Test structures to measure the Seebeck coefficient of CMOS ICpolysilicon

We report on two thermal characterization structures to measure the Seebeck coefficient α of CMOS IC polysilicon thin films relevant for integrated thermal microtransducers. The test structures were fabricated using a commercial 1.2 μm CMOS process of Austria Mikro Systeme (AMS). The fabrication of the first structure relies on silicon micromachining. In contrast the second, planar, structure is ready for measurement after IC fabrication. The temperature dependent α of the two polysilicon layers of the AMS process was measured with both devices. The agreement between the thermoelectric coefficients obtained with the two types of structures is better than 2.1 μV at 300 K