A new gate driver integrated circuit for IGBT devices with advanced protections

The aim of this paper is to discuss new solutions in the design of insulated gate bipolar transistor (IGBT) gate drivers with advanced protections such as two-level turn-on to reduce peak current when turning on the device, two-level turn-off to limit over-voltage when the device is turned off, and an active Miller clamp function that acts against cross conduction phenomena. Afterwards, we describe a new circuit which includes a two-level turn-off driver and an active Miller clamp function. Tests and results for these advanced functions are discussed, with particular emphasis on the influence of an intermediate level in a two-level turn-off driver on overshoot across the IGBT.     

一种有强健的续流开关的新型槽栅逆导IGBT

The phenomenon that the wide P-emitter region in the conventional reverse conducting insulated gate bipolar transistor （RC-IGBT） results in the non-uniform current distribution in the integrated freewheeling diode （FWD）, and then causes a parasitic thyristor to latch-up during its reverse-recovery process, which induces a hot spot in the local region of the device is revealed for the first time. Furthermore, a novel RC-IGBT based on double trench IGBT is proposed. It not only solves the snapback problem but also has uniform current distribution and high ruggedness during the reverse-recovery process.     

IGBT关断瞬态电压尖峰影响及抑制

绝缘栅双极晶体管(IGBT)是一种性能优良的全控型电力电子器件,由于线路和器件内部分布电感的存在,关断时集电极电流的快速变化会感应产生一个较大的电压尖峰从而引起过电压击穿。分析了栅极结电容放电时间常数和拖尾电流对电压尖峰的影响,通过改变栅极驱动电阻和温度可以抑制电压尖峰。分析了电压尖峰引起过压击穿的失效机理以及失效模式,表明IGBT过压击穿引起失效的本质仍然是结温过高引起的热击穿失效。     

Capacitive effects in IGBTs limiting their reliability under short circuit

The short-circuit oscillation mechanism in IGBTs is investigated in this paper by the aid of semiconductor device simulation tools. A 3.3-kV IGBT cell has been used for the simulations demonstrating that a single IGBT cell is able to oscillate together with the external circuit parasitic elements. The work presented here through both circuit and device analysis, confirms that the oscillations can be understood with focus on the device capacitive effects coming from the interaction between carrier concentration and the electric field. The paper also shows the 2-D effects during one oscillation cycle, revealing that the gate capacitance changes according with the shape of the electric field due to the charge distribution in the n-base. It has been identified that the time-varying capacitance leads to parametric oscillations together with the stray gate inductance, which limit the reliability of the IGBT.     

Zero-Current Soft-Switching Performance of 1200-V PT Clustered Insulated Gate Bipolar Transistor

Zero-current soft-switching performance of a 1200-V, 20-A punch-through (PT) clustered insulated gate bipolar transistor (CIGBT) is evaluated in this paper. Turn-on over-voltage transients have been witnessed in 2D numerical simulations and experimental results. These have been shown to be influenced by circuit parameters and internal device structure. Conductivity modulation lag within the device is found to be dependant upon dI/dt; however, this alone does not explain the significant over-voltages at turn-on. The device structure is found to influence the magnitude of such voltage peaks. By optimization of the structure, over-voltages can be minimized, resulting in a significant improvement in losses compared to an IGBT. The current bump associated with zero-current turn-off has been analyzed under various dV/dt values and is influenced by circuit capacitance, switching timings, and carrier lifetime. Internal dynamics of the CIGBT have been analyzed to give an insight into the performance under zero-current switching (ZCS). ZCS tests at 600 V, 20 A have shown that the CIGBT performs well with respect to a commercial IGBT of the same rating. Dynamic saturation voltage of the CIGBT has been shown to be 15% lower at room temperatures to that of an equivalent IGBT.     

