Radiation Effects Of SiGe BiCMOS Devices

In recent years,with the rapid development of space exploration,more and more spacecraft are operating in the space radiation environment.The optimization of power level and working frequency of pure silicon devices is approaching its theoretical limit,and it is more difficult to improve both performance and frequency characteristics.In order to meet the requirements of RF communication applications for high performance devices,the research focus in this field has gradually shifted to new semiconductor materials and devices.SiGe BiCMOS technology combines the advantages of SiGe HBTs such as high frequency,low noise,high speed and low temperature resistance with the advantages of Si CMOS,which is mature,low cost,high integration and low power.In order to promote the applications and development of domestic SiGe BiCMOS process technology in the aerospace field,it is necessary and urgent to study the radiation effects of domestic SiGe BiCMOS process devices.The experimental samples in this paper selected 4 new types of 0.35 μm SiGe BiCMOS process devices with different processes and structures independently developed by the 24 th Research Institute of China Electronics Corporation,,high dose rate(100 rad(Si)/s),low dose rate(0.05 rad(Si)/s)and low dose rate(0.1 rad(Si)/s)60Co-γ radiation environment control experiment,analyzed its radiation response characteristics and damage mechanism..The results show that ELDRS of the domestic 0.35 μm SiGe BiCMOS process devices under different dose rates and different bias conditions is obvious,It is found that the main mechanism of ELDRS is the competition mechanism of electron-hole trapping under low dose rate irradiation,which leads to the increase of interface traps in the base emitter oxide layer and field oxide layer(FOX)of SiGe BiCMOS devices.Under the space charge competition model,high dose rate ionizing radiation damage is inhibited,resulting in ELDRS under different dose rate effects.Under different dose rates and different bias conditions,the device under forward bias bias showed increased damage compared to low-dose damage under zero bias bias.The reason is that domestic process and structural devices have been pressurized for more than 7 months for a long time,and the reliability of the device A serious problem has occurred.A systematic study of four domestic 0.35 μm SiGe BiCMOS process and structure devices has been carried out.The results show that under high-dose rate irradiation,high-speed process devices under the conditions of forward bias and zero bias are not as capable of resisting the total ionization dose effect as high-voltage process devices.The reliability of high-speed process devices is better than high-voltage devices under partial conditions.Under low-dose rate irradiation,the performance degradation of high-speed process devices and high-voltage process devices is not much different.At high and low dose rates,the performance of devices with long emitter lengths in B and D structures is better than that of devices with small emitter lengths in A and C structures.This research has important scientific significance and reference value for understanding and mastering the radiation resistance of domestic 0.35 μm SiGe BiCMOS process and structural devices,improving the process structure,and optimizing its radiation reinforc ement measures.