European Inventor Award Category 'Industry' 2007
When German inventors Dr. Franz Lärmer and Andrea Urban created the Bosch Process by adapting micro-process techniques, they opened up a new world of affordable car safety devices.
Lärmer and Urban developed a method for manufacturing high-precision silicon sensors using plasma technology while working in sensor and process development at Robert Bosch Corporate Research. The purpose of their invention was to etch deep microstructures with vertical sidewalls into silicon wafers at high speed and with great accuracy.
The invention concerns a method for the anisotropic etching of features defined by an etching mask (preferably recesses with precisely defined sides in silicon) produced using a plasma etching technique.
The etching process has been around for some 30 years in the world of MEMS. A common problem with etching deep into silicon was that the process also etched sideways, eating into the wall of the structure being created and resulting in distorted walls.
The inventors' method overcame the problem by using a fluorocarbon-based plasma to deposit an etch-resistant layer before taking a subsequent etch step. The technique, nowadays simply referred to as the Bosch Process, allows deep etching in a well-defined manner.
The technology revolutionised MEMS at the time and is currently used worldwide to manufacture silicon MEMS.