Exploring Electrochemical Methods for Precision Stress Control in Nanoscale Devices.

Tuning the local film stress (and associated strain) provides a universal route toward exerting dynamic control on propagating fields in nanoscale geometries and engineering controlled interactions between them. The majority of existing techniques are adapted for engineering either uniform stresses or fixed stress gradients, but there is a need to develop methods that can provide independent precision control over the local stress at the nanoscale in the 2D plane. Here, we explore electrochemical absorption of hydrogen in structured palladium thin-film electrodes and the associated shape-dependent stress to engineer controlled, localized stresses in thin films. We discuss the prospects of this technique for precision dynamic tuning of nanoscale opto-electro-mechanical devices and the development of field-programmable non-volatile set-and-forget architectures. We also outline some of the key challenges that need to be addressed with a view toward incorporating electrochemical stress tuning methods for post-processing foundry devices.