A study on the short-circuit capability of field-stop IGBTs

The short-circuit failure mechanism of 1200 V trench gate field-stop insulated gate bipolar transistor (IGBT) has been investigated in this paper. Experimental testing shows that most of the devices failed during the blocking state after a few hundred microseconds of the short-circuit turn-off condition. This unusual failure mode was analyzed both with experimental and numerical investigation. It has been determined that due to significantly large leakage current, thermal run-away can occur causing device failure after short circuit turn-off. Due to the smaller heat capacity of the FS-IGBT structure, the device temperature after the turn-off becomes so high that the local heating produced by the high temperature leakage current results in the thermal run-away.     

SOI铁电负电容晶体管亚阈值特性研究

随着微电子技术进入纳米领域,功耗成为制约技术发展的主要因素,因此,低功耗器件成为半导体器件领域的研究热点。负电容场效应晶体管基于铁电材料的负电容效应可有效地降低器件的亚阈值摆幅,从而降低器件的功耗。该文设计了一种基于绝缘体上硅(SOI)结构的铁电负电容场效应晶体管,利用TCAD Sentaurus仿真工具对负电容晶体管进行仿真研究,得到了亚阈值摆幅为30.931 mV/dec的负电容场效应晶体管的器件结构和参数。最后仿真研究了铁电层厚度、等效栅氧化层厚度对负电容场效应晶体管亚阈值特性的影响。     

CASFET: A MOSFET-JFET cascode device with ultralow gate capacitance

A field-effect transistor is described that combines a short-gate MOSFET with a long-channel JFET in a cascode configuration. The composite device, a CASFET, can have a very low input capacitance due to the short gate of the MOSFET combined with the reduced Miller capacitance of the cascode. The long channel of the JFET insures that the CASFET has high output resistance. This paper discusses CASFET fabrication, performance, and modeling.     

Reduce Afterpulsing of Single Photon Avalanche Diodes Using Passive Quenching With Active Reset

In this paper, we report a passive-quenching-with-active-reset circuit designed to reduce afterpulsing for single photon avalanche diodes. This circuit uses a large resistor to passively quench the avalanche current and a transistor to actively reset the device to the operating voltage after a specified hold-off time. Afterpulsing can be reduced by minimizing the stray capacitance of the package to reduce the total charge flow during avalanche. Proof of principle is demonstrated with discrete components. It is expected that by integrating the transistor with the avalanche photodiode the stray capacitance can be minimized to significantly reduce afterpulsing.     

An advanced physics-based sub-circuit model of a punch-trough insulated gate bipolar transistor

An advanced sub-circuit model of the punch-trough insulated gate bipolar transistor (PT IGBT) based on the physics of internal device operation has been described in this article. The one-dimensional physical model of low-gain wide-base BJT is employed based on the equivalent non-linear lossy transmission line, whereas a SPICE Level 3 model is used for the diffused MOST part. The influence of voltage dependent drain-to-gate overlapping capacitance and the conductivity modulated base (drain) ohmic resistance are modelled separately. The main advantages of novel PT IGBT model are a small set of model parameters, an easy implementation in SPICE simulator and the high accuracy confirmed by comparing the simulation results with the electrical measurements of test power circuit.     

金属氧化物半导体控制晶闸管的di/dt优化

金属氧化物半导体控制晶闸管(MCT)相比于绝缘栅双极型晶体管(IGBT)具有高电流密度、低导通压降和快速开启等优势,在高压脉冲功率领域具有广阔的应用前景.作为脉冲功率开关,MCT开启过程对输出脉冲信号质量有很大影响.采用理论分析并结合仿真优化重点研究了MCT开启瞬态特性.通过对MCT开启过程进行详细地理论分析推导,给出了MCT开启过程中阳极电流和上升时间的表达式.结合Sentaurus TCAD仿真优化,将MCT开启过程中电流上升速率(di/dt)由40 kA/s提升至80 kA/s,极大地改善了器件开启瞬态特性.最后,总结提出了提高器件开启瞬间di/dt的设计途径.     

