Lederer Maximilian, Kämpfe Thomas, Vogel Norman, Utess Dirk, Volkmann Beate, Ali Tarek, Olivo Ricardo, Müller Johannes, Beyer Sven, Trentzsch Martin, Seidel Konrad, Eng And Lukas M
Fraunhofer IPMS, Dresden, Germany.
Technische Universität Dresden, Institut für Angewandte Physik, Dresden, Germany.
Nanomaterials (Basel). 2020 Feb 22;10(2):384. doi: 10.3390/nano10020384.
The microstructure of ferroelectric hafnium oxide plays a vital role for its application, e.g., non-volatile memories. In this study, transmission Kikuchi diffraction and scanning transmission electron microscopy STEM techniques are used to compare the crystallographic phase and orientation of Si and Zr doped HfO thin films as well as integrated in a 22 nm fully-depleted silicon-on-insulator (FDSOI) ferroelectric field effect transistor (FeFET). Both HfO films showed a predominately orthorhombic phase in accordance with electrical measurements and X-ray diffraction XRD data. Furthermore, a stronger texture is found for the microstructure of the Si doped HfO (HSO) thin film, which is attributed to stress conditions inside the film stack during crystallization. For the HSO thin film fabricated in a metal-oxide-semiconductor (MOS) like structure, a different microstructure, with no apparent texture as well as a different fraction of orthorhombic phase is observed. The 22 nm FDSOI FeFET showed an orthorhombic phase for the HSO layer, as well as an out-of-plane texture of the [111]-axis, which is preferable for the application as non-volatile memory.
铁电氧化铪的微观结构对其应用（如非易失性存储器）起着至关重要的作用。在本研究中，使用透射菊池衍射和扫描透射电子显微镜（STEM）技术来比较硅和锆掺杂的HfO薄膜的晶体相和取向，以及集成在22纳米全耗尽绝缘体上硅（FDSOI）铁电场效应晶体管（FeFET）中的情况。根据电学测量和X射线衍射（XRD）数据，两种HfO薄膜均主要呈现正交相。此外，发现硅掺杂的HfO（HSO）薄膜的微观结构具有更强的织构，这归因于结晶过程中膜堆叠内部的应力条件。对于以金属氧化物半导体（MOS）类似结构制备的HSO薄膜，观察到不同的微观结构，没有明显的织构以及不同比例的正交相。22纳米FDSOI FeFET的HSO层呈现正交相，以及[111]轴的面外织构，这对于作为非易失性存储器的应用是有利的。
