CaBi2Nb2O9铁电薄膜的生长取向调控和性能研究

doi:10.15541/jim20240208

摘要/Abstract

摘要：

铋层状铌酸铋钙(CaBi₂Nb₂O₉, CBN)铁电薄膜具有良好的铁电性能和疲劳特性, 是铁电随机存储器的重要候选材料之一。铋层状结构薄膜a轴外延生长对其高质量集成和应用具有重要意义, 然而CBN结构的各向异性使其根据晶体学调节自发极化更具挑战性。本研究采用脉冲激光沉积技术, 在MgO(100)衬底上通过改变沉积温度的方式, 实现了CBN薄膜的取向生长。在500、600和700 ℃沉积温度下分别生长出(115)、(200)和(00l)取向的CBN薄膜, 并且随着沉积温度升高, CBN薄膜发生了(115)-(200)-(00l)取向的转变。扫描电子显微镜(SEM)结果表明, 600 ℃是CBN薄膜在MgO衬底上高质量a轴外延生长的最优沉积温度, 薄膜与衬底键合良好, 粗糙度较低。高分辨X射线衍射(HRXRD)和高分辨透射电子显微镜(HRTEM)分析表明, (200)取向的CBN薄膜为异质外延生长, 其与MgO衬底之间形成半共格界面, CBN/MgO异质结构外延关系为(100)[001]CBN//(100)[001]MgO。CBN界面处的(200)平均间距为0.5312 nm, 结合晶格匹配关系, 提出了一种可能的外延匹配方式: 4个CBN晶胞共同占用5个MgO晶格。此外, 通过压电力显微镜(PFM)发现了(115)取向CBN薄膜具有纳米畴结构, 以及(200)取向CBN薄膜表现出良好的面外极化翻转。

关键词: 外延薄膜, 生长机制, 取向调控, 铌酸铋钙

Abstract:

CaBi₂Nb₂O₉(CBN) thin films with a bismuth layered structure are important precursors for ferroelectric memories, due to their high fatigue resistance, and good ferroelectric properties. The epitaxial growth of CBN along the a-axis is desirable for the integration and application. However, the structural anisotropic makes it challenging to regulate the polarization with respect to the crystallography. In this paper, a new strategy is proposed for the growth of a-axis oriented CBN thin films on MgO(100) single crystal substrate. This strategy is realized by changing the deposition temperature using the pulsed laser deposition technique. The CBN thin films are grown along (115)-, (200)-, and (00l)-crystallographic direction, when the films are deposited at 500, 600 and 700 ℃, respectively. As the deposition temperature increases, the CBN films undergo (115)-(200)-(00l) orientation transition. Meanwhile, SEM results show that 600 ℃ is the optimal deposition temperature for high-quality a-axis epitaxial growth of CBN films on MgO substrates. Under this condition, the films are well bonded to the substrate with a low roughness. HRXRD and HRTEM analyses show that the (200)-oriented CBN films are heterogeneous epitaxial growth, forming a semiconformal lattice interface between the (200)-oriented CBN film and the MgO substrate, also revealing a crystallographic relationship between the as-grown thin film and the substrate, i.e., (100)[001]CBN//(100)[001]MgO. The average (200) spacing at the CBN/MgO interface was measured to be 0.5312 nm. Based on the lattice-matching relationship, a theoretical model is proposed that four CBN unit cells matching five MgO unit cells. Moreover, the nanodomain structure of the (115)-oriented CBN thin films and the out-of-plane polarization switching of the (200)-oriented CBN thin films are demonstrated by PFM.

Key words: epitaxial film, growth mechanism, orientation regulation, calcium bismuth niobate

中图分类号:

TQ174

任冠源, 李宜冠, 丁冬海, 梁瑞虹, 周志勇. CaBi₂Nb₂O₉铁电薄膜的生长取向调控和性能研究[J]. 无机材料学报, 2024, 39(11): 1228-1234.

REN Guanyuan, LI Yiguan, DING Donghai, LIANG Ruihong, ZHOU Zhiyong. CaBi₂Nb₂O₉ Ferroelectric Thin Films: Modulation of Growth Orientation and Properties[J]. Journal of Inorganic Materials, 2024, 39(11): 1228-1234.

