Application of cluster-plus-glue-atom model to barrierless Cu-Ni-Ti and Cu-Ni-Ta films

作者：Li, Xiaona^*; Ding, Jianxin; Wang, Miao; Chu, Jinn P.; Dong, Chuang

来源：Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films , 2014, 32(6): 061510.

DOI：10.1116/1.4897616

• HIGH THERMAL-STABILITY
• DIFFUSION BARRIER
• ALLOY-FILMS
• THIN-FILMS
• METALLIZATION
• RESISTIVITY
• INTERCONNECTS
• LAYERS
• MO

To improve the thermal stability of copper and avoid its diffusion into surrounding dielectrics or interfacial reactions with them, the authors applied the cluster-plus-glue-atom model to investigate barrierless Cu-Ni-M (M = Ti or Ta) seed layers. The dissolution of the third element (Ti or Ta) in the Cu lattice with the aid of Ni significantly improved the thermal stability of the Cu seed layer. The appropriate M/Ni (M = Ti or Ta) ratio was selected to obtain a low resistivity: the resistivity was as low as 2.5 mu Omega cm for the (Ti1.5/13.5Ni12/13.5)(0.3)Cu-99.7 film and 2.8 mu Omega cm for the (Ta1.1/13.1Ni12/13.1)(0.4)Cu-99.6 film after annealing at 500 degrees C for 1 h. After annealing at 500 degrees C for 40 h, the two films remained stable without forming a Cu3Si compound. The authors confirmed that the range of applications of the cluster-plus-glue-atom model could be extended. Therefore, a third element M with negative enthalpies of mixing with both Cu and Ni could be selected, under the premise that the mixing enthalpy of M-Ni is more negative than that of M-Cu.

• 出版日期2014-11
• 单位大连理工大学