| CPC H10D 84/038 (2025.01) [H01L 21/02532 (2013.01); H01L 21/02603 (2013.01); H10D 30/031 (2025.01); H10D 30/6713 (2025.01); H10D 30/6735 (2025.01); H10D 30/6757 (2025.01); H10D 62/121 (2025.01); H10D 64/017 (2025.01); H10D 64/018 (2025.01); H10D 84/0167 (2025.01); H10D 84/017 (2025.01); H10D 84/0172 (2025.01); H10D 84/0184 (2025.01); H10D 84/85 (2025.01)] | 20 Claims |

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1. A method, comprising:
forming a stack over a substrate, the stack including first semiconductor layers interleaved by second semiconductor layers;
forming a first fin-shaped structure from the stack over a first area of the substrate;
forming a second fin-shaped structure from the stack over a second area of the substrate;
forming a dummy gate stack over the first fin-shaped structure and the second fin-shaped structure;
depositing a first gate spacer layer over the substrate and the dummy gate stack;
depositing a second gate spacer layer over the first gate spacer layer;
after the depositing of the second gate spacer layer, forming a first source/drain trench over the first fin-shaped structure while the second fin-shaped structure is covered by a first mask layer;
after the forming of the first source/drain trench, forming first inner spacer features to interleave the second semiconductor layers in the first area, while the second fin-shaped structure remains covered by the first mask layer;
forming a first source/drain feature in the first source/drain trench such that the first source/drain feature is in direct contact with the first and the second gate spacer layers;
forming a first etch stop layer over the first source/drain feature;
forming a second mask layer on the first etch stop layer;
after the forming of the second mask layer, removing the first mask layer;
after the removing of the first mask layer, forming a second source/drain trench over the second fin-shaped structure while the first fin-shaped structure is covered by the second mask layer;
forming second inner spacer features to interleave the second semiconductor layers in the second area, while the first fin-shaped structure remains covered by the second mask layer;
forming a second source/drain feature in the second source/drain trench;
forming a second etch stop layer over the second source/drain feature; and
after the forming of the second etch stop layer, removing the second mask layer.
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