) interfaces were characterized by means of UV photoemission spectroscopy (UPS) and field-emission measurements. Different surface cleaning procedures including annealing in ultrahigh vacuum (UHV) and rf plasma treatments were used before metal deposition. This resulted in diamond surfaces terminated by oxygen, hydrogen, or free of adsorbates. The electron affinity and Schottky barrier height of Zr or Co thin films were correlated by means of UPS. A negative electron affinity (NEA) was observed for Zr on any diamond surface. Co on diamond resulted in NEA characteristics except for oxygen-terminated surfaces. The lowest Schottky barrier heights were obtained for the clean diamond surfaces. Higher values were measured for H termination, and the highest values were obtained for O on diamond. For Zr, the Schottky barrier height ranged from 0.70 eV for the clean to 0.90 eV for the O-terminated diamond (100) surface. Values for Co ranged fr...
TL;DR: In this paper, temperature dependent impedance spectroscopy in a broad frequency range (10−1−107 Hz) was used to find that the ac behavior of indium-tin oxide (ITO)/poly-(p-phenylene-vinylene) (PPV)/aluminum light-emitting diodes shows several features which cannot be described by the usual double RC circuit representing a depleted junction region and an undepleted bulk.
Abstract: Using temperature dependent impedance spectroscopy in a broad frequency range (10−1–107 Hz), we have found that the ac behavior of indium-tin oxide (ITO)/poly-(p-phenylene-vinylene) (PPV)/aluminum light-emitting diodes shows several features which cannot be described by the usual simple double RC circuit representing a depleted junction region and an undepleted bulk. Instead, our measurements in combination with a theoretical modeling suggest that the PPV bulk is composed of a highly doped region at the ITO interface and a region with lower doping at a higher distance to the ITO. Moreover, the boundary between these two regions is not sharp but there is a gradual change in dopant concentration. The large frequency range allowed us to identify two distinct processes corresponding to the PPV bulk and a third one to the junction. The bulk relaxation frequencies correspond to the characteristic dielectric relaxation frequencies of charge carriers in the high and low conducting sublayers and are proportional to the respective conductivities. The magnitude and activation energy of the relaxation time correlates well with results obtained from temperature dependent DC conductivity measurements. For ITO substrates we obtain activation energies of 0.4 eV and room temperature conductivity of about 10−7 and 10−9 S/cm for the high and low conducting sublayers, respectively. On gold substrates only one bulk process and no junction process with an activation energy of about 0.6 eV and a corresponding conductivity of 3×10−11 S/cm at room temperature is observed. The Schottky junction has been studied by temperature dependent capacitance–voltage spectroscopy at a low frequency of 0.16 Hz. The obtained acceptor dopant concentration from 1/C2 plots varies from 1.4×1017 at room temperature to 6.9×1016 cm−3 at 200 K. Assuming a density of states between 5×1020 and 5×1021 cm−3 for the valence band the temperature dependent acceptor dopant density can be described with an acceptor ionization energy between 0.16 and 0.2 eV.
TL;DR: In this article, the Ni/Au layers prepared by electron beam evaporation and thermal alloying were used to form Ohmic contacts on p-type GaN films.
Abstract: In this study, the Ni/Au layers prepared by electron beam evaporation and thermal alloying were used to form Ohmic contacts on p-type GaN films. Before thermal alloying, the current–voltage (I–V) characteristic of Ni/Au contact on p-type GaN film shows non-Ohmic behavior. As the alloying temperature increases to 700 °C, the I–V curve shows a characteristic of Ohmic contact. The Schottky barrier height reduction may be attributed to the presence of Ga–Ni and Ga–Au compounds, such as Ga4Ni3, Ga3Ni2, GaAu, and GaAu2, at the metal-semiconductor interface. The diffusing behavior of both Ni and Au have been studied by using Auger electron spectroscopy and Rutherford backscattering spectrometry. In addition, x-ray diffraction measurements indicate that the Ni3N and Ga4Ni3 compounds were formed at the metal-semiconductor interface.
TL;DR: In this article, Er-doped GaN Schottky barrierdiodes were used to obtain visible light electroluminescence (EL) from Si-based Si-nodes.
