Suppression of native oxide growth in sputtered TaN films and its application to Cu electroless plating
Suppression of native oxide growth in sputtered TaN films and its application to Cu electroless plating
复制标题
DOI：
10.1063/1.1609644
复制
发表时间：
2003-09
影响因子：
3.2
通讯作者：
Zengling Wang;O. Yaegashi;H. Sakaue;T. Takahagi;S. Shingubara
中科院分区：
文献类型：
--
作者：
Zengling Wang;O. Yaegashi;H. Sakaue;T. Takahagi;S. Shingubara
当通过湿法化学蚀刻去除表面氧化物层时，可以通过置换电镀在TaN表面上沉积化学镀铜。对于超大规模集成（ULSI）互连技术的应用，其中使用非常薄的TaN阻挡膜，形成具有最小自然氧化物厚度的稳定TaN膜是必要的。在这项研究中，氮化钽薄膜与各种N/Ta原子比的反应溅射和自然氧化物生长的表面上进行了研究，通过X射线光电子能谱，高分辨率卢瑟福背散射光谱，和X射线衍射（XRD）。发现当膜中的N/Ta原子比低于1.2时，TaN膜的表面氧化随时间推进。当该比率高于1.2时，TaN膜的氧化在1 ML时停止。XRD谱表明，当N/Ta原子比在0.82 ~ 1.25之间时，形成面心立方结构的TaN薄膜，电阻率随N/Ta原子比的增大而增大。
Electroless plated copper can be deposited on a TaN surface initiated by displacement plating when the surface oxide layer is removed by wet chemical etching. For application to ultra-large-scale integrated (ULSI) interconnection technology in which very thin TaN barrier films are used, it is essential to form a stable TaN film with minimal native oxide thickness. In this study, TaN films with various N/Ta atomic ratios were fabricated by reactive sputtering and native oxide growth on the surface was investigated by x-ray photoelectron spectroscopy, high resolution Rutherford backscattering spectrometry, and x-ray diffraction (XRD). It was found that when the N/Ta atomic ratio in the film was lower than 1.2, surface oxidation of the TaN film advanced with time. When the ratio was higher than 1.2, oxidation of the TaN film stopped at 1 ML. The XRD spectra indicated that when the N/Ta atomic ratio was between 0.82 and 1.25, face-centered-cubic TaN films were formed and the resistivity increased with an incr...