A radiation-hardened instrumentation amplifier (IA) that allows precise measurement in radiation environments, including nuclear power plants, space environments, and radiation therapy rooms, was designed and manufactured, and its characteristics were verified. Most electronic systems are currently designed using silicon-based complementary metal-oxide semiconductor (CMOS) integrated circuits (ICs) to achieve a highly integrated low-power design. However, fixed charges induced in silicon by ionization radiation cause various negative effects, resulting in, for example, the generation of leakage current in circuits, performance degradation, and malfunction. Given that such problems in radiation environments may directly lead to a loss of life or environmental contamination, it is critical to implement radiation-hardened CMOS IC technology. In this study, an IA used to amplify fine signals of the sensors was designed and fabricated in the 0.18 μm CMOS bulk process. The IA contained sub-circuits that ensured the stable voltage supply needed to implement system-on-chip (SoC) solutions. It was also equipped with special radiation-hardening technology by applying an I-gate n-MOSFET that blocks the radiation-induced leakage currents. Its ICs were verified to provide the intended performance following a total cumulative dose of up to 25 kGy(Si), ensuring its safety in radiation environments.

In the present study, the layout structure of an n-MOSFET, which is vulnerable to radiation, was designed in a different way to enhance its tolerance to radiation. Radiation damage assessment was conducted using modeling and simulation (M&S) techniques before actual semiconductor process fabrication and radiation tests to verify its tolerance properties. Based on the M&S techniques, the role of each layer was determined to improve the radiation tolerance of semiconductors, and the layout design of an n-MOSFET with enhanced radiation tolerance was optimized. The optimized radiation-tolerant n-MOSFET design was implemented in the 0.18-um CMOS bulk process, and radiation exposure tests were conducted on the device. A cumulative radiation dose up to 2 Mrad(Si) was applied to verify its radiation-tolerant performance. Developing new devices using M&S techniques for radiation damage assessment allows reliable estimates of their electrical and radiation-tolerant properties to be obtained in advance of the actual manufacturing process, thereby minimizing development costs and time.

Electronic equipment in nuclear power plants and nuclear warfare is damaged by transient effects that cause high-energy pulsed radiation. There is a concern that this type of damage can even cause enormous economic losses and human casualties by paralyzing control systems. To solve this problem, this study proposes a complementary metal-oxide semiconductor (CMOS) logic-based, switching detection circuit that can detect pulsed radiations at a fast rate. This circuit improved response speed and power consumption by using the switching operation of digital logic compared with conventional circuits. Furthermore, radiation tolerance to total ionizing dose (TID) effects was achieved even in a cumulative radiation environment because of the use of the design using p-metal-oxide semiconductor field effect transistor (p-MOSFET). The proposed detection circuit was manufactured by a 0.18 µm CMOS bulk process for integration. Normal operation in the detection range of 2.0 × 10⁷ rad(si)/s was verified by pulsed radiation test evaluations, and the tolerance properties to a radiation of 2 Mrad was verified based on cumulative radiation test evaluations.