CMOS compatible pyroelectric applications enabled by doped HfO2 films on deep-trench structures
Fully functional pyroelectric films are fabricated on a silicon substrate with deep-trench structures, for the first time. Future integrated pyroelectric applications such as infrared sensors, energy harvesters or temperature manipulation devices require large current responses at low device footprints. In this work, pyroelectric Si-doped HfO2 is deposited in trench structures to considerably increase the pyroelectric response, yielding a coefficient of p = -1560 mC/m2K, which is four times larger than that of PZT projected to the device area. A large harvestable energy density of FE = 542 J/m3K2 is measured. Simultaneously, CMOS compatible and RoHS compliant manufacturing is demonstrated. Metalorganic atomic layer deposition (ALD) is used to coat the 1:16 aspect ratio structures conformally with uniform silicon dopant levels.