Abstract
An electroplating spring-bridge micro-tensile specimen is demonstrated and fabricated here. The specimen is fit into a specially designed micro-mechanical apparatus to carry out a series of tensile testing on sub-micron freestanding thin films. Freestanding thin films were then loaded by performing monotonic loading/ unloading up to 20 μm/(10^<-1>s) and tension-tension fatigue experiments at 25 Hz up to 〜10^5cycles. Loading was applied using a piezoelectric actuator with 0.1 μm resolution connected through pin hole into the test chip. Loads were measured by connected specimens through a pin connected rod using its bottom pivot to transfer loads and displacement from sample load sensing beam into a capacitor load cell. For the monotonic loading/unloading experiments, we found the modulus of copper thin films with thickness of 200 nm at ambient temperature. Displacement controlled tension-tension fatigue experiments on copper thin films have also been performed and a trend of decreasing cycles to failure with increasing mean displacement has been noted but requires further experimental exploration.
