Flicker noise in nitrided high-k dielectric NMOS transistors

In order to replace the conventional Si O2 in MOSFETs and minimize gate tunneling currents, high permittivity dielectric materials have been proposed as alternatives. These materials have successfully resolved the gate leakage problem with thicker oxide dielectric. However, other issues such as lower effective mobility and increased low frequency noise due to higher oxide trap density, limit its further development. Among these candidates, HfSiON offers many advantages compared to other high-k devices such as suppression of Boron penetration, remaining amorphous during high temperature annealing, and offering better thermal stability and interface quality. In addition, the extracted oxide trap density from measured 1/f noise shows lower values compared to other high-k MOSFETs. This paper presents low frequency noise characteristics of MOSFETs with HfSiON and SiON gate dielectrics of varying gate length dimensions and effective oxide thickness. The measured noise spectra as well as DC parameters will be compared between HfSiON and SiON MOSFETs. The noise parameters are extracted from the measured noise data using the interface-generated, correlated number and mobility fluctuation model.