MOS-controlled Thyristor Research Articles

Displacement Damage Effects of Pulse Discharge Circuit Switched by Anode-Short MOS-Controlled Thyristor

The anode-short metal–oxide–silicon (MOS)-controlled thyristor (AS-MCT) is the latest generation of MCT. Due to its MOS gating, high-current-rise rate, normally-OFF, and high blocking capabilities, the AS-MCT is an ideal switch for pulse discharge application. Previously, we show that the static behaviors of AS-MCT are susceptible to displacement damage (DD) as it contains bipolar structures. As a continuation of our previous work, this article reports the experimental results for the degradation of pulse discharge circuit (PDC) characteristics induced by the DD of its XND1 AS-MCT switch following fast neutron exposure up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$7.8\times {10}^{13}\,\,{\text {cm}}^{-2}$ </tex-math></inline-formula> . Both the charging time and the peak surge current of the PDC decrease significantly once the neutron flux surpasses a critical value, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim {10}^{12}\,\,{\text {cm}}^{-2}$ </tex-math></inline-formula> . From device and circuit physics perspectives, an analytical model based on equivalent leakage current resistance is proposed to describe the degradation of the two parameters, and then, this article suggests the mechanisms behind such degradations from the neutron exposure of AS-MCT switch.

Design, fabrication, and characterization of the modular integrated exploding foil initiator system based on low temperature co-fired ceramic technology

In this study, the flyback high-voltage conversion unit, capacitor discharge unit, and EFI chip of the exploding foil initiator (EFI) system were highly integrated using low temperature cofired ceramic technology and MEMS, forming a modular integrated system with boost, discharge, and firing functions. The modular integrated EFI system used the design idea of system in a package, selected chip-level or planar components, eliminating the need for connecting wires and reducing the volume of the EFI system to 5.67 cm3. Compared with the traditional EFI system, while analysis from the characterization showed that the integrated structure reduced the loop inductance of the system to 27 nH, which was 55 % lesser, it accelerated the flyer to 3800 m/s, which was 15.2 % faster. These accomplishments indicated that the energy utilization rate of the integrated system was higher. The input voltage of the system was reduced from traditionally high voltage of 1250 V to lower voltage of 24 V due to the integrated-system boost function. Simultaneously, the 5 V MOS controlled thyristor (MCT) chip was selected to replace 1800 V∼2500 V spark gap switch as the working voltage, thus making 5 V the switching voltage of the system. These changes made high safety operation of the system. Moreover, the system had used modular design and manufacturing to improve its reliability and obtained the characteristics of mass production.

A Study on Ionization Damage Effects of Anode-Short MOS-Controlled Thyristor

The mymargin metal–oxide–semiconductor mymargin (MOS)-controlled thyristor (MCT) has been characterized by MOS gating, high current rise rate, and high blocking capabilities. The anode-short MCT (AS-MCT) is distinguished from the conventional MCT by an anode-short structure, which forms an extracting path for the electron current at the gate ground and develops a normally-OFF characteristic. As a composite structure made of MOS and bipolar junction transistors, the AS-MCT is susceptible to ionization damage. The total ionization dose (TID) effects on the XND1 AS-MCT (breakdown voltage 1800 V grade) with a dose up to 9160 Gy(SiO2) are reported. The experimental results of transfer, forward conductive, and forward blocking characteristics are presented. A novel phenomenon, denoted as “self-trigger”, is identified for the AS-MCT following $\gamma $ -ray exposures, which can account for the significant increase in anode current in the AS-MCT. This article proposes the mechanism behind the characteristic degradation from the TID damage in the AS-MCT, from a device physics perspective.

Design and Experimental Verification of an Efficient SSCB Based on CS-MCT

A novel solid state circuit breaker (SSCB), which uses the cathode-short MOS-controlled thyristor (CS-MCT) as the main switch to achieve high power efficiency, is proposed for direct current (dc) microgrid protection. The proposed SSCB features the commutating circuit with a one-shot triggering characteristic and a compact size, which makes the SSCB realize a simple tripping process and easy integration. Furthermore, the SSCB charges the commutating capacitor and offers the interruption capability before the main switch is turned on . This avoids the possible failure of the breaker under the fault that occurs at the initial stage of the turn- on of the main switch, thus providing highly reliable and robust interruption capability for the SSCB. Circuit analysis and design guidelines are discussed in detail through the mathematical modeling. Moreover, the practical value and the feasibility of the SSCB are validated by 600-V/15-kW prototype experiments and further verified in dc microgrids through simulations.

