Simulation Research Of ESD Protection Low Voltage Devices In Integrated Circuit

The semiconductor industry is an important support for the development of the country.With the development of the semiconductor industry,the reliability of the chip is faced with a series of problems due to the appearance of new technology and new dimensions.The most serious problem is electrostatic discharge(ESD),so the research on the electrostatic protection of the chip is concerned.However the cost used to test and study the performance of the chip is high,in addition,the ESD simulation software,represented by Sentaurus-TCAD,can solve this problem.The software can greatly shorten the research design cycle and reduce the cost.Electrostatic protection low voltage device is the object of this paper.Firstly,this paper studies the basic structure,normal operating characteristics,and the working mechanism under ESD stress in device model diodes,GGNMOS,and SCR.Secondly,the carrier transport model,energy band model,carrier mobility model,avalanche ionization model and carrier recombination model are studied.what's more,ESD low voltage device model structure and working mechanism are studied.Thirdly,the device-adapted mathematical physics model is selected.In order to accurately reflect the actual situation,the convergence of simulation and the setting of boundary conditions is studied,which provides theoretical basis for simulation research.Fourthly,SDE and SDevice in the Sentaurus-TCAD are used to model and analyze the electrical characteristics of low voltage device objects.At the same time,using the signal excitation of transient single-pulse and transient single-pulse TLP waveforms,In the case of electrostatic discharge,the internal electrical characteristics of the diode,GGNMOS,and DTSCR are simulated.Finally,the simulation results and real results are compared to verify the feasibility of the device simulation results.Fifthly,in order to improve the accuracy of the simulation,the simulation method of multi-pulse transient TLP waveform excitation was proposed to calculate the average electrical characteristics of the effective plateau of each pulse.This method can reduce the influence of overshoot voltage and time of single pulse,improve the simulation accuracy of triggering voltage and holding voltage and ensure that the error between simulation and test is within 10%.In addition to the above study,giving the research and analysis of the Darlington effect in the diode string by simulation ideas and methods.It is proposed that the Schottky diode string can effectively overcome the Darlington effect and provide multiple sets of simulation data.Comparing the simulation results with actual results of diode,GGNMOS and DTSCR electrostatic protection low-voltage device models,the following conclusions can be drawn: The multi-pulse transient TLP waveform based on Sentaurus-TCAD software simulation can effectively reflect the turn-on voltage and sustain voltage of ESD low-voltage devices.In addition,the simulation model proposed in this paper can be used in the ESD protection low-voltage device design process,which provides a good reference for research and production of this kind of device.In addition,using the above-mentioned simulation idea to verify the Schottky diode string structure can effectively eliminate the Darlington effect in the PN junction diode,and provide reference for its application research.