Study On The Influence Of Metal Gate Work Function Variation On New Integrated Nanodevices

In the last few decades,the Complementary Metal Oxide Semiconductor(CMOS)technology has dominated the mainstream silicon integrated circuit industry.As technology strides into the deepsubmicron regime,CMOS integrated circuits are moving into unprecedented operating frequencies and accomplishing unprecedented integration levels.However,the effects of random variations in the atomic-level process during the manufacturing process have also increased dramatically.Especially in the 45 nm node and beyond,the use of metal gates introduces metal work-function variation.This lead to that the overall work function of all Metal-Oxide-Semiconductor Field-Effect Transistor(MOSFET)with the same design in the integrated circuit is different.Therefore,the impact of random variations in this process poses a significant challenge to the manufacturing performance and yield of integrated circuit.This dissertation mainly uses the Sentaurus TCAD simulation software to carry out numerical simulation and statistical analysis of the electrical characteristics of nanometer CMOS devices,and further explore the impact of the new CMOS device structure on random behavior.These simulations provides insights for circuit design and manufacture of new nanometer CMOS integrated devices and circuits.The main research content of this dissertation is arranged as follows.In the first part of this thesis,due to the current research status and shortcomings and based on the concept of Ratio of Average Grain Size to Gate Area,the device structure model is established,and the appropriate physical simulation model is adopted.Metal work function random fluctuations on Fin FET(Fin Field-Effect Transistor)and traditional inversion model GAA(Gate-All-Around)nanowire transistors have been analyzed and compared.The simulation results show that the cylindrical structure of GAA can suppress the negative effects caused by the random fluctuation of metal work function.In the second and third parts,based on the new Fin FET structure,the dual metal gate has been applied.Firstly,the effects of three random variation sources on device performance are studied.Secondly,the effects of random fluctuations of two metal gates under different ratios on device performance are discussed.The results show that the length of the control gate has a worse impact on the negative random-induced device performance variation.