中文摘要：

采用脉冲激光沉积（PLA）法,在单晶Si试样表面沉积制备了一系列TiN/AlN硬质多层膜,并采用基于免疫算法的免疫径向基函数（IRBF）神经网络对AlN厚度建立预测模型,设计出具有可控调制周期和调制比的TiN/AlN多层膜。X射线衍射（XRD）结果表明,小调制层周期下,过高或过低的工艺条件下薄膜通常为非晶态,适当的工艺条件下TiN、AlN形成具有强烈织构的超晶格柱状晶多层膜;与此相应,纳米多层膜产生了硬度和弹性模量异常增高;随着调制比增加,使纳米多层膜形成非晶AlN层和纳米晶TiN层的多层结构,多层膜的硬度和弹性模量逐渐下降。XPS结果表明,薄膜界面由Ti＋4、Ti＋3离子组成,N的负二价、三价亚谱结构预示着非当量TiN、AlN的形成。AFM研究显示,薄膜的调制周期均在10~200 nm范围内,且薄膜表面较均匀;当多层薄膜调制周期在50 nm以下时,薄膜的纳米硬度值明显高于TiN和AlN的混合硬度值,达30 Gpa。

英文摘要：

The TiN/AlN thin films are deposited on silicon substrate by pulsed laser ablation.By using the constructed neural network model,a multilayer struture with modulation period ranged from 10 to 200 nm is designed accurately.Both composition and structure of the films are analyzed by microhardness tester,SEM XPS and XRD.TiN film exhibits nanocrystalline columns,whereas AlN shows amphous state.The TiN/AlN multilayer presents microstructural features typical for both materials.The film hardness of 16.9 GPa for AlN,18.8 GPa for TiN and 30 GPa for TiN/AlN is found respectively by the nanoindentation.It is also found by XPS that the filml interface is made of Ti＋4 and Ti＋3,and TixAl1-xN phase is formed.When modulation period is close to 50 nm,their hardness is slightly enhanced over rule-of-mixture value.