Metal gate for advanced CMOS applications

• Main Author: Lai, Donny Jiancheng
• Other Authors: Lee Pooi See
• Format: Theses and Dissertations
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering::Materials
• Online Access: http://hdl.handle.net/10356/42280
• Institution: Nanyang Technological University

A potential metal gate candidate must possess good thermal stability to withstand high anneal temperature and it must also have an effective workfunction (EWF) that is near to the silicon band edges. DC sputtered tungsten nitride (W2N) metal gate on high- K dielectrics is investigated for this application. Rutherford backscattering (RBS) data reveals that oxygen incorporation into tungsten nitride films occurred after the rapid thermal anneal (RTA) treatment and yet the resulting tungsten oxynitride (W0.377O0.322N0.301) maintained its conductivity. Nonetheless, the effective gate oxide thickness increases with the presence of the oxynitride (SiON). To rectify this issue and reduce the leakage current density, a ruthenium (Ru) capping layer was introduced.