EB-PVD工艺中基板温度对材料形成过程的影响

针对电子束物理气相沉积（EB-PVD）设备的特点，研究基板温度对材料形成过程的影响。首先建立薄膜生长的基本扩散模型，然后用嵌入原子法（EAM）计算扩散激活能，以入射粒子跃迁概率表征入射原子在表面上的稳定程度，研究基板温度对低能Ni在Ni表面上扩散过程的影响。分别在较低（250～450K）和较高（750～1000K）两种温度下进行上述计算。研究结果表明，基板温度对跃迁概率的影响存在临界值，Ni为375K；当基板温度低于375K时，基板温度对跃迁概率影响很小，而当基板温度高于375K时，跃迁概率随基板温度增加呈指数增长；基板温度较低（Ni低于375K）时入射原子在表面上不扩散，易形成多孔疏松状材料，而较高的基板温度则有利于密实材料的形成。

Effect of Substrate Temperature on Material Establishment in EB- PVD Technology

Corresponding to the properties of Electron Beam-Physical Vapor Deposition,the effects of substrate temperature on material establishment are studied.First,basic diffusion models of thin film growth are established,then embedded atoms method is used to compute diffusion activation energies,and jumping probability is used as the weight criterion for expression of degrees of stability of surface atoms and for study of the effects of substrate temperature on diffusion of Ni on Ni surface.The approach is executed in two kinds of conditions:lower substrate temperature(250 to 450 K) and higher substrate temperature(750 to 1 000 K),and when studying the effects of substrate temperature on material establishment critical substrate temperature is found,Ni is 375 K.When substrate temperature below 375 K,there is no effect of temperature on jumping probability,however,when substrate above 375 K,the jumping probability shows exponential increase following the substrate temperature increasing.When substrate temperature is lower(Ni is 375 K),incidence atoms do not diffuse on surface,and material with many voids are easy to form,however,compact material is easy to be produced in higher substrate temperature.