Electroplated copper

Abstract

An electroplated copper metal having certain grain misorientations between adjacent grains at a <111> crystal plane direction provides for improved properties of the copper. A method of electroplating the copper metal on substrates, including dielectric substrates, is also disclosed.

What is claimed is: 
     
         1 . A copper metal comprising twin fractions of 30% or greater of grain boundaries between adjacent copper grains having angles of misorientation from 55° to 65° with respect to a crystal plane direction of <111>. 
     
     
         2 . The copper metal of  claim 1 , further comprising an XRD area ratio of (111) plane orientation/(200) plane orientation at diffraction angle 2θ (°) is equal to or greater than 1. 
     
     
         3 . The copper metal of  claim 2 . wherein the XRD area ratio of (111) plane orientation/(200) plane orientation at the diffraction angle 2θ (°) is equal to or greater than 5. 
     
     
         4 . The copper metal of  claim 1 , wherein a copper grain diameter is 100 nm or greater after thermal annealing. 
     
     
         5 . A method of electroplating copper comprising:
 a) providing a substrate;   b) providing a copper electroplating bath comprising one or more sources of copper ions to provide the copper ions at concentrations of 20 g/L to 55 g/L, one or more reaction products of one or more imidazole compounds, or one or more 2-aminopyridine compounds with one or more bisepoxides, wherein the one or more reaction products are at concentrations of 2 ppm to 15 ppm; an electrolyte; one or more accelerators, wherein the one or more accelerators are at concentrations of 0.5 ppm to 100 ppm; and one or more suppressors, wherein the one or more suppressors are at concentrations of 0.5 g/L to 10 g/L;   c) immersing the substrate in the copper electroplating bath;   d) electroplating copper on the substrate to deposit a copper layer on the substrate; and,   e) annealing the copper layer to a temperature of at least 200 ° C. in an inert atmosphere to provide a copper layer comprising twin fractions of 30% or greater of grain boundaries between adjacent copper grains having angles of misorientation of 55° to 65° with respect to a crystal plane direction of <111>.   
     
     
         6 . The method of  claim 5 , wherein a current density during electroplating the copper is 2-8 ASD. 
     
     
         7 . The method of  claim 5 , wherein the substrate comprises a dielectric with a metal seed layer adjacent the dielectric, and wherein the copper layer is deposited adjacent the metal seed layer of the dielectric.