Solution Combustion-Derived Hf0.5Zr0.5O2 Ferroelectrics for Negative Capacitance Field Effect Transistors

Fabricating solution combustion-derived Hf0.5Zr0.5O2-ferroelectric films for negative capacitors is presented for the first time. The precursor used for the solution combustion reaction to form equimolar hafnia-based ferroelectric, i.e., Hf0.5Zr0.5O2 are designed to act as both combustible elements and cation sources - Hf and Zr. Jain’s method, mainly used for calculating the stoichiometric quantities of precursors in propellant chemistry, has also been modified and applied in the present study. The assumption for this method that molecular oxygen does not take part in the reaction is not only refuted but also stoichiometric combustion in the presence of molecular oxygen is proposed. This reaction is followed by post-rapid thermal processing to crystallize the metastable, non-centrosymmetric orthorhombic phase. The thin-film stacks of ferroelectric and dielectric, Hf0.5Zr0.5O2/HfO2, are used to achieve small sub-thermionic swing magnitudes (forward sweep: 25.42 ± 8.05 mV dec−1, reverse sweep: 42.56 ± 4.87 mV dec−1) in 2-dimensional MoS2 negative capacitance field-effect transistors with a hysteresis of ≈40 mV at 1 nA that results in ultra-low-power operation.