Ferroelectric-Antiferroelectric Transition of Hf1-XZrXO2 on Indium Arsenide with Enhanced Ferroelectric Characteristics for Hf0.2Zr0.8O2

The ferroelectric (FE)-antiferroelectric (AFE) transition in Hf1-xZrxO2 (HZO) is for the first time shown in a metal-ferroelectric-semiconductor (MFS) stack based on the III-V material InAs. As InAs displays excellent electron mobility and a narrow band gap, the integration of ferroelectric thin films for nonvolatile operations is highly relevant for future electronic devices and motivates further research on ferroelectric integration. When increasing the Zr fraction x from 0.5 to 1, the stack permittivity increases as expected, and the transition from FE to AFE-like behavior is observed by polarization and current-voltage characteristics. At x = 0.8 the polarization of the InAsbased stacks shows a larger FE-contribution as a more open hysteresis compared to both literature and reference metal-ferroelectric-metal (MFM) devices. By field-cycling the devices, the switching domains are studied as a function of the cycle number, showing that the difference in FE-AFE contributions for MFM and MFS devices is stable over switching and not an effect of wake-up. The FE contribution of the switching can be accessed by successively lowering the bias voltage in a proposed pulse train. The possibility of enhanced nonvolatility in Zr-rich HZO is relevant for device stacks that would benefit from an increase in permittivity and a lower operating voltage. Additionally, an interfacial layer (IL) is introduced between the HZO film and the InAs substrate. The interfacial quality is investigated as frequency-dependent capacitive dispersion, showing little change for varying ZrO2 concentrations and with or without included IL. This suggests material processing that is independently limiting the interfacial quality. Improved endurance of the InAs-Hf1-xZrxO2 devices with x = 0.8 was also observed compared to x = 0.5, with further improvement with the additional IL for Zr-rich HZO on InAs.

Automated summary

The ferroelectric-antiferroelectric transition in Hf1-xZrxO2 (HZO) is demonstrated in a metal-ferroelectric-semiconductor stack based on InAs for the first time. The integration of ferroelectric thin films in nonvolatile operations is highly relevant for future electronic devices. The increase in Zr fraction leads to enhanced nonvolatility and a transition from ferroelectric to antiferroelectric behavior.