SiC MOSFET因其高击穿电压、高开关速度、低导通损耗等性能优势而被广泛应用于各类电力电子变换器中。然而,由于其短路耐受时间仅为2~7μs,且随母线电压升高而缩短,快速可靠的短路保护电路已成为其推广应用的关键技术之一。为应对不同...SiC MOSFET因其高击穿电压、高开关速度、低导通损耗等性能优势而被广泛应用于各类电力电子变换器中。然而,由于其短路耐受时间仅为2~7μs,且随母线电压升高而缩短,快速可靠的短路保护电路已成为其推广应用的关键技术之一。为应对不同母线电压下的Si C MOSFET短路故障,文中提出一种基于漏源电压积分的自适应快速短路保护方法(drain-sourcevoltageintegration-basedadaptivefast short-circuit protection method,DSVI-AFSCPM),研究所提出的DSVI-AFSCPM在硬开关短路(hardswitchingfault,HSF)和负载短路(fault under load,FUL)条件下的保护性能,进而研究不同母线电压对DSVI-AFSCPM的作用机理。同时,探究Si CMOSFET工作温度对其响应速度的影响。最后,搭建实验平台,对所提出的DSVI-AFSCPM在发生硬开关短路和负载短路时不同母线电压、不同工作温度下的保护性能进行实验测试。实验结果表明,所提出的DSVI-AFSCPM在不同母线电压下具有良好的保护速度自适应性,即母线电压越高,短路保护速度越快,并且其响应速度受Si CMOSFET工作温度影响较小,两种短路工况下工作温度从25℃变化到125℃,短路保护时间变化不超过90 ns。因此,该文为Si CMOSFET在不同母线电压下的可靠使用提供一定技术支撑。展开更多
在评估和优化半导体器件开关瞬态特性领域,解析模型因具有简单、直观、应用便捷等优点得到广泛研究。相较同等功率等级的硅基功率器件,碳化硅(silicon carbide,SiC)金属氧化物半导体场效应晶体管(metal-oxide-semiconductor field effec...在评估和优化半导体器件开关瞬态特性领域,解析模型因具有简单、直观、应用便捷等优点得到广泛研究。相较同等功率等级的硅基功率器件,碳化硅(silicon carbide,SiC)金属氧化物半导体场效应晶体管(metal-oxide-semiconductor field effect transistor,MOSFET)可以应用于更高开关速度,其开关瞬态特性更为复杂,开关瞬态解析建模也更加困难。该文总结现有的针对SiC MOSFET与二极管换流对的开关瞬态解析建模方法,在建模过程中依次引入各种简化假设,按照简化程度由低到高的顺序,梳理解析建模的逐步简化过程。通过对比,评估各模型的优缺点以及适用场合,对其中准确性、实用性都较强的分段线性模型进行详细介绍;之后,对开关瞬态建模中关键参数的建模方法进行总结与评价;最后,指出现有SiC MOSFET开关瞬态解析模型中存在的问题,并对其未来发展给出建议。展开更多
The energy bandgap is an intrinsic character of semiconductors, which largely determines their properties. The ability to continuously and reversibly tune the bandgap of a single device during real time operation is o...The energy bandgap is an intrinsic character of semiconductors, which largely determines their properties. The ability to continuously and reversibly tune the bandgap of a single device during real time operation is of great importance not only to device physics but also to technological applications. Here we demonstrate a widely tunable bandgap of few-layer black phosphorus （BP） by the application of vertical electric field in dual-gated BP field-effect transistors. A total bandgap reduction of 124 meV is observed when the electrical displacement field is increased from 0.10 V/nm to 0.83 V/nm. Our results suggest appealing potential for few-layer BP as a tunable bandgap material in infrared optoelectronies, thermoelectric power generation and thermal imaging.展开更多
An analytical model for current-voltage behavior of amorphous In-Ga-Zn-O thin-film transistors（a-IGZO TFTs）with dual-gate structures is developed.The unified expressions for synchronous and asynchronous operating mo...An analytical model for current-voltage behavior of amorphous In-Ga-Zn-O thin-film transistors（a-IGZO TFTs）with dual-gate structures is developed.The unified expressions for synchronous and asynchronous operating modes are derived on the basis of channel charges,which are controlled by gate voltage.It is proven that the threshold voltage of asynchronous dual-gate IGZO TFTs is adjusted in proportion to the ratio of top insulating capacitance to the bottom insulating capacitance（C_（TI）/C_（BI））.Incorporating the proposed model with Verilog-A,a touch-sensing circuit using dual-gate structure is investigated by SPICE simulations.Comparison shows that the touch sensitivity is increased by the dual-gate IGZO TFT structure.展开更多
