Semiconductor structure and method for forming the same

A method for forming a semiconductor structure, comprising:

• forming a first FinFET device and a second FinFET device over a substrate;
• forming a metal gate feature coupling the first FinFET device and the second FinFET device;
• cutting the metal gate feature to form a trench interrupting the metal gate feature;
• performing a flowable chemical vapor deposition (FCVD) to form a dielectric material to fill the trench;
• performing a nitrogen-containing treatment to form a dielectric layer under the dielectric material;
• and
• performing a UV curing to convert the dielectric material into a dielectric feature over the dielectric layer.

A method for forming a semiconductor structure, comprising:

• forming a first FinFET device, a second FinFET device and a dielectric structure surrounding the first FinFET device and the second FinFET device;
• forming a metal gate feature coupling the first FinFET device and the second FinFET device;
• removing a portion of the metal gate feature to form a trench to cut the metal gate feature to form a first metal gate structure in the first FinFET device and a second metal gate structure in the second FinFET device;
• performing a nitrogen-containing treatment to form a dielectric layer in the trench;
• performing a flowable chemical vapor deposition (FCVD) to form a dielectric material to fill the trench after the nitrogen-containing treatment;
• and
• performing a UV curing to convert the dielectric material into a dielectric feature over the dielectric layer.