Dry etching of poly-Si/TaN/HfSiON gate stack for advanced complementary metal-oxide-semiconductor devices  

作　　者：李永亮 徐秋霞 

机构地区：[1]Institute of Microelectronics,Chinese Academy of Sciences

出　　处：《Journal of Semiconductors》2011年第7期145-149,共5页半导体学报（英文版）

基　　金：Project supported by the Special Funds for Major State Basic Research Projects,China(No.2006CB302704 );the National Natural Science Foundation of China(No.60776030)

摘　　要：A novel dry etching process of a poly-Si/TaN/HfSiON gate stack for advanced complementary metal-oxide-semiconductor（CMOS） devices is investigated.Our strategy to process a poly-Si/TaN/HfSiON gate stack is that each layer of gate stack is selectively etched with a vertical profile.First,a three-step plasma etching process is developed to get a vertical poly-Si profile and a reliable etch-stop on a TaN metal gate.Then different BCl_3-based plasmas are applied to etch the TaN metal gate and find that BCl_3/Cl_2/O_2/Ar plasma is a suitable choice to get a vertical TaN profile.Moreover,considering that Cl_2 almost has no selectivity to Si substrate, BCl_3/Ar plasma is applied to etch HfSiON dielectric to improve the selectivity to Si substrate after the TaN metal gate is vertically etched off by the optimized BCl_3/Cl_2/O_2/Ar plasma.Finally,we have succeeded in etching a poly-Si/TaN/HfSiON stack with a vertical profile and almost no Si loss utilizing these new etching technologies.A novel dry etching process of a poly-Si/TaN/HfSiON gate stack for advanced complementary metal-oxide-semiconductor（CMOS） devices is investigated.Our strategy to process a poly-Si/TaN/HfSiON gate stack is that each layer of gate stack is selectively etched with a vertical profile.First,a three-step plasma etching process is developed to get a vertical poly-Si profile and a reliable etch-stop on a TaN metal gate.Then different BCl_3-based plasmas are applied to etch the TaN metal gate and find that BCl_3/Cl_2/O_2/Ar plasma is a suitable choice to get a vertical TaN profile.Moreover,considering that Cl_2 almost has no selectivity to Si substrate, BCl_3/Ar plasma is applied to etch HfSiON dielectric to improve the selectivity to Si substrate after the TaN metal gate is vertically etched off by the optimized BCl_3/Cl_2/O_2/Ar plasma.Finally,we have succeeded in etching a poly-Si/TaN/HfSiON stack with a vertical profile and almost no Si loss utilizing these new etching technologies.

关 键 词：TaN metal gate HfSiON high-k plasma etching SELECTIVITY INTEGRATION 

分 类 号：TN386.1[电子电信—物理电子学]