Fabrication of a micro-biochemical reactor with thick thermal isolation layer and integrated Pt heater/sensor in the micro-well

Recently many micro-biochemical reaction devices have been developed using MEMS technology because of the advantages of less required sample and reagent, fast reaction and less environmental contamination. The most important thing in biochemical reaction is temperature control. Unlike conventional micro-machined biochemical reactors which have an integrated heater and sensor at the backside of the wafer we have fabricated a thin Pt film heater and sensor on the bottom of the microwell at the frontside. In order to pattern inside the well, we used a thick negative Su-8 PR. As a desirable thermal isolation layer at the bottom of the well, we used a thick OPSL (oxidized porous silicon layer) formed by anodic reaction and multistep oxidation.