Researches On Experiment And Damage Mechanism Of Transient Dose Rate Effect In Double-power Integrated Circuit

Transient dose rate effect of device or circuit refers to the production of photocurrents under transient dose rate radiation and a series of errors which include disturbance,upset,latchup and even burnout caused by it.Among them,the ability of power supply to resist transient dose rate radiation directly affect the function of circuit.As the scale of integrated circuit continues to increase,the application of double-power circuit has become more extensive.When various parts of circuit have different functions and complex structures,it is crucial to study the impacts of different power supplies and supply voltages on transient dose rate effect of integrated circuit.In this paper,based on 0.18?m bulk silicon CMOS devices,damage mechanism and effect law of transient dose rate radiation from simple to complex integrated circuits are studied by the combination of TCAD simulation,SPICE simulation,pulsed laser experiment and ?-ray experiment.The main research results are as follows:(1)Based on a inverter circuit,the influences of well contact,output level,substrate type and SOI structure on transient dose rate effect of integrated circuit are revealed.Among them,adding well contacts could accelerate the absorption of photocurrents by electrodes,thereby reducing the disturbance and recovery time of circuit,which plays a hardening role.The parasitic transistors inside MOS device are closely related to substrate,which cause the output disturbance of P-substrate inverter at low level to be greater than that at high level,while N-substrate inverter is just the opposite.By blocking the parasitic paths between wells and substrate through SOI dielectric isolation,the parasitic bipolar effect of MOS device can be weakened,and the purpose of transient dose rate radiation hardening in integrated circuit is achieved.(2)Based on a double-power inverter chain and a double-power microprocessor,the influences of different power supplies and supply voltages on double-power integrated circuit under transient dose rate radiation are investigated.The disturbance amplitude of output voltage in double-power integrated circuit is positively correlated with both supply voltages and more affected by the core voltage.For two power supplies themselves,the disturbance amplitude of IO voltage is greater,but the recovery time of core voltage is longer.The recovery of circuit output depends on the recovery of core power.Therefore,core power is considered to be an important part in transient dose rate radiation hardening of double-power integrated circuit.(3)Aiming at the weak resistance of core power to transient dose rate disturbance,this paper designs a LDO module to complete on-chip conversion of IO voltage and replace the function of core power in a double-power SRAM.The LDO adopts the hardening structure of time-skewed and space-split power transistors,that is,splitting the power MOS of large area into small MOS in parallel and adding a normally-open transmission gate between adjacent MOS gates,which effectively reduces the recovery time of LDO output disturbance.By comparing double-power SRAM with and without LDO in power supply,the results show that the resistance capability of transient dose rate radiation in SRAM power supply with LDO is better than that without LDO.Using LDO instead of core power is proved to be an effective way to realize transient dose rate radiation hardening of power supply and overall integrated circuit.