Fabrication of a high-temperature microreactor with integrated heater and sensor patterns on an ultrathin silicon membrane

In this paper crit. steps in the fabrication process of a microreactor for high-temp. catalytic partial oxidn. gas phase reactions are evaluated. The microreactor contains a flow channel etched in silicon, capped with an ultrathin composite membrane consisting of silicon and silicon nitride layers, on which on the topside thin-film heaters and sensors, and on the other side a thin-film catalyst patch are placed. The membrane is designed to have sp. heat cond. and mech. properties. The paper focuses on three fabrication issues: definition and etching of sub-micron uniform single-cryst. silicon membranes, deposition of well-defined heater structures and temp. sensors on a thin composite membrane, and deposition of well-defined catalytic patches on the same membrane. For the latter two processes novel micromachined shadow masks were developed. Preliminary expts. on the controlled oxidn. of hydrogen gas in the explosive regime are discussed, which expts. confirm that heat management in the microreactor is excellent. [on SciFinder (R)