摘要
采用2种电阻率的钒掺杂半绝缘6H-SiC晶体制作了横向结构的碳化硅光导开关,分别加载不同的偏压、并使用不同能量的激光触发开展光电导实验。对比实验结果表明:高暗态电阻率的碳化硅光导开关耐压特性远远优于低暗态电阻率的碳化硅光导开关,耐压从4kV提高到了32kV;但高暗态电阻率的开关导通电阻也较大,导通电阻为kΩ量级,比低暗态电阻率的碳化硅光导开关的近百Ω增加了1个量级。通过激光脉冲波形与光电流脉冲波形的比较,估算出2种光导开关的载流子寿命和载流子迁移率。将这2个参数与砷化镓光导开关进行比较,推导出低的载流子迁移率是碳化硅开关导通电阻较大的主要原因。在实验和分析的基础上改进设计,研制出了工作电压超过10kV、工作电流超过90A的碳化硅光导开关。
Two photoconductive semiconductor switches（PCSSs） were fabricated using V-doped semi-insulating 6H-SiC transverse-cut wafer with different dark resistivities.A series of photoconductive experiments with different bias voltages and different triggering laser energies were done on the two samples.The experimental results indicate that,the sample with higher dark resistivity can endure much higher bias voltage,and the maximum bias voltage are elevated from 4.2 kV for the sample with lower dark resistivity to 32 kV for the sample with higher dark resistivity.However,the sample with higher dark resistivity has higher on-state resistance of kΩ level,at least one order-of-magnitude higher than that of the sample with lower dark resistivity,less than 100 Ω.Carrier mobilities and lifetimes were estimated by comparing laser waveforms and photo-current waveforms.In comparison with GaAs-PCSSs,the extremely low carriers lifetime and mobility are found to be the reasons for the high on-state resistance of SiC-PCSSs.Then an improved V：6H-SiC PCSS was fabricated and measured.The maximum working voltage is 10 kV,the photocurrent is 90 A,and the on-state performance is elevated greatly.
出处
《强激光与粒子束》
EI
CAS
CSCD
北大核心
2012年第3期607-611,共5页
High Power Laser and Particle Beams
基金
国家自然科学基金项目(50837004)
国家自然科学基金青年基金项目(51007085)
中国工程物理研究院科学技术发展基金项目(2009B0402040
2011B0402010)
关键词
光导开关
碳化硅
导通电阻
载流子迁移率
载流子寿命
photoconductive semiconductor switch
silicon carbide
on-state resistance
carrier mobility
carrier lifetime
