The optimization of electrolytes and the material removal mechanisms for Cu electrochemical mechanical planarization(ECMP)at different pH values including 5-methyl-1H-benzotriazole(TTA),hydroxyethylidenediphosphoric a...The optimization of electrolytes and the material removal mechanisms for Cu electrochemical mechanical planarization(ECMP)at different pH values including 5-methyl-1H-benzotriazole(TTA),hydroxyethylidenediphosphoric acid(HEDP),and tribasic ammonium citrate(TAC)were investigated by electrochemical techniques,X-ray photoelectron spectrometer(XPS)analysis,nano-scratch tests,AFM measurements,and polishing of Cu-coated blanket wafers.The experimental results show that the planarization efficiency and the surface quality after ECMP obtained in alkali-based solutions are superior to that in acidic-based solutions,especially at pH=8.The optimal electrolyte compositions(mass fraction)are 6% HEDP,0.3% TTA and 3% TAC at pH=8.The main factor affecting the thickness of the oxide layer formed during ECMP process is the applied potential.The soft layer formation is a major mechanism for electrochemical enhanced mechanical abrasion.The surface topography evolution before and after electrochemical polishing(ECP)illustrates the mechanism of mechanical abrasion accelerating electrochemical dissolution,that is,the residual stress caused by the mechanical wear enhances the electrochemical dissolution rate.This understanding is beneficial for optimization of ECMP processes.展开更多
In this article,the characteristic of the field plastic mulch, the craft for mechanization removal and land preparation of plastic mulch and the mechanism frequently used in the removal and land preparation of plasti...In this article,the characteristic of the field plastic mulch, the craft for mechanization removal and land preparation of plastic mulch and the mechanism frequently used in the removal and land preparation of plastic mulch were introduced, which offered references for the design of removal mechanism and land preparation of plastic mulch and structural optimization combination of working components.展开更多
The electric double layer with the transmission of particles was presented based on the principle of electrochemistry.In accordance with this theory,the cavitation catalysis removal mechanism of ultrasonic-pulse elect...The electric double layer with the transmission of particles was presented based on the principle of electrochemistry.In accordance with this theory,the cavitation catalysis removal mechanism of ultrasonic-pulse electrochemical compound machining(UPECM) based on particles was proposed.The removal mechanism was a particular focus and was thus validated by experiments.The principles and experiments of UPECM were introduced,and the removal model of the UPECM based on the principles of UPECM was established.Furthermore,the effects of the material removal rate for the main processing parameters,including the particles size,the ultrasonic vibration amplitude,the pulse voltage and the minimum machining gap between the tool and the workpiece,were also studied through UPECM.The results show that the particles promote ultrasonic-pulse electrochemical compound machining and thus act as the catalyzer of UPECM.The results also indicate that the processing speed,machining accuracy and surface quality can be improved under UPECM compound machining.展开更多
基金Project(50975058)supported by the National Science Foundation of China
文摘The optimization of electrolytes and the material removal mechanisms for Cu electrochemical mechanical planarization(ECMP)at different pH values including 5-methyl-1H-benzotriazole(TTA),hydroxyethylidenediphosphoric acid(HEDP),and tribasic ammonium citrate(TAC)were investigated by electrochemical techniques,X-ray photoelectron spectrometer(XPS)analysis,nano-scratch tests,AFM measurements,and polishing of Cu-coated blanket wafers.The experimental results show that the planarization efficiency and the surface quality after ECMP obtained in alkali-based solutions are superior to that in acidic-based solutions,especially at pH=8.The optimal electrolyte compositions(mass fraction)are 6% HEDP,0.3% TTA and 3% TAC at pH=8.The main factor affecting the thickness of the oxide layer formed during ECMP process is the applied potential.The soft layer formation is a major mechanism for electrochemical enhanced mechanical abrasion.The surface topography evolution before and after electrochemical polishing(ECP)illustrates the mechanism of mechanical abrasion accelerating electrochemical dissolution,that is,the residual stress caused by the mechanical wear enhances the electrochemical dissolution rate.This understanding is beneficial for optimization of ECMP processes.
基金Supported by Heilongjiang Province "Tenth Five-Year Plan"the Key Tackling Item (GC01B708)
文摘In this article,the characteristic of the field plastic mulch, the craft for mechanization removal and land preparation of plastic mulch and the mechanism frequently used in the removal and land preparation of plastic mulch were introduced, which offered references for the design of removal mechanism and land preparation of plastic mulch and structural optimization combination of working components.
基金Project(51275116)supported by the National Natural Science Foundation of ChinaProject(2012ZE77010)supported by the Aero Science Foundation of ChinaProject(LBH-Q11090)supported by the Postdoctoral Science Research Development Foundation of Heilongjiang Province,China
文摘The electric double layer with the transmission of particles was presented based on the principle of electrochemistry.In accordance with this theory,the cavitation catalysis removal mechanism of ultrasonic-pulse electrochemical compound machining(UPECM) based on particles was proposed.The removal mechanism was a particular focus and was thus validated by experiments.The principles and experiments of UPECM were introduced,and the removal model of the UPECM based on the principles of UPECM was established.Furthermore,the effects of the material removal rate for the main processing parameters,including the particles size,the ultrasonic vibration amplitude,the pulse voltage and the minimum machining gap between the tool and the workpiece,were also studied through UPECM.The results show that the particles promote ultrasonic-pulse electrochemical compound machining and thus act as the catalyzer of UPECM.The results also indicate that the processing speed,machining accuracy and surface quality can be improved under UPECM compound machining.
