Method for fabricating a notched gate structure of a field effect transistor

摘要

A method of fabricating a gate structure of a field effect transistor comprising a gate dielectric that is notched beneath a gate electrode using an isotropic plasma etch process. In one embodiment, the etch process uses a gas comprising a halogen gas (e.g., chlorine (Cl₂)), a hydrocarbon gas (e.g., methane (CH₄)), and an optional reducing gas (e.g., carbon monoxide (CO)), applies a substrate bias of not greater than 20 W, and maintains the substrate temperature of not less than 200 degrees Celsius.