Fin and Gate Dimensions for Optimizing Gate Formation

A method comprising:

• forming a first fin, a second fin, a third fin, and a fourth fin over a substrate, wherein the first fin and the second fin are separated by a first distance in an input/output (I/O) region, the third fin and the fourth fin are separated by a second distance in a logic region, and the first distance is greater than the second distance;
• forming an isolation region over a lower portion of the first fin, a lower portion of the second fin, a lower portion of the third fin, and a lower portion of the fourth fin;
• forming a first gate structure and a second gate structure, wherein the first gate structure is disposed over a channel region of an upper portion of the first fin and a channel region of an upper portion of the second fin and the second gate structure is disposed over a channel region of an upper portion of the third fin and a channel region of an upper portion of the fourth fin, and further wherein the first gate structure includes a first dummy gate and the second gate structure includes a second dummy gate;
• forming first epitaxial source/drain features and second epitaxial source/drain features, wherein the first epitaxial source/drain features are disposed over source/drain regions of the first fin and source/drain regions of the second fin and the second epitaxial source/drain features are disposed over source/drain regions of the third fin and source/drain regions of the fourth fin;
• forming an interlevel dielectric layer over the first epitaxial source/drain features, the second epitaxial source/drain features, the first gate structure, and the second gate structure;
• removing the first dummy gate from the first gate structure to form a first opening and the second dummy gate from the second gate structure to form a second opening, wherein the first opening exposes the channel region of the upper portion of the first fin and the channel region of the upper portion of the second fin and the second opening exposes the channel region of the upper portion of the third fin and the channel region of the upper portion of the fourth fin;
• and
• forming a first metal gate in the first opening and a second metal gate in the second opening, wherein the first metal gate includes a first gate electrode disposed over a first gate dielectric having a first thickness, the second metal gate includes a second gate electrode disposed over a second gate dielectric having a second thickness, and the first thickness is greater than the second thickness.

A method comprising:

• forming a first fin-like field effect transistor that includes a first gate structure traversing first fins, wherein the first gate structure includes a first gate dielectric and a first gate electrode;
• forming a second fin-like field effect transistor that includes a second gate structure traversing second fins, wherein the second gate structure includes a second gate dielectric and a second gate electrode;
• wherein the first gate dielectric has a first thickness, the second gate dielectric has a second thickness, and the first thickness is greater than the second thickness;
• and
• wherein a spacing between the first gate dielectric disposed over sidewalls of directly adjacent first fins is substantially the same as a spacing between the second gate dielectric disposed over sidewalls of directly adjacent second fins.