IC-foundry compatible fabrication of low-cost and tiny-sized dog-bone resonant chemical sensors in non-SOI single-wafer

This paper reports a single-side micromachining technology for batch-fabrication of dog-bone resonant gas sensors in single non-SOI wafer. The process has been transferred to the standard IC-foundry company of ASMC, showing advantage in low-cost volume production. The dog-bone structured resonant chemical sensors are designed and fabricated with the novel micro-machining technology. The 0.5mm×0.5mm sized sensor-chip can be high-yield (>93%) fabricated in 6-inch non-SOI wafer to achieve an ultra-low fabrication cost (one US-cent per chip), which supports disposable biochemical applications. Measurement shows that the low-cost sensor has equal resonating performance to its expensive counterpart fabricated from double sides of SOI-wafer. With gas sensitive material loaded, the sensor experimentally exhibits reproducible detection to 1ppm organophosphur VOC vapor and linear output in terms of gas concentration.