Two dimensional simulation and modeling of the electrical characteristics of the a-SiC/c-Si(p) based, thyristor-like, switches (original) (raw)
Related papers
2015
We presented here for the first time a parametric study for a series of technological and geometrical parameters affecting the electrical characteristics of Al/a-SiC/c-Si(p)/c-Si(n +)/Al thyristor like switches using two dimensional simulation techniques. A series of factors affecting the electrical characteristics of the switches are studied here. Three factors, among all others studied here, exerting most significant influence on both first and second breakdown of the switches are amorphous SiC film width and both c-Si(p) region width and doping concentration. The above factors can be easily varied on device manufacture procedure and their combination, also including all other factors studied here, led to improved electrical characteristics of the switches. This means lowering of forward breakover voltage V BF at first breakdown and forward voltage drop V F after first breakdown at the ON state of the switch to 11V and 9.5V, respectively. This in conjunction with exhibited high anode current density values of 12A/mm 2 before second breakdown and also their cheap and easy fabrication techniques and their high switching speed behavior, makes the switches candidates for ESD protection applications.
Journal of Semiconductors, 2017
A parametric study for a series of technological and geometrical parameters affecting rise time of Al/a-SiC/c-Si (p)/c-Si (n+)/Al thyristor-like switches, is presented here for the first time, using two-dimensional simulation techniques.By varying anode current values in simulation procedure we achieved very good agreement between simulation and experimental results for the rising time characteristics of the switch.A series of factors affecting the rising time of the switches are studied here.Two factors among all others studied here, exerting most significant influence, of more than one order of magnitude on the rising time, are a-SiC and c-Si (p) region widths, validating our earlier presented model for device operation.The above widths can be easily varied on device manufacture procedure.We also successfully simulated the rising time characteristics of our earlier presented simulated improved switch, with forward breakover voltage VBF=11 V and forward voltage drop VF=9.5 V at the ON state, exhibiting an ultra low rise time value of less than 10 ps, which in conjunction with its high anode current density values of 12 A/mm2 and also cheap and easy fabrication techniques, makes this switch appropriate for ESD protection as well as RF MEMS and NEMS applications.
Journal of Applied Physics, 2008
The electrical characteristics of the Al/a-SiC/c-Si(p)/c-Si(n +)/Al switches were successfully simulated here for the first time. Forward breakover voltage V BF , forward voltage drop V F and anode current simulated values of the device showed very good agreement with the experimental results. Electric field and impact generation rate across the switches are also simulated for different anode current conditions extending to second breakdown region of the device, showing a shifting of the phenomena caused by electric field and impact generation rate, from c-Si(p) region to a-SiC film as anode voltage values increase from V BF up to second breakdown region of the device. A both simulation and experimental based model describing the device behavior, is also presented here. Two critical facts leading to switching transition are proved to be at first a-SiC/c-Si(p) heterojunction breakdown dominated by impact generation rate and second subsequent trap filling in the amorphous film. Al/a-SiC/c-Si(p +)/c-Si(p)/c-Si(n +)/Al switches with reduced V BF and V F values, were also fabricated and successfully simulated here, enhancing the validity of our simulation procedure and making the switches candidates for ESD protection devices, also due to their advantages of high anode current value density of 5 A/mm 2 before reaching second breakdown conditions in conjunction with cheap and easy fabrication procedure mainly due to r.f. sputtering technique used for a-SiC film fabrication.
New High-Speed a-Si/c-Si- and a-SiC/c-Si-Based Switches
Active and Passive Electronic Components, 1996
The electrical and optical characteristics of the new high-speed Al/a-Si/c-Si(p)/c-Si(n+)/Al and Al/a- SiC/c-Si(p)/c-Si(n+)/Al optically controlled switches are presented in this paper. These switches exhibit the lowest ever reported values of rise and fall times, for this kind of switches, of about 3ns. They also exhibit a temperature and light reversibly controlled forward breakover voltage (VBF), together with high values of light triggering sensitivity.
Experimental and Modeling Study of Optically Triggered SiC 1000 V p–i–n Diode Switches
Applied Physics Express, 2012
SiC photoconductive switches combine the advantages of both SiC power electronics for high power and high efficiency at high temperature, and optically controlled devices for fast switching, enhanced reliability, and electromagnetic interference (EMI) immunity. In this work, SiC optically triggered diode (OTD) was designed and fabricated. The diode successfully switched 1000 V when illuminated by a single laser pulse of 337.1 nm wavelength and 1.2 mJ optical energy. A physical device model was validated by test results, from which the on-state resistance and peak photocurrent under different bias voltages and optical energies were calculated, and the potential of these optical diodes was further explored.