IGBT modules robustness during turn-off commutation

The behaviour in terms of robustness during turn-off of power IGBT modules is presented. The experimental characterisation is aimed to identify the main limits during turn-off in power IGBT modules in typical hard switching applications. In this paper an experimental characterization of high power IGBT modules at output currents beyond RBSOA, at high junction temperatures and under different driving conditions is presented. Several devices of different generations, current and voltage ratings have been considered. The experimental characterisation has been performed by means of a non-destructive experimental set-up where IGBT modules are switched in presence of a protection circuit that is able to prevent device failure at the occurrence of any possible instable behaviour. The experimental analysis confirms the very good robustness of high power IGBT modules which can withstand large current overstress well beyond the declared RBSOA limits even at temperatures larger than those one declared by manufacturers. A comparison between IGBT device generation is also presented.     

A rugged 650 V SOI-based high-voltage half-bridge IGBT gate driver IC for motor drive applications

This paper proposes a rugged high-voltage N-channel insulated gate bipolar transistor (IGBT) gate driver integrated circuit. The device integrates a high-side and a low-side output stages on a single chip, which is designed specifically for motor drive applications. High-voltage level shift technology enables the high-side stage of this device to operate up to 650 V. The logic inputs are complementary metal oxide semiconductor (CMOS)/transistor transistor logic compatible down to 3.3 V. Undervoltage protection functionality with hysteresis characteristic has also been integrated to enhance the device reliability. The device is fabricated in a 1.0 μm, 650 V high-voltage bipolar CMOS double-diffused metal oxide semiconductor (BCD) on silicon-on-insulator (SOI) process. Deep trench dielectric isolation technology is employed to provide complete electrical isolation with advantages such as reduced parasitic effects, excellent noise immunity and low leakage current. Experimental results show that the isolation voltage of this device can be up to approximately 779 V at 25°C, and the leakage current is only 5 nA at 650 V, which is 15% higher and 67% lower than the conventional ones. In addition, it delivers an excellent thermal stability and needs very low quiescent current and offers a high gate driver capability which is needed to adequately drive IGBTs that have large input capacitances.     

The complementary insulated-gate bipolar transistor (CIGBT)-a newpower switching device

A new power switching device, the complementary insulated-gate bipolar transistor (CIGBT), is described. The device achieves very high switching speeds typical of DMOS transistors, while it maintains the low on-state resistance of the insulated-gate bipolar transistor (IGBT) on which it is based. The device incorporates a p-channel MOS transistor which acts to draw excess charge out of the base region of the IGBT as the device is turned off. Fabricated devices whose specific on-resistance is only 20% greater than that of equal-area IGBTs display turn-off times under 700 ns, while the IGBTs require 35 μs to reach the off state. The device is compared to equal-area IGBTs, DMOS transistors, and IGBTs whose minority-carrier lifetime has been reduced to achieve 700-ns turn-off times     

Modeling the [dV/dt] of the IGBT during inductive turn off

Insulated gate bipolar transistor (IGBT)-based pulsewidth modulation (PWM) inverters are commonly used in inductive load circuits such as motor control. During clamped inductive load turn off of the IGBT, high-power losses occur during two phases. Due to the large inductive motor load, the voltage across the IGBT rises to the bus voltage while carrying the full-rated current. In the second phase, the current decreases as the IGBT goes into its forward blocking mode. In this paper, the turn-off process during the first phase is analyzed in detail for the first time. A simple analytical model has been derived, based upon the initial steady-state minority carrier distribution, which allows predicting the rate of rise of the voltage during this time period where the collector current remains constant. The predictions of the analytical model are in excellent agreement with results obtained from two-dimensional (2-D) numerical simulations over a broad range of minority carrier lifetime values. This analytical model provides a good estimate (within 10%) of the power losses incurred during the first phase of turn off     

