Simulation Research On Radiation Resistance Of MOSFET Devices

With the rapid improvement of integrated circuit technology,more and more chips are widely used in aerospace,national defense,space exploration and other fields.Due to the radiation environment in these fields,there are many high-energy particles such as heavy ions,rays,and neutrons.After these particles pass through the chips,they will cause serious equipment damage.Therefore,how to improve the ability of chips to resist radiation has become the main challenge for our country to develop rapidly in the abovementioned fields.The common radiation effects are single event effect(SEE)and total ionizing dose(TID)effect.The SEE is a series of effects caused by a single particle passing through the device,which can be divided into single event transient(SET),single event upset(SEU),single event latch-up(SEL),etc.The SEE can upset the circuit node voltages,disrupt the circuit logic,and generate transient currents which can activate parasitic effects between devices and cause chips burnout.The TID effect will generate many charges in the gate oxide or isolation oxide of the transistors,which will affect the threshold voltage,turnoff current,and carrier mobility,resulting in degradation of chips performance.Thesis mainly introduces the mechanism of SEE and TID effect,as well as the formation,recombination,transport,collection and trapping of electron-hole pairs,and explains the negative impact of irradiation effect on devices from a microscopic perspective.Thesis firstly studies the TID effect and proposes four reinforcement structures for the TID effect.Firstly,based on the Sentaurus TCAD software,three-dimensional simulation model of normal NMOS and the first reinforcement structure is built,and the transfer characteristic curves under different total dose are simulated.The results show that the first reinforcement structure can effectively improve the resistance of TID effect.In order to prove the effectiveness of the first reinforcement structure,the process of 0.18?m is used to fabricate them.The Radiation Effect Laboratory of Electronic Components,Xinjiang Institute of Physics and Chemistry,Chinese Academy of Sciences is entrusted to complete a two-part irradiation experiment.The first part of the experiment is to test transfer characteristic curves of the samples when the total dose is 200 krad(Si).And the second part of this experiment is to test the transfer characteristic curves at 300 krad(Si),600 krad(Si),900 krad(Si),1200 krad(Si),1500 krad(Si)and 1800 krad(Si).The experimental results show that,under a certain total dose,the variation of the turn-off current and threshold voltage of the first reinforced structure device is much less than that of normal NMOS,proving that the first reinforced structure device can effectively resist the TID effect.In addition,the three-dimensional simulation models of other three reinforcement structures are also established in thesis.The simulation results show that the other three reinforcement structures proposed in thesis can also effectively improve the ability of the device to resist the TID effect.For the single event effect,the two-dimensional simulation models of normal CMOS inverter and triple-well CMOS inverter are also constructed in thesis.The simulation results show that the triple-well process can effectively resist the SEE.