Abstract: Visible lightelectroluminescence(EL) has been obtained from Er-doped GaN Schottky barrierdiodes. The GaN was grown by molecular beam epitaxy on Si substrates using solid sources (for Ga, and Er) and a plasma source for N 2 . Al was utilized for both the Schottky (small-area) and ground (large-area) electrodes. Strong green light emission was observed under reverse bias, with weaker emission present under forward bias. The emission spectrum consists of two narrow green lines at 537 and 558 nm and minor peaks at 413 and at 666/672 nm. The green emission lines have been identified as Er transitions from the 2 H 11/2 and 4 S 3/2 levels to the 4 I 15/2 ground state and the blue and red peaks as the 2 H 9/2 and 4 F 9/2 Er transitions to the same ground state. The reverse bias EL intensity was found to increase linearly with bias current.
TL;DR: In this article, the authors demonstrate that Si growth can electrochemically be initiated preferentially at surface defects created in an $n$-type Si substrate by focused ion beam bombardment.
Abstract: We report a principle that allows one to write visible light emitting silicon patterns of arbitrary shape down to the submicrometer scale. We demonstrate that porous Si growth can electrochemically be initiated preferentially at surface defects created in an $n$-type Si substrate by ${\mathrm{Si}}^{++}$ focused ion beam bombardment. For $n$-type material in the dark, the electrochemical pore formation potential (Schottky barrier breakdown voltage) is significantly lower at the implanted locations than for an unimplanted surface. This difference in the threshold voltages is exploited to achieve the selectivity of the pore formation process.
Patent•
21 Jan 1998
TL;DR: In this paper, a semiconductor diode structure with a Schottky junction is considered, where a metal contact and a silicon carbide semiconducting layer of a first conducting type form said junction and where the edge of the junction exhibits a junction termination divided into a transition belt (TB) having gradually increasing total charge or effective sheet charge density closest to the metal contact, and a junction termination extension (JTE) outside the transition belt, said JTE having a charge profile with a stepwise or uniformly decreasing total charge from an initial value to a zero or almost zero
Abstract: A semiconductor diode structure with a Schottky junction, where a metal contact (2) and a silicon carbide semiconducting layer (1) of a first conducting type form said junction and where the edge of the junction exhibits a junction termination divided into a transition belt (TB) having gradually increasing total charge or effective sheet charge density closest to the metal contact and a Junction Termination Extension (JTE) outside the transition belt, said JTE having a charge profile with a stepwise or uniformly decreasing total charge or effective sheet charge density from an initial value to a zero or almost zero total charge at the outermost edge of the termination following a radial direction from the center part of the JTE towards the outermost edge of the termination. The purpose of the transition belt is to reduce the electric field concentration at the edge of the metal contact of the Schottky diode, while the purpose of the junction termination extension is to control the electric field at the periphery of the diode.
TL;DR: In this paper, the electron affinity of various diamond surfaces has been calculated by the ab-initio pseudopotential method, and the barrier height of a diamond/graphite Schottky barrier is found.
03 Jun 1998
TL;DR: In this paper, the authors measured the forward and reverse electrical characteristics of trench MOS barrier Schottky diodes with various device parameters and found that resistivity and width of the mesa region are the main parameters which affect device characteristics.
Abstract: Measurements of forward and reverse electrical characteristics of trench MOS barrier Schottky diodes with various device parameters reveal that the resistivity and width of the mesa region are the main parameters which affect device characteristics. An on/off current ratio of two orders is obtained.
TL;DR: In this article, the authors present simulation results of a silicon-based metal-oxide-semiconductor field effect transistor (MOSFET) with metal/silicon Schottky junctions.
Abstract: We present simulation results of a silicon-based metal-oxide-semiconductor field-effect transistor (MOSFET), which has a structure similar to that of a conventional MOSFET, but the source and drain regions are now entirely replaced by metals. By using abrupt metal/silicon Schottky junctions, short-channel effects are avoided. Based on a few commonly used physical assumptions, we have calculated the transistor characteristics, and we find that this new three-terminal transistor can offer gain and impedance isolation, desirable for logic circuit applications.
TL;DR: In this article, the distribution of Schottky barrier heights over the contact area in Au/n-Si diodes was determined by ballistic electron emission microscopy, where negatively charged species containing F at the interface were thought to be responsible for the high barrier Gaussian components.
