Method of forming semiconductor device having embedded strain-inducing pattern
A semiconductor device can include an active region having a fin portion providing a channel region between opposing source and drain regions. A gate electrode can cross over the channel region between the opposing source and drain regions and first and second strain inducing structures can be on opposing sides of the gate electrode and can be configured to induce strain on the channel region, where each of the first and second strain inducing structures including a respective facing side having a pair of {111} crystallographically oriented facets.
1. A method of forming a semiconductor device, comprising:
forming an active region having an upper surface, a first side surface, a second side surface opposite the first side surface, and a third side surface in contact with the upper surface and the first and second side surfaces on a substrate;
forming a gate electrode covering at least one of the upper surface, the first side surface, and the second side surface;
forming a strain-inducing pattern in contact with the third side surface of the active region,
wherein the third side surface of the active region includes two or more planes of which a first plane forms an acute angle with respect to the first side surface, and a second plane forms an acute angle with respect to the second side surface.
2. The method of claim 1 , wherein the formation of the strain-inducing pattern comprises,
forming a first trench in the active region;
forming a second trench by etching the active region exposed in the first trench using a directional etching process; and
forming the strain-inducing pattern in the first and second trenches.
3. The method of claim 2 , wherein the directional etching process comprises using NH4OH, NH3OH, Tetra Methyl Ammonium Hydroxide (TMAH), KOH, NaOH, benzyl trimethyl ammonium hydroxide (BTMH), or a combination thereof.
4. The method of claim 1 , wherein the strain-inducing pattern comprises SiGe formed using selective epitaxial growth (SEG) technology.