A Study of Pt/AlN/6H-SiC MIS Structures for Device Applications

2000 ◽  
Vol 622 ◽  
Author(s):  
Margarita P. Thompson ◽  
Gregory W. Auner ◽  
Changhe Huang ◽  
James N. Hilfiker

ABSTRACTAlN films with thicknesses from 53 to 79 nm were deposited on 6H-SiC substrates via Plasma Source Molecular Beam Epitaxy (PSMBE). The influence of deposition temperature on the growth mode and film roughness was assessed. The optical constants of the films in the range 0.73-8.75 eV were determined using spectroscopic ellipsometry. Pt/AlN/6H-SiC MIS structures were created and current-voltage (I-V) and capacitance-voltage (C-V) measurements were performed at room temperature and at 250°C. Most of the MIS structures showed rectifying I-V characteristics regardless of growth temperature. A 120-nm-thick AlN film was deposited at 500°C. MIS structures created on this film showed a very low leakage current densities of 6×10−8 A/cm2. The dielectric constant of the film was estimated at approximately 9. The relation between film structure and electrical properties of the films is discussed.

2021 ◽  
Vol 24 (2) ◽  
pp. 68-72
Author(s):  
Natalia V. Sachuk ◽  
Margarita B. Shalimova

The electrical properties of MIS structures with rare-earth element fluorides on germanium substrates were studied to analyze the possibility of using these materials as gate dielectrics of devices. The structures are also studied from the point of view of assessing the degradation of their electrophysical properties under the action of electric fields of ~108 V/m, which act on the dielectric during electroforming, since the MIS structures with rare-earth element fluorides have the property of bistable switching. Studies of the I-V and C-V characteristics show that all structures have approximately the same value of the density of surface states at the rare-earth element / Ge fluoride interface. The leakage currents in the MIS structures with TmF3 and SmF3 film are less than in the MIS structures with NdF3 film of greater thickness. There is also no effect of reducing the current density when using the double film structure CeF3/DyF3. The most promising material with a low leakage current at a fairly high value of the dielectric constant in germanium MIS structures is thin-film samarium fluoride.


2003 ◽  
Vol 786 ◽  
Author(s):  
Y.W. Kwon ◽  
Y. Li ◽  
Y.W. Heo ◽  
M. Jones ◽  
Vijay ◽  
...  

ABSTRACTThe synthesis and properties of oxide-based thin film transistors (TFTs) is reported using pulsed laser deposition. The field effect transistors use ZnO as the channel material. Low leakage current density is achieved with amorphous (CeTb)MgAl11O19 (CTMA) serving as the gate oxide, whose dielectric strength is measured to be > 5MV/cm for structures fabricated on Indium Tin oxide (ITO) substrates. Capacitance-voltage properties show that n-type active layers are realized with undoped ZnO. Charge densities in undoped ZnO are measured to be 1018 to 1019 / cm3 using Hall measurement and CV plots. Current-voltage measurements for TFT operation are reported. Channel materials on patterned substrates show high conductance and modulation of channel conductance. C-V measurements with MOS structure using doped ZnO and ZnxMg1-xO will also be described. The properties of depletion mode TFTs fabricated with doped and undoped oxide channel will be discussed in detail.


1998 ◽  
Vol 535 ◽  
Author(s):  
M. Hong ◽  
J. Kwo ◽  
A. R. Kortan ◽  
J. P. Mannaerts ◽  
M. C. Wu ◽  
...  

AbstractSingle crystal Gd2O3 dielectric thin films were epitaxially grown on GaAs. The Gd2O3 film has a cubic structure isomorphic to Mn2O3, and is (110) oriented in single domain on the (100) GaAs surface. The oxide film has low leakage current densities ˜ 10–9 – 10–10 A/cmT2 at zero bias. Typical breakdown field is 4 MV/cm for an oxide film 185 Å thick, and >10 MV/cm for an oxide less than 50 Å thick. Both accumulation and inversion layers were observed in the Gd2O3-GaAs metal oxide semiconductor (MOS) diodes using capacitance-voltage (C-V) measurements, with an interfacial density of states around 1011 cm–2 eV–1.


2014 ◽  
Vol 1635 ◽  
pp. 75-81
Author(s):  
Anders Olsson ◽  
Abuduwayiti Aierken ◽  
Jani Oksanen ◽  
Harri Lipsanen ◽  
Jukka Tulkki

ABSTRACTLight-emitting diodes (LEDs) based on the conventional III-V compound semiconductors are known to exhibit internal quantum efficiencies (IQE) that are very close to unity. Ideally, the high IQE is expected to enable electroluminescent cooling with a cooling capacity of several Watts per cm2 of emitter area. One key requirement in enabling such cooling is the ability to fabricate high quality large area LEDs. However, detailed information on the performance of relevant large area devices and their yield is extremely scarce. In this report we present data on the yield and related large area scaling of InP/InGaAs LEDs by using current-voltage measurements performed on LED wafers fabricated at five different facilities. The samples were processed to contain square shaped mesas of sizes 0.25 mm2 and 16 mm2 operating as LEDs. While most of the smaller mesas showed relatively good electrical characteristics and low leakage current densities, some of them also exhibited very large leakage currents. In addition, in some cases the large area devices exhibited large, and even almost linearly behaving leakage currents. Such information on the scaling and unidealities of diodes fabricated using established fabrication technologies is crucial for the development of the optical cooling technologies relying on large area devices.


Author(s):  
Н.А. Малеев ◽  
М.А. Бобров ◽  
А.Г. Кузьменков ◽  
А.П. Васильев ◽  
М.М. Кулагина ◽  
...  