图/表 7

图1 MgO衬底上不同温度沉积CBN薄膜的HRXRD图谱

Fig. 1 HRXRD patterns of CBN films deposited at different temperatures on MgO substrate CBN70, CBN65, CBN60, CBN55, and CBN50 denote the thin films grown at 700, 650, 600, 550, and 500 ℃, respectively.

图2 不同温度沉积CBN薄膜的择优取向度

Fig. 2 Optimized orientation degree of CBN films deposited at different temperatures

图3 不同取向CBN薄膜的断面形貌图

Fig. 3 Cross-sectional images of CBN films with different orientations (a) (115) CBN; (b) (200) CBN; (c) (00l) CBN

图4 (200)取向CBN/MgO异质结构的HRXRD Phi扫描图谱

Fig. 4 HRXRD Phi scanning patterns of (200)-oriented CBN/MgO heterogeneous structure

图5 界面处(200)取向的CBN薄膜的TEM照片和SAED图案

Fig. 5 TEM images and SAED patterns of (200)-oriented CBN films (a) Cross-sectional TEM image of CBN film; (b-d) SAED patterns of (b) CBN film, (c) MgO substrate, and (d) CBN/MgO heterostructure; (e) HRTEM image of CBN film

图6 (200)取向的CBN薄膜与MgO衬底的外延匹配方式

Fig. 6 Epitaxial matching modes between (200)-oriented CBN film and MgO substrate (a) [001]; (b) [010]

图7 不同取向CBN薄膜的表面形貌以及PFM图

Fig. 7 Surface topographies and PFM images of CBN films with different orientations (a-c) Surface topographies of (a) (115) CBN, (b) (200) CBN and (c) (00l) CBN; (d-f) VPFM images of (d) (115) CBN, (e) (200) CBN and (f) (00l) CBN; (g-i) LPFM images of (g) (115) CBN, (h) (200) CBN and (i) (00l) CBN

