A new punch-through IGBT having a new n-buffer layer

Insulated gate bipolar transistors (IGBTs) based on the non-punch-through (NPT) design approach exhibit excellent safe operating area (SOA) and short-circuit endurance, a positive temperature coefficient of on-state voltage over the operating current range, and low silicon cost. These merits have supported the development and commercialization of NPT IGBTs above the 1200-V class. However, the need for quite thin silicon to obtain competitive on-state losses at 1200-V and below classes has hindered the use of the NPT approach in this area. A new punch-through (PT) IGBT has been developed which exhibits the merits of the NPT approach, rugged SOA and short-circuit endurance, while also having a better tradeoff relation between on-state voltage and turn-off loss than either existing NPT or third-generation PT IGBTs     

Rated overload Characteristics of IGBTs for low-voltage and high-voltage devices

By a vertical shrink of the nonpunchthrough insulated gate bipolar transistor (NPT IGBT) to a structure with a thin n-base and a low-doped field stop layer a new IGBT can be realized with drastically reduced overall losses. In particular, the combination of the field stop concept with the trench transistor cell results in an almost ideal carrier concentration for a device with minimum on-state voltage and lowest switching losses. This concept has been developed for IGBTs and diodes from 600 V up to 6.5 kV. While the tradeoff behavior (on-state voltage V/sub CEsat/ or V/sub F/ to tail charge) and the overall ruggedness (short circuit, positive temperature coefficient in V/sub CEsat/, temperature independence in tail charge, etc.) is independent of voltage and current ratings the switching characteristics of the lower voltage parts (blocking voltage V/sub Br/<2 kV) is different in handling to the high-voltage transistors (V/sub Br/>2kV). With the HE-EMCON diode and the new field stop NPT IGBT up to 1700 V there is almost no limitation in the switching behavior, however, there are some considerations-a certain value in the external gate resistor has to be taken. High-voltage parts usually have lower current density compared to low-voltage transistors so that the "dynamic" electrical field strength is more critical in high-voltage diodes and IGBTs.     

Comparison of Static and Switching Characteristics of 1200 V 4H-SiC BJT and 1200 V Si-IGBT

In this paper, static and switching characteristics of a 1200 V 4H-silicon carbide (SiC) bipolar junction transistor (BJT) at a bus voltage of 600 V are reported for the first time. Comparison was made between the SiC BJT and a 1200 V Si insulated gate bipolar transistor (IGBT). The experimental data show that the SiC BJT has much smaller conduction and switching losses than the Si IGBT. The SiC BJT also shows an extremely large reverse bias safe operation area, and no second breakdown was observed. This removes one of the most unattractive aspects of the BJT. The results prove that, unlike Si BJTs, BJTs in 4H-SiC are good competitors for Si IGBTs.     

Recent advances in insulated gate bipolar transistor technology

Device design of the insulated gate bipolar transistor (IGBT) has been optimized to reduce the distributed transmission-line effect. In addition, cell geometry is chosen to yield high latchup current capability and low forward-voltage drop simultaneously. The vertical structure is optimized to enhance both the turn-off speed and the safe operating area of the IGBTs. The turn-off time of the n-IGBT has been shortened to be as low as 40 ns. The p-channel IGBT latchup current has been improved four to six times over the previously reported results through innovative design and processes. An open-base bipolar transistor model has been implemented to investigate transient IGBT characteristics     

Evaluation of modern power semiconductor devices and future trendsof converters

The author reviews the modern power semiconductor devices that appeared in the 1980s, i.e., the insulated gate bipolar transistor (IGBT), static induction transistor (SIT), static induction thyristor (SITH), and the recently introduced MOS-controlled thyristor (MCT). The characteristics of these devices are discussed and compared from the viewpoint of power electronics applications. Although the IBGT is well known, the power electronics community is somewhat unfamiliar with the latter three devices. For completeness, a brief review of other power devices, such as the thyristor, triac, gate turn-off thyristor (GTO), bipolar transistor (BJT), and power MOSFET is also incorporated. Future trends are outlined     

