Failure Mechanism And Experimental Analysis Of Gold Thin Film Heating Interconnect

With the continuous improvement of device integration and power density, the micro / nano thin film heater used in microelectronic industry is more and more widely. And the metal is the most-used material especially in highly integrated devices. Now the size of metal thin film has reached nanometer level. Therefore, the reliability of metal thin films with small line width and unique thermal effect has become the focus of research. Based on the demand of reliability analysis of gold film heating interconnect in thermo optic devices a theory-experiment combined method is applied to research the various factors of gold film heating interconnect which have the obvious influence on device life and the corresponding strategy of optimization design was presented.First, for the film interconnect common failure forms, the failure characteristics of thermo optic devices and practical products were understood and then the gold thin film heating interconnect failure mode was determined. Through theoretical and simulation analysis, and consequent tests, the main mechanism for the failure of gold film was found electromigration. Based on the analysis of the mechanism of electromigration failure, the failure model of gold thin film heating interconnect was established.Secondly, based on the theoretical model, the finite element simulation software was used to analyze the influence of temperature, current and shape parameters on the gold thin film interconnect lifetime. In order to obtain the atomic massflux divergence, FEM coupled thermal-electric and thermal-structure simulation model was established to obtain the values of relevant parameters, such as temperature, current density, temperature gradient and stress gradient. The temperature, current and arc radius of the multi factor orthogonal experiment were designed by using the divergence value(and the life span) as the index. The results show that the lifetime of the gold film is most affected by the temperature.Finally, based on the theoretical and simulation research, the gold thin film heating interconnects were designed and fabricated, and the relevant measurement and test system was built. Through a series of diagnostic tests and orthogonal experiments, the results were summaried as follow:(1) Failure mainly occurred in the largest temperature gradient arc region.(2) Interconnect lifetime is mainly determined by the length of the stable stage.(3) The temperature influences the interconnect lifetime most significantly.The research on failure of interconnect on gold film heater revealed the rule of various factors on the gold film heating interconnect lifetime. And it provides scientific guidance and theoretical support for the analysis of optoelectronic devices and improve the reliability of gold thin film heater, provides scientific guidance and theoretical support, and has offered a solid theoretical basis for a new generation of photoelectric device development and application promotion and lay.