| AVS 57th International Symposium & Exhibition | |
| Vacuum Technology | Monday Sessions |
| Session VT+MN-MoM |
| Session: | MEMS Sensors, Vacuum Gauges, Measurements and Pumps |
| Presenter: | M. Wuest, INFICON Ltd, Liechtenstein |
| Authors: | B. Andreaus, INFICON Ltd, Liechtenstein R. Enderes, INFICON Ltd, Liechtenstein M. Wuest, INFICON Ltd, Liechtenstein |
| Correspondent: | Click to Email |
In modern Pirani heat transfer gauges a filament is usually kept at a constant temperature and the necessary heating power is measured as a function of pressure.
Pirani gauges operated in coating and etching applications suffer from degradation due to process contamination or corrosion. Eventually, the Pirani may fail because the filament is etched away, its resistance and/or its emissivity have changed. Standard procedure for those processes is to use a corrosion resistant filament material adapted to the process in question, e.g. Nickel. Yet the choice of suitable filament material is limited as it needs to be manufactured as very thin coils, be electrically conducting, have a high and well-defined temperature coefficient for the resistance and be chemically inert. For some of the latest manufacturing processes in semiconductor industry none of the available filament materials is sufficiently resistant against corrosion.
We will present here a different approach in that we present first data on a coated Pirani sensor. The coating allows for a much broader field of application as electrical and mechanical requirements of the filament are separated from its chemical properties. Chemical stability is solely due to the coating, all other requirements, unaffected by the coating, can be met using a standard filament material.