MOSFET辐照诱生界面陷阱形成过程的1/f噪声研究

A 1/f noise based research of radiation induced interface trap buildup process

基于界面陷阱形成的氢离子运动两步模型和反应过程的热力学平衡假设,推导了金属-氧化物-半导体-场效应晶体管(MOSFET)经历电离辐照后氧化层空穴俘获与界面陷阱形成间关系的表达式.利用初始1/f噪声功率谱幅值与氧化层空穴俘获之间的联系,建立了辐照前的1/f噪声幅值与辐照诱生界面陷阱数量之间的半经验公式,并通过实验予以验证.研究结果表明,由于辐照诱生的氧化层内陷阱通过与分子氢作用而直接参与到界面陷阱的建立过程中,从而使界面陷阱生成数量正比于这种陷阱增加的数量,因此辐照前的1/f噪声功率谱幅值正比于辐照诱生的界面陷阱数量.研究结果为1/f噪声用作MOSFET辐照损伤机理研究的新工具,对其抗辐照性能进行无损评估提供了理论依据与数学模型.

Based on the two-step interface trap buildup model and the statistical thermodynamics mechanism of point defects in solids, a relation between the radiation induced increase of oxide hole-traps and the buildup of interface traps in MOSFET is proposed. Then, based on the correlation between pre-irradiation 1/f noise power spectral density and post-irradiation oxide-trap charge, a sim-empirical expression of pre-irradiation 1/f noise and post-irradiation interface traps buildup is established which agrees well with the experimental results. This model shows that the process of interface trap buildup was influenced by the increasing of oxide hole-traps that could dissociated hydrogen into proton under irradiation. So, the magnitude of pre-irradiation 1/f noise is directly proportional to post-irradiation interface-trap charge and sub-threshold slope. Our results not only proves that the 1/f noise can play a important role in MOSFET irradiation effects, but also proves a new nondestructive method to estimate MOSFET radiation response.