Integrated circuit with thicker metal lines on lower metallization layer

An IC structure, comprising:

• a first transistor, a second transistor, a third transistor and a fourth transistor formed on a substrate;
• a first net electrically connecting the first transistor and the second transistor, the first net comprising a plurality of first metal lines routed on a first metallization layer, and a plurality of first metal vias electrically connecting the plurality of first metal lines to the first and second transistors;
• and
• a second net electrically connecting the third transistor and the fourth transistor, the second net comprising a plurality of second metal lines routed on a second metallization layer, and a plurality of second metal vias electrically connecting the plurality of second metal lines to the third and fourth transistors, wherein a count of the plurality of first metal vias of the first net is less than a count of the plurality of second metal vias of the second net, and a line-to-line spacing between adjacent two of the plurality of first metal lines of the first net is greater than a line-to-line spacing between adjacent two of the plurality of second metal lines of the second net.

An IC structure, comprising:

• a first transistor, a second transistor, a third transistor and a fourth transistor formed on a substrate;
• a first net electrically connecting the first transistor and the second transistor, the first net comprising a plurality of first metal lines routed on a first metallization layer, and a plurality of first metal vias electrically connecting the plurality of first metal lines to the first and second transistors;
• and
• a second net electrically connecting the third transistor and the fourth transistor, the second net comprising a plurality of second metal lines routed on a second metallization layer above the plurality of first metal lines, and a plurality of second metal vias electrically connecting the plurality of second metal lines to the third and fourth transistors, wherein a count of the plurality of first metal vias of the first net is less than a count of the plurality of second metal vias of the second net, and a total length of the plurality of first metal lines of the first net is longer than a total length of the plurality of second metal lines of the second net.