Fully Silicided Metal Gates for High-Performance CMOS Technology: A Review

Full silicidation ~FUSI! of polysilicon gates promises to be a simple approach for formation of metal gate electrodes for highly scaled complementary metal oxide semiconductor ~CMOS! transistors. Devices have been reported with several different silicides, prominently with nickel. NiSi was shown to produce different work functions, covering a large portion of silicon bandgap, in relation to a dopant type and amount present in polysilicon. Elimination of polysilicon gate electrode depletion has been demonstrated. Data indicates that significant reduction of gate tunneling current is possible. A summary of developments of this new approach to metal gates and discussion of issues and challenges of the FUSI process and its applicability to highly scaled technologies is presented. © 2005 The Electrochemical Society. @DOI: 10.1149/1.1924307# All rights reserved.