In this work, we investigated the influence of incorporating zirconia (ZrO 2) in HfO 2 gate dielectric on the electrical properties and reliability of n-channel metal oxide semiconductor field effect transistors (nMOSFETs). Detailed film physical, chemical and optical properties of Hf 1-xZr xO 2 as a function of Zr content were studied using high resolution transmission electron microscopy (HR-TEM), angle resolved X-ray photoelectron spectroscopy (AR-XPS), and spectroscopic ellipsometer (SE). Compared to HfO 2, Hf 1-xZr xO 2 provides not only higher k values for further equivalent oxide thickness (EOT) scaling but also lower capacitance-voltage (C-V) hysteresis, lower threshold voltage (V t) shift (δ V t), and higher time-to-failure (TTF) lifetimes. Improved TTF lifetime of as high as three orders of magnitude and 35% lower Vt shift were achieved from the Hf 1-xZr xO 2 gate stack with x = 0:8. The improved reliability of the Hf 1-xZr xO 2 gate dielectric is attributed to the reduced charge trapping in the Hf 1-xZr xO 2 gate dielectric caused by the ZrO 2 incorporation.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)