Expeditiously Crystallized Pure Orthorhombic-Hf_0.5Zr_0.5O₂for Negative Capacitance Field Effect Transistors

Abstract

Ultralow-power logic devices are next-generation electronics in which their maximum efficacies are realized at minimum input power expenses. The integration of ferroelectric negative capacitors in the regular gate stacks of two-dimensional field-effect transistors addresses two intriguing challenges in today's electronics; short channel effects and high operating voltages. The complementary-metal-oxide-semiconductor-compatible Hf 0.5 Zr 0.5 O 2 (HZO) is an excellent ferroelectric material crystallized in a noncentrosymmetric o-phase. The present work is the first to utilize pulsed laser deposition (PLD)-grown phase-pure ferroelectric HZO to achieve steep slope negative capacitance (NC) in field effect transistors (FETs). A dual-step growth strategy is designed to achieve phase-pure orthorhombic HZO on silicon and other conducting substrates. The room-temperature PLD-grown amorphous HZO is allowed to crystallize using rapid thermal annealing at 600 °C. The polycrystalline orthorhombic HZO is further integrated with atomic layer deposition-grown HfO 2 to achieve a stable NC transition. The stack is further integrated into the molybdenum disulfide channel to achieve steep switching and a hysteresis-free operation of the resulting FETs. The subthreshold swings of the FETs are 20.42 and 26.16 mV/dec in forward and reverse bias conditions, respectively.

Phases in HfO2-Based Ferroelectric Thin Films and Their Integration in Low-Power Devices

“…Further, the performance of NCFETs using ALD-/PLD-/CSD-grown HfO 2 -ferroelectrics are compared and tabulated in Table S1. Although all deposition methods resulted in a subthermionic SS at room temperature, they possess different advantages and disadvantages in stabilizing the orthorhombic phase. , The benefits and drawbacks of these deposition techniques are tabulated in Table S2 …”

“…Although all deposition methods resulted in a subthermionic SS at room temperature, they possess different advantages and disadvantages in stabilizing the orthorhombic phase. 29,30 The benefits and drawbacks of these deposition techniques are tabulated in Table S2. 14 Ferroelectric Memories.…”

The Potential of ferroelectric HfO2 for Next-Generation Memory Device: Ferroelectric Properties and Applications

“…[45] 2021) with the permission of AIP Publishing [42] . Copyright 2023 American Chemical Society [46] .…”

Observation of stabilized negative capacitance effect in hafnium-based ferroic films

“…In addition, the existence of non-polar phases, such as the monoclinic phase, which are in parallel with the negative capacitor, would also weaken the NC effect [29]. Although the hysteresis in some multi-phase and polycrystalline HZO films can be reduced to be very small [27,30,31], the counterclockwise hysteresis induced by the polarization switching [32,33] is inevitable and never disappears. Moreover, the drain current range of SS smaller than 60 mV dec −1 is seriously limited.…”