Study On Microstructure And Texture Of High Purity Copper Extrusion

With the rapid development of semiconductor technology,the requirement for sputtering targets is further improved.Since copper and its alloys have the advantages of low resistivity,good electrical conductivity,low RC delay and easy cooling,the integrated circuit wired by copper has become an important development trends.The thickness and uniformity of the deposited film are effected by microstructure and texture of the high-purity copper sputtering target.However,at present,there is a lack of research on the preparation technology of highpurity copper target in China,especially for the high purity copper rotary sputtering targets.Therefore,this paper systematically studies the microstructure and texture of the extruded highpurity copper,aiming at providing theoretical basis for the preparation technology of highpurity copper drilling target.The microstructure evolution,grain size and uniformity,texture evolution and special grain boundary of extruded high-purity copper are studied by optical microscopy(OM),X-ray diffraction(XRD),scanning electron microscopy(SEM)and backscattered electron microscopy(EBSD).The main conclusions are as follows:(1)The extrusion temperature has a great influence on the grain size and microstructure uniformity of the extruded rods:The grain size increases with the extrusion temperature increased;The best uniformity of the microstructure can be obtained when the extrusion temperature is between 500? and 550?,and meanwhile,the grain size is lower than 30 ?m.(2)The deformation behavior of grain with different oriented is different and results in the inconsistent dynamic recrystallization process.Increasing deformation temperature can effectively improve the uniformity of the microstructure.The fine grain size and good the microstructure uniformity can be aqured when the extrusion temperature is 500??550? and the deformation is 78%.(3)Dynamic recrystallization has an important influence on the microstructure,texture,mechanical properties and physical properties of the extruded rod.Dynamic recrystallization can be found at severe distortion region at 300?.Complete recrystallization occures at 450?,and some grains were grown abnormally at 750?.(4)The extrusion temperature has a significant effect on the extrusion texture of highpurity copper.The texture is characterised by a strong deformation texture<111>//ED while the extrusion temperature is below 300? and transforms into the weaker deformation texture<111>//ED+recrystallization texture<100>//ED at 350?;The texture is weak and random at 400??700?.At 750?,the texture is recrystallization texture<100>//ED.(5)Extrusion temperature has significant influence on the special crystal distribution in high-purity copper extrusion rod.The extrusion temperature affects the special grain boundary distributed by affecting the proportion of the ?3 grain boundary during extrusion.There is almost no special grain boundary at low extrusion temperature.The proportion of the special grain boundary in the extruded rod increases rapidly and eventually stabilizes as the extrusion temperature increases.