Journal of Nanoscience and Nanotechnology, 2016
The silicon carbide (SiC) material is being spotlighted as a next-generation power semiconductor material due to the characteristic limitations of the existing silicon materials. SiC has a wider band gap, higher breakdown voltage, higher thermal conductivity, and higher saturation electron mobility than Si. When using this material to implement Schottky Barrier Diode (SBD) devices, SBD-state operation loss and switching loss can be greatly reduced compared to traditional Si. However, actual SiC SBDs exhibit a lower dielectric breakdown voltage than the theoretical breakdown voltage that causes the electric field concentration, a phenomenon that occurs on the edge of the contact surface as in the conventional power semiconductor devices. Therefore in order to obtain a high breakdown voltage, it is necessary to distribute the electric field concentration using the edge termination structure. In this paper, we designed an edge termination structure using a field plate structure through oxide etch angle control, and optimized the structure to obtain a high breakdown voltage. We designed the edge termination structure for a 650 V breakdown voltage using Sentaurus Workbench provided by IDEC. We conducted a field plate experiments under the following conditions: 15 , 30 , 45 , 60 , and 75. The experiment results indicated that oxide etch angle was 45 when the breakdown voltage characteristics of the SiC SBD were optimized and a breakdown voltage of 681 V was obtained.
Gate Current and Snapback of 4H-SiC Thyristors on N+ Substrate for Power-Switching Applications
Electronics, 2020
High-power switching applications, such as thyristor valves in a high-voltage direct current converter, can use 4H-SiC. The numerical simulation of the 4H-SiC devices requires specialized models and parameters. Here, we present a numerical simulation of the 4H-SiC thyristor on an N+ substrate gate current during the turn-on process. The base-emitter current of the PNP bipolar junction transistor (BJT) flow by adjusting the gate potential. This current eventually activated a regenerative action of the thyristor. The increase of the gate current from P+ anode to N+ gate also decreased the snapback voltage and forward voltage drop (Vf). When the doping concentration of the P-drift region increased, Vf decreased due to the reduced resistance of a low P-drift doping. An increase in the P buffer doping concentration increased Vf owing to enhanced recombination at the base of the NPN BJT. There is a tradeoff between the breakdown voltage and forward characteristics. The breakdown voltage i...
Development of process technology for fabrication of 4H-SiC silicon carbide schottky barrier diodes
In recent times, 4H-SiC has been at the center of power semiconductor device research due to its superior material properties such as large bandgap (E g ~3.26 eV), high breakdown electric field (E c ~3 MV/cm which is almost 10 times that of Si), high saturated electron velocity (~2.0×10 7 cm/s which is almost 2 times that in Si), high thermal conductivity (K ~4.9 W/cm.K) and most importantly ability to form a stable native oxide SiO 2. Schottky barrier diodes (SBDs) based on 4H-SiC offer superior dynamic performance (<20 nC reverse recovery charge for a 1200 V, 1A SBD), almost 100 times lower specific-on resistance compared to Si SBDs and PiN diodes. The higher bandgap results in much higher schottky barrier height compared to Si and GaAs resulting in extremely low leakage currents even at elevated temperatures (>300 o C operation). Edge termination and passivation is a critical technology for power devices to fully realize their voltage blocking potential. The objective of this research was to develop the process technology for fabrication of high voltage 4H-SiC SBDs. We decided to use a simple edge termination technique based on Field-Plate (FP) termination. The simplicity of FP termination lies in the fact that unlike other termination techniques such as guard rings, mesa and Junction Termination Extensions (JTE), it does not need high temperature ionimplantations. Such high temperature implantation requires the substrate to be maintained at 700-1000 o C during implantation. It also needs subsequent extreme high temperature anneals in excess of 1500 o C to reduce implantation damage. There are also design issues such as the need to optimize ring spacing. FP termination technique has long been a power horse of Si power device technology using thick SiO 2 field oxide and poly silicon as electrode overlapping the oxide. For past decade or so since its first application to SiC power device ATTENTION: The Singapore Copyright Act applies to the use of this document. Nanyang Technological University Library XI 6.5.3 Electric Field profile of FP terminated 4H-SiC SBDs along the schottky edge with 2-step Breakdown………………………………. 6.6 Conclusions………………………………………………………………. 7. Conclusions and Recommendations for Future Work………………………… 7.1 Conclusions………………………………………………………………. 7.2 Recommendations for Future Work…………………………………….
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.
Characteristics of Ni/SiC Schottky diodes grown by ICP-CVD
Solid-state Electronics, 2006
A Ni/SiC Schottky diode was fabricated with an a-SiC thin film grown by the inductively coupled plasma chemical vapor deposition, ICP-CVD method on a (1 1 1) Si wafer. The a-SiC film was grown on a carbonized Si layer that the Si surface had been chemically converted to a very thin SiC layer by the ICP-CVD method at 700°C. To reduce defects between the Si and a-SiC, the surface of the Si wafer is slightly carbonized. The film characteristics of a-SiC were investigated by employing TEM and FT-IR. A sputtered Ni thin film was used for the anode metal. The boundary status of the Ni/SiC contact was investigated by AES as a function of annealing temperature. It is shown that the ohmic contact could be acquired below 1000°C annealing temperature. The forward voltage drop of the Ni/a-SiC Schottky diode is 1.0 V at 100 A/cm 2 . The breakdown voltage is 545 V which is five times larger than the ideal breakdown voltage of a silicon device. Also, the dependence of barrier height on temperature was observed.