Abstract: The distribution of Schottky barrier heights over the contact area in Au/n-Si diodes was determined by ballistic electron emission microscopy. For samples on which an aqueous HF pretreatment of the Si substrate was applied, the histogram contains several high barrier Gaussian distribution components. After a short rinse, in de-ionized water or methanol, it was mainly the most important lower Gaussian component which was left. Using additional x-ray photoemission spectroscopy and atomic force microscopy measurements allowed us to propose a model, wherein negatively charged species containing F at the interface, are thought to be responsible for the high barrier Gaussian components.
TL;DR: In this article, the authors investigated the temperature dependence of both the grain boundary potential barrier height and the conductivity across the grain-boundary space-charge depletion layer in acceptor-doped SrTiO3 ceramics.
Abstract: The temperature dependence of both the grain-boundary potential barrier height and the conductivity across the grain-boundary space-charge depletion layer in acceptor-doped SrTiO3 ceramics has been investigated by a numerical simulation technique. The underlying model is that of a back-to-back double Schottky barrier at the grain boundary. The influence of the amount of positively charged donorlike grain-boundary interface states on the charge transport behavior of the grain-boundary region is also discussed. An interpretation in terms of a defect chemistry model of the bulk and the space-charge depletion layer, which on both sides surrounds the grain-boundary core is presented. The temperature behavior of the potential barrier at the grain boundary can be divided into three different regimes: a linear regime, and subsequently, saturation and decreasing regimes. The theoretical explanation for this behavior is given. Two different spatial conductivity profiles at the grain boundaries have to be considered...
TL;DR: In this paper, the authors analyzed the valence-band discontinuities of layered semiconductors and the barrier heights of the Schottky contact compounds, and they consistently described the continuum of interface-induced gap states as the primary mechanism that governs the band lineup at semiconductor interfaces.
Abstract: Many metal chalcogenides are layered semiconductors. They consist of chalcogen–metal–chalcogen layers that are themselves bound by van der Waals forces. Hence, heterostructures involving layered compounds are abrupt and strain-free. Experimental valence-band offsets of heterostructures between GaSe, InSe, SnS2, SnSe2, MoS2, MoTe2, WSe2, and CuInSe2 and between some of these compounds and ZnSe, CdS, and CdTe as well as barrier heights of Au contacts on GaSe, InSe, MoS2, MoTe2, WSe2, ZnSe, CdS, and CdTe are analyzed. The valence-band discontinuities of the heterostructures and the barrier heights of the Schottky contact compounds are consistently described by the continuum of interface-induced gap states as the primary mechanism that governs the band lineup at semiconductor interfaces.
TL;DR: Gold and nickel Schottky barrier photovoltaic detectors have been fabricated on Si-doped AlxGa1−xN layers (0.22Ga0.78N/Au) grown on sapphire by metalorganic vapor phase epitaxy as mentioned in this paper.
Abstract: Gold and nickel Schottky barrier photovoltaic detectors have been fabricated on Si-doped AlxGa1−xN layers (0⩽x⩽0.22) grown on sapphire by metalorganic vapor phase epitaxy. Responsivity is independent of the Schottky metal or diode size, and also of the incident power in the range measured (10 mW/m2–2 kW/m2). A higher visible rejection has been observed in the spectral response of Au photodiodes (>103). Time response is resistance-capacitance limited, with time constants as short as 14 ns in Al0.22Ga0.78N diodes. Low frequency noise studies are also presented, and detectivities of 6.1×107 and 1.2×107 mHz1/2 W−1 are determined in GaN/Au and Al0.22Ga0.78N/Au detectors, at −2 V bias.
TL;DR: In this paper, high-voltage Schottky barrier diodes with low reverse leakage current were processed on hot-wall chemical vapor deposition grown 4H-SiC films.
Abstract: High-voltage Schottky barrier diodes with low reverse leakage current were processed on hot-wall chemical vapor deposition grown 4H-SiC films. A metal overlap onto the oxide layer was employed to reduce electric field crowding at the contact periphery. By utilizing a 42–47 μm thick, high-quality epitaxial layers with doping in the range of 7×1014–2×1015 cm−3, a record blocking voltage of above 3 kV was achieved. The large diodes with 1.0 mm diameter showed breakdown at 2.1 kV. The reverse leakage current density at 1.0 kV was measured to be 7.0×10−7 A cm−2. Specific on-resistance of the diode with breakdown voltage at 3 kV was 34 mΩ cm2.