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US 11,769,696 B2Granted
Method for fabricating a semiconductor device
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChun-Yuan Chen, Li-Zhen Yu, Huan-Chieh Su, Lo-Heng Chang, Cheng-Chi Chuang, Chih-Hao Wang
Life of this patent
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Abstract
During a front side process of a wafer, a hard mask layer is formed under a metal portion of a semiconductor device, and an epitaxial layer is deposited to form epitaxial portions of the semiconductor device. In a back side process of the wafer to cut the epitaxial layer, the metal portion is covered and protected by the hard mask layer from damages during etching of the epitaxial layer.
Claims20
A method for fabricating a semiconductor device that has a gate electrode and a pair of source/drain features, comprising:
- forming a semiconductor fin feature on a substrate at a first side of the substrate;
- forming, at the first side of the substrate, a hard mask feature over the substrate at a region that corresponds in position to a portion of the gate electrode of the semiconductor device that is to be formed on the substrate;
- forming, after the hard mask feature is formed, the gate electrode of the semiconductor device at the first side of the substrate, wherein the portion of the gate electrode is disposed at the first side of the hard mask feature;
- forming an epitaxial layer at the first side of the substrate;
- and
- etching a to-be-removed portion of the epitaxial layer from a second side of the substrate to form the source/drain features of the semiconductor device, wherein the second side is opposite to the first side, and the hard mask feature covers the portion of the gate electrode during the etching of the to-be-removed portion of the epitaxial layer to protect, the portion of the gate electrode from being damaged.
3 more elements
A method for fabricating a semiconductor circuit, comprising:
- forming fin features on a semiconductor substrate at a first side of the semiconductor substrate, the fin features extending in an X-direction and arranged in a Y-direction transverse to the X-direction;
- forming, at the first side of the semiconductor substrate, a hard mask layer in isolation recesses between the fin features, the isolation recesses extending in the X-direction;
- etching the fin features to form base fins and source/drain recesses at the first side of the semiconductor substrate, the source/drain recesses extending along the Y-direction between the base tins;
- removing a portion of the hard mask layer in the source/drain recesses;
- forming an epitaxial layer in the source/drain recesses at the first side of the semiconductor substrate to form source/drain features of semiconductor devices of the semiconductor circuit;
- forming gate features of the semiconductor devices on the base fins at the first side of the semiconductor substrate, the gate features extending in the Y-direction and overlapping a remaining portion of the hard mask layer that remains after removing the portion of the hard mask layer;
- and
- etching a to-be-removed portion of the epitaxial layer from a second side of the semiconductor substrate, wherein the second side is opposite to the first side, and the remaining portion of the hard mask layer covers portions of the gate features of the semiconductor devices during the etching of the to-be-removed portion of the epitaxial layer to protect the portions of the gate features of the semiconductor devices from being damaged.
5 more elements
A method of fabricating a semiconductor circuit, comprising:
- forming a plurality of semiconductor device features at a first side of a semiconductor substrate, the semiconductor device features including semiconductor fins, a gate metal layer to form gate features connected to the semiconductor fins, an epitaxial layer to form source/drain features connected to the semiconductor fins, and hard mask features disposed at a second side of the gate metal layer, wherein the second side is opposite to the first side;
- and
- etching a to-be-removed portion of the epitaxial layer from the second side of the semiconductor substrate to form the source/drain features, wherein the hard mask features cover a portion of the gate metal layer during the etching of the to-be-removed portion of the epitaxial layer to protect the portion of the gate metal layer from being damaged.
Dependencies are inferred from the claim text.