Design of IGBT with integral freewheeling diode

A new power structure integrating a freewheeling diode in the termination region of a punch-through (PT) insulated gate bipolar transistor (IGBT) is presented. The proposed solution requires virtually no silicon area penalty with respect to a standard IGBT. Static and dynamic experimental results show the correct behavior of both IGBT and freewheeling diode. Further, it is shown that the lateral diode surrounding the multicellular IGBT can support IGBT direct current with low on-state voltage drop. The operation mechanisms of the composite structure and design techniques to improve structure dynamic behavior are investigated through two-dimensional numerical device simulations     

高压Trench IGBT的研制

介绍了当前绝缘栅双极晶体管(IGBT)的几种结构及沟槽型IGBT的发展现况,分析了高电压沟槽型非穿通(NPT)IGBT的结构及工艺特点。通过理论分析计算出初步器件的相关参数,再利用ISE仿真软件模拟器件的结构及击穿和导通特性,结合现有沟槽型DMOS工艺流程,确定了器件采用多分压环加多晶场板的复合终端、条状元胞、6μm深度左右沟槽、低浓度背面掺杂分布与小于180μm厚度的器件结构,可以很好地平衡击穿特性与导通特性对器件结构的要求。成功研制出1 200 V沟槽型NPT系列产品,并通过可靠性考核,经过电磁炉应用电路实验,结果表明IGBT器件可稳定工作,满足应用要求。该设计可适合国内半导体生产线商业化生产。     

A study on IGBT junction temperature (Tj) online estimation using gate-emitter voltage (Vge) at turn-off

A novel method is presented for online estimation of the junction temperature (Tj) of semiconductor chips in IGBT modules, based on evaluating the gate-emitter voltage (Vge) during the IGBT switch off process. It is shown that the Miller plateau width (in the Vge waveform) depend linearly on the junction temperature of the IGBT chips. Hence, a method can be proposed for estimating the junction temperature even during converter operation – without the need of additional thermal sensors or complex Rth network models. A measurement circuit was implemented at gate level to measure the involved time duration and its functionality was demonstrated for different types of IGBT modules. A model has been proposed to extract Tj from Vge measurements. Finally, an IGBT module with semiconductor chips at two different temperatures has been measured using Vge method and this method was found to provide the average junction temperature of all the semiconductor chips.     

IGBT SPICE model

During the last few years, great progress in the development of new power semiconductor devices has been made. The new generation of power semiconductors is capable of conducting more current and blocking higher voltage. The IGBT (insulated gate bipolar transistor) is an outgrowth of power MOSFET technology. More like a MOSFET than a bipolar transistor in structure, the IGBT has some of the electrical characteristics of both. Like a MOSFET, the gate of the IGBT is isolated, and drive power is very low. The on-state conduction voltage of an IGBT is similar to that of a bipolar transistor. However, SPICE users are constantly faced with the inability to analyze circuits that contain devices that are not in the SPICE library of the semiconductor models. With the authors' own computer program, a complete macromodel of the IGBT for the SPICE simulator has been computed. In this paper, a complete IGBT SPICE macromodel is described and verified with experimental results     

功率MOS和IGBT器件在无嵌位电感开关条件下的动态雪崩特性研究

The ability of high-voltage power MOSFETs and IGBTs to withstand avalanche events under unclamped inductive switching(UIS) conditions is measured.This measurement is to investigate and compare the dynamic avalanche failure behavior of the power MOSFETs and the IGBT,which occur at different current conditions.The UIS measurement results at different current conditions show that the main failure reason of the power MOSFETs is related to the parasitic bipolar transistor,which leads to the deterioration of the avalanche reliability of power MOSFETs.However,the results of the IGBT show two different failure behaviors.At high current mode,the failure behavior is similar to the power MOSFETs situation.But at low current mode,the main failure mechanism is related to the parasitic thyristor activity during the occurrence of the avalanche process and which is in good agreement with the experiment result.