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Comparative Investigation of Flat-Band Voltage Modulation by Nitrogen Plasma Treatment for Advanced HKMG Technology

MetadataDetails
Publication Date2018-01-01
JournalECS Journal of Solid State Science and Technology
AuthorsJiaxin Yao, Huaxiang Yin, Zhenhua Wu, Jianfeng Gao, Qingzhu Zhang
InstitutionsInstitute of Microelectronics, University of Chinese Academy of Sciences
Citations8

This paper presents a comparative investigation of flatband voltage (VFB) adjustment scheme with the nitrogen plasma treatment (NPT) in the high-k/metal-gate (HKMG) Metal-Oxide-Semiconductor Capacitor (MOSCAP) for scaling of the further CMOS fabrication technology. The NPT process on the first ALD-TiN capping layer demonstrates significant VFB modulation capability and causes a controllable effective gate work function in metal-gate: 1) shifting to band center with the increasing of RF powers both for P-/N-MOSCAPs; 2) shifting to opposite directions (P- to band edge, N- to band center) with reduced nitrogen flow ratio for P-/N-MOSCAPs; 3) shifting from −220mV to +60mV and from +130mV to +420mV for P-/N-MOSCAPs, respectively. One unique theoretical model including N-vacancy/Al-trap effect is successfully proposed to illustrate the complicated shift behaviors both for HKMG P-/N-MOSCAPs. The demonstrated process results and the physical model indicate that the advanced NPT technology is a simple, effective and CMOS-compatible method for both P-/N-logic devices scaling beyond 7nm technology node.