A Modified Scheme to Reduce the Specific Contact Resistivity of NiSi/Si Contacts by Means of Dopant Segregation Technique. (1st January 2017)

• Record Type: Journal Article
• Authors: Duan, Ningyuan; Wang, Guilei; Luo, Jun; Mao, Shujuan; Luo, Xue; Xu, Jing; Wang, Wenwu; Liu, Shi; Chen, Dapeng; Li, Junfeng; Zhao, Chao; Ye, Tianchun
• Is Part Of: ECS journal of solid state science and technology. Volume 6:Number 12(2017)
• Page Start: P904
• Page End: P908
• Publication Date: 2017-01-01
• Subjects: dopant segregation -- NiSi -- specific contact resistivity; Solid state chemistry -- Periodicals; Electronics -- Materials -- Periodicals; Electrochemistry -- Periodicals; 541.0421
• DOI: 10.1149/2.0431712jss
• Languages: English
• ISSNs: 2162-8777

Abstract

Abstract : In this work, a proposed modified scheme to reduce the specific contact resistivity (ρc ) of NiSi/Si contacts by means of dopant segregation (DS) technique is presented. In contrast to conventional scheme in which NiSi is formed at 500°C/30s followed by B or As implantation and subsequently drive-in anneals to induce DS at the NiSi/Si interface, this modified scheme consists of the following steps: (1) Deposited Ni films undergo a rapid thermal anneal (RTA1) at a low temperature 300°C/60 s to form Ni-rich silicide i.e. Ni2 Si instead of NiSi followed by the removal of un-reacted Ni; (2) implant boron (B) or arsenic (As) into pre-formed Ni-rich silicide and perform RTA2 at 500–700°C/30 s to transform Ni-rich silicide to NiSi as well as to induce DS at the NiSi/Si interface. For NiSi/n- and p-Si contacts, the ρc values at 600°C drive-in anneal temperature is reduced from 6.5 × 10 −9 Ω-cm 2 and 1.3 × 10 −7 Ω-cm 2 using conventional scheme to 5.1 × 10 −9 Ω-cm 2 and 1.0 × 10 −7 Ω-cm 2 using modified scheme respectively, with the presence of As or B DS. Enhanced DS at the NiSi/Si interface accounts for improved ρc in the modified scheme. This proposed modified scheme can be also applied to reduce the ρc values in the state-of-the-art NiGe/Ge contacts.