论文信息 - The Study of Effective Work Function Modulation by As Ion Implantation in TiN/TaN/HfO2 Stacks

The Study of Effective Work Function Modulation by As Ion Implantation in TiN/TaN/HfO2 Stacks

The impact on the metal gate effective work function (EWF) of As ion implantation through TiN/TaN/HfO2 gate stack was investigated. An As implantation at 20 KeV reduces the flat-band voltage (VFB) for TiN/TaN/HfO2 capacitors (or equivalently reduces the EWF) by a maximum of 600 mV at a dose of 5×1015 cm-2. This VFB reduction is correlated to the As pile-up at the TaN–HfO2 interface, as evidenced by a secondary ion mass spectroscopy (SIMS) study. The As ion accumulation at the interface of the gate electrode–dielectric interface is suggested to induce an interface dipole, contributing to the observed phenomena.

S. Kubicek | K. Meyer | R. Singanamalla | H. Yu | T. Janssens

[1] S. De Gendt,et al. Estimation of fixed charge densities in hafnium-silicate gate dielectrics , 2006, IEEE Transactions on Electron Devices.

[2] K. Shibahara,et al. Workfunction Tuning Using Various Impurities for Fully Silicided NiSi Gate , 2004 .

[3] W. Vandervorst,et al. Sputter rate variations in silicon under high-k dielectric films , 2004 .

[4] D. Kwong,et al. Fermi pinning-induced thermal instability of metal-gate work functions , 2004, IEEE Electron Device Letters.

[5] D.S.H. Chan,et al. Fermi-level pinning induced thermal instability in the effective work function of TaN in TaN/SiO/sub 2/ gate stack , 2004, IEEE Electron Device Letters.

[6] Luigi Pantisano,et al. Passivation and interface state density of SiO2/HfO2-based/polycrystalline-Si gate stacks , 2003 .

[7] Chenming Hu,et al. Metal-dielectric band alignment and its implications for metal gate complementary metal-oxide-semiconductor technology , 2002 .

[8] C. Hu,et al. Metal gate work function adjustment for future CMOS technology , 2001, 2001 Symposium on VLSI Technology. Digest of Technical Papers (IEEE Cat. No.01 CH37184).

[9] H. Z. Massoud,et al. Charge‐transfer dipole moments at the Si–SiO2 interface , 1988 .

[10] T. W. Hickmott. Dipole layers at the metal‐SiO2 interface , 1980 .