20120304742 | INTEGRATED CMOS POROUS SENSOR - A single chip wireless sensor comprises a microcontroller and transmit/receive interface, which is coupled to a antenna by an L-C matching circuit. The sensor senses gas or humidity and temperature. The device is an integrated chip manufactured in a process in which the electronics and sensor components are manufactured using CMOS processing techniques, applied to achieve both electronic and sensing components in an integrated process. A Low-K material with an polymer component is spun onto the wafer to form a top layer incorporating sensing electrodes. This material is cured at 300° C., lower than CVD temperatures. The polyimide when cured becomes thermoset, and the lower mass-to-volume ratio resulting in its dielectric constant, reducing to 2.9. The thermoset dielectric, not regarded as porous in the conventional sense, has sufficient free space volume to admit enough gas or humidity for sensing. | 12-06-2012 |