Influence of substrate on high-temperature behavior of copper film studied in situ by electron backscatter diffraction

Change in the in-plane orientation of (111) grains in the copper film was studied in situ by electron backscatter diffraction (EBSD) during its thermal treatment inside the scanning electron microscope (SEM). Two separate investigations were carried out each at different locations of the film. Both of the investigations showed the presence of (111) fiber texture with increased strengths of {111}〈112〉 and {111}〈110〉 orientations. During the first investigation, the {111}〈110〉 component became sharper relative to {111}〈112〉, while in the second investigation the sharpness decreased relative to {111} 〈112〉 with increasing temperature. No such changes in the in-plane orientation of the (111) grains were observed during the similar experiment carried out on the Cu film in freestanding condition. The role of silicon subtrate on influencing these changes has been proposed based on dislocation activity within the grains. The increase in the inclination of (111) planes to the specimen surface in {111}〈110〉 and {111}〈112〉 grains as a function of temperature was linked to the stress relaxation. The inclination of the (111) planes to the specimen surface leads to decrease in the sharpness of the (111) texture components. Finally, similar transformation in the texture of (111) grains in Cu damascene interconnects was investigated.