IGBT的低温特性及计算机仿真

研究了非穿通型(Non-PunchThrough,NPTI)GBT在77～300K之间的暂稳态特性。研究表明,低温环境下NPT-IGBT的通态压降、寄生PNP晶体管电流增益和关断时间均有减小,门槛电压和跨导增加。在总结并改进硅材料主要参数在低温区的温度模型基础上,分析了NPT-IGBT低温特性的物理机制,并实现其关键参数随温度变化趋势的计算机仿真,仿真结果与实验数据取得一致。     

Characteristics and utilization of a new class of low on-resistanceMOS-gated power device

A new class of MOS-gated power semiconductor devices Cool MOS (Cool MOS is a trademark of Infineon Technologies, Germany) has been introduced with a supreme conducting characteristic that overcomes the high on-state resistance limitations of high-voltage power MOSFETs. From the application point of view, a very frequently asked question immediately arises: does this device behave like a MOSFET or an insulated gate bipolar transistor (IGBT)? The goal of this paper is to compare and contrast the major similarities and differences between this device and the traditional MOSFET and IGBT. In this paper, the new device is fully characterized for its: (1) conduction characteristics; (2) switching voltage, current, and energy characteristics; (3) gate drive resistance effects; (4) output capacitance; and (5) reverse-bias safe operating areas. Experimental results indicate that the conduction characteristics of the new device are similar to the MOSFET but with much smaller on-resistance for the same chip and package size. The switching characteristics of the Cool MOS are also similar to the MOSFET in that they have fast switching speeds and do not have a current tail at turn-off. However, the effect of the gate drive resistance on the turn-off voltage rate of rise (dv/dt) is more like an IGBT. In other words, a very large gate drive resistance is required to have a significant change on dv/dt, resulting in a large turn-off delay. Overall, the device was found to behave more like a power MOSFET than like an IGBT     

Untersuchungen und Erfahrungen mit abschaltbaren Leistungshalbleitern

Übersicht Vorgestellt werden neue abschaltbare Leistungshalbleiter (GTO, bipolare Transistoren, IGT, MOSFET, SIT und schnelle Dioden), die in den letzten Jahren die Leistungselektronik in allen Leistungsbereichen entscheidend verändert haben. Diskutiert werden das Schaltverhalten (Ein- und Ausschalten) und der sich daraus ergebende Frequenzbereich. PWM-Wechselrichter mit 20 kHz Pulsfrequenz mit verschiedenen Transistortypen werden verglichen: hier hat der IGT die besten Eigenschaften. Steuergeneratorschaltungen und Steuerleistungsbedarf werden angegeben. Für GTOs werden verlustarme Beschaltungen erörtert. Anwendungen und Entwicklungstrends werden aufgezeigt.

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Measurements and experiences with turn-off semiconductor power devices

Contents Presented are new turn-off semiconductor power devices (GTO, bipolar transistor, IGT, MOSFET, SIT and fast recovery diodes), which have changed decisively power electronics in all power ranges during the last years. Discussed are the switching behavior (turn-on and turn-off) and the applicable frequency range. PWM-inverters with different types of transistors are compared; here the IGT has the best properties. Gate driver circuits and gate power demand are given. Low-loss snubbers for GTOs are presented. Applications and development trends are shown.

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Herrn Prof. Dr. phil. nat. W. Gerlach zum 60. Geburtstag gewidmet.     

Experimental verification of the physics and structure of thebipolar junction transistor

The authors present an electrical characterization of discrete bipolar junction transistor (BJT) devices, with nonuniform doped emitter and base zones. The measurement of the I-V and C-V characteristics of the emitter-base and the collector-base junctions and the common emitter current gain allows to determine relevant parameters of the device. These are the built-in voltage of both junctions, the impurity gradient profiles, the electrical area of both junctions, the base and the emitter Gummel numbers and the collector doping. The whole experiment can be conducted in a laboratory session of 3-4 hour length and it is specifically addressed to students taking lectures in semiconductor device physics. The results obtained give a deep insight into both the physical structure and the physical processes involved in the transistor behavior     

