摘要
Owing to the fifll isolation and minimization of the silicon active volume, silicon-on-insulator （SOI） tech- nology has better resistance against transient ionizing effects like single event effects （SEE） or latch up.However, the total ionizing dose （TID） irradiation responses of SOI transistors are more complex than bulk-silicon devices. In addition to the gate and par- asitic field leakage current, which are common to SOI and bulk-silicon devices, irradiation induced charges trapped in the SOI buried oxide （BOX） can also affect SOI device performance. Typically, there is a par- asitic edge transistor in the back-gate of SOI devices paralleled with the main transistor, which is formed by the corner region of the silicon island. Due to the high electric field induced by the back-gate voltage at the corner of the silicon island, the threshold of the parasitic edge transistor is lower than the main transistor, resulting in a sub-threshold hump in the transfer characteristic of the back-gate transistor. Even though the threshold of the parasitic edge tran- sistor is lower than the main transistor, it is still larger than zero, which has no effect on the front- gate of devices. However, the sub-threshold hump in the back-gate is the ＇Achilles heel＇ for total dose responses of deep sub-micron SOI n-type metal-oxide- semiconductor field-effect transistors （MOSFETs） iso- lated by shallow trench isolation （STI）. As reported in Refs., the threshold of the parasitic edge transis- tor is negative shifted by radiation-induced charges trapped in STI, leading to off-state leakage in the front-gate of devices.
Owing to the fifll isolation and minimization of the silicon active volume, silicon-on-insulator （SOI） tech- nology has better resistance against transient ionizing effects like single event effects （SEE） or latch up.However, the total ionizing dose （TID） irradiation responses of SOI transistors are more complex than bulk-silicon devices. In addition to the gate and par- asitic field leakage current, which are common to SOI and bulk-silicon devices, irradiation induced charges trapped in the SOI buried oxide （BOX） can also affect SOI device performance. Typically, there is a par- asitic edge transistor in the back-gate of SOI devices paralleled with the main transistor, which is formed by the corner region of the silicon island. Due to the high electric field induced by the back-gate voltage at the corner of the silicon island, the threshold of the parasitic edge transistor is lower than the main transistor, resulting in a sub-threshold hump in the transfer characteristic of the back-gate transistor. Even though the threshold of the parasitic edge tran- sistor is lower than the main transistor, it is still larger than zero, which has no effect on the front- gate of devices. However, the sub-threshold hump in the back-gate is the ＇Achilles heel＇ for total dose responses of deep sub-micron SOI n-type metal-oxide- semiconductor field-effect transistors （MOSFETs） iso- lated by shallow trench isolation （STI）. As reported in Refs., the threshold of the parasitic edge transis- tor is negative shifted by radiation-induced charges trapped in STI, leading to off-state leakage in the front-gate of devices.
