Enhancing integrated circuit density with active atomic reservoir

A method comprising:

• forming a first power rail, a second power rail, a first conductor, and a second conductor in a first metal layer of an interconnect structure, wherein the first power rail and the second power rail extend lengthwise along a first direction, the first conductor and the second conductor extend lengthwise along a second direction that is different than the first direction, and the first conductor and the second conductor are connected to the first power rail;
• forming a third power rail and a fourth power rail in a second metal layer of the interconnect structure, wherein the third power rail and the fourth power rail are oriented lengthwise along the second direction;
• and
• forming a first via, a second via, a third via, and a fourth via, wherein the first via connects the first power rail to the third power rail, the second via connects the first power rail to the fourth power rail, the third via connects the first conductor to the third power rail, and the fourth via connects the second conductor to the fourth power rail.

A method comprising:

• forming a first dielectric layer over a substrate;
• performing a first lithography process to define a first trench and a second trench in the first dielectric layer, wherein the first trench extends lengthwise along a first direction, the second trench extends lengthwise along a second direction that is different than the first direction, and the second trench is connected to the first trench;
• filling the first trench and the second trench with a first metal material to form a first power rail having a first portion that extends lengthwise along the first direction and a second portion that extends lengthwise along the second direction, wherein the second portion is connected to the first portion;
• forming a second dielectric layer over the first dielectric layer;
• performing a second lithography process to define a third trench in the second dielectric layer, wherein the third trench is disposed directly over the second portion of the first power rail and extends lengthwise along the second direction, and further wherein the third trench has a first lower portion that exposes the first portion of the first power rail, a second lower portion that exposes the second portion of the first power rail, and an upper portion that spans the first lower portion and the second lower portion;
• and
• filling the third trench with a second metal material to form a first via in the first lower portion of the third trench, a second via in the second lower portion of the third trench, and a second power rail in the upper portion of the third trench, wherein the first via connects the first portion of the first power rail to the second power rail and the second via connects the second portion of the first power rail to the second power rail.