集成电路用钨溅射靶材制备技术的研究进展

钨靶材是溅射沉积制备集成电路中栅极和布线层的重要原材料,在芯片制造领域扮演着重要的角色。随着芯片的制程越来越小,对沉积薄膜的性能要求越来越高,这就对钨靶材提出了更高的要求,钨靶材制备工艺的优化已成为国内外研究的热点。集成电路对钨靶材的性能指标,如纯度、致密度、晶粒尺寸及均匀性、织构等,均具有严格的要求;这些指标亦是评价钨靶材优劣的重要依据。本文主要归纳了钨靶材主要的制备手段(以热等静压和热轧为主的各种热机械工艺的组合),并分析了各工艺路径的特点,最后预测了钨靶材制备技术的发展趋势,认为进一步控制钨靶材制备过程中的晶粒尺寸和降低钨薄膜的电阻率将成为未来重要的研究内容。

Research Progress of Preparation Technology of Tungsten Sputtering Targets for Integrated Circuits

As an important raw material for preparing grid and wiring layers in integrated circuits by sputtering deposition,tungsten target plays an important role in the field of chip manufacturing.As the chip manufacturing process becomes smaller and smaller,the performance requirements for deposited thin films become higher and higher,which puts forward higher requirements for tungsten targets.Optimization of tungsten target preparation process has become a hot research topic at home and abroad.Integrated circuits have strict requirements on the performance indexes of tungsten targets,such as purity,compactness,grain size and uniformity,texture,etc.These indexes are also an important basis for evaluating tungsten targets.At present,there are many preparation technologies for tungsten targets.This paper mainly summarizes the main preparation methods of tungsten targets(the combination of various thermo-mechanical processes,mainly hot isostatic pressing and hot rolling),and analyzes the characteristics of each process path.Finally,the development trend of tungsten target preparation technology is predicted.It is considered that further control of grain size and reduction of resistivity of tungsten thin films will become important research contents in the future.