Semiconductor devices and methods of fabricating semiconductor devices

摘要

Semiconductor devices are provided. A semiconductor device includes a substrate including first through fourth areas. Moreover, first through fourth gate insulating layers are on the first through fourth areas, respectively. Amounts of work function control materials in the first through fourth gate insulating layers, nitrogen concentrations in the first through fourth gate insulating layers, and/or thicknesses of the first through fourth gate insulating layers vary among the first through fourth gate insulating layers. Methods for fabricating semiconductor devices are also provided.

主权项

1. A method of fabricating a semiconductor device, the method comprising:
forming a gate insulating layer on first through fourth areas of a substrate; providing a first concentration of nitrogen to portions of the gate insulating layer that are formed on the first and second areas of the substrate, and a second concentration of nitrogen to portions of the gate insulating layer that are formed on the third and fourth areas of the substrate, wherein the second concentration of nitrogen comprises a different concentration from the first concentration of nitrogen; forming a work function control material layer on the first through fourth areas of the substrate; forming a capping layer on the work function control material layer, wherein the capping layer is formed to a first thickness on the first and third areas of the substrate, and to a second thickness that is different from the first thickness, on the second and fourth areas of the substrate; and annealing the substrate.