Copper metal is widely electroplated for microelectronic interconnections such as redistribution layers(RDL),pillar bumps,through silicon vias,etc.With advances of multilayered RDL,via-on-via structures have been deve...Copper metal is widely electroplated for microelectronic interconnections such as redistribution layers(RDL),pillar bumps,through silicon vias,etc.With advances of multilayered RDL,via-on-via structures have been developed for ultrahigh-density any-layer interconnection,which expects superconformal filling of interlayer low aspect-ratio vias jointly with coplanar lines and pads.However,it poses a great challenge to electrodeposition,because current via fill mechanisms are stemming from middle to high aspect-ratio(>0.8)vias and lacking applicability in low aspect-ratio(<0.3)RDL-vias,where via geometry related electric-flow fields coupling must be reconsidered.In the present work,a four-additive strategy has been developed for RDL-vias fill and thoroughly investigated from additive electrochemistry,in situ Raman spectroelectrochemistry,and quantum chemistry perspectives.A novel adsorbate configuration controlled(ACC)electrodeposition mechanism is established that at weak-convection bilateral edges and lower corners,the adsorbate displays a weakly-adsorbing configuration to assist accelerator-governed deposition,whereas at strong-convection center,the adsorbate exhibits a mildlyadsorbing configuration to promote leveler-determined inhibition.Deposit profiles can be tailored from dished,flat to domed,depending on predominance of leveler over accelerator.This study should lay theoretical and practical foundations in design and application of copper electroplating additives of multiple adsorbate configurations to cope with complicated interconnect scenarios.展开更多
On-line detection of additive concentrations in acidic copper(Cu)electroplating solution,including the suppressor,accelerator and leveler,is crucial for the industrial production of integrated circuit metal interconne...On-line detection of additive concentrations in acidic copper(Cu)electroplating solution,including the suppressor,accelerator and leveler,is crucial for the industrial production of integrated circuit metal interconnections.For this purpose,a portable electrochemical microfluidic workstation(EMW)is developed.The polymer electrochemical microfluidic chip is designed and fabricated by 3D printing,in which a liquid mixer is integrated with an electrochemical microcell.The asymmetrically distributed herringbone microstructures in the microchannels(width:400μm,height:300μm,length:4 cm)ensure the highly efficient mixture of solutions.In the electrochemical microcell,a 12.5μm radius platinum ultramicroelectrode(Pt UME)acts as the working electrode.Based on the suppressing or accelerating effects of the additives on Cu electroplating,the calibration curves can be obtained by the stripping charge of electrodeposited Cu.Thus,the concentration of each additive in the acidic Cu electroplating solution can be detected on line and adjusted in time.The solution volume needed for each additive is approximately 220μL.The detection error is lower than 10%,meeting the analytic requirements in industry.The automated EMW has the potential to replace the current manual cyclic voltammetry stripping(CVS)employed in lab analysis.展开更多
基金supported by Key-Area Research and Development Program of Guangdong Province(No.2023B0101040002)National Natural Science Foundation of China(Nos.62304143,52303092 and 62274172)Guangdong Basic and Applied Basic Research Fund(No.2022B1515120037).
文摘Copper metal is widely electroplated for microelectronic interconnections such as redistribution layers(RDL),pillar bumps,through silicon vias,etc.With advances of multilayered RDL,via-on-via structures have been developed for ultrahigh-density any-layer interconnection,which expects superconformal filling of interlayer low aspect-ratio vias jointly with coplanar lines and pads.However,it poses a great challenge to electrodeposition,because current via fill mechanisms are stemming from middle to high aspect-ratio(>0.8)vias and lacking applicability in low aspect-ratio(<0.3)RDL-vias,where via geometry related electric-flow fields coupling must be reconsidered.In the present work,a four-additive strategy has been developed for RDL-vias fill and thoroughly investigated from additive electrochemistry,in situ Raman spectroelectrochemistry,and quantum chemistry perspectives.A novel adsorbate configuration controlled(ACC)electrodeposition mechanism is established that at weak-convection bilateral edges and lower corners,the adsorbate displays a weakly-adsorbing configuration to assist accelerator-governed deposition,whereas at strong-convection center,the adsorbate exhibits a mildlyadsorbing configuration to promote leveler-determined inhibition.Deposit profiles can be tailored from dished,flat to domed,depending on predominance of leveler over accelerator.This study should lay theoretical and practical foundations in design and application of copper electroplating additives of multiple adsorbate configurations to cope with complicated interconnect scenarios.
基金the National Natural Science Foundation of China(22132003,22202166)National Key Research and Development Program of China(2023YFF0713900).
文摘On-line detection of additive concentrations in acidic copper(Cu)electroplating solution,including the suppressor,accelerator and leveler,is crucial for the industrial production of integrated circuit metal interconnections.For this purpose,a portable electrochemical microfluidic workstation(EMW)is developed.The polymer electrochemical microfluidic chip is designed and fabricated by 3D printing,in which a liquid mixer is integrated with an electrochemical microcell.The asymmetrically distributed herringbone microstructures in the microchannels(width:400μm,height:300μm,length:4 cm)ensure the highly efficient mixture of solutions.In the electrochemical microcell,a 12.5μm radius platinum ultramicroelectrode(Pt UME)acts as the working electrode.Based on the suppressing or accelerating effects of the additives on Cu electroplating,the calibration curves can be obtained by the stripping charge of electrodeposited Cu.Thus,the concentration of each additive in the acidic Cu electroplating solution can be detected on line and adjusted in time.The solution volume needed for each additive is approximately 220μL.The detection error is lower than 10%,meeting the analytic requirements in industry.The automated EMW has the potential to replace the current manual cyclic voltammetry stripping(CVS)employed in lab analysis.
