Leakage reduction methods and structures thereof

A method, comprising:

• providing a substrate including a first active region and a second active region that abuts the first active region at a boundary;
• forming a first fin within the first active region, a second fin within the second active region, and a dummy fin at the boundary, wherein the dummy fin has a first threshold voltage;
• and
• performing a threshold voltage implant into the dummy fin to provide an ion-implanted dummy fin having a second threshold voltage greater than the first threshold voltage.

A method, comprising:

• depositing a silicon germanium (SiGe) layer within a recess at a cell boundary between a first cell region and a second cell region;
• forming a first active fin within the first cell region, a second active fin within the second cell region, and a dummy fin within the SiGe layer at the cell boundary;
• and
• forming a gate stack over the first active fin, the second active fin, and the dummy fin.