大马士革铜阻挡氮化硅薄膜沉积工艺优化研究

在铜大马士革（Damascene）工艺中，为避免由于铜向FSG中扩散所致电迁移的问题，需要在铜表面沉积一层氮化硅作为隔离铜和随后的介电材料的直接接触，通常人们使用HDP—CVD来沉积该氮化硅层。但针对HDP—CVD沉积速率快和工艺设备成本高等问题，文中研究了一种优化了的PECVD氮化硅沉积工艺来取代HDP—CVD氮化硅工艺。优化主要包含硬件改进和工艺参数调整。硬件改进主要通过引入锥形阴极盘面代替传统的直通形阴极盘面，以实现气体分子的更有效电离。在工艺参数上从RF功率、SiH4流量等方面也有所调整。优化后形成的氮化硅薄膜与HDP—CVD氮化硅薄膜性能非常接近，完全符合大马士革工艺的要求。同时氮化硅薄膜的沉积速率也有明显提高，工艺成本随之降低。

Research on Process Optimization of Copper Diffusion Barrier Layer(SiN) in Copper Dual-Damascene Technology

Since copper in Damascene structure easily diffuses into low K material, which deteriorates the characteristic of the material and raise the leakage current and leads to the breakdown of the dielectric layer, a SiN layer as copper diffusion barrier layer is required between copper layer and the dielectric later. Usually, HDP- CVD, which is a process with low deposition rate and high equipment cost is used to deposit this silicon nitride layer. In order to decrease the process cost, an optimized PECVD process of silicon nitride deposition is studied to achieve better combination of performance and economy in mass production in this paper. The optimization includes modification on both hardware and process parameters. Hardware modification is the replacement of the standard cathode faceplate with hollow cathode faceplate, which adds the efficiency of gas molecule ionization. The film properties of optimized PECVD nitride are very comparable to that of HDP-CVD nitride, which well meet Damascene process requirement.