THE ELETRICAL CHARACTERISTICS OF W/WN_x/POLY SI_(1-x)GE_x AND THE MOSCAP STRUCTURES WITH W/WN_x/POLY SI_(1-x)GE_x GATES STACK

摘要

We investigated the electrical characteristics of W/WN_x/poly Si_(1-x)Ge_x and the MOSCAP structures with W/WN_x/poly Si_(1-x)Ge_x gates stack using 4-point probe, XRD, and TEM as well as C-V and I-V. The sheet resistance of W/WN_x/poly Si_(1-x)Ge_x films was decreased with the increase of the annealing temperature and increased with the increase of Ge content in the poly Si_(1-x)Ge_x films. The low frequency C-V measurements demonstrated that the flat band voltage of the W/ WN_x /poly Si_(1-x)Ge_x stack was lower than that of W/ WN_x /poly Si stack by 0.3V, and showed less gate-poly-depletion-effect than that of W/ WN_x /poly-Si 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 QBD became higher.