Ion-Implanted TiN Metal Gate With Dual Band-Edge Work Function and Excellent Reliability for Advanced CMOS Device Applications

• Published in: IEEE transactions on electron devices 2015-12, Vol.62 (12), p.4199-4205
• Main Authors: Xu, Qiuxia, Xu, Gaobo, Zhou, Huajie, Zhu, Huilong, Liang, Qingqing, Liu, Jinbiao, Li, Junfeng, Xiang, Jinjuan, Xu, Miao, Zhong, Jian, Xu, Weijia, Zhao, Chao, Chen, Dapeng, Ye, Tianchun
• Format: Article
• Language: English
• Subjects: CMOS; CMOS integrated circuits; CMOSFETs; Devices; dual band-edge (DBE) effective work function (EWF); Gates; Hafnium compounds; Hafnium oxide; High K dielectric materials; Magnesium; Oxides; P/BF₂ ion-implanted TiN metal gate (MG); single MG and single high-k (HK); Tin; Titanium; Work functions
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2015.2494080

This paper proposed, for the first time, that the dual band-edge effective work functions are achieved by employing a single metal gate (MG) and single high-k (HK) dielectric via ion implantation into a TiN MG for HP CMOS device applications under a gate-last process flow. The P/BF 2 ion-implanted TiN/HfO 2 /ILSiO 2 gate-stack does not degrade the gate leakage, reliability, and carrier mobility, and reduces the effective oxide thickness. The impact of P/BF2 ion implant energy, dose, and TiN gate thickness on the properties of implanted TiN/HfO 2 /ILSiO 2 gate-stack is studied, and the corresponding possible mechanisms are discussed. This technique has been successfully applied to the replacement MG and HK/MG last process flow to fabricate HP CMOSFETs and CMOS 32 frequency dividers with a minimum gate length of 25 nm.