The optimizations to metal gate structure and film process were extensively investigated for great metalgate stress（MGS） in 20 nm high-k/metal-gate-last（HKVMG-last） nMOS devices.The characteristics of advanced MGS...The optimizations to metal gate structure and film process were extensively investigated for great metalgate stress（MGS） in 20 nm high-k/metal-gate-last（HKVMG-last） nMOS devices.The characteristics of advanced MGS technologies on device performances were studied through a process and device simulation by TCAD tools. The metal gate electrode with different stress values（0 to—6 GPa） was implemented in the device simulation along with other traditional process-induced-strain（PIS） technologies like e-SiC and nitride capping layer.The MGS demonstrated a great enhancing effect on channel carriers transporting in the device as device pitch scaling down.In addition,the novel structure for a tilted gate electrode was proposed and relationships between the tilt angle and channel stress were investigated.Also with a new method of fully stressed replacement metal gate（FSRMG） and using plane-shape-HfO to substitute U-shape-HfO,the effect of MGS was improved.For greater film stress in the metal gate,the process conditions for physical vapor deposition（PVD） TiN-x- were optimized.The maximum compressive stress of—6.5 GPa TiN_x was achieved with thinner film and greater RF power as well as about 6 sccm N ratio.展开更多
基金supported by the Ministry of Science and Technology of China(No.2009ZX02035)
文摘The optimizations to metal gate structure and film process were extensively investigated for great metalgate stress（MGS） in 20 nm high-k/metal-gate-last（HKVMG-last） nMOS devices.The characteristics of advanced MGS technologies on device performances were studied through a process and device simulation by TCAD tools. The metal gate electrode with different stress values（0 to—6 GPa） was implemented in the device simulation along with other traditional process-induced-strain（PIS） technologies like e-SiC and nitride capping layer.The MGS demonstrated a great enhancing effect on channel carriers transporting in the device as device pitch scaling down.In addition,the novel structure for a tilted gate electrode was proposed and relationships between the tilt angle and channel stress were investigated.Also with a new method of fully stressed replacement metal gate（FSRMG） and using plane-shape-HfO to substitute U-shape-HfO,the effect of MGS was improved.For greater film stress in the metal gate,the process conditions for physical vapor deposition（PVD） TiN-x- were optimized.The maximum compressive stress of—6.5 GPa TiN_x was achieved with thinner film and greater RF power as well as about 6 sccm N ratio.