Ionization Damage Effects of Pulse Discharge Circuit Switched by Anode-Short MOS-Controlled Thyristor

The MOS-controlled Thyristor (MCT) has been characterized by MOS-gating, high current rise rate, and high blocking capabilities. The anode short MCT (AS-MCT) is distinguished from the conventional MCT by an anode-short structure, which forms an extracting path for the leakage current at the gate-ground and develops a normally-off characteristic. The AS-MCTs are ideal switches for pulse discharge application. As a composite structure made of metal-oxide-silicon and bipolar junction transistors, AS-MCT is susceptible to ionization damage. This work reports the experimental results for the degradation of zero-load (or short) pulse discharge circuit characteristics induced by the ionization damage of its AS-MCT switch following cobalt-60 γ-ray dose up to 9160 Gy(SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ). The radiation-induced leakage current in AS-MCT accounts for the degradations of charging time and peak surging current of the pulse discharge circuit. These degradations show a “tick”-like dependence on the γ-ray dose which are recoverable after high dose exposures, thousands of Gy(SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ). From device and circuit physics perspectives, the damages on pulse discharge circuit are modelled, and then, this article proposes, the mechanism behind the characteristics degradation of pulse discharge circuit from the total ionization dose damage of AS-MCT switch.

Modeling the Displacement Damage on Trigger Current of Anode-Short MOS-Controlled Thyristor

The MOS-controlled Thyristor (MCT) has been characterized by MOS-gating, high current rise rate, and high blocking capability. The anode short MCT (AS-MCT) is distinguished from conventional MCT by an anode-short structure, which develops a normally-off characteristic. As a composite structure made of metal-oxide-silicon and bipolar junction transistors, AS-MCT is susceptible to displacement damage induced by energetic radiation. The anode trigger current which denotes the latch-up of internal thyristor structure is a key parameter for AS-MCTs. From the aspects of devices physics, we propose a model to describe the displacement damage on trigger current. Our model provides an excellent fit to the experimental data of the AS-MCT samples subjected to fission neutrons with flux in the range of $3.1\times 10^{9}-5.5\times 10^{13}\,\,\mathrm {cm}^{-2}$ . Moreover, this work shows that the high injection effect can alleviate the displacement damage of trigger current following high flux exposures.

A Novel Insulated Gate Triggered Thyristor With Schottky Barrier for Improved Repetitive Pulse Life and High-&lt;italic&gt;di/dt&lt;/italic&gt; Characteristics

In this paper, a novel insulated gate triggered thyristor with the Schottky barrier (SB-IGTT) is proposed for improved the repetitive pulse life and high- di/dt characteristics. Different from the conventional cathode shorted MOS-controlled thyristor (CS-MCT), an SB is specially imbedded to enlarge the effective turn-on area and enhance the electron–hole plasma spread during short duration pulse, which contributes significantly to relaxing the thermal concentration and improving the repetitive pulse life as well as achieves superior di/dt characteristics. The experimental results show that the proposed SB-IGTT continuously undergoes more than 220 000 shots at the pulse frequency of 5 Hz, yielding a $10\times $ longer repetitive pulse life than the conventional CS-MCT. Simultaneously, SB-IGTT performs a di/dt up to 120 kA/ $\mu \text{s}$ with peak current near 10 kA, increasing di/dt by about 20%. Improved repetitive pulse life and simultaneous superior di/dt characteristics indicate that the proposed SB-IGTT is suitable for repetitive pulse power applications.

Design and Characterization of High $di/dt$ CS-MCT for Pulse Power Applications

A high di/dt MOS-controlled thyristor with cathode-short structure (CS-MCT) is developed for pulse power applications. Compared with conventional MCT (con-MCT), the cathode short in the proposed CS-MCT greatly improves the dV/dt robustness. To achieve simultaneously high di/dt capability, special design of device characteristics parameter and consideration of 2-D transient carrier transport are carried out for the first time. Experimental results show that the proposed CS-MCT exhibits di/dt over 357 kA/cm $^{{\textsf {2}}}$ / $\mu \text{s}$ and peak current of 27.1 kA/cm $^{{\textsf {2}}}$ . Meanwhile, the improved practical dV/dt characteristics are validated in comparison with con-MCT at the same condition. The high di/dt property and simultaneously high dV/dt robustness indicate the proposed CS-MCT is a promising semiconductor pulse switch for pulse power applications.

On the Investigation of the “Anode Side” SuperJunction IGBT Design Concept

In this letter, we present the “anode-side” SuperJunction trench field stop+ IGBT concept with drift region SuperJunction pillars placed at the anode side of the structure rather than the cathode side. The extent of the pillars toward the cathode side is shown to pose a tradeoff between fabrication technology capabilities (and cost) versus the device performance, by extensive TCAD simulations. The proposed device structure simplifies the fabrication requirements by steering clear from the need to align the cathode side features with the SuperJunction pillars. It also provides an extra degree of freedom by decoupling the cathode design from the SuperJunction structure. Additionally, the presence of SuperJunction technology in the drift region of the “anode-side” SJ Trench FS+ IGBT results in 20% reduction of ON-state losses for the same switching energy losses or, up to 30% switching losses reduction for the same ON-state voltage drop, compared with a 1.2-kV breakdown rated conventional FS+ Trench IGBT device. The proposed structure also finds applications in reverse conducting IGBTs, where a reduced snapback can be achieved, and in MOS-controlled thyristor devices.