具有低能耗的场截止型IGBT研究

开发出场截止型IGBT并深入研究了场截止型IGBT的核心技术和关键工艺。相比非穿通型IGBT,通过场截止层的形成,芯片厚度降至105 μm,器件导通压降低于2V,关断时间小于250 ns,电学性能得到了显著提高。IGBT应用于电磁炉,在不同功率下的管壳温升为25℃~35℃,远低于非穿通型IGBT,达到了更低的能量损耗。     

Controlling the ON-resistance in SOI LDMOS using parasitic bipolar junction transistor

We present a new parasitic bipolar junction transistor (BJT) enhanced silicon on insulator (SOI) laterally double diffused metal oxide semiconductor (LDMOS), called BJT enhanced LDMOS (BE-LDMOS). The proposed device utilizes the parasitic BJT present in an LDMOS to increase the drain current for a given gate voltage, resulting in a reduction in the ON-resistance by 26.2 % and improving the switching speed by 7.8 % for BE-LDMOS as compared to the comparable LDMOS. These improvements are without degradation in other performance parameters such as off state breakdown voltage and transconductance. The process steps for fabricating BE-LDMOS are same as that for LDMOS except for an additional metal contact.     

高速集电极沟槽绝缘栅双极晶体管

在前期高速绝缘栅双极晶体管(IGBT)的基础上提出一种高速集电极沟槽绝缘栅双极晶体管(CT-IGBT)。该器件沟槽集电极与漂移区的内建电势差感应形成电子沟道而加快关断速度,且集电极沟槽具有不同于传统电场截止层(FS)的电场截止机制,并引入低浓度N型层以降低集电极沟槽对空穴注入的抑制作用。硅基材料有限元仿真结果表明,新结构CT-IGBT的关断下降时间比传统沟槽FS-IGBT少49%,且前者耐受的雪崩能量比后者高32%。因此,新结构CT-IGBT具有比FS-IGBT更优越的关断速度和强度,可应用于大功率高速电力电子系统。     

Toward 99% efficiency for transistor inverters

Developments in power switching devices have been made toward reducing the conduction drop and improving the switching characteristics, in order to meet the demanding requirements for high efficiency. On the other hand, many efforts have been made to reduce the switching losses. Since bipolar junction transistors (BJTs) have the lowest on-state drops among those existing semiconductor switches with turn-off capability, BJTs are most suitable for realizing inverters of high efficiency at power levels under a few hundred kVA. However in the Darlington structure, there is higher on-state drop due to the driver transistors. It is therefore important to reduce the on-state drop in order to realize high efficiency with the Darlington transistors. In this article, two methods are proposed to greatly reduce their on-state drops. Firstly, a base drive circuit is presented that provides a direct drive to the output transistor of a Darlington transistor rather than through its driver transistors. To eliminate the disadvantage related to the direct base drive, an on-state drop cancellation method is then proposed, in which a DC voltage source is inserted in series with the driver transistor of a Darlington transistor to offset its on-state drop     

A Two-Quadrant Transistor Chopper for an Electric Vehicle Drive

A two-quadrant dc-dc transistor converter capable of delivering 400 A motoring current and of generating 200 A braking current is described. The chopper operates from a 108-V dc source (54 lead-acid cells) and supplies the armature current of a separately excited dc machine in an electric vehicle application (3000-lb commuter-type vehicle). The chopper employs high-current transistors specifically developed for the application and power diodes packaged together in power module form. Snubber networks which reduce both turn-on and turn-off device stresses are employed. The interaction of the snubber networks for the motoring and braking transistors is described and design considerations presented. It was found that for these snubbers a minimum on-time and a minimum off-time for the transistors must be maintained to ensure that the transistors' dynamic load lines never enter into the region of forward bias or reversed bias second breakdown. A technique is described which instantaneously detects a transistor failure and initiates the appropriate action in order to prevent machine overcurrent and overtorque. Factors are discussed which are crucial to ensure proper transitions from motoring to braking and to inhibit device power dissipation due to parasitic currents. The selection of a variable-frequency/variable-pulsewidth switching strategy and protection and control techniques unique to high-current transistor choppers are discussed.     

