Fabrication process for a large volume silicon nitride micro-combustor

Micro-channels with large internal volumes are desired in highly exothermal micro-reactors, such as an integrated Wobbe index meter with on-chip microscale natural gas combustion and localized temperature sensing, or a propellant micro-thruster. State of the art experimental studies on microscale combustor devices have rarely been reported due to flame extinction phenomena in the small micro channels. The underlying reason for micro-flame extinction is that the small channel dimensions result in large surface-to-volume ratios, which induces thermal quenching and radical quenching of flames. Therefore, good thermal isolation and a chemically inert chamber inner wall material are needed with well controlled heating of the chamber walls and local temperature sensing. The structure needs to be mechanically strong and survive large temperature gradients. In this abstract we report a fabrication method for large volume micro-channels and reaction chambers with chemically inert silicon-rich silicon nitride (SiRN) walls and embedded silicon heaters. Additional platinum heaters and temperature sensors are deposited on top of the structures.