The microstructure of electroplated Cu thin films has been investigated using texture analysis. It is found that film thickness has a significant effect on the texture of the films, both as deposited and after annealing. Thin films tend to have a sharp <111> fiber texture. As the film thickness increases, the volume fraction of <111> component decreases and other texture components such as the <100> and the <110> fibers become more apparent.
The mechanical properties of these electroplated Cu films have been determined by measuring the deflection of Si-framed, pressurized Cu membranes. The membranes were deformed under plane-strain conditions, which makes it possible to convert the pressure-deflection data into stress-strain curves by means of simple analytical formulae. Both yield stress and Young's modulus increase with decreasing film thickness and correlate well with changes in the microstructure and texture of the films.