Advanced silicon etching (original) (raw)

Advanced silicon etching (ASE) is a deep reactive-ion etching (DRIE) technique to etch deep and high aspect ratio structures in silicon.ASE was created by Surface Technology Systems Plc (STS) in 1994 in the UK. STS has continued to develop this process with faster etch rates.STS developed and first implemented the switched process, originally invented by Dr. Larmer in Bosch, Stuttgart.ASE consists in combining the faster etch rates achieved in an isotropic Si etch (usually making use of an SF6 plasma) with a deposition or passivation process (usually utilising a C4F8 plasma condensation process) by alternating the two process steps. This approach achieves the fastest etch rates while maintaining the ability to etch anisotropically, typically vertically in Microelectromechanical Systems (mi