FinFET device and methods of fabrication
Embodiments of the present invention provide a novel method and structure for forming finFET structures that comprise standard cells. An H-shaped cut mask is used to reduce the number of fins that need to be removed, hence increasing the fin efficiency.
1. A method of forming a standard cell semiconductor structure, comprising:
forming a plurality of semiconductor fins having a fin pitch;
forming a drain contact strip;
forming a source contact strip;
performing a contact area cut process to form a gap in the drain contact strip and form a gap in the source contact strip, wherein each gap has a distance less than two times the fin pitch; and
forming a gate contact within the gap of the source contact strip.
2. The method of claim 1 , wherein forming a drain contact strip comprises depositing tungsten.
3. The method of claim 1 , wherein performing a contact area cut process comprises:
forming a cut mask; and
performing an etch process on the drain contact strip and the source contact strip.
4. The method of claim 1 , wherein performing an etch process comprises performing an anisotropic etch process.
5. The method of claim 4 , wherein performing an etch process comprises performing an etch with a plasma etcher using a gas mixture comprising SF6 and Cl2.
6. The method of claim 4 , wherein performing an etch process comprises performing an etch with a plasma etcher using a gas mixture comprising SF6 and HBr.
7. The method of claim 3 , wherein forming a cut mask comprises forming a cut mask comprising an H shape.
8. The method of claim 7 , wherein forming a cut mask comprising an H shape comprises forming a cut mask having an outer gap ranging from about 25 nanometers to about 30 nanometers.
9. The method of claim 7 , wherein forming a cut mask comprising an H shape comprises forming a cut mask having an outer gap ranging from about 15 nanometers to about 25 nanometers.
10. The method of claim 2 , wherein forming a gate contact comprises forming a tungsten contact.