Enhancement of the Flatband Modulation of Ni-Silicided Gates on Hf-Based Dielectrics

• Published in: IEEE transactions on electron devices Vol. 55; no. 8; pp. 2238 - 2245
• Main Authors: YANG, Jian-Jun, WANG, Xin-Peng, ZHU, Chun-Xiang, LI, Ming-Fu, YU, Hong-Yu, LOH, Wei-Yip, KWONG, Dim-Lee
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.08.2008; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Chemical vapor deposited (CVD); Chemical vapor deposition; Electrodes; Electronics; Exact sciences and technology; Fermi-level pinning; flatband voltage (V_{\rm fb}); Gates; Hafnium oxide; hbox{HfO}_{2}; HfLaO; Microelectronic fabrication (materials and surfaces technology); Modulation; Ni-based fully silicided (FUSI) gate; Nickel; physical vapor deposited (PVD); Physical vapor deposition; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Silicon; Fermi-level pinning; flatband voltage (Vfb); HfO2; physical vapor deposited (PVD); Polycrystal; Transistor gate; Multiple layer; Chemical vapor deposition; Microelectronic fabrication; Flat band voltage; Fermi level; Manufacturing process; Physical vapor deposition; Chemical vapor deposited (CVD); HfLaO; Ni-based fully silicided (FUSI) gate; Conduction band; Gates; Electrical characteristic
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2008.926581

For the first time, the effect of the poly-Si gate electrode deposition process on the electrical characteristics of Ni-based fully silicided/HfO 2 gate stacks is investigated. The flat- band voltage V fb of Ni 2 Si/HfO 2 (or Ni 3 Si/HfO 2 ) with a physical vapor deposited (PVD) Si electrode was found to significantly shift to the positive direction by 0.27 V (or 0.15 V), compared to the case with a chemical vapor deposited (CVD) Si electrode. On the contrary, the V fb of NiSi/HfO 2 with a PVD Si electrode slightly shifts to the negative direction from that with a CVD Si electrode (~0.05 V). Further, La is incorporated into HfO 2 to enhance the V fb modulation of Ni X Si gates with a PVD Si gate to near the conduction band edge of Si (~4.0 eV). We believe that the V fb shift of Ni X Si/HfO 2 is attributed to the release of Fermi-level pinning at the interface between the Si gate electrode and HfO 2 , arising from the different Si electrode formation process.