Application of Transistor Emitter-Open Turn-Off Scheme to High Voltage Power Inverters

A transistor emitter-open turn-off scheme has been implemented in an experimental operating high voltage power inverter. Not only the transistor turn-off speed is greatly increased by using such a turn-off scheme but also the reverse-biased second breakdown phenomenon is eliminated. Therefore the very same device can be fully utilized for higher voltage and higher frequency applications.     

Turn-On and Turn-Off Characteristics of a 4.5-kV 3000-A Gate Turn-Off Thyristor

A 4.5-kV 3000-A gate turn-off (GTO) thyristor has been developed for use in high-power motor drive control equipment such as inverters and choppers. The high gate turn-off current of 3000 A is achieved by decreasing the variation of on-state voltages as well as turn-off times between segments which compose the GTO thyristor. This idea is supported by observation of infrared radiation during the turn-off process in the parallel operation of two segments with different on-state voltages or turn-off times. The parallel operation behavior is well simulated by a two-dimensional numerical simulation. Such design considerations and electrical characteristics of the newly developed high-power GTO thyristor are described. The device has a forward blocking capability of 4.5 kV, a maximum gate turn-off current of 3000 A, on-state voltage of 3.0 V at 3000 A, turn-on time of 10 ?s, and turn-off time of 25 ?s.     

The QP Triangle: A Graphical Method for Bias Design

A graphical design procedure is presented based upon a QP triangle for the design of bipolar transistor (BJT) bias circuits. The design technique stresses quiescent point (QP) location on the IC-VCE characteristics and considers the effects of simultaneous variations in the BJT parameters hFE, VBE, and ICO upon QP location. The QP triangle method is developed for the standard one-battery BJT CE stage discussed in many introductory electronic circuits textbooks. The QP triangle method is applied to a specific CE stage which has to meet certain design specifications. One important specification is that the circuit must operate over the temperature range 25-100°C with silicon N-P-N BJT's having values of h 40 and hFE 100°C) < 200. The available tradeoffs between the peak-to-peak voltage Vpp and the current gain AI are stressed and the best available design is selected. The performance of the selected design was simulated on a digital computer and measured in the laboratory. Both the computer simulation and the experiment are in good agreement with the design. The QP triangle method has been used in an introductory electronic circuits course with success for several years. Students understand this graphical design procedure and are able to apply it. It is recommended for beginning electronics students. An interactive computer program AMPDSN to aid students and instructors design the standard one-battery BJT CE stage is also described. An algorithm based upon the QP triangle is used. The program language is Basic.     

寄生电感对于功率MOSFET开关特性的影响

分散在MOSFET栅极、源极、漏极的寄生电感由于封装以及印制电路板（PCB）走线,改变了MOSFET的开关特性。通过仿真分析对比,指出MOSFET寄生电感存在如下特性：源极电感对栅极驱动形成负反馈,导致开关速度变慢,采用开尔文连接,可以将栅极回路与功率回路解耦,提高驱动速度;在米勒效应发生时刻需要合理地降低栅极电感来降低栅极驱动电流;漏极电感通过米勒电容影响MOSFET的开通速度,在关断时刻导致电压应力增加;在并联的回路当中,非对称的布局将导致MOSFET之间的动态不均流;当MOSFET在开关过程中,环路电感与MOSFET自身的结电容产生振荡时,可以在电路增加吸收电容减小环路电感,改变振荡特性。     

Electrical Characteristics of High-Voltage High-Power Fast-Switching Reverse-Conducting Thyristor and Its Applications for Chopper Use

The structures, features, electrical characteristics, and successful application results of two types of high-voltage high-power reverse-conducting thyristors are described. The first has blocking voltage ratings of 1300 V and current ratings of 400 A in the forward direction and 150 A in the reverse direction, with a turn-off time of 30 ?s. The second has ratings of blocking voltage of 2500 V, current ratings of 400 A in the forward direction and 150 A in the reverse direction, with a turn-off time of 40?s.