三代半导体功率器件的特点与应用分析

以S i双极型功率晶体管为代表的第一代半导体功率器件和以GaAs场效应晶体管为代表的第二代半导体功率器件为雷达发射机的大规模固态化和可靠性提高做出了贡献。近年来以S iC场效应功率晶体管和GaN高电子迁移率功率晶体管为代表的第三代半导体--宽禁带半导体功率器件具有击穿电压高、功率密度高、输出功率高、工作效率高、工作频率高、瞬时带宽宽、适合在高温环境下工作和抗辐射能力强等优点。人们寄希望于宽禁带半导体功率器件来解决第一代、第二代功率器件的输出功率低、效率低和工作频率有局限性以至于无法满足现代雷达、电子对抗和通信等电子装备需求等方面的问题。文中简要介绍了半导体功率器件的发展背景、发展过程、分类、特点、应用、主要性能参数和几种常用的半导体功率器件;重点叙述了宽禁带半导体功率器件的特点、优势、研究进展和工程应用;对宽禁带半导体功率器件在新一代雷达中的应用前景和要求进行了探讨。     

Challenges and potential payoff for crystalline oxides in wide bandgap semiconductor technology

While growth of wide bandgap semiconductor materials on crystalline oxides (sapphire, lithium gallate, lithium aluminate, zinc oxide and others) has become routine, growth of crystalline oxides on wide bandgap materials remains challenging and minimally explored. The potential payoff in terms of enhanced device performance, increased functionality and reliability warrants examining this option. This presentation aims at targeting key areas, where crystalline oxides could improve wide bandgap semiconductor device performance. Some of these include the use of ferroelectric oxides for power switching applications, oxides with anisotropic dielectric constants for high voltage termination and oxides with large electric flux density near breakdown. Unique polarization engineered structures are described that are enabled by using lithographically defined poled regions in a ferroelectric substrate. The desired crystalline oxide properties, potential implementation challenges and potential pitfalls will be discussed.     

Power Semiconductor Devices for Hybrid, Electric, and Fuel Cell Vehicles

Power semiconductor devices are key components in all power electronic systems, particularly in hybrid, electric, and fuel cell vehicles. This paper reviews the system requirement and latest development of power semiconductor devices including IGBTs, freewheeling diodes, and advanced power module technology in relating to electric vehicle applications. State-of-the-art silicon device technologies, their future trends, and theoretical limits are discussed. Emerging wide bandgap semiconductor devices such as SiC devices and their potential applications in electric vehicles are also reviewed     

GaN-Based RF Power Devices and Amplifiers

The rapid development of the RF power electronics requires the introduction of wide bandgap material due to its potential in high output power density, high operation voltage and high input impedance. GaN-based RF power devices have made substantial progresses in the last decade. This paper attempts to review the latest developments of the GaN HEMT technologies, including material growth, processing technologies, device epitaxial structures and MMIC designs, to achieve the state-of-the-art microwave and millimeter-wave performance. The reliability and manufacturing challenges are also discussed.     

宽禁带半导体器件环境适应性验证技术

应用验证是新型元器件走向实际工程应用必不可少的关键环节。从实际工程应用角度出发,给出了宽禁带半导体(SiC/GaN等)微波功率器件环境适应性验证过程中的验证分级(解决及时发现问题与验证周期、费用矛盾)、验证载体与工程应用统一性设计(器件研制源于工程、用于工程)、验证数据的可对比性设计(验证环节可追溯)方法及相关分析(指导工程设计),为宽禁带半导体微波功率器件的工程化研制提供数据支撑。文中的试验数据和设计思想可作为其他相关工程设计参考。     

Silicon carbide benefits and advantages for power electronics circuits and systems

Silicon offers multiple advantages to power circuit designers, but at the same time suffers from limitations that are inherent to silicon material properties, such as low bandgap energy, low thermal conductivity, and switching frequency limitations. Wide bandgap semiconductors, such as silicon carbide (SiC) and gallium nitride (GaN), provide larger bandgaps, higher breakdown electric field, and higher thermal conductivity. Power semiconductor devices made with SiC and GaN are capable of higher blocking voltages, higher switching frequencies, and higher junction temperatures than silicon devices. SiC is by far the most advanced material and, hence, is the subject of attention from power electronics and systems designers. This paper looks at the benefits of using SiC in power electronics applications, reviews the current state of the art, and shows how SiC can be a strong and viable candidate for future power electronics and systems applications.     

