基底偏压对Zr-B-O-N薄膜结构及性能的影响-中国材料进展

文章信息/Info

Title:: Effect of Substrate Bias on Structure and Properties of Zr-B-O-N Thin Films

作者:: 孟瑜1; 宋忠孝2; 王小艳1; 钱旦2; 刘明霞1; 李晓华3; （1.西安文理学院陕西省表面工程与再制造重点实验室，陕西西安 710065） (2.西安交通大学金属材料强度国家重点实验室, 陕西西安 710049) (3.中车永济电机有限公司，山西永济 044502)

Author(s):: MENG Yu1; SONG Zhongxiao2; WANG Xiaoyan1; QIAN Dan2; LIU Mingxia1; LI Xiaohua3; （1.Shaanxi Key Laboratory of Surface Engineering and Remanufacturing, Xi’an University, Xi’an 710065, China）（2.State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China）（3. CRRC Yongji Motor Co., Ltd., Yongji 044502, China）

Keywords:: Zr-B-O-N thin films; magnetron sputtering; substrate bias; microstructure; diffusion barrier performance

摘要:: 二硼化锆（ZrB2）薄膜因具有高熔点、低电阻率等特点，在硅基器件Cu互连工艺中具有广阔的应用前景。然而，沉积态ZrB2薄膜多呈现结晶态，其晶界会为Cu原子提供快速扩散通道，通过非金属元素（N或O）掺杂可以得到非晶结构的ZrB2薄膜，以提高其扩散阻挡性能。采用反应磁控溅射技术，在不同基底偏压下在单晶Si（100）基底上沉积了Zr-B-O-N薄膜和Cu/Zr-B-O-N双层膜，分别利用原子力显微镜、X射线衍射仪、透射电子显微镜、扫描电子显微镜和四点探针仪等检测方法对薄膜的微观组织结构、电学和扩散阻挡性能进行表征分析。研究结果表明：沉积态Zr-B-O-N薄膜表面平整，粗糙度随基底偏压增加而增加，且薄膜均呈现非晶结构；当基底偏压为150 V时，10 nm厚的非晶Zr-B-O-N薄膜可以在700 ℃有效阻挡Cu原子扩散。因此，Zr-B-O-N薄膜是一种具有应用潜力的扩散阻挡层材料。

Abstract:: Zirconium diboride(ZrB2) thin films possess high melting point and low resistivity, and has a wide application potential in Cu interconnection of silicon based devices. However, the deposited ZrB2 films usually show crystal structure, and its grain boundary provides a fast diffusion path for Cu atoms. Amorphous structure can be obtained by doping nonmetallic elements (N or O atoms) to improve its diffusion barrier performance. In this paper, Zr-B-O-N films were deposited on single crystal Si (100) substrates by reactive magnetron sputtering under different substrate bias voltages. The microstructure, electrical and diffusion barrier performance of the films were characterized by atomic force microscopy, Xray diffraction, transmission electron microscopy, scanning electron microscopy and four point probe. The results show that the deposited Zr-B-O-N films are amorphous and have flat surface, the roughness increases with the increase of substrate bias voltage. When the substrate bias voltage is 150 V, the formed amorphous Zr-B-O-N film with a thickness of 10 nm can effectively block Cu atom diffusion at 700 ℃. Therefore, Zr-B-O-N film is a kind of potential diffusion barrier materials in the future.