Research On Experiment And Simulation Of Electromigration Failure For Metal Interconnect

With the development of microelectronics technology,the characteristic scale of integrated circuits continue to decrease,as the cross-sectional area of the metal film very large scale integrated circuit(VLSI)interconnects are getting smaller and smaller,a sharp increase in its exposure of the current density.When the interconnect width developed into deep submicron dimension,the current density grows to MA/cm2 magnitude.Interconnect failure induced by electromigrationn has become particularly prominent.Currently,the metal interconnect electromigration has become one of the main failure mechanisms to VLSI.Electromigration is a very complex process associated with many factors,including the operating current density,current crowding,Joule heat,temperature gradient,stress gradient,alloy composition,size and shape of the interconnection.So far,electromigration is not enough understanding of the issues,although recent research has made great progress,a lot of important basic issues remain to be addressed.In this paper,finite element analysis and experimental research technique combines theoretical study of electromigration phenomenon of metal interconnects in integrated circuits were studied systematically.Based on Black equation,a modified electromigration models of failure mechanisms of metal interconnect was established.And a detailed process for electromigration accelerated life test carried out on aluminumsilicon alloy interconnection line for the study,getting relevant parameters of the corrected Black equation,analized influence among different ambient temperature,current density,different initial resistance and other factors on the aluminum interconnect electromigration.Then,using the finite element analysis software ABAQUS,electromigration process for aluminum-silicon alloy interconnect electric-thermal coupling were studied to analyze the the relationship among different current densities,the potential gradient,the heat flux,the internal interconnects and the total energy.And also made comparisons of regular pattern in different frame sizes for aluminum interconnect electromigration failure.Finally,the high-temperature creep finite element analysis of aluminum-silicon alloy interconnect was studied,analized the effects of interconnect internal stress field by different creep temperature,heating rate and other parameters,so as to provides an important technology platform for the integrated circuit reliability analysis and design.