| With the rapid development of semiconductor technology,the feature size of the chip is evolving towards smaller and smaller,and the scale is also growing.Power consumption has become a bottleneck restricting the development of semiconductor technology.Tunnel FET(TFET)utilize the quantum effects of band-to-band tunneling(BTBT)to break through the subthreshold swing limit of 60 mV/dec,making them one of the most powerful candidates in low-power circuits.Electrostatic Discharge(ESD)is one of the main reasons for affecting the function of integrated circuits and even destroying chips,and as the size of the device continues to shrink,the oxide layer with lower power consumption,thinner gate and new process devices greatly reduce the ability of ESD protection.In this thesis,the electrical characteristics of the proposed TFET-based ESD protection device are studied based on TCAD simulation.The main contents are as follows:1.The thesis first explains the background and significance of ESD protection,introduces the research status of tunneling transistor and TFET-MOSFET hybrid integration at home and abroad,and explains that this topic has clear scientific significance.2.Voltage detector based on TFET.The TFET is used instead of the diode to form a structure similar to the inverted amplifier.The phase of the input VDD and the output VDetect-TFET is opposite,achieving higher detection sensitivity.Compared with the existing diode-in-series voltage detector,the newly proposed voltage detector has a small layout area,high detection sensitivity,lower power consumption and better thermal stability,and can be used to detect ESD events.Then the proposed voltage detector is used in the EOS protection circuit.Through surge simulation and ESD simulation,it is verified that the proposed voltage detector can detect surge and ESD conditions and open the SCR discharge current in time.3.TFET-triggered SCR(TTSCR).The high trigger voltage of the traditional SCR limits its application in advanced ESD protection.Although DTSCR has its advantages,it has to compromise between area and leakage.Therefore,a SCR device using tunnel current to assist trigger is proposed,which can reduce the trigger voltage of SCR.The characteristics of TTSCR and DTSCR with the same process parameters are compared.Under the VFTLP simulation of 2A current,the overshoot voltages of TTSCR and DTSCR are 6.4V and 12.4V,respectively,and the FOM is 0.7A/μm and 0.2A/μm,respectively.The parasitic capacitance of TTSCR is also smaller.At 125℃,the leakage current of TTSCR(0.95μA)is lower than that of DTSCR(1.3μA).The implementation of TTSCR under advanced processes is discussed and analyzed.Finally,the influence of TFET structure on the electrical characteristics is also discussed.The trigger voltage of SCR triggered by line tunneling TFET is about 6.2V,which is lower than that of point tunneling.In summary,this thesis studies some ESD protection technologies based on TFET.On this basis,a voltage detector based on TFET and a SCR device triggered by tunnel current are proposed,and some meaningful results are obtained through TCAD simulation,which provides some ideas and help for related ESD protection design. |
