Patent ID: 9324834
Filing Date: 2016-04-26
CPC Classification: H01L

Claim Text:
1. A method of forming a semiconductor device comprising: preparing a substrate having an active region; forming a gate electrode on the active region; forming a lightly doped drain (LDD) in the active region adjacent to the gate electrode; forming a trench, which passes through the LDD, in the active region adjacent to the gate electrode, wherein the forming of the trench includes: forming a sacrificial spacer on the side surface of the gate electrode; anisotropically etching the active region exposed to an outer side of the sacrificial spacer to form a first trench; isotropically etching the active region exposed to an interior of the first trench to form a second trench; and directionally etching the active region exposed to an interior of the second trench to form a third trench; and forming a strain-inducing pattern within the trench, wherein the active region includes an upper surface, a first side surface facing the strain-inducing pattern below the upper surface, a second side surface facing the strain-inducing pattern below the first side surface, a first edge between the upper surface and the first side surface, and a second edge between the first side surface and the second side surface, wherein the second edge is nearer than the first edge with respect to a vertical line that is perpendicular to the substrate and passes a side surface of the gate electrode, and wherein the second edge is formed on a surface of the LDD.