The SPTS µEtch is a single wafer hydrofluoric acid vapor etcher used to release silicon microstructures in microelectromechanical systems (MEMS) devices. It uses a combination of liquid hydrofluoric acid and alcohol to create a vapor that isotropically etches silicon dioxide without etching silicon and without damaging fragile suspended structures. The tool is capable of creating microscale and nanoscale silicon structures that are freely suspended by etching a sacrificial layer of silicon dioxide underneath the silicon device layer on substrates from small pieces up to 200 mm wafers.