IEEE Electron Device Letters · 2004 · 54 citations · 12 references
Hfn Dummy GateVlsi DesignEngineeringIntegrated CircuitsGate DielectricSemiconductor DeviceSub-1-nm EotNanoelectronicsMixed-signal Integrated CircuitCmos TechnologyHbox Hfo_2Replacement Gate ProcessMaterials ScienceMaterials EngineeringElectrical EngineeringBias Temperature InstabilityTime-dependent Dielectric BreakdownMicroelectronicsHfn Replacement GateApplied Physics
A replacement gate process employing a HfN dummy gate and sub-1-nm equivalent oxide thickness (EOT) HfO/sub 2/ gate dielectric is demonstrated. The excellent thermal stability of the HfN-HfO/sub 2/ gate stack enables its use in high temperature CMOS processes. The replacement of HfN with other metal gate materials with work functions adequate for n- and pMOS is facilitated by a high etch selectivity of HfN with respect to HfO/sub 2/, without any degradation to the EOT, gate leakage, or time-dependent dielectric breakdown characteristics of HfO/sub 2/. By replacing the HfN dummy gate with Ta and Ni in nMOS and pMOS devices, respectively, a work function difference of /spl sim/0.8 eV between nMOS and pMOS gate electrodes is achieved. This process could be applicable to sub-50-nm CMOS technology employing ultrathin HfO/sub 2/ gate dielectric.
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Fermi Pinning-Induced Thermal Instability of Metal-Gate Work Functions
H.Y. Yu, C. Ren, Yee‐Chia Yeo et al. · IEEE Electron Device Letters · 2004 · 131 citations