A negative capacitance(NC)effect has been proposed as a critical pathway to overcome the‘Boltzmann tyranny’of electrons,achieve the steep slope operation of transistors and reduce the power dissipation of current se...A negative capacitance(NC)effect has been proposed as a critical pathway to overcome the‘Boltzmann tyranny’of electrons,achieve the steep slope operation of transistors and reduce the power dissipation of current semiconductor devices.In particular,the ferroic property in hafnium-based films with fluorite structure provides an opportunity for the application of the NC effect in electronic devices.However,to date,only a transient NC effect has been confirmed in hafnium-based ferroic materials,which is usually accompanied by hysteresis and is detrimental to low-power transistor operations.The stabilized NC effect enables hysteresis-free and low-power transistors but is difficult to observe and demonstrate in hafnium-based films.This difficulty is closely related to the polycrystalline and multi-phase structure of hafnium-based films fabricated by atomic layer deposition or chemical solution deposition.Here,we prepare epitaxial ferroelectric Hf_(0.5)Zr_(0.5)O_(2) and antiferroelectric ZrO_(2) films with single-phase structure and observe the capacitance enhancement effect of Hf_(0.5)Zr_(0.5)O_(2)/Al_(2)O_(3) and ZrO_(2)/Al_(2)O_(3) capacitors compared to that of the isolated Al_(2)O_(3) capacitor,verifying the stabilized NC effect.The capacitance of Hf_(0.5)Zr_(0.5)O_(2) and ZrO_(2) is evaluated as−17.41 and−27.64 pF,respectively.The observation of the stabilized NC effect in hafnium-based films sheds light on NC studies and paves the way for low-power transistors.展开更多
基金The National Key R&D Program of China(Grant No.2021YFB3601301)the National Natural Science Foundation of China(Grant No.52225106 and 12241404)the Natural Science Foundation of Beijing,China(Grant No.JQ20010).
文摘A negative capacitance(NC)effect has been proposed as a critical pathway to overcome the‘Boltzmann tyranny’of electrons,achieve the steep slope operation of transistors and reduce the power dissipation of current semiconductor devices.In particular,the ferroic property in hafnium-based films with fluorite structure provides an opportunity for the application of the NC effect in electronic devices.However,to date,only a transient NC effect has been confirmed in hafnium-based ferroic materials,which is usually accompanied by hysteresis and is detrimental to low-power transistor operations.The stabilized NC effect enables hysteresis-free and low-power transistors but is difficult to observe and demonstrate in hafnium-based films.This difficulty is closely related to the polycrystalline and multi-phase structure of hafnium-based films fabricated by atomic layer deposition or chemical solution deposition.Here,we prepare epitaxial ferroelectric Hf_(0.5)Zr_(0.5)O_(2) and antiferroelectric ZrO_(2) films with single-phase structure and observe the capacitance enhancement effect of Hf_(0.5)Zr_(0.5)O_(2)/Al_(2)O_(3) and ZrO_(2)/Al_(2)O_(3) capacitors compared to that of the isolated Al_(2)O_(3) capacitor,verifying the stabilized NC effect.The capacitance of Hf_(0.5)Zr_(0.5)O_(2) and ZrO_(2) is evaluated as−17.41 and−27.64 pF,respectively.The observation of the stabilized NC effect in hafnium-based films sheds light on NC studies and paves the way for low-power transistors.
