Study on Trench-Filling and Microstructure of Copper Damascene Process via Molecular Dynamics Simulation

• Main Authors: Rong-Tai Hong, 洪榮泰
• Other Authors: 黃美嬌
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/13109247951449274512

博士 === 國立臺灣大學 === 機械工程學研究所 === 94 === The trench filling and microstructures of depositing copper atoms on the titanium and tantalum diffusion barrier layers in a damascene process have been studied using parallel molecular dynamics simulation with the embedded atom method (EAM) as interaction potential for the present alloy metal system which is based on the invariance transformation of alloy system. The effects of different process parameters including incident energies of depositing atoms, substrate temperature, the different surface indices of tantalum and the aspect ratio of trench were investigated. The surface indices of tantalum layer considered were (100), (110) and (111) and the aspect ratios were 1, 1.5 and 2, respectively. The coverage of trench filling is improved as increasing the substrate temperature and incident copper atoms energy. Comparing with titanium and tantalum diffusion barrier layers under the same process parameters, it is found that due to a better thermal stability significant improvement in coverage percentage can be obtained using the tantalum barrier layer, especially at higher substrate temperatures. The enhancement of trench filling is studied in case of (110) and (111) crystal structure of tantalum because there are fewer open structures in sidewall of diffusion barrier layers. In microstructure of trench filling, the alloy formation is serious in the case of titanium than that of tantalum diffusion barrier layers. The orientations of textures are changed with different surface energies and the deposited copper within trench has fiber structure with lower surface energy. To treat a larger system, parallel molecular dynamics simulation is also implemented and we compare the efficiency of different PC cluster computing environments including homogeneous and heterogeneous computer systems. The clarification of the suitability is studied between such systems. In this work, the different parallel schemes are developed including atomic and spatial decomposition methods. Comparing the efficiencies between the two schemes, the spatial decomposition performs better in this work.