等离子体增强原子层沉积制备压电AlN薄膜  

Piezoelectric AlN Thin Films Prepared by Plasma Enhanced Atomic Layer Deposition

作　　者：乌李瑛 瞿敏妮 沈赟靓 田苗 马玲 王英[1] 程秀兰 Wu Liying;Qu Minni;Shen Yunliang;Tian Miao;Ma Ling;Wang Ying;Cheng Xiulan(Center for Advanced Electronic Materials and Devices,School of Electronic Information and Electrical Engineering,Shanghai Jiao Tong Universityy Shanghai 200240,China)

机构地区：[1]上海交通大学电子信息与电气工程学院,先进电子材料与器件平台,上海200240

出　　处：《半导体技术》2021年第9期725-732,共8页Semiconductor Technology

基　　金：国家科技部“十三五”高性能计算重点研发计划项目子课题资助项目(2016YFB0200205);2018年度上海研发公共服务平台建设项目(18DZ2295400);上海交通大学决策咨询课题资助项目(JCZXSJB2019-005,JCZXSJB2020-010)。

摘　　要：采用等离子体增强原子层沉积(PEALD)技术在单晶硅衬底上成功制备了具有(002)晶面择优取向的氮化铝(AlN)晶态薄膜,为设计新型压电功能器件提供了思路。利用椭圆偏振光谱仪(SE)、原子力显微镜(AFM)、X射线衍射仪(XRD)、X射线光电子能谱仪(XPS)对样品的生长速率、表面形貌、晶体结构、薄膜成分进行了表征和分析。结果表明,在250℃沉积温度下,以N_(2)、H_(2)和Ar的混合气体的等离子体作为共反应物,在相同工艺条件下仅增加前驱体三甲基铝(TMA)脉冲注入之后的氮气吹扫时间(t_(p1)),制备的AlN薄膜的(002)晶面择优取向趋于显著,说明t_(p1)的增加可以促进Al和N原子的有序排列,并促进(002)晶面择优取向形成。实验中,t_(p1)为30 s且循环次数为1 150时,PEALD制备的AlN薄膜表面平整光滑,均方根表面粗糙度为0.885 nm,(002)晶面衍射峰最明显,薄膜中氧原子数分数为11.04%,氧原子在AlN薄膜中形成氧缺陷并形成一种稳定的基于八面体配位铝的新型氧缺陷相,XPS结果证明了N—O—Al键的形成。AlN crystalline thin films with preferred orientation of(002) crystal plane were successfully prepared on monocrystalline silicon substrates by plasma enhanced atomic layer deposition(PEALD) technique.It provides an idea for the design of novel piezoelectric functional devices.By using the spectroscopic ellipsometer(SE),atomic force microscope(AFM),X-ray diffractometer(XRD) and X-ray photoelectron spectrometer(XPS),the growth rate, surface morphology, crystal structure and thin film composition of the samples were characterized and analyzed.The results show that at a deposition temperature of 250 ℃,with the mixed plasmas of N_(2),H_(2)and Ar as co-reactants, under the same process condition and only by increasing the nitrogen purge time(t_(p1)) after the pulse injection of precursor trimethylaluminum(TMA),the preferred orientation of(002) crystal plane of the prepared AlN thin films tends to be significant.It shows that the increase of t_(p1) can promote the orderly arrangement of Al and N atoms and the formation of preferred orientation of(002) crystal plane.In the experiments, when t_(p1) is 30 s with 1 150 cycles, the surface of the AlN thin film prepared by PEALD is smooth with a root mean square surface roughness of 0.885 nm, and the(002) crystal plane diffraction peak intensity is maximum.The atom fraction of oxygen in AlN thin film is 11.04%.Oxygen atoms form oxygen defects in AlN thin films and a new stable phase of oxygen defect based on octahedral coordination aluminum.The XPS results show that N—O—Al bond is formed.

关 键 词：等离子增强原子层沉积(PEALD) ALN 晶态薄膜 结合能 氧缺陷 

分 类 号：TB43[一般工业技术]