High-power robust semiconductor electronics technologies in the new millennium

This paper presents an overview of power semiconductor devices for the development of advanced robust high-performance power electronic systems for the new millennium. Material and device technologies on silicon and wide energy band-gap semiconductors are discussed along with switching circuits and topologies. Short-term and long-term reliability issues of power semiconductor devices are discussed. An approach is presented to correlate converter field failures to dynamic switching stresses, residual defects and contaminants left in the semiconductor power switch, packaging, and thermal management. Component and system level simulation, modeling and CAD requirements are evaluated. System-level optimization is proposed as an essential requirement to develop robust power systems at affordable cost.     

A 1-MHz hard-switched silicon carbide DC-DC converter

Silicon Carbide (SiC) is a wide bandgap semiconductor material that offers performance improvements over Si for power semiconductors with accompanying benefits for power electronics applications that use these semiconductors. The wide bandgap of SiC results in higher junction forward voltage drops, so SiC is best suited for majority carrier devices such as field effect transistors (FETs) and Schottky diodes. The wide bandgap of SiC results in it having a high breakdown electric field, which in turn results in lower resistivity and narrower drift regions in power devices. This dramatically lowers the resistance of the drift region and means that SiC devices with substantially less area than their corresponding Si devices can be used. The lower device area reduces the capacitance of the devices enabling higher frequency operation. Here, the results from a 1-MHz hard-switched dc-dc converter employing SiC JFETs and Schottky diodes will be presented. This converter was designed to convert 270Vdc to 42Vdc such as may be needed in future electric cars. The results provide the performance obtained at 1MHz and demonstrate the feasibility of a hard-switched dc-dc converter operating at this frequency.     

Current state-of-the-art and future prospects for power semiconductor devices in power transmission and distribution applications

Since the first commercially viable thyristors appeared in the early 1960s, there has been a dramatic increase in the switched power ratings and versatility of high-voltage power semiconductor devices. By the mid 1970s, thyristors with switched power ratings of several MVA were being applied in high voltage dc transmission systems and static VAr compensators. The introduction, in the 1980s, of controlled turn-off devices, such as the gate turn-off thyristor (GTO) and insulated gate bipolar transistor (IGBT), broadened the application of high-voltage power devices to hard-switched converters and, by the start of the 21st century, controllable silicon power devices were available with voltage ratings of 12?kV and switched power capabilities of up to 40?MVA. A review of the current state-of-the-art in silicon high-voltage power semiconductor technology covers gate-commutated thyristors (GCT, IGCT) and IGBT devices, including the injection-enhanced IGBT or IEGT. Despite these considerable achievements, there is now mounting evidence that silicon-based power semiconductors are reaching their limit, both in terms of voltage rating and of switched power capability. The introduction of wide-band-gap semiconductor materials such as silicon carbide offers the potential to break through the voltage-switching frequency limitations of silicon, with power-switching frequency products more than two orders of magnitude higher. An analysis of the current status and future prospects for silicon carbide power electronic devices is presented, together with a case study comparing a variety of silicon and silicon carbide solutions in a 10?kV hard-switched converter application. It is shown that an all-silicon carbide switch offers the best electrical performance and lowest cost solution, in spite of higher per unit area device costs.     

