Influence of characteristics' measurement sequence on total ionizing dose effect in PDSOI nMOSFET  

作　　者：Xin Xie Da-Wei Bi Zhi-Yuan Hu Hui-Long Zhu Meng-Ying Zhang Zheng-Xuan Zhang Shi-Chang Zou 解鑫;毕大伟;胡志远;朱慧龙;张梦映;张正选;邹世昌

机构地区：[1]State Key Laboratory of Functional Materials for Informatics,Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,Shanghai 200050,China [2]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Chinese Physics B》2018年第12期551-558,共8页中国物理B（英文版）

摘　　要：The influence of characteristics’ measurement sequence on total ionizing dose effect in partially-depleted SOI nMOSFET is comprehensively studied. We find that measuring the front-gate curves has no influence on total ionizing dose effect.However, the back-gate curves’ measurement has a great influence on total ionizing dose effect due to high electric field in the buried oxide during measuring. In this paper, we analyze their mechanisms and we find that there are three kinds of electrons tunneling mechanisms at the bottom corner of the shallow trench isolation and in the buried oxide during the backgate curves’ measurement, which are: Fowler–Nordheim tunneling, trap-assisted tunneling, and charge-assisted tunneling.The tunneling electrons neutralize the radiation-induced positive trapped charges, which weakens the total ionizing dose effect. As the total ionizing dose level increases, the charge-assisted tunneling is enhanced by the radiation-induced positive trapped charges. Hence, the influence of the back-gate curves’ measurement is enhanced as the total ionizing dose level increases. Different irradiation biases are compared with each other. An appropriate measurement sequence and voltage bias are proposed to eliminate the influence of measurement.The influence of characteristics' measurement sequence on total ionizing dose effect in partially-depleted SOI nMOSFET is comprehensively studied. We find that measuring the front-gate curves has no influence on total ionizing dose effect.However, the back-gate curves' measurement has a great influence on total ionizing dose effect due to high electric field in the buried oxide during measuring. In this paper, we analyze their mechanisms and we find that there are three kinds of electrons tunneling mechanisms at the bottom corner of the shallow trench isolation and in the buried oxide during the backgate curves' measurement, which are: Fowler–Nordheim tunneling, trap-assisted tunneling, and charge-assisted tunneling.The tunneling electrons neutralize the radiation-induced positive trapped charges, which weakens the total ionizing dose effect. As the total ionizing dose level increases, the charge-assisted tunneling is enhanced by the radiation-induced positive trapped charges. Hence, the influence of the back-gate curves' measurement is enhanced as the total ionizing dose level increases. Different irradiation biases are compared with each other. An appropriate measurement sequence and voltage bias are proposed to eliminate the influence of measurement.

关 键 词：total ionizing dose(TID) silicon-on-insulator(SOI) measurement sequence tunneling effect 

分 类 号：O4[理学—物理]