| In both space and nuclear environments,the presence of semiconductor radiation effects may cause performance degradation or even damage to silicon-based devices and integrated circuits,leading to system failure and catastrophic consequences.Foreign research in this area has accumulated significantly,especially in the aerospace field,where many mature commercial radiation-hardened chips and modules have been developed.However,domestic research in core technologies related to this field started relatively late and still lags behind advanced foreign technologies to some extent.Therefore,while intensifying research efforts on radiation-hardening techniques for silicon-based devices and integrated circuits,strengthening research on radiation-hardening for devices and circuits based on standard processes will accelerate the formation and widespread application of domestic radiation-hardening technologies.Mastering key radiation-hardening methods,breaking through foreign technological barriers,is of great significance in promoting the development of related industries in China.Based on the analysis of the current research status at home and abroad,especially the methods of radiation hardening and radiation effects testing,this dissertation is based on the standard 180nm BCD process and focuses on the design of radiation-hardened layouts and circuits for silicon-based devices and integrated circuits,specifically enclosed latout transistors and LDO circuits.The research includes various aspects of radiation-hardening,such as the structures of enclosed latout transistors,their applications in integrated circuits,total dose radiation detection and compensation,among others.The main work and contributions of this dissertation are as follows:1.A comparison is made between radiation-hardening by process and radiation-hardening by design,and a deep study is conducted on the radiation-hardening by design method,which is more advantageous in terms of development cycle and cost.On the layout of radiation-hardening by design level,a design flow for radiation-hardened enclosed layout transistors based on standard processes is summarized.Unit libraries of enclosed layout transistors,such as b-shape NMOS,8-shape NMOS,racetrack-shape NLDMOS,and square-shape NLDMOS,are established.Cases and methods of circuit of radiation-hardening by design for analog integrated circuits and digital integrated circuits are provided,and three verification techniques for radiation effects are summarized.2.The total dose effects of b-shape NMOS are simulated,and the equivalent aspect ratio model and parasitic capacitance model of 8-shape NMOS are deeply studied.Chip tests and radiation tests are also conducted.The test results show that the 8-shape NMOS still has good electrical characteristics under 1Mrad（Si）.In response to the application background in complex radiation environments,and also under low dose rate radiation environments,it was verified that there was no leakage current in the 8-shaped NMOS before and after radiation,and there was no significant difference in the drain current.3.The structural characteristics and electrical characteristics of racetrack-shape NLDMOS are explained.In response to more stringent design rules,the structure of square-shape NLDMOS is proposed,and a deep study is conducted,followed by chip tests and radiation tests.The test results show that the square-shape NLDMOS still has good electrical characteristics under 1Mrad（Si）.4.In response to the dual requirements of total dose effects and displacement damage effects in complex radiation environments,a fully MOSFET architecture LDO and a reference voltage source circuit based on LDO architecture are designed based on b-shape NMOS and racetrack-shape NLDMOS,8-shape NMOS and square-shape NLDMOS,respectively.Chip tests and radiation tests are conducted.Among them,the fully MOSFET architecture LDO can withstand total dose radiation of 300krad（Si）and neutron radiation of 1.2×1012n/cm2.With output voltages of 1.2V and 5V,the output voltage stability before and after radiation is very good.The reference voltage source circuit based on LDO architecture can withstand total dose radiation of 400krad（Si）,and the 5V output voltage has good stability before and after radiation.5.Taking a digital LDO with a voltage controlled oscillator as an example,the key sub-circuit,the voltage controlled oscillator,is designed for radiation-hardening.A total dose radiation detection circuit and a total dose radiation compensation circuit are proposed and used for radiation-hardening of the voltage controlled oscillator.The results show that under simulation conditions with leakage currents of 1μA,10μA,and 100μA,the detection circuits can operate normally.Under simulation conditions with leakage currents of 10μA and 1μA,the compensation circuits and the hardened circuits can operate normally. |
