不同结构nMOS管的总剂量辐射效应  

Total Radiation Dose Effects of Different Structures nMOS Transistors

作　　者：闫旭亮[1] 孟丽娅[1] 袁祥辉[1] 黄友恕[1] 吕果林[1] 

机构地区：[1]重庆大学光电工程学院光电技术及系统教育部重点实验室,重庆400044

出　　处：《半导体技术》2014年第11期861-866,共6页Semiconductor Technology

基　　金：国家自然科学基金资助项目(61071043)

摘　　要：X射线直接成像的CMOS图像传感器由于工作在X射线辐射下,其内部器件会因为辐射效应引起性能恶化,因此需要对器件进行抗辐射加固并研究辐射对器件参数的影响。辐射导致的氧化物陷阱电荷及界面陷阱电荷受到栅氧厚度、偏置电压大小、辐射总剂量以及剂量率等多种因素影响。设计了n型场效应晶体管辐射加固结构版图,用0.5μm CMOS工艺流片,并进行了30 kGy(Si)的总剂量辐照效应实验。实验结果显示,所设计的n型场效应晶体管在辐射之后漏电流有所增加、跨导减小、阈值电压向负向漂移;辐射加固晶体管在漏电流性能上较未加固晶体管更好,在跨导改变和阈值电压漂移上未能表现出其更优的性能。The CMOS image sensor for direct X-ray imaging works under the X-ray radiation and the performance of its interal device will deteriorate caused by the radiation effect, and thus it is necessary to design radiation-hardened structure and to study the effects of radiation on the device parameters. Oxide trapped charge and interface trap charges caused by radiation are affected by the gate oxide thickness, the size of the bias voltage, the total radiation dose and dose rate, etc. The radiation-hardened structure lay- out for nMOS transistors was designed and it was fabricated in a 0.5 μm CMOS process. The tests for the total radiation dose effects of the transistors were carried out with a total dose up to 30 kGy （Si） . The experimental results show that after irradiation the leakage current of nMOS transistors increased, the transconductance decreased and the threshold voltage drifted negatively. The drain current of radiation- hardened transistor is less than that of traditional structure transistor, but the transconductance and threshold voltage shift couldn＇t show better performance.

关 键 词：NMOS 总剂量辐射 抗辐射加固 漏电流 阈值电压漂移 

分 类 号：TN386[电子电信—物理电子学]