문턱전압 조절 이온주입에 따른 MCT (MOS Controlled Thyristor)의 스위칭 특성 연구

문턱전압 조절 이온주입에 따른 MCT (MOS Controlled Thyristor)의 스위칭 특성 연구

Novel reverse conducting insulated gate bipolar transistor with anti-parallel MOS controlled thyristor

Novel reverse-conducting IGBT (RC-IGBT) with anti-parallel MOS controlled thyristor (MCT) is proposed. Its major feature is the introduction of an automatically controlled MCT at the anode, by which the anode-short effect is eliminated and the voltage snapback problem is solved. Furthermore, the snapback-free characteristics can be realized in novel RC-IGBT by a single cell with a width of 10 μm with more uniform current distribution. As numerical simulations show, compared with the conventional RC-IGBT, the forward conduction voltage is reduced by 35% while the reverse conduction voltage is reduced by 50% at J = 150 A/cm2.

A behavioral model for MCT surge current analysis in pulse discharge

In this work, a behavioral model for MOS Controlled-Thyristor (MCT) surge current analysis is proposed together with a design criterion. In this model, the relationships between the surge current characteristics including peak current (Ipeak) and high current rising rate (di/dt) of MCT and the device resistance (R) have been discussed, and then a readily measurable parameter, critical resistance (Rc), is presented to estimate the device surge current capability. According to the analytical results, both Ipeak and di/dt of MCT have been found to remain approximately constant with increasing resistance unless its resistance approaches and exceeds this Rc. It is therefore referred to as a design criterion for guiding the device design. The accuracy of the developed model and criterion are verified by comparing the obtained results with those resulting from simulation and experiment results.

An Investigation of a Novel Snapback-Free Reverse-Conducting IGBT and With Dual Gates

A novel reverse-conducting insulated-gate bipolar transistor (RC-IGBT) with an automatically controlled anode gate, named AG-RC-IGBT, is proposed in this paper, wherein a gate on the reverse IGBT is intrinsically off in the forward conduction state and can be automatically turned on in the reverse conduction state. Therefore, bidirectional conduction capability with snapback-free characteristics is achieved in the novel RC-IGBT. Depending on the parameters set on the reverse IGBT, its operation mode can be either like an antiparallel IGBT or like an antiparallel MOS-controlled thyristor (MCT). The antiparallel MCT mode can yield low snapback current densities and low on-state voltages in both forward and reverse conductions. Two-dimensional numerical simulations show that snapback-free characteristics are obtained in the AG-RC-IGBT antiparallel with an IGBT by a 15-μm-wide half-pitch in both forward and reverse conduction states. The antiparallel MCT mode achieves low on-state voltages of 0.97 and 1.6 V at the current density of 200 A/cm2 in reverse and forward conduction states, respectively.

Clustered Insulated Gate Bipolar Transistor in the Super Junction Concept: The SJ-TCIGBT

We report results of comprehensive 2-D simulation evaluation of the first MOS-controlled thyristor structure employing the super junction concept on a 1.2-kV field stop structure. In comparison to a standard device, simultaneous reduction in Vce(sat) and Eoff can be achieved in a super junction trench clustered insulated gate bipolar transistor (SJ-TCIGBT). The simulation results show that up to 80% reduction in Eoff is possible. Unlike the super junction insulated gate bipolar transistors, there is no significant increase in the saturation current with the anode voltage or the depth of the pillars. SJ-TCIGBT is a highly promising next generation device concept with record-breaking Vce(sat)-Eoff tradeoff enhancement to improve converter efficiency.

Comparison of Trench Gate IGBT and CIGBT Devices for Increasing the Power Density From High Power Modules

Recently much research has been focused on increasing the functionality and output power density per unit area in power electronic modules without increasing board space. In high power applications, MOS-controlled devices with trench gates are the most desirable as their reduced <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ce</sub> (sat) enables increased conduction current density. However, with increased drift region thickness, there is significant increase in conduction loss in trench gate-insulated gate bipolar transistor (T-IGBT) due to low plasma density from inherent p-n-p transistor action. In comparison, a well-designed MOS-controlled thyristor structure such as the trench-clustered insulated gate bipolar transistor (T-CIGBT), can provide low on-state conduction loss with gate voltage turn-on and turn-off. The comparison of 3.3 kV/800 A simulation results presented in this paper shows that the T-CIGBT is a superior candidate over TIGBT to increase the power density from existing high-voltage IGBT module footprints.