参考文献 27

[1]	SETTER N, DAMJANOVIC D, ENG L, et al. Ferroelectric thin films: review of materials, properties, and applications. Journal of Applied Physics, 2006, 100(5): 051606.
[2]	SCOTT J F. Applications of modern ferroelectrics. Science, 2007, 315(5814): 954. PMID
[3]	GUO R, YOU L, ZHOU Y, et al. Non-volatile memory based on the ferroelectric photovoltaic effect. Nature Communications, 2013, 4: 1990. DOI PMID
[4]	PARK B H, KANG B S, BU S D, et al. Lanthanum-substituted bismuth titanate for use in non-volatile memories. Nature, 1999, 401(6754): 682.
[5]	ZHOU Z, CHEN T, DONG X. Research progress of perovskite layer structured piezoelectric ceramics with super high Curie temperature. Journal of Inorganic Materials, 2018, 33(3): 251.
[6]	DE ARAUJO C A P, CUCHIARO J D, MCMILLAN L D, et al. Fatigue-free ferroelectric capacitors with platinum electrodes. Nature, 1995, 374(6523): 627.
[7]	ZHANG Y, LI C, LI J, et al. Enhancing speed and stability of polarization reversal in predominantly a/b-axes-oriented Bi₄Ti₃O₁₂ thin films deposited on Pt/Ti/SiO₂/Si. Physica Status Solidi (RRL) - Rapid Research Letters, 2019, 13(12): 1900370.
[8]	BLAKE S, FALCONER M, MCREEDY M, et al. Cation disorder in ferroelectric Aurivillius phases of the type Bi₂ANb₂O₉ (A = Ba, Sr, Ca). Journal of Materials Chemistry, 1997, 7(8): 1609.
[9]	IRIE H, MIYAYAMA M, KUDO T. Structure dependence of ferroelectric properties of bismuth layer-structured ferroelectric single crystals. Journal of Applied Physics, 2001, 90(8): 4089.
[10]	ISUPOV V A. Two types of ABi₂B₂O₉ layered perovskite-like ferroelectrics. Inorganic Materials, 2006, 43(9): 976.
[11]	WITHERS R L, THOMPSON J G, RAE A D. The crystal chemistry underlying ferroelectricity in Bi₄Ti₃O₁₂, Bi₃TiNbO₉, and Bi₂WO₆. Journal of Solid State Chemistry, 1991, 94(2): 404.
[12]	NEWNHAM R E, WOLFE R W, DORRIAN J F. Structural basis of ferroelectricity in the bismuth titanate family. Materials Research Bulletin, 1971, 6(10): 1029.
[13]	SHIMAKAWA Y, KUBO Y, NAKAGAWA Y, et al. Crystal structure and ferroelectric properties of ABi₂Ta₂O₉ (A = Ca, Sr, and Ba). Physical Review B, 2000, 61(10): 6559.
[14]	SIMOES A Z, RIES A, RICCARDI C S, et al. High Curie point CaBi₂Nb₂O₉ thin films: a potential candidate for lead-free thin-film piezoelectrics. Journal of Applied Physics, 2006, 100(7): 299.
[15]	SIMOES A Z, RAMIREZ M A, RIES A, et al. Microwave synthesis of calcium bismuth niobate thin films obtained by the polymeric precursor method. Materials Research Bulletin, 2006, 41(8): 1461.
[16]	WANG Y L, OUYANG J. Orienting high Curie point CaBi₂Nb₂O₉ ferroelectric ferroelectric films on Si at 500 ℃. Ceramics International, 2019, 45(16): 20818.
[17]	AHN Y, JANG J, SON J Y. Ferroelectric properties of lead-free polycrystalline CaBi₂Nb₂O₉ thin films on glass substrates. AIP Advances, 2016, 6(3): 035123.
[18]	ZHANG Y, WANG C M, LI Y, et al. Enhancing electromechanical properties of CaBi₂Nb₂O₉ thin films grown on Si. Ceramics International, 2016, 42(15): 17928.
[19]	LI Y, HAO Y, JU M, et al. Significantly enhanced electrostrain in oriented epitaxial self-assembled Aurivillius-type piezoelectric films via regulating polarization vectors. ACS Applied Materials & Interfaces, 2023, 15(19): 23470.
[20]	ZHANG Y, OUYANG J, ZHANG J, et al. Strain engineered CaBi₂Nb₂O₉ thin films with enhanced electrical properties. ACS Applied Materials & Interfaces, 2016, 8(26): 16744.
[21]	LEE H N, HEESSE D, ZAKHAROV N. et al. Ferroelectric Bi_3.25La_0.75Ti₃O₁₂ films of uniform a-axis orientation on silicon substrates. Science, 2002, 296(5575): 2006.
[22]	董显林, 李宜冠, 周志勇. 一种c轴择优取向的铌酸铋钙薄膜及其制备方法: CN112813385A. 2021-05-18.
[23]	CHO H S, DESU S B. Structural and electrical properties of oriented ferroelectric CaBi₂Nb₂O₉ thin films deposited on n+-Si (100) by pulsed laser deposition. Physica Status Solidi Applied Research, 1997, 161(2): 371.
[24]	LI Y, YU Z, FU Z, et al. Epitaxial growth mechanism and ferroelectric property of c-oriented bismuth-layered CaBi₂Nb₂O₉ film. Applied Physics Letters, 2023, 123(24): 242901.
[25]	LU C J, QIAO Y, QI Y J, et al. Large anisotropy of ferroelectric and dielectric properties for Bi_3.15Nd_0.85Ti₃O₁₂ thin films deposited on Pt/Ti/SiO₂/Si. Applied Physics Letters, 2005, 87(22): 222901.
[26]	YAO H J, LI Y, LUO J H, et al. Epitaxial growth of perovskite oxide SrTiO₃/BaTiO₃ multilayer films on SrTiO₃ substrate. Journal of Functional Materials, 2004, 35(z1): 2890.
[27]	吴自勤, 王兵主. 薄膜生长. 北京: 科学出版社, 2003: 262.

CaBi₂Nb₂O₉铁电薄膜的生长取向调控和性能研究

CaBi₂Nb₂O₉ Ferroelectric Thin Films: Modulation of Growth Orientation and Properties

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