Electrical Characterization of Ion-Implanted n+/p 6H-SiC Diodes (original) (raw)
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Solid-State Electronics, 2015
In this work different experimental current-voltage behaviours of several Al implanted 4H-SiC p-i-n diodes are investigated by means of numerical simulations in a wide range of currents and temperatures. Some devices for which recombination and tunneling are the dominant current processes at all biases are classified as ''leaky'' diodes. The well behaved diodes, instead, show good rectifying characteristics with a current conduction due to tunneling below 1.7 V, recombination between 1.7 V and 2.5 V, and diffusion processes above 2.5 V. At higher current regimes, a series resistance in excess of 1 mX cm 2 becomes the main current limiting factor. Depending on the relative weight between the contact resistances and the internal diode resistance, different temperature dependencies of the current are obtained. A good agreement between numerical and measured data is achieved employing temperature-dependent carrier lifetime and mobility as fitting parameters.
The Response of High Voltage 4H-SiC P-N Junction Diodes to Different Edge Termination Techniques
MRS Proceedings, 1998
Edge termination is an important aspect in the design of high power p-n junction devices. In this paper, we compare the breakdown characteristics of 4H-SiC p+-n diodes with oxide passivation and with edge termination using either low or high energy ion implantations. N- and p-type epilayers of 4H-SiC were grown by chemical vapor deposition on n+ 4H-SiC wafers. Circular mesa structures of different diameters were patterned and isolated by reactive ion etching. Four types of samples were fabricated. The first group was not implanted or passivated and was left for control. The second type consisted of oxide-passivated diode structures while the third and fourth types were ion implanted with 30 keV Ar+ and 2.2 MeV He+ ions, respectively. The time dependent breakdown characteristics were determined using a fast voltage ramp technique. The reverse bias breakdown voltages and leakage currents of these diodes were different for the different types of the edge termination. Diodes terminated ...
Microelectronics Journal, 2007
In this work the forward J-V characteristics of 4H-SiC p-in diodes are analysed by means of a physics based device simulator tuned by comparison to experimental results. The circular devices have a diameter of 350 mm. The implanted anode region showed a plateau aluminium concentration of 6 Â 10 19 cm À3 located at the surface with a profile edge located at 0.2 mm and a profile tail crossing the n-type epilayer doping at 1.35 mm. Al atom ionization efficiency was carefully taken into account during the simulations. The final devices showed good rectifying properties and at room temperature a diode current density close to 370 A/cm 2 could be measured at 5 V. The simulation results were in good agreement with the experimental data taken at temperatures up to about 523 K in the whole explored current range extending over nine orders of magnitude. Simulations also allowed to estimate the effect of a different p + doping electrically effective profile on the device current handling capabilities.
Evaluation of the characteristics of silicon carbide diodes using transient-IBIC technique
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2003
Transient ion beam induced current (TIBIC) was used to characterise the quality of the electrodes of p þ n and n þ p SiC diodes fabricated on epitaxial 6H-SiC using different fabrication procedures. The diodes were irradiated with 15 MeV O 4þ and 12 MeV Ni 3þ microbeams. Non-uniform charge collection was observed for p þ n diodes with sintered Al electrode, thus, indicating that the electrode of such diode has spatially poor characteristics. On the other hand, for diodes with electrode formed using Al re-evaporation over the sintered area, uniform TIBIC charge maps were observed. Hence, the quality of electrodes of SiC p þ n diodes can be improved by using Al re-deposition procedure. As for n þ p diode, the degradation of Al sintered electrode due to hydrofluoride acid (HF) treatment was revealed by the basis of non-uniformity of the charge map. Since such spatial information cannot be measured using standard electrical means such as current-voltage measurement, the TIBIC technique can be very useful in evaluating the spatial quality of device electrodes.
Superlattices and Microstructures, 2009
The comparison between cathodoluminescence and deep level transient spectroscopy is a powerful tool to analyze the defect formation in implanted materials. In this work aluminium implanted 4H-SiC p + /n diodes are studied. Different structures, implanted with different ion energy and fluencies, are analyzed in order to understand the process related effects. The comparison between the epilayer and the implanted areas shows an increase of the concentration of intrinsic defects in the implanted areas. The 4H-SiC band-edge emission decreases, increasing the aluminium ion dose, due to the enhancement of the lattice disorder, partially recovered by the post-implantation annealing.
Correlation between Leakage Current and Ion-Irradiation Induced Defects in 4H-SiC Schottky Diodes
Materials Science Forum, 2006
The defects formation in ion-irradiated 4H-SiC was investigated and correlated with the electrical properties of Schottky diodes. The diodes were irradiated with 1 MeV Si+-ions, at fluences ranging between 1×109cm-2 and 1.8×1013cm-2. After irradiation, the current-voltage characteristics of the diodes showed an increase of the leakage current with increasing ion fluence. The reverse I-V characteristics of the irradiated diodes monitored as a function of the temperature showed an Arrhenius dependence of the leakage, with an activation energy of 0.64 eV. Deep level transient spectroscopy (DLTS) allowed to demonstrate that the Z1/Z2 center of 4H-SiC is the dominant defect in the increase of the leakage current in the irradiated material.
Electrical Characterization of the Forward Currentvoltage of Al Implanted 4H-SIC Pin Diodes
2015
In this work,theforward current-voltagecharacteristics of n-type Al implanted 4H-SiC pin diodeshave been investigated experimentally and by mean of numerical simulations in the 298-378K temperature range. Our simulations were performed using proprietary simulations software. The model parameters to be calibrated in the simulation are the electron and hole minority carriers lifetimes.The measured forward I-V characteristics showed two differentbehaviour, the leaky behaved and well behaved diode. The later diodes were considered for simulation comparison.Employing temperature-dependent carrier lifetimes as a fitting parameter, the simulation indicates that drift layer and bulk carrier lifetime ranging from 10ns to 50ns. We achieved a good agreement between simulations and measured data. The measured and the simulated forward characteristics indicate an ideality factor of about1.3for the region 2.5V-2.78Vand 2.14 in the low injection region. Activation energies of about 1.61eV and 2.51...