Patterning layer stacks for electronic devices

There is provided a method of patterning a stack of layers defining one or more electronic device elements, comprising: creating a first thickness profile in an uppermost portion of the stack of layers by laser ablation; and etching the stack of layers to translate the first thickness profile into a second thickness profile at a lower level; wherein the etching reduces the thickness of said uppermost portion of the stack and one or more lower layers of the stack under said uppermost portion.