Method of cutting metal gate

A method comprising:

• forming a plurality of metal gate stacks over a substrate such that the plurality of gate stacks connect to each other to form a metal-gate line, wherein the plurality of metal gate stacks have sidewall spacers disposed along sidewalls of the metal gate stacks;
• forming source/drain features in the substrate adjacent the metal gate stacks;
• forming an interlayer dielectric (ILD) layer over the metal gate stacks and the source/drain features;
• recessing the plurality of metal gate stacks and the sidewall spacers;
• forming a hard mask over the recessed plurality of metal gate stacks and the recessed sidewall pacers;
• removing a portion of the ILD layer to expose the source/drain features while the hard mask protects the recessed metal gate stacks and the recessed sidewall spacers;
• forming a contact metal layer over the exposed source/drain features;
• forming a line-cut to cut the metal-gate line into sub-metal-gate lines;
• and
• forming an isolation region within the line cut.

A method comprising:

• forming a plurality of fins on a substrate, each of the fins having a gate region;
• forming dummy gate stack in each gate region;
• forming sidewall spacers along sidewalls of each dummy gate stack;
• forming an interlayer dielectric (ILD) layer over the substrate, including beside the dummy gate stacks;
• removing the dummy gate stacks to expose portions of the fins in the gate region;
• forming metal gate stacks over the exposed portions of the fins, wherein the metal gate stack form a metal-gate line;
• recessing the metal gate stacks;
• forming a hard mask over the recessed metal gate stacks;
• forming a line-cut to cut the metal-gate line into sub-metal-gate lines while the hard mask protects the metal gate stacks;
• and
• forming an isolation region within the line cut.