Semiconductor structure and fabrication method thereof
AssigneesSemiconductor Manufacturing International (Shanghai) Corporation, Semiconductor Manufacturing International (Beijing) Corporation
InventorsHaiyang Zhang, Panpan Liu
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Abstract
A semiconductor structure and its fabrication method are provided in the present disclosure. The method includes providing a substrate, forming a plurality of fins on the substrate, and forming an isolation structure layer including a plurality of isolation structures on the substrate, each isolation structure being formed between adjacent fins. The method further includes forming a first opening by etching at least one isolation structure of the plurality of isolation structures and a portion of the substrate, and forming a power rail by filling the first opening with a conductive material, where a top surface of the power rail is lower than a top surface of the plurality of fins.
Claims13
A method for fabricating a semiconductor structure, comprising:
- providing a substrate;
- forming a plurality of fins on the substrate;
- forming an isolation structure layer including a plurality of isolation structures on the substrate, each isolation structure being formed between adjacent fins;
- forming a first opening by etching at least one isolation structure of the plurality of isolation structures and a portion of the substrate, wherein a remaining portion of the at least one isolation structure of the plurality of isolation structures has a top surface lower than a top surface of the isolation structure layer;
- and
- forming a power rail by filling the first opening with a conductive material, wherein a top surface of the power rail is lower than a top surface of the plurality of fins, lower than the top surface of the remaining portion of the at least one isolation structure of the plurality of isolation structures, and higher than a top surface of the substrate.
A method for fabricating a semiconductor structure, comprising:
- providing a substrate;
- forming a plurality of fins on the substrate;
- forming an isolation structure layer including a plurality of isolation structures on the substrate, each isolation structure being formed between adjacent fins;
- forming a first opening by etching at least one isolation structure of the plurality of isolation structures and a portion of the substrate;
- and
- forming a power rail by filling the first opening with a conductive material, wherein a top surface of the power rail is lower than a top surface of the plurality of fins,
- wherein forming the first opening by etching the at least one isolation structure and the portion of the substrate includes:
- etching the at least one isolation structure till a surface of the portion of the substrate is exposed to form a first trench;
- continuously etching the portion of the substrate along the first trench to form the first opening;
- and
- etching the at least one isolation structure includes:
- forming a patterned photoresist layer on the isolation structure layer;
- using the patterned photoresist layer as a mask, etching the at least one isolation structure to form a second trench;
- removing the patterned photoresist layer;
- forming a first mask layer on the isolation structure layer, and on sidewalls and a bottom of the second trench;
- etching the first mask layer to form a second opening and exposing the bottom of the second trench by the second opening;
- and
- etching the at least one isolation structure along the second opening till the surface of the substrate is exposed to form the first trench.
Dependencies are inferred from the claim text.