工作气压对Y掺杂HfO_(2)结构及电学性能的影响  

Effect of Working Pressure on Structure and Electrical Properties of Y-Doped HfO_(2) Thin Films

作　　者：惠迎雪[1] 刘雷 赵吉武 张长明 秦兴辉 刘卫国[1] XI Ying-xue;LIU Lei;ZHAO Ji-wu;ZHANG Chang-ming;QIN Xing-hui;LIU Wei-Guo(School of Optoelectronic Engineering,Xi'an Technological University,Xi'an 710021,China)

机构地区：[1]西安工业大学光电学院,西安710021

出　　处：《表面技术》2023年第8期340-345,354,共7页Surface Technology

基　　金：国家重点研发计划–政府间科技创新合作重点专项(2018YFE0199200);国防科技重点实验室基金(JZX7Y202001SY006201)。

摘　　要：目的基于Y掺杂高纯铪靶和钛靶的反应磁控溅射方法,在Si(100)基底上沉积掺杂Y氧化铪薄膜,以及TiN/X-HfO_(2)/TiN三层异质结构,探究Y掺杂对氧化铪基异质结构铁电性的影响。方法针对反应磁控溅射制备的Y掺杂HfO_(2)薄膜和异质结构,分别采用白光干涉仪、掠入射X射线衍射(GIXRD)、X光电子能谱仪(XPS)和铁电分析仪,对薄膜的沉积速率、退火后薄膜的晶体结构、掺杂元素组分及含量,以及HfO_(2)基异质结薄膜P-E电滞回线和I-V曲线进行测量。结果在相同工艺条件下,薄膜的沉积速率随着工作气压的增大呈先增大后减小的趋势,在工作气压为1.1 Pa时沉积速率达到最高值。XRD结果表明,薄膜经过退火后存在正交相(o相)和单斜相(m相)。当工作气压为0.7 Pa时,所制备HYO薄膜在28°~30°内代表o(111)相的衍射峰最强,具有最佳的铁电性。随着工作气压的增大,代表m(111)相的衍射峰强度逐渐下降。采用XPS分析了薄膜中各元素的化学状态和含量,在工作气压为0.7 Pa时,Y的掺杂浓度(物质的量分数)为5.6%,铁电分析结果表明,在工作气压从0.7 Pa增至1.3 Pa的过程中,Y掺杂的HfO_(2)基异质结的电滞回线逐渐收缩。在工作气压为0.7 Pa时,剩余极化强度P_(r)的最大值为14.11μC/cm^(2),矫顽场Ec约为1 MV/cm。结论利用Y掺杂高纯铪靶反应磁控溅射制备的掺杂铁电薄膜,在工作气压0.7 Pa下得到的薄膜经过700℃退火后具备良好的铁电性能。HfO_(2)-based high dielectric constant(high-k)materials have been successfully used as a ferroelectric or memristive material in nonvolatile memory devices and for novel neuromorphic computing concepts.Ferroelectric HfO_(2)thin film is demonstrated by incorporating various cation dopants into HfO_(2).Doped HfO_(2)thin film has been widely studied as the most promising candidate material for microelectronic devices in the last decade.Several methods have been reported for achieving ferroelectricity in HfO_(2),such as atomic layer deposition(ALD),physical vapor deposition(PVD),and chemical vapor deposition(CVD).Compared with ALD and CVD,the Reactive magnetron sputtering method has a low pollution level due to the high purity of target material and has been well appreciated in the industry due to the high deposition rate of compounds.Doped HfO_(2)thin films have been prepared by RF reactive magnetron co-sputtering using Hf target and cation dopants target,However,uniformity of doping and thickness is limited to the size of the area oblique angle of two different targets.In this work,High quality Y-doped thin films have been deposited using a Y-doped hafnium cathode sputtering target several small pieces of Y metal were put evenly into the sputtering zone of the target surface.In order to ensure a low leakage current of hafnium hafnium-based heterostructure,TiN thin films are deposited by DC reactive magnetron sputtering which is a reaction of the nitrogen gas with the surface of the sputtered Ti target used as electrode materials.TiN thin film with(200)crystallographic orientation has obtained a lower resistivity value of 29.3μΩ·cm via a metal shadow mask.The effects of working pressure on the structure and ferroelectric properties are studied for Y-doped HfO_(2)thin films deposited on Si(100)substrate by reactive magnetron sputtering using a cathode target made of high-purity hafnium with Y-doped.Deposition rate,phase structure,and component are characterized by using a light interferometer,brook-swept incident

关 键 词：磁控溅射 HfO_(2)基异质结 铁电薄膜 工作气压 钇掺杂 

分 类 号：TB34[一般工业技术—材料科学与工程]