Characterization of Silver Microheaters for Vertical- Cavity Enhanced Resonant Thermal Emission
Sprache des Titels:
2017 IEEE Sensors Proceedings
We designed, simulated and experimentally
characterized thin silver microheater structures placed on a
dielectric multilayer membrane, which represent the concept of
vertical-cavity enhanced resonant thermal emission (VERTE).
This concept has the goal to achieve selective and coherent
thermal emission on the backside of the multilayer membrane.
The dielectric stack also is responsible for the thermal insulation,
i.e. is preventing heat to be conducted away into the silicon
substrate. However, the large fractions of silver demanded by the
VERTE concept seem to contradict the goal of high thermal
insulation for efficient heating. Here, we focus on microheater
structures with high fractions of silver on the area of the
membrane. We show that target operation temperatures up to
800 K (suitable for mid IR region) could be reached in finite element simulations and experiments with reasonable amounts of
electric power supply, despite conduction losses into the
substrate. Sample devices featuring the multilayers were
fabricated using PECVD and dry etching. The multilayer
membranes showed remarkable mechanical and thermal
stability, making the structures suitable for a source for optical on-a-chip mid-infrared sensing.