Advanced silicon trench etching in MEMS applications

Publisher Website
Google Scholar
Abstract
A high performance silicon dry etch process (STS Advanced Silicon Etch ASE) which in many cases is a beneficial replacement for the usual anisotropic wet etch methods like KOH etching is presented. During fabrication of Micro-Electro- Mechanical Systems (MEMS) the patterning of silicon is an essential step. Conventional wet or dry etching processes used up to now cannot meet the majority of future MEMS patterning needs. The process described in this paper allows a wide range of possible geometries and freedom of design and mask layout for novel MEMS applications. The installed etch system is working with an inductively coupled plasma source (ICP) which produces high plasma densities at low pressure to achieve deep silicon etching (greater than 200 micrometer) with high etch rates up to 5 micrometer/min and a high passivation layer selectivity. The new ASE process uses only fluorine based chemistry and operates at room temperature. ASE uses photoresists and silicon oxid layers as an etch passivation and allows the manufacturing of silicon structures with nearly vertical side walls in bulk and surface micromachining illustrated by several MEMS applications carried out at the Fraunhofer Institute for Solid State Technology. With depths up to 100 micrometer realized at the institute now and an excellent anisotropic profile control ASE is obviously the tool, useful from device development to volume production of microsystems.

This publication has 0 references indexed in Scilit: