SEMICONDUCTOR DEVICE AND PROCESS FOR PRODUCTION THEREOF

摘要

A first MIS transistor and a second MIS transistor respectively comprise: first and second gate insulating films (13a, 13b) respectively formed on first and second active regions both on a semiconductor substrate; first and second gate electrodes (14a, 14b) respectively formed on the first and second gate insulating films; first and second side walls (23A, 23B) which respectively have first and second inner side walls (18a, 18b) each having an L-shaped cross-section and respectively formed on the side surfaces of the first and second gate electrodes; and first and second source drain regions (26a, 26b) of first- and second-conductivity types which are respectively formed in outside lower places of the first and second side walls respectively formed in the first and second active regions. The first source drain region is formed in a trench (20) that is provided in the first active region, and contains a mixed silicon crystal layer (21) along the gate length direction in the channel region in the first active region, wherein the mixed silicon crystal layer can generate a first stress. The width (W18a) of the first inside side wall (18a) is smaller than the width (W18b) of the second inside side wall (18b).