A Novel Plasma Release Process and a Super High Aspect Rat..

This paper presents two recent developments in deep silicon etching for MEMS applications using an Alcatel ICP deep dry etching system. In the first part of the paper, a new technique for doubling the state-of-the-art Trench Aspect Ratio from 30 to 60 is introduced. Results are presented showing submicron 0.4 μm wide trenches etched to a depth of 24 μm. In the second part, a new method for dry release etching of silicon sacrificial layers is presented. This new method is based on the Alcatel patented ICP plasma chamber design. RF MEMS manufacturing is used as an example. Process performances and most relevant process parameters are detailed. Results are also presented for this novel plasma release process with 250 lateral Aspect Ratio, silicon etch rate up to 15 μm/min and Si:SiO2 selectivity of 30000:1.