How tantalum proceeds phase change on tantalum nitride underlayer with sequential Ar plasma treatment
How tantalum proceeds phase change on tantalum nitride underlayer with sequential Ar plasma treatment
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DOI：
10.1016/j.matchemphys.2012.09.053
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发表时间：
2013-01
影响因子：
4.6
通讯作者：
Jung-Chih Tsao;Chuan-Pu Liu;Hsin-Chiao Fang;Ying-Lang Wang
中科院分区：
文献类型：
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作者：
Jung-Chih Tsao;Chuan-Pu Liu;Hsin-Chiao Fang;Ying-Lang Wang
在沉积钽之前，通过对钽层表面进行连续氩等离子体处理，钽可以在钽衬底上由高阻β-Ta相转变为低阻α-Ta相。基于高分辨率透射电镜系统的微观结构检测，提出了相演化机理。图像表明，经氩处理后，TaN膜上部由非晶TaN转变为bcc-Ta(N)和非晶TaN混合物的复合相，x射线衍射图也证实了这一点。由少量氮组成的复合膜为限制稳定α-Ta相生长提供了理想的立方基质。经适当氩处理得到的α-Ta/bcc-Ta(N)薄膜的电阻率比传统的Ta/TaN薄膜低10倍。
Tantalum can change its phase from high resistive β-Ta to low resistive α-Ta phase on a TaN substrate with sequential Ar plasma treatment on the TaN layer surface prior to Ta deposition. The underlined mechanism of phase evolution is proposed based on systematic microstructure examination by high-resolution transmission electron microscopy. The images show that, with argon treatment, the upper part of the TaN film is transformed from amorphous-TaN to a composite phase of bcc-Ta(N) and amorphous-TaN mixture, which is also confirmed by X-ray diffraction patterns. The composite film composed of less nitrogen provides an ideal cubic matrix to confine the stable α-Ta phase to be grown. The α-Ta/bcc-Ta(N) film obtained by proper argon treatment results in film resistivity 10 times lower than the traditional Ta/TaN film.