交联SU-8光刻胶与Ni基底结合性的分子动力学模拟

应用分子动力学模拟软件Materials Studio构建SU-8光刻胶与Ni基底的界面结构,研究后烘温度对界面结合性的影响.结合工艺中所采用的后烘温度,模拟计算了338～368K时Ni基底上SU-8胶的交联反应,在经过反复的能量最小化和分子动力学模拟后,对最终得到的平衡结构进行了界面结合能的计算.计算结果表明界面结合能随着后烘温度的升高而增大,在368K时结合能达到最大值,说明此时界面结合最好.对分子体系进行了能量分析,结果表明界面分子间的范德华力作用能是影响界面结合的主要因素.对体系界面原子间进行了径向分布函数分析,发现范德华力作用范围内(0.31～0.60nm)出现两组Ni—O的强峰,也证实了上述结论。

MOLECULAR DYNAMICS SIMULATION OF THE BINDIND PROPERTY BETWEEN CROSS-LINKED SU-8 PHOTORESIST AND Ni SUBSTRATE

The interfacial structure between SU-8 photoresist and Ni substrate was constructed by using molecular dynamics(MD) simulation software Materials Studio.The influence of postbaking temperature on the interfacial binding property was studied.According to postbaking temperature adopted by experimental process,cross-linking reaction of SU-8 photoresist was performed at different postbaking temperatures within 338 ～ 368 K.Several circles of energy minimization(MM) and MD simulation were applied to the interfacial structure.The binding energy was calculated after the interfacial system getting equalization.It can be seen that with increasing the postbaking temperature the binding energy of the interface between SU-8 photoresist and Ni substrate becomes larger.The value of the binding energy achieved maximum at 368 K.So it can draw the conclusion that the binding property is best at this temperature.By analysing the energy of the molecular system,it can be found that the key influencing factor for the interfacial adhesion is van der Waals force between interface molecules.Pair correlation function(PCF) between atoms of the interfacial structure was analysed.Two strong peaks were found in the range of 0.31 nm to 0.6 nm which belonged to the range of van der Waals force.