Utilizing a shallow trench isolation parasitic transistor to characterize the total ionizing dose ef

• 作 者: 彭超 胡志远 宁冰旭 黄辉祥 樊双 张正选 毕大炜 恩云飞
• 机 构: State Key Laboratory of Functional Materials for Informatics,Shanghai Institute of Microsystem and I
• 出 处: Chinese Physics B
• 发表日期: 2014年09期
• 关键词: transistor parasitic trench depleted shallow drain irradiation doping buried lea

We investigate the effects of 60 Co γ-ray irradiation on the 130 nm partially-depleted silicon-on-isolator(PDSOI)input/output(I/O) n-MOSFETs. A shallow trench isolation(STI) parasitic transistor is responsible for the observed hump in the back-gate transfer characteristic curve. The STI parasitic transistor, in which the trench oxide acts as the gate oxide,is sensitive to the radiation, and it introduces a new way to characterize the total ionizing dose(TID) responses in the STI oxide. A radiation enhanced drain induced barrier lower(DIBL) effect is observed in the STI parasitic transistor. It is manifested as the drain bias dependence of the radiation-induced off-state leakage and the increase of the DIBL parameter in the STI parasitic transistor after irradiation. Increasing the doping concentration in the whole body region or just near the STI sidewall can increase the threshold voltage of the STI parasitic transistor, and further reduce the radiation-induced off-state leakage. Moreover, we find that the radiation-induced trapped charge in the buried oxide leads to an obvious front-gate threshold voltage shift through the coupling effect. The high doping concentration in the body can effectively suppress the radiation-induced coupling effect.

We investigate the effects of 60 Co γ-ray irradiation on the 130 nm partially-depleted silicon-on-isolator (PDSOI) input / output (I / O) n-MOSFETs. the observed hump in the back-gate transfer characteristic curve. The STI parasitic transistor, in which the trench oxide acts as the gate oxide, is sensitive to the radiation, and it introduces a new way to characterize the total ionizing dose (TID) responses in the STI oxide. A radiation enhanced drain induced barrier lower (DIBL) effect is observed in the STI parasitic transistor. It is manifested as the drain bias dependence of the radiation-induced off-state leakage and the increase of the DIBL parameter in the STI parasitic transistor after irradiation. Increasing the doping concentration in the whole body region or just near the STI sidewall can increase the threshold voltage of the STI parasitic transistor, and further reduce the radiation-induced off-state leakage. Mor eover, we find that the radiation-induced trapped charge in the buried oxide leads to an obvious front-gate threshold voltage shift through the coupling effect. The high doping concentration in the body can effectively suppress the radiation-induced coupling effect.