Increasing thickness of functional layer according to increasing recess area

摘要

A method of manufacturing a semiconductor device includes providing a substrate having first and second semiconductor fins, forming an insulating layer on the substrate having first and second recesses exposing a portion of the respective first and second semiconductor fins, forming a gate dielectric layer on the first and second recesses and the exposed portions of the first and second semiconductor fins, forming a first work function adjustment layer on the gate dielectric layer, forming a functional layer on the first function adjustment layer, and forming first and second gates on portions of the functional layer of the respective first and second semiconductor fins. The opening area of the first recess is larger than the opening area of the second recess. The thickness of the functional layer on the first semiconductor fin is greater than the thickness of the functional layer on the second semiconductor fin.