Power cycling analysis method for high-voltage SiC diodes (original) (raw)

Thermal Stability of Silicon Carbide Power Diodes

IEEE Transactions on Electron Devices, 2000

Silicon carbide (SiC) power devices can operate at much higher junction temperature than those made of silicon. However, this does not mean that SiC devices can operate without a good cooling system. To demonstrate this, the model of a merged p-i-n Schottky (MPS) SiC diode is presented, and its parameters are identified with experimental measurements. This model is then used to study the ruggedness of the diode regarding the thermal runaway phenomenon. Finally, it is shown that, where a purely unipolar diode would be unstable, the MPS structure brings increased stability.

Pulse Evaluation of High Voltage SiC Diodes

2007 IEEE Pulsed Power Plasma Science Conference, 2007

The U. S. Army Research Laboratory (ARL) is evaluating silicon carbide switches and diodes to determine the range of high power and pulsed power applications for which SiC is a sensible material to use. This study focused on 6 kV, SiC P-i-N diodes which were designed by Cree Inc. and packaged and pulse tested at ARL. Diodes were pulsed at a single shot rate both individually and in parallel. Individual diodes were pulsed as high as 5.9 kA (corresponding to an action of 4.5 x 10 3 A 2 s) for 25 single shots before failing, and as high as 5.0 kA (with an action of 3.5 x 10 3 A 2 s) for over 100 shots without failure. Five diodes paralleled in the pulse testbed carried a total current of 23 kA with each diode sharing 19-21% of the total peak current. Eight diodes in parallel reached over 39 kA peak current. The ultimate goal is to combine 8-10 diodes in a single, compact package for higher current applications.

A comparative study between 4H-SiC and silicon power PiN diode having the same breakdown voltage 4KV

2013 International Conference on Electrical Engineering and Software Applications, 2013

The exploitation of silicon carbide semiconductor devices in power electronic field have made exceptional improvements by their fast switching and low dissipated losses especially at high operating temperatures, However, physical performances of silicon power components have reached their limits. This paper presents a comparative study, through numerical simulation and using the finite element method modeling, between 4H-SiC and silicon power PiN diode having the same breakdown voltage "4KV". This comparative study highlights the benefits of silicon carbide.

Characterization of SiC Diodes in Extremely High Temperature Ambient

Twenty-First Annual IEEE Applied Power Electronics Conference and Exposition, 2006. APEC '06., 2006

This paper discusses the static and dynamic behavior of the body diode buried in SiC JFETs and SiC Schottky Barrier Diodes (SBDs). The device parameters are extracted from experimental results and their temperature dependencies are discussed. There is reverse current flow from source to drain in the channel of JFETs for on condition at low temperatures. In higher temperatures, it tends to flow through the body diode due to the increase of the resistance across the channel. The dynamic characteristics indicate that the reverse recovery phenomena of the body diode in a SiC JFET deteriorates with increasing temperature. It is therefore desirable to add an external SiC SBD for improving the static and dynamic behavior for high temperature operation of SiC JFETs.

On the Crossing-Point of 4H-SiC Power Diodes Characteristics

IEEE Electron Device Letters, 2014

The presence of crossing points in the forward J D-V D curves of 4H-SiC pin diodes is analyzed by means of numerical and analytical models. The analysis allows one to justify the different temperature coefficients reported in the literature for SiC diodes and the interlacing behavior of their J D-V D curves. A simple formula for predicting the position of the crossing-point is proposed.

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.

Physics-based modeling and characterization for silicon carbide power diodes

Solid-State Electronics, 2006

Silicon carbide Schottky, merged PiN Schottky (MPS), and PiN diode technologies are modeled for on-state and reverse recovery conditions. The on-state operation of the PiN diode is modeled through four unique regimes of operation, including current densities resulting in emitter recombination, which results in a stored charge plateau during reverse recovery of SiC PiN diodes. An expression for the moving boundary redistribution capacitance is developed to accurately describe the reverse recovery process in PiN diodes. Furthermore, the extraction of stored charge and junction capacitance from transient reverse recovery measurements is also demonstrated for all diode technologies. The on-state operation of Schottky and merged PiN Schottky diodes is described and a method to model the surge current in MPS diodes is discussed. The performance of the model is demonstrated for a commercially available 600 V, 4 A Schottky diode and a 10 kV, 7.5 A PiN diode. Measurements demonstrating the extraction of model parameters and model validation results are included.

Local non invasive study of SiC diodes with abnormal electrical behavior

Solid-State Electronics, 2015

In this work, Silicon Carbide Schottky Barrier Diodes (SBDs) were inspected by Infrared Lock-In Thermography to study and determine the origin of structural weak spots resulting from their manufacturing and electro-thermal stressing tests. These spots are frequency modulated following three different approaches representative of the SBDs operating regimes and detected by their infrared emission, as they behave as hot spots. According to thermal results, such weak spots have originated from barrier modification due to the wire-bonding process, non-uniform active area resistance due to bad metallization electrical contact, deep level traps creation due to high energy implantation in the edge termination, and internal propagation of lattice defects during thermal cycling.

Steady-state and transient characteristics of 10 kV 4H-SiC diodes

Solid-state Electronics, 2004

Steady-state and transient characteristics of 10 kV 4H-SiC diodes have been measured in the temperature interval from 293 to 514 K. The results obtained demonstrate a high level of base modulation: at forward current density j F ¼ 180 A cm À2 , the differential resistance r d of the diode is 24 times lower than the ohmic resistance r 0 of the unmodulated base at room temperature. The minority carrier lifetime s p has been measured by open circuit voltage decay (OCVD) and current recovery time (CRT) techniques. The lifetimes s p values measured by OCVD are 1.55 ls at room temperature and 6.52 ls at T ¼ 514 K, which are the highest reported values for SiC diodes. CRT measurements indicate a uniform distribution of carrier lifetime across the diode base. However, comparison of the experimental results with the results of adequate simulation reveals reduced values of electron lifetime in highly doped part of the p þemitter.

Paradoxes" of carrier lifetime measurements in high-voltage SiC diodes

IEEE Transactions on Electron Devices, 2001

For Silicon Carbide (SiC) high-voltage rectifier diodes, contradictions appear when the most important parameter of the diodes, the minority carrier lifetime, is measured by different techniques. A qualitative analysis and a computer simulation have been carried out to clarify the origin of these contradictions. For 4H-SiC p + n diodes with 6-kV blocking capability, data on residual voltage drop at high current densities, switch-on time, reverse current recovery, and post-injection voltage decay are analyzed. It is shown that the whole set of experimental data can be explained by the existence of a thin ( 0 1 m) layer near the metallurgical boundary of the p + n junction with very small carrier lifetime that is essentially smaller than the carrier lifetime across the remaining part of the 50-m n-base. It is emphasized that the existence of such a layer allows, under certain conditions, the combination of a relatively low residual forward voltage drop and very fast reverse recovery. Approaches to minority carrier lifetime measurements are discussed.