Optimal capacitance-voltage characteristic is critical for heterobarrier varactor diode (HBV) performance in terms of multiplication efficiency in mm- and sub-mm wave ranges. Numerical model of capacitance-voltage characteristics and leakage current for HBV with arbitrary heterostructure composition and doping profile was verified on published data and original experimental results. Designed HBV heterostructure with three undoped InAlAs/AlAs/InAlAs barriers surrounded with non-uniformly doped n-InGaAs modulation layers was grown by molecular-beam epitaxy on InP substrate and test HBV diodes have been fabricated. Test HBV diodes demonstrate capacitance-voltage characteristics with cosine shape at bias voltage up to two volts, increased capacitance ratio and low leakage current values.


2007 ◽  
Vol 556-557 ◽  
pp. 101-104
Author(s):  
Jie Zhang ◽  
Esteban Romano ◽  
Janice Mazzola ◽  
Swapna G. Sunkari ◽  
Carl Hoff ◽  
...  

In this paper we present highly uniform SiC epitaxy in a horizontal hot-wall CVD reactor with wafer rotation. Epilayers with excellent thickness uniformity of better than 1% and doping uniformity better than 5% are obtained on 3-in, 4° off-axis substrates. The same growth conditions for uniform epitaxy also generate smooth surface morphology for the 4° epiwafers. Well controlled doping for both n- and p-type epilayers is obtained. Abrupt interface transition between n- and pdoped layers in a wide doping range is demonstrated. Tight process control for both thickness and doping is evidenced by the data collected from the epi operations. The average deviation from target is 2.5% for thickness and 6% for doping. PiN diodes fabricated on a standard 3-in, 4° epiwafer have shown impressive performance. More than half of the 1 mm2 devices block 1 kV (2.3 MV/cm) with a low leakage current of 1 μA.


2017 ◽  
Vol 897 ◽  
pp. 63-66
Author(s):  
Selsabil Sejil ◽  
Loic Lalouat ◽  
Mihai Lazar ◽  
Davy Carole ◽  
Christian Brylinski ◽  
...  

This study deals with the electrical characterization of PiN diodes fabricated on a 4°off-axis 4H-SiC n+ substrate with a n- epilayer (1×1016 cm-3 / 10 µm). Optimized p++ epitaxial areas were grown by Vapour-Liquid-Solid (VLS) transport to form p+ emitters localized in etched wells with 1 µm depth. Incorporated Al level in the VLS p++ zones was checked by SIMS (Secondary Ion Mass Spectroscopy), and the doping level was found in the range of 1-3×1020 at.cm-3. Electrical characterizations were performed on these PiN diodes, with 800 nm deposit of aluminium as ohmic contact on p-type SiC. Electrical measurements show a bipolar behaviour, and very high sustainable forward current densities ≥ 3 kA.cm-2, preserving a low leakage current density in reverse bias. These measurements were obtained on structures without any passivation and no edge termination.


1987 ◽  
Vol 2 (3) ◽  
pp. 322-328 ◽  
Author(s):  
J. K. Cochran ◽  
A. T. Chapman ◽  
D. N. Hill ◽  
K. J. Lee

Field emitter array cathodes were fabricated from unidirectionally solidified composites of tungsten fibers in an insulating yttria-stabilized-zirconia (YSZ) matrix. A close-spaced molybdenum gate film (extractor) was formed utilizing c-beam evaporation of alumina as an insulator, which was overlayed by the molybdenum extractor. The high resistivity of the composite matrix coupled with the alumina insulator resulted in low leakage current and permitted dc operation of the device. Emission testing demonstrated current densities of 1–5 A/cm2 with leakage in the μA range for applied potentials of 125–200 V. Variation of emitter tip geometries from hemispheres to right circular cylinders to pointed cones produced increases in emission consistent with reduced tip radii.


2012 ◽  
Vol 6 (2) ◽  
pp. 97-101 ◽  
Author(s):  
Zhi-Wei He ◽  
Shi-Qiu Zhu ◽  
Sheng-Li Wang ◽  
Zheng Qi ◽  
Yu-Yuan Guan

The effects of catalyst HF concentration on the dielectric and electrical properties of SiOF films are discussed. From the current density-voltage and capacitance-voltage curves, we observed that the film catalyzed with the special concentration of HF (the ratio of HF/H2O = 1/5) shows good moisture resistance, low leakage current (10-11 A/cm2 at 1 MV/cm) and high breakdown field (6 MV/cm), which can be explained by the results of Fourier transform infrared spectra. The dielectric constant value is also very low and reaches about 1.75 after annealing at the temperature of 450?C. Therefore, the concentration of HF catalyst is an important factor in the sol-gel process.


2002 ◽  
Vol 736 ◽  
Author(s):  
Yifan Xu ◽  
Paul Berger ◽  
Jai Cho ◽  
Richard B. Timmons

ABSTRACTPolyallylamine films, deposited on Si wafers by radio frequency (RF) pulsed plasma polymerization (PPP), were employed as insulating layers of metal-insulator-semiconductor (MIS) capacitors. The insulating polymer films were deposited at substrate temperatures of 25°C and 100°C. Multiple frequency capacitance-voltage (C-V) measurements indicated that an in-situ heat treatment during film deposition increased the insulator dielectric constant. The dielectric constant, calculated from the C-V data, rose from 3.03 for samples with no heat treatment to 3.55 for samples with an in-situ heat treatment. For both sample sets, the I-V data demonstrate a low leakage current value (<20fA) up to 100V with an area of 0.0307 mm2, resulting in a current density of <0.65 pA/mm2. Hysteresis in the C-V curves with differing sweep directions was more pronounced for in-situ heat-treated samples indicative of positive mobile ions.


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