Silicon Carbide Emitter Turn-Off Thyristor

A novel MOS-controlled SiC thyristor device, the SiC emitter turn-off thyristor (ETO) is a promising technology for future high-voltage switching applications because it integrates the excellent current conduction capability of a SiC thyristor with a simple MOS-control interface. Through unity-gain turn-off, the SiC ETO also achieves excellent Safe Operation Area (SOA) and faster switching speeds than silicon ETOs. The world's first 4.5-kV SiC ETO prototype shows a forward voltage drop of 4.26 V at 26.5 A/cm2 current density at room and elevated temperatures. Tested in an inductive circuit with a 2.5 kV DC link voltage and a 9.56-A load current, the SiC ETO shows a fast turn-off time of 1.63 microseconds and a low 9.88 mJ turn-off energy. The low switching loss indicates that the SiC ETO could operate at about 4 kHz if 100 W/cm2 conduction and the 100 W/cm2 turn-off losses can be removed by the thermal management system. This frequency capability is about 4 times higher than 4.5-kV-class silicon power devices. The preliminary demonstration shows that the SiC ETO is a promising candidate for high-frequency, high-voltage power conversion applications, and additional developments to optimize the device for higher voltage (&gt;5 kV) and higher frequency (10 kHz) are needed.

A UNIQUE INDUCTION HEATED COOKING APPLIANCES RANGE USING HYBRID RESONANT CONVERTER

The present paper describes a converter where both series and parallel resonant circuits are used. In order to minimize losses, switching is made at zero current crossover (ZCS). The converter described in this paper has four MOS-controlled thyristor (MCTs) in H-bridge configuration (Full bridge). It is used for an induction cooking-range with two hot zones. The switching frequency is 50 kHz. To optimize the system efficiency, different control strategies are discussed.

수평 구조의 MOS-controlled Thyristor에서 채널에서의 길이 및 불순물 농도에 의한 스위칭 특성

The switching characteristics of MOS-Controlled Thyristor(MCT) is studied with variation of the channel length and impurity concentration in ON and OFF FET channel. The proposed MCT power device has the lateral structure and P-epitaxial layer in substrate. Two dimensional MEDICI simulator and PSPICE simulator are used to study the latch-up current and forward voltage-drop from the characteristics of I-V and the switching characteristics with variation of channel length and impurity concentration in P and N channel. The channel length and N impurity concentration of the proposed MCT power device show the strong affect on the transient characteristics of current and power. The N channel length affects only on the OFF characteristics of power and anode current, while the N doping concentration in P channel affects on the ON and OFF characteristics.

수평 구조의 MOS-controlled Thyristor에서 채널 길이 및 불순물 농도에 의한 Anode 전류 특성

The latch-up current and switching characteristics of MOS-Controlled Thyristor(MCT) are studied with variation of the channel length and impurity concentration. The proposed MCT power device has the lateral structure and P-epitaxial layer in substrate. Two dimensional MEDICI simulator is used to study the latch-up current and forward voltage-drop from the characteristics of I-V and the switching characteristics with variation of impurity concentration. The channel length and impurity concentration of the proposed MCT power device show the strong affect on the anode current and turn-off time. The increase of impurity concentration in P and N channels is found to give the increase of latch-up current and forward voltage-drop.

Comparative performance evaluations of IGBTs and MCT incorporated into voltage‐source‐type single‐ended quasi‐resonant zero‐voltage soft switching inverter

AbstractA cost‐effective high‐efficiency, simple, low‐noise voltage‐source‐type single‐ended quasi‐resonant high‐frequency inverter using a single power semiconductor switching device and its modified circuit topologies are commonly applied to consumer induction‐heated rice cookers with a warmer function, cooking heaters, and microwave ovens. This paper presents some comparative performance evaluations of several generations of IGBTs and MCT (MOS Controlled Thyristor) incorporated into the typical voltage‐source quasi‐resonant inverter operating in zero‐voltage soft switching transition mode. The latest generation of IGBT upgraded by lowering the saturation voltage characteristics was designed for consumer power applications in order to reduce conduction losses. The comparative steady‐state characteristics of some simple power semiconductor switching devices of several generations of IGBTs are examined on the basis of the simplest single‐ended quasi‐resonant inverter circuit operating under the zero‐voltage soft switching commutating principle. In addition, the power losses and temperature performance analysis of the latest IGBT are discussed and evaluated relative to previously developed IGBTs. Finally, the further reduced saturation voltage and conduction loss characteristics of MCT which are more suitable for consumer utilizations are presented in comparison with the conventional IGBT. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 144(3): 58–68, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10151