利用等效1 MeV中子和γ射线对1200 V SiC功率MOSFET进行辐射,研究了电离损伤和位移损伤对器件的影响,并分析了辐射后器件栅氧长期可靠性。结果表明:中子辐射后器件导通电阻发生明显退化,与辐射引入近界面缺陷降低载流子寿命和载流子迁...利用等效1 MeV中子和γ射线对1200 V SiC功率MOSFET进行辐射,研究了电离损伤和位移损伤对器件的影响,并分析了辐射后器件栅氧长期可靠性。结果表明:中子辐射后器件导通电阻发生明显退化,与辐射引入近界面缺陷降低载流子寿命和载流子迁移率有关。时间依赖的介质击穿(TDDB)结果表明,栅泄漏电流呈现先增加后降低趋势,与空穴捕获和电子捕获效应有关。中子辐射后栅漏电演化形式未改变,但氧化层击穿时间增加,这是中子辐射缺陷增加了Fowler-Nordheim(FN)隧穿势垒的缘故。总剂量辐射在器件氧化层内引入陷阱电荷,使得器件阈值电压负向漂移。随后的TDDB测试表明,与中子辐射一致,总剂量辐射未改变栅漏电演化形式,但氧化层击穿时间提前。这是总剂量辐射在氧化层内引入额外空穴陷阱和中性电子陷阱的缘故。展开更多
SiC MOSFET是一种高性能的电力电子器件,其开通/关断过程中积累/释放的栅电荷Q_(g)对MOSFET的开关速度、功率损耗等参数有重要影响。通常采用在栅极设置恒流源驱动,对时间进行积分的方法来测量Q_(g)。为了降低驱动复杂度,提高测试结果...SiC MOSFET是一种高性能的电力电子器件,其开通/关断过程中积累/释放的栅电荷Q_(g)对MOSFET的开关速度、功率损耗等参数有重要影响。通常采用在栅极设置恒流源驱动,对时间进行积分的方法来测量Q_(g)。为了降低驱动复杂度,提高测试结果精度和可视性,基于双脉冲测试平台的感性负载回路,改用耗尽型MOSFET限制栅极电流实现恒流充电,对SiC MOSFET进行测试。同时利用反馈电阻将较小的栅极电流信号转换为较大的电压信号。实验结果表明:在误差允许范围(±5%)内该测试方案能较为准确地测得SiC MOSFET的Q_(g),测试结果符合器件规格书曲线。展开更多
基金Supported by the National Basic Research Program of China under Grant Nos 2013CB921900 and 2014CB920900the National Natural Science Foundation of China under Grant No 11374021)(S.Yan,Z.Xie,J.-H,Chen)+1 种基金support from the Elemental Strategy Initiative conducted by the MEXT,Japana Grant-in-Aid for Scientific Research on Innovative Areas"Science of Atomic Layers"from JSPS
文摘The energy bandgap is an intrinsic character of semiconductors, which largely determines their properties. The ability to continuously and reversibly tune the bandgap of a single device during real time operation is of great importance not only to device physics but also to technological applications. Here we demonstrate a widely tunable bandgap of few-layer black phosphorus （BP） by the application of vertical electric field in dual-gated BP field-effect transistors. A total bandgap reduction of 124 meV is observed when the electrical displacement field is increased from 0.10 V/nm to 0.83 V/nm. Our results suggest appealing potential for few-layer BP as a tunable bandgap material in infrared optoelectronies, thermoelectric power generation and thermal imaging.
基金Supported by the National Key Research and Development Program of China under Grant No 2017YFA0204600the National Natural Science Foundation of China under Grant No 61404002the Science and Technology Project of Hunan Province under Grant No 2015JC3041
文摘An analytical model for current-voltage behavior of amorphous In-Ga-Zn-O thin-film transistors（a-IGZO TFTs）with dual-gate structures is developed.The unified expressions for synchronous and asynchronous operating modes are derived on the basis of channel charges,which are controlled by gate voltage.It is proven that the threshold voltage of asynchronous dual-gate IGZO TFTs is adjusted in proportion to the ratio of top insulating capacitance to the bottom insulating capacitance（C_（TI）/C_（BI））.Incorporating the proposed model with Verilog-A,a touch-sensing circuit using dual-gate structure is investigated by SPICE simulations.Comparison shows that the touch sensitivity is increased by the dual-gate IGZO TFT structure.
文摘利用等效1 MeV中子和γ射线对1200 V SiC功率MOSFET进行辐射,研究了电离损伤和位移损伤对器件的影响,并分析了辐射后器件栅氧长期可靠性。结果表明:中子辐射后器件导通电阻发生明显退化,与辐射引入近界面缺陷降低载流子寿命和载流子迁移率有关。时间依赖的介质击穿(TDDB)结果表明,栅泄漏电流呈现先增加后降低趋势,与空穴捕获和电子捕获效应有关。中子辐射后栅漏电演化形式未改变,但氧化层击穿时间增加,这是中子辐射缺陷增加了Fowler-Nordheim(FN)隧穿势垒的缘故。总剂量辐射在器件氧化层内引入陷阱电荷,使得器件阈值电压负向漂移。随后的TDDB测试表明,与中子辐射一致,总剂量辐射未改变栅漏电演化形式,但氧化层击穿时间提前。这是总剂量辐射在氧化层内引入额外空穴陷阱和中性电子陷阱的缘故。
