Titanium nitride as promising gate electrode for MOS technology

Abstract

AbstractTitanium nitride (TiN) films have been grown on Si (100) substrates by DC. reactive magnetron sputtering from a titanium (Ti) metallic target at different nitrogen partial pressures (80–10 sccm) and different power (500–1500 W). The effects of the nitrogen pressure and power on structural and electrical properties of TiN films were investigated by measuring their X‐ray diffraction (crystal orientation), Atomic Force Microscopy (surface roughness), four‐probe technique (electrical resistivity) and film thickness. It is show that deposition rate (13–65 nm/min) decrease with an increase of nitrogen pressure. The films have the grain size (0.001–0.027 μm2) along the sample surface and the size of the grain increase with an increase of nitrogen partial pressure. The X‐ray diffraction measurement show that films were crystalline (with preferred orientation (311)), but some of them were polycrystalline ((311) and (111) preferred orientation). These films have been used as gate electrodes in MOS capacitors, which were fabricated with TiN and SiNxOy as gate electrode and dielectric, respectively. With 20 minutes of annealing time, the extracted TiN work function and flat‐band voltage were about 4.65 eV and ‐0.29 V, which indicates that TiN can be used as mig‐gap electrode for MOS technology. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)