The Electrical Characteristics of the MOSCAP Structures with W/WN_x/poly Si_(1-x)Ge_x Gates Stack

摘要

We investigated the electrical characteristics of the MOSCAP structures with W/WN_x/poly Si_(1-x)Ge_x gates stack using C-V and Ⅰ-Ⅴ. The low frequency C-V measurements demonstrated that the flat band voltage of the W/WN_x/poly Si_(0.4)Ge_(0.6) stack was lower than that of W/WN_x /poly Si_(0.2)Ge_(0.8) stack by 0.3V, and showed less gate-poly-depletion-effect than that of W/WN_x/poly- Si_(0.2)Ge_(0.8) gates due to the increase of dopant activation rate with the increase of Ge content in the poly Si_(1-x)Ge_x films. As Ge content in poly Si_(1-x)Ge_x increased, the leakage current level increased a little due to the increase of direct tunneling and Q_(BD) became higher due to the lower boron penetration.