Abstract: Fin field-effect transistors (FinFETs) and fabrication methods thereof are provided. An exemplary fabrication method includes providing a base substrate having a plurality of fins; forming gate structures over the base substrate; forming a photoresist film having a plurality of exposure regions and non-exposure regions over the base substrate, the fins and the gate structures, wherein the exposure regions have first regions above the top surfaces of the gate structures and second regions below the top surfaces of the gate structures; performing an exposure process to the photoresist film; performing a post-baking process to cause photoacid in the second regions of the exposure regions to diffuse into portions of the photoresist film below the top surfaces of the gate structures in the non-exposure regions; developing exposed photoresist film to form photoresist layers; and performing a function doping process to the fins using the photoresist layers as a mask.

Abstract: Fin field-effect transistors (FinFETs) and fabrication methods thereof are provided. An exemplary fabrication method includes providing a base substrate having a plurality of fins; forming gate structures over the base substrate; forming a photoresist film having a plurality of exposure regions and non-exposure regions over the base substrate, the fins and the gate structures, wherein the exposure regions have first regions above the top surfaces of the gate structures and second regions below the top surfaces of the gate structures; performing an exposure process to the photoresist film; performing a post-baking process to cause photoacid in the second regions of the exposure regions to diffuse into portions of the photoresist film below the top surfaces of the gate structures in the non-exposure regions; developing exposed photoresist film to form photoresist layers; and performing a function doping process to the fins using the photoresist layers as a mask.