Semiconductor device having backside via and method of fabricating thereof
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsLin-Yu Huang, Li-Zhen Yu, Chia-Hao Chang, Cheng-Chi Chuang, Kuan-Lun Cheng, Chih-Hao Wang
Life of this patent
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Abstract
Structures and methods that include a device such as a gate-all-around transistor formed on a frontside and a contact to one terminal of the device from the frontside of the structure and one terminal of the device from the backside of the structure. The backside contact may include selectively etching from the backside a first trench extending to expose a first source/drain structure and a second trench extending to a second source/drain structure. A conductive layer is deposited in the trenches and patterned to form a conductive via to the first source/drain structure.
Claims20
A method, comprising:
- providing a structure with a frontside and a backside, the structure including a gate-all-around transistor having a gate structure, a source structure and a drain structure formed on a frontside;
- selectively etching the structure from the backside of the structure to form a first trench extending to expose the source structure and a second trench extending to expose the drain structure;
- depositing a conductive layer over the backside of the structure and within the first trench and the second trench;
- patterning the conductive layer to remove the conductive layer from the second trench;
- after the patterning, depositing a dielectric layer in the second trench.
A method, comprising:
- forming a bottom layer over a frontside of a substrate;
- forming a transistor having a gate structure, a source feature and a drain feature, wherein the gate structure overlies the bottom layer;
- providing a first contact structure to at least one of the source feature or the drain feature from the frontside of the substrate;
- and
- providing a second contact structure to the other one of the source feature or the drain feature from a backside of the substrate, wherein the second contact structure extends through an opening in the bottom layer, and wherein the providing the second contact structure includes:
- depositing a conductive material interfacing the bottom layer;
- patterning the conductive material to form the second contact structure interfacing a first region of the bottom layer;
- and
- after the patterning, depositing a dielectric layer on a second region of the bottom layer.
A semiconductor structure, comprising:
- two source/drain (S/D) features;
- one or more channel semiconductor layers connecting the two S/D features;
- a gate structure engaging the one or more channel semiconductor layers and interposing the two S/D features;
- a bottom dielectric layer below the gate structure and the one or more channel semiconductor layers;
- a first contact extending from above a first S/D feature of the two S/D features to the first S/D feature;
- a second contact extending from below a second S/D feature of the two S/D features to the second S/D feature, wherein the second contact has a first width at one terminal end and a second width adjacent the bottom dielectric layer, wherein the first width is less than the second width;
- a metal line connected to the terminal end of the second contact.
Dependencies are inferred from the claim text.