Xenon Difluoride Dry Etching of Si, SiGe Alloy and Ge

Xenon diflouride (XeF₂) vapor has been known to be able to spontaneously etch Si isotropically at high rates up to 10 mum/min. This dry etching process does not require plasmas or catalysts, and thus causes little damage to the electronic properties. It is useful for releasing free standing structures by etching away Si sacrificial layers or for gate oxide failure analysis by etching away the backside Si. In this work, the etching of Si, SiGe alloys and Ge was studied and results were discussed. Both SiGe and Ge were found to be etched by XeF₂ vapor, and at faster rates than Si