氧化铪基铁电薄膜负电容效应及其超低功耗应用研究

利用铁电薄膜的负电容效应，降低金属-氧化物-半导体(MOS)场效应晶体管的亚阈值摆幅，是一种降低微电子元器件操作电压和功耗的有效方法。与传统钙钛矿结构铁电薄膜相比，氧化铪基铁电薄膜以其更好的尺寸缩小能力、与CMOS工艺更兼容、工艺更加简单等优点，成为目前学术界和产业界的一个研究热点。本申请项目拟对氧化铪基铁电薄膜及其器件的负电容效应进行系统研究。理论上，采用第一性原理和数值模拟方法，探索氧化铪基铁电薄膜负电容的物理机制和影响因素，揭示氧化铪基铁电薄膜负电容产生的规律，阐明负电容效应在晶体管逻辑开关与存储过程中的调控作用。实验上，采用原子层淀积法与标准CMOS工艺，制备出具有负电容效应的氧化铪基铁电薄膜及器件，获得优良亚阈值特性(SS<60mV/dec)、高速转换的场效应晶体管逻辑与存储器件。研究成果可以为氧化铪基铁电薄膜场效应晶体管在微电子芯片中的低功耗应用提供科学指导和实验依据。

Use of ferroelectric thin film negative capacitance (NC) is considered as an effective way for decreasing the power dissipation of microelectronic devices, which is through reducing the subthreshold swing of the metal-oxide-semiconductor (MOS) field-effect transistor (FET). Compared to traditional perovskite type ferroelectric thin film, ferroelectric hafnium oxide thin film materials behave many advantages, such as better scaling ability, more compatible with CMOS technology and more simple process. It has become a hot research topic in both academic and industry communities at present. In this project, the effect of NC in the ferroelectric hafnium oxide materials will be investigated systematically. In theory, first principles calculation and numerical simulation will be used to explore the physical mechanism and the factors of the NC, to reveal the rules of NC, and to clarify the regulating role of NC effect in the process of switching and storage of the field-effect transistor. In experiment, high performance NC ferroelectric hafnium oxide thin films and devices will be prepared using the atomic layer deposition method and CMOS process, and high speed switching logic and storage field effect transistor devices with low value of subthreshold swing (SS < 60 mV/dec) will also be obtained. It is expected that this project will provide scientific guidelines and experimental evidence for the low power dissipation application of the ferroelectric hafnium oxide thin films FETs in the microelectronic chips.