The fused quartz hemispherical resonator is the core component of the hemispherical resonator gyroscope.It features a complex shape and is Made from a Material that is difficult to process.Scratches are easily introdu...The fused quartz hemispherical resonator is the core component of the hemispherical resonator gyroscope.It features a complex shape and is Made from a Material that is difficult to process.Scratches are easily introduced during grinding,potentially degrading the mass-stiffness-damping symmetry;however,the underlying mechanisms of this influence have not been fully understood.This paper aims to investigate the effects of scratch defects on the frequency splitting and quality factor of the hemispherical resonator.First,finite element models of the hemispherical resonator with scratches are established.Then,the effects of the mass-stiffness factor,as well as the latitude and length of the scratches,on frequency splitting are analyzed.Furthermore,the impacts of latitude,length,and the first four harmonics of the unbalanced mass caused by scratches on thermoelastic damping and anchor loss are examined.Simulation results indicate that scratches above 55°latitude cause frequency splitting solely due to stiffness changes.Frequency splitting caused by scratches of the same size on the inherent rigidity shaft at the rim is approximately 50%of that near the transition fillet.Frequency splitting varies linearly with the volume of material removed by scratches.Scratches have little effect on thermoelastic damping.The first three harmonics of the unbalanced mass due to scratches at the rim are the primary contributors to anchor loss.Finally,focused ion beam trimming experiments are conducted at different locations on the hemispherical resonator.The trends observed in the experimental results are consistent with the simulation results.This work provides guidance for evaluating the impact of scratches on the performance of hemispherical resonators and for developing appropriate trimming processes.展开更多
Chemical mechanical planarization(CMP)has become one of the most critical processes in semiconductor device fabrication to achieve global planarization.To achieve an efficient global planarization for device node dime...Chemical mechanical planarization(CMP)has become one of the most critical processes in semiconductor device fabrication to achieve global planarization.To achieve an efficient global planarization for device node dimensions of less than 32 nm,a comprehensive understanding of the physical,chemical,and tribo-mechanical/chemical action at the interface between the pad and wafer in the presence of a slurry medium is essential.During the CMP process,some issues such as film delamination,scratching,dishing,erosion,and corrosion can generate defects which can adversely affect the yield and reliability.In this article,an overview of material removal mechanism of CMP process,investigation of the scratch formation behavior based on polishing process conditions and consumables,scratch formation mechanism and the scratch inspection tools were extensively reviewed.The advantages of adopting the filtration unit and the jet spraying of water to reduce the scratch formation have been reviewed.The current research trends in the scratch formation,based on modeling perspective were also discussed.展开更多
基金Supported by National Key Research and Development Program of China(Grant No.2022YFB3403600)the National Natural Science Foundation of China(Grant No.52305461)。
文摘The fused quartz hemispherical resonator is the core component of the hemispherical resonator gyroscope.It features a complex shape and is Made from a Material that is difficult to process.Scratches are easily introduced during grinding,potentially degrading the mass-stiffness-damping symmetry;however,the underlying mechanisms of this influence have not been fully understood.This paper aims to investigate the effects of scratch defects on the frequency splitting and quality factor of the hemispherical resonator.First,finite element models of the hemispherical resonator with scratches are established.Then,the effects of the mass-stiffness factor,as well as the latitude and length of the scratches,on frequency splitting are analyzed.Furthermore,the impacts of latitude,length,and the first four harmonics of the unbalanced mass caused by scratches on thermoelastic damping and anchor loss are examined.Simulation results indicate that scratches above 55°latitude cause frequency splitting solely due to stiffness changes.Frequency splitting caused by scratches of the same size on the inherent rigidity shaft at the rim is approximately 50%of that near the transition fillet.Frequency splitting varies linearly with the volume of material removed by scratches.Scratches have little effect on thermoelastic damping.The first three harmonics of the unbalanced mass due to scratches at the rim are the primary contributors to anchor loss.Finally,focused ion beam trimming experiments are conducted at different locations on the hemispherical resonator.The trends observed in the experimental results are consistent with the simulation results.This work provides guidance for evaluating the impact of scratches on the performance of hemispherical resonators and for developing appropriate trimming processes.
文摘Chemical mechanical planarization(CMP)has become one of the most critical processes in semiconductor device fabrication to achieve global planarization.To achieve an efficient global planarization for device node dimensions of less than 32 nm,a comprehensive understanding of the physical,chemical,and tribo-mechanical/chemical action at the interface between the pad and wafer in the presence of a slurry medium is essential.During the CMP process,some issues such as film delamination,scratching,dishing,erosion,and corrosion can generate defects which can adversely affect the yield and reliability.In this article,an overview of material removal mechanism of CMP process,investigation of the scratch formation behavior based on polishing process conditions and consumables,scratch formation mechanism and the scratch inspection tools were extensively reviewed.The advantages of adopting the filtration unit and the jet spraying of water to reduce the scratch formation have been reviewed.The current research trends in the scratch formation,based on modeling perspective were also discussed.