SiC/GaN IMPATT二极管的交流性能研究

利用p型宽带隙材料SiC替代p型GaN,制作了一种p-SiC/n-GaN异质结双漂移(DDR)IMPATT二极管.对器件的交流大信号输出特性进行数值模拟仿真.结果表明,相比传统GaN单漂移(SDR)IMAPTT二极管,p-SiC/n-GaN新结构DDR器件的击穿电压、最佳负电导、交流功率密度和直流-交流转换效率都获得了...     

GaN功率器件栅驱动电路技术综述

第三代宽禁带半导体GaN晶体管具有低导通阻抗、低寄生参数和更快的开关速度,有望取代传统Si MOSFET,成为未来高性能电源系统实现方案。GaN器件的优势在400 V以上高压系统中更为明显,可以实现更高的开关频率和功率密度,显著提高系统的转换效率,特别适合电源模块小型化发展趋势。介绍了200 V以下低压GaN驱动电路的应用和关键技术。分析了从低压系统拓展到400 V以上高压系统时需要作出的优化与改进。详细介绍了高压GaN系统中基于无磁芯变压器耦合隔离的隔离驱动技术和耗尽型GaN负压栅驱动技术。最后,总结了目前高压GaN驱动电路在工业领域的具体应用。     

High-temperature electronics - a role for wide bandgap semiconductors?

The fact that wide bandgap semiconductors are capable of electronic functionality at much higher temperatures than silicon has partially fueled their development, particularly in the case of SiC. It appears unlikely that wide bandgap semiconductor devices will find much use in low-power transistor applications until the ambient temperature exceeds approximately 300/spl deg/C, as commercially available silicon and silicon-on-insulator technologies are already satisfying requirements for digital and analog VLSI in this temperature range. However practical operation of silicon power devices at ambient temperatures above 200/spl deg/C appears problematic, as self-heating at higher power levels results in high internal junction temperatures and leakages. Thus, most electronic subsystems that simultaneously require high-temperature and high-power operation will necessarily be realized using wide bandgap devices, once they become widely available. Technological challenges impeding the realization of beneficial wide bandgap high ambient temperature electronics, including material growth, contacts, and packaging, are briefly discussed.     

Wide bandgap semiconductor materials and devices

Given a matrix of all semiconductor materials and their properties, the highest and the lowest of these property values will almost always be associated with wide bandgap materials. The many possible combinations of these “poles and zeros” lead not only to superlative electron device performance, but to new device concepts as well. An overview of wide bandgap semiconductor properties is presented followed by several concepts for both new and enhanced devices. Finally, impediments to immediate exploitation and a time-oriented appraisal of the various materials and devices is presented     

Full-chip subthreshold leakage power prediction and reduction techniques for sub-0.18-/spl mu/m CMOS

The driving force for the semiconductor industry growth has been the elegant scaling nature of CMOS technology. In future CMOS technology generations, supply and threshold voltages will have to continually scale to sustain performance increase, control switching power dissipation, and maintain reliability. These continual scaling requirements on supply and threshold voltages pose several technology and circuit design challenges. With threshold voltage scaling, subthreshold leakage power is expected to become a significant portion of the total power in future CMOS systems. Therefore, it becomes crucial to predict and reduce subthreshold leakage power of such systems. In the first part of this paper, we present a subthreshold leakage power prediction model that takes into account within-die threshold voltage variation. Statistical measurements of 32-bit microprocessors in 0.18-/spl mu/m CMOS confirm that the mean error of the model is 4%. In the second part of this paper, we present the use of stacked devices to reduce system subthreshold leakage power without reducing system performance. A model to predict the scaling nature of this stack effect and verification of the model through statistical device measurements in 0.18-/spl mu/m and 0.13-/spl mu/m are presented. Measurements also demonstrate reduction in threshold voltage variation for stacked devices compared to nonstack devices. Comparison of the stack effect to the use of high threshold voltage or longer channel length devices for subthreshold leakage reduction is also discussed.     

