NaMLab gGmbH , 01187 Dresden, Germany.
Fraunhofer IPMS-CNT , 01099 Dresden, Germany.
ACS Appl Mater Interfaces. 2017 Feb 1;9(4):3792-3798. doi: 10.1021/acsami.6b13866. Epub 2017 Jan 24.
The recent discovery of ferroelectricity in thin hafnium oxide films has led to a resurgence of interest in ferroelectric memory devices. Although both experimental and theoretical studies on this new ferroelectric system have been undertaken, much remains to be unveiled regarding its domain landscape and switching kinetics. Here we demonstrate that the switching of single domains can be directly observed in ultrascaled ferroelectric field effect transistors. Using models of ferroelectric domain nucleation we explain the time, field and temperature dependence of polarization reversal. A simple stochastic model is proposed as well, relating nucleation processes to the observed statistical switching behavior. Our results suggest novel opportunities for hafnium oxide based ferroelectrics in nonvolatile memory devices.
最近在薄氧化铪薄膜中发现铁电性,这导致人们对铁电存储器件重新产生了兴趣。尽管对这个新的铁电系统已经进行了实验和理论研究,但关于其畴结构和开关动力学仍有很多待揭示之处。在这里,我们证明了在超小型铁电场效应晶体管中可以直接观察到单个畴的开关。我们使用铁电畴成核模型解释了极化反转的时间、场和温度依赖性。我们还提出了一个简单的随机模型,将成核过程与观察到的统计开关行为联系起来。我们的结果表明,基于氧化铪的铁电体在非易失性存储器件中有新的应用机会。