SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD OF THE SAME

• Main Author: OKUNO MASAKI
• Format: Patent
• Language: English; Japanese
• Published: 30.03.2015
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PROBLEM TO BE SOLVED: To provide a semiconductor device which can differentiate threshold voltages of a plurality of MOS transistors each having a metal gate with a circumference covered with an insulation film.SOLUTION: The semiconductor device comprises a first gate electrode 16a and a second gate electrode 16b each of which includes a first metal layer formed via a gate insulation film 12, a second metal layer including work function metal and a third metal layer, in a first and a second region, respectively, on a semiconductor substrate 1. The semiconductor device includes a structure in which the third metal layer in the second gate electrode 16b is thinner than the third metal layer in the first gate electrode 16a; and a concentration of work function metal in the first metal layer in the second gate electrode 16b is higher than a concentration of work function metal in the first metal layer in the first gate electrode 16a. 【課題】周囲が絶縁膜で覆われたメタルゲートを有する複数のＭＯＳトランジスタの閾値電圧を相違させることができる半導体装置を提供する。【解決手段】半導体基板１のうち第１領域の上にゲート絶縁膜１２を介して形成される第１金属層と、仕事関数金属を含む第２金属層と、第３金属層をそれぞれ含む第１ゲート電極１６ａ、第２ゲート電極１６ｂを有し、第２ゲート電極１６ｂ内の第３金属層は第１ゲート電極１６ａ内の第３金属層よりも薄く、第２ゲート電極１６ｂ内の第１金属層内の仕事関数金属の濃度は、第１ゲート電極１６ａ内の第１金属層内の仕事関数金属の濃度より高い構造を含む。【選択図】図７