Power thyristor rating practices

The power thyristor is the most important semicoductor device used in the control of electric power. An explanation of thyristor ratings and rating presentation is required for the complete understanding and successful application of these devices. This paper not only explains the meaning of thyristor temperature, voltage, current, and gate ratings but also presents insights into how these ratings are developed. Both the semiconductor controlled rectifier (SCR), which is properly called a reverse blocking triode thyristor, and the bidirectional thyristor rating methods are discussed. SCR rating are further divided into those applying to phase control applications at power frequencies and those applying to high repetition rate inverter and pulse current appications.     

A new n-level high voltage inversion system

This paper deals with a new multilevel high-voltage source inverter with gate-turn-off (GTO) thyristors. Recently, a multilevel approach seemed to be the best suited for implementing high-voltage power conversion systems because it leads to a harmonic reduction and deals with safe high-power conversion systems independent of the dynamic switching characteristics of each power semiconductor device. A conventional multilevel inverter has some problems; voltage unbalance between DC-link capacitors and larger blocking voltage across the inner switching devices. To solve these problems, the novel multilevel inverter structure is proposed     

Germanium power switching devices

Two-terminal and three-terminal germanium power switching devices have been developed, utilizing a metal semiconductor contact as an electron injector in a multijunction device. The principles of operation, fabrication techniques, and electrical characteristics of this new device are discussed. Devices capable of switching up to 25 amperes and blocking up to 350 volts have been fabricated and applied to power control circuits. The low impedance voltage drop is of the order of 0.5 volt and the dynamic resistance is a few hundredths of an ohm. A switch-on time less than 0.1 microsecond has been measured with a switch-off time of the order of microseconds.     

Diamond semiconductor and elastic strain engineering

Diamond,as an ultra-wide bandgap semiconductor,has become a promising candidate for next-generation microelec-tronics and optoelectronics due to its numerous advantages over conventional semiconductors,including ultrahigh carrier mo-bility and thermal conductivity,low thermal expansion coefficient,and ultra-high breakdown voltage,etc.Despite these ex-traordinary properties,diamond also faces various challenges before being practically used in the semiconductor industry.This review begins with a brief summary of previous efforts to model and construct diamond-based high-voltage switching diodes,high-power/high-frequency field-effect transistors,MEMS/NEMS,and devices operating at high temperatures.Following that,we will discuss recent developments to address scalable diamond device applications,emphasizing the synthesis of large-area,high-quality CVD diamond films and difficulties in diamond doping.Lastly,we show potential solutions to modulate diamond’s electronic properties by the“elastic strain engineering”strategy,which sheds light on the future development of diamond-based electronics,photonics and quantum systems.     

An assessment of wide bandgap semiconductors for power devices

An advantage for some wide bandgap materials, that is often overlooked, is that the thermal coefficient of expansion (CTE) is better matched to the ceramics in use for packaging technology. It is shown that the optimal choice for uni-polar devices is clearly GaN. It is further shown that the future optimal choice for bipolar devices is C (diamond) owing to the large bandgap, high thermal conductivity, and large electron and hole mobilities. A new expression relating the critical electric field for breakdown in abrupt junctions to the material bandgap energy is derived and is further used to derive new expressions for specific on-resistance in power semiconductor devices. These new expressions are compared to the previous literature and the efficacy of specific power devices, such as heterojunction MOSFETs, using GaN are discussed.     

Reliability assurance of individual semiconductor components

Where small numbers of highly reliable semiconductor devices are required, conventional methods of procurement are found to have deficiencies. An approach to procurement is proposed which is cost effective, accommodates new device types, and assures reliability in the individual device. Although principally applied to silicon planar transistors, the approach can be extended to other semiconductor types. A critical evaluation is made of the manufacturer and his technology. The devices obtained from each diffused wafer are grouped into separate lots. Selected tests are performed on these lots in order to discover possible failure mechanisms. Tests may involve simple electrical measurements or detailed techniques such as scanning electron microscopy and X-ray microprobe analysis. The Canadian/U.S.A. Communications Technology Satellite (CTS) program has adopted this procurement procedure.