Methods of fabricating semiconductor devices using preliminary trenches with epitaxial growth
AssigneeSamsung Electronics Co., Ltd.
InventorsKevin Ahn, Sang-Jine Park, Jae-Jik Baek, Bo-Un Yoon, Jeong-Nam Han
Life of this patent
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Abstract
A method of fabricating a semiconductor device can be provided by etching sidewalls of a preliminary trench in a substrate that are between immediately adjacent gate electrode structures, to recess the sidewalls further beneath the gate electrode structures to provide recessed sidewalls. Then, the recessed sidewalls and a bottom of the preliminary trench can be etched using crystallographic anisotropic etching to form a hexagonally shaped trench in the substrate.
Claims24
A method of fabricating a semiconductor device comprising:
- forming a gate electrode on a substrate;
- forming a spacer on sidewalls of the gate electrode;
- etching a predetermined portion of the substrate exposed by the spacer and the gate electrode to form a first preliminary trench;
- forming a sacrificial layer on a bottom surface of the first preliminary trench that exposes a sidewall of the first preliminary trench;
- laterally etching the sidewall of the first preliminary trench to form a second preliminary trench;
- removing the sacrificial layer;
- etching the second preliminary trench to form a trench;
- and
- forming a SiGe epitaxial layer in the trench.
A method of fabricating a semiconductor device comprising:
- forming a gate electrode on a substrate;
- forming a spacer on sidewalls of the gate electrode;
- forming a first trench by etching a predetermined portion of the substrate exposed by the spacer and the gate electrode;
- forming a sacrificial layer on a bottom surface of the first trench;
- and
- forming a second trench having a maximum width greater than that of the first trench by laterally etching the sidewalls of the first trench exposed by the sacrificial layer.
A method of fabricating a semiconductor device comprising:
- etching sidewalls of a preliminary trench in a substrate between immediately adjacent gate electrode structures to recess the sidewalls further beneath the gate electrode structures to provide recessed sidewalls;
- and then
- etching the recessed sidewalls and a bottom of the preliminary trench using crystallographic anisotropic etching to form a hexagonally shaped trench in the substrate.
24-26. (canceled)
Dependencies are inferred from the claim text.