Single Atomic Layer Ferroelectric on Silicon

A single atomic layer of ZrO₂ exhibits ferroelectric switching behavior when grown with an atomically abrupt interface on silicon. Hysteresis in capacitance-voltage measurements of a ZrO₂ gate stack demonstrate that a reversible polarization of the ZrO₂ interface structure couples to the carriers in the silicon. First-principles computations confirm the existence of multiple stable polarization states and the energy shift in the semiconductor electron states that result from switching between these states. This monolayer ferroelectric represents a new class of materials for achieving devices that transcend conventional complementary metal oxide semiconductor (CMOS) technology. Significantly, a single atomic layer ferroelectric allows for more aggressively scaled devices than bulk ferroelectrics, which currently need to be thicker than 5-10 nm to exhibit significant hysteretic behavior (Park, et al. Adv. Mater. 2015, 27, 1811).