High Temperature SQI CMOS Tungsten Micro-Heaters

Here we present for the first time, the design, fabrication and characterization of novel high temperature SOI micro-hotplates employing tungsten resistive heaters. Tungsten has a high operating temperature, good mechanical strength, and could be used for CMOS interconnects. These devices have been fabricated using a commercial SOI-CMOS process followed by a DR1E back-etch step, offering low cost and the option of circuit integration. Here we report on micro-hotplates with two different diameters (560mum and 300mum), 3D electro-thermal simulation in ANSYS and their electro-thermal characterization. Results show that these devices can operate at a high temperature (600degC), have ultra low DC power consumption (12mW at 600degC), fast transient time (as low as 2ms to 600degC), stability in time and temperature and, more importantly, a high reproducibility both within a wafer and from wafer to wafer. The SOI micro-hotplates could be used in fully integrated micro-calorimeters or resistive gas sensors.