Considerations of anodic bonding for capacitive type silicon/glass sensor fabrication

The author discusses the suitability of various glass types for different applications, and in particular for absolute capacitive pressure sensors. Some process induced effects which can affect the yield and performance of such devices are investigated and solutions suggested for improving these properties. Effects considered include electrolysis and process induced compositional changes. These can manifest themselves as bowed or warped assemblies, degraded bonds and metallized layers, and poor sensitivity and temperature stability of the resulting devices. Some solutions to these problems are discussed.