Title :
TiN Metal Gate Electrode Thickness Effect on BTI and Dielectric Breakdown in HfSiON-Based MOSFETs
Author :
Chen, Chien-Liang ; King, Ya-Chin
Author_Institution :
Inst. of Electron. Eng., Nat. Tsing Hua Univ., Hsinchu, Taiwan
Abstract :
Effects of a TiN gate electrode on interface trap density, bias temperature instability (BTI), and time-dependent dielectric breakdown (TDDB) in HfSiON metal-oxide-semiconductor field-effect transistors are investigated in this paper. Based on experimental data, we found that the TiN metal gate electrode thickness plays an important role in determining the final dielectric stability and the interface quality. Samples with thicker TiN gate electrode, which prevent oxygen diffusion from the high-κ layers toward the α-Si electrode, exhibit a lower Dit level. In addition, the levels of oxygen vacancies are expected to be suppressed by thicker TiN gate electrode, which subsequently alleviates damage at the Si/SiO2 interface and improves both the BTI and TDDB performances.
Keywords :
MOSFET; electric breakdown; hafnium compounds; high-k dielectric thin films; interface states; silicon compounds; titanium compounds; BTI; HfSiON; MOSFET; Si-SiO2; TiN; bias temperature instability; dielectric stability; high-κ layers; interface quality; interface trap density; metal gate electrode thickness effect; metal-oxide-semiconductor field-effect transistors; oxygen diffusion; time-dependent dielectric breakdown; Dielectrics; Electrodes; Logic gates; MOS devices; Stress; Tin; $D_{rm it}$; AlO; LaO; TiN metal gate electrode; bias temperature instability (BTI); high- $kappa$ gate dielectrics; time-dependent dielectric breakdown (TDDB);
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2011.2163819