Integrated circuit, system and method of forming the same

An integrated circuit, comprising:

• a first cell region extending in a first direction and having a first height in a second direction different from the first direction, the first cell region including a clock circuit, the clock circuit comprising:
• a set of buffer circuits including a first set of transistors;
• or
• a set of inverters including the first set of transistors;
• and
• a second cell region extending in the first direction and having a second height in the second direction, the second height being different from the first height, the second cell region being adjacent to the first cell region along a first boundary, the first boundary extending in the first direction, the second cell region including:
• a first set of gates extending in the first direction;
• and
• a second set of gates extending in the first direction, and being separated from the first set of gates in the second direction;
• and
• a feed-through via between the first set of gates and the second set of gates, the feed-through via extending from a front-side to a back-side of a substrate, the feed-through via configured to electrically couple elements on the front-side and the back-side together, the feed-through via comprising:
• a first conductor on the back-side of the substrate, and extending in the first direction;
• a second conductor extending in the first direction, being on a first level and being above the first conductor;
• a first contact extending in at least the first direction or the second direction, being on a second level different from the first level, and being above the first conductor;
• and
• a first via extending in the first direction, being on a third level different from the first level and the second level, and being above the first conductor.

A method of fabricating an integrated circuit, the method comprising:

• fabricating a first set of transistors in a front-side of a substrate in a first cell region, the first cell region extending in a first direction and having a first height in a second direction different from the first direction, the first set of transistors including a set of buffer circuits of a clock circuit, or a set of inverters of the clock circuit;
• fabricating a feed-through via in a second cell region, the second cell region extending in the first direction and having a second height in the second direction, the second height being different from the first height, the second cell region being adjacent to the first cell region along a first boundary, the first boundary extending in the first direction, wherein fabricating the feed-through via in the second cell region comprises:
• depositing a first conductive material on the front-side of the substrate on a first level thereby forming a first set of contacts, the first set of contacts extending in at least the first direction or the second direction;
• fabricating a first set of gates on the front-side of the substrate on a second level, the first set of gates extending in the second direction;
• depositing a second conductive material on the front-side of the substrate on a third level thereby forming a first set of vias, the first set of vias extending in at least the first direction or the second direction, overlapping at least the first set of contacts or the set of gates, and being electrically coupled to at least the first set of contacts or the first set of gates;
• and
• depositing a third conductive material in a first opening of the substrate thereby forming a first set of conductors, the first set of conductors extending in the first direction, being on a fourth level and being electrically coupled to the first set of contacts, the fourth level being different from the first level, the second level and the third level;
• and
• depositing a fourth conductive material on a back-side of the substrate on a first metal level thereby forming a second set of conductors, the back-side of the substrate being opposite from the front-side of the substrate, the second set of conductors extending in the first direction, and being electrically coupled to the first set of conductors.