Transmission Line Structures for Three-Dimensional Integrated Circuit and the Methods Thereof

A method comprising:

• forming a dielectric layer over a substrate;
• forming a transmission line structure in the dielectric layer, wherein the transmission line structure extends lengthwise along a first direction;
• and
• forming a dielectric structure in the dielectric layer, wherein the dielectric structure is disposed in a plurality of planes along a second direction that is different than the first direction, the planes are spaced apart from each other along the first direction, and the dielectric structure has a dielectric constant that is greater than a dielectric constant of the dielectric layer.

A method comprising:

• forming an electrically insulative layer;
• forming a transmission line structure in the electrically insulative layer, wherein the forming the transmission line structure includes:
• forming a first electrically conductive line, a second electrically conductive line, and a third electrically conductive line in the electrically insulative layer,
• wherein the first electrically conductive line, the second electrically conductive line, and the third electrically conductive line extend lengthwise along a first direction, the first electrically conductive line is disposed between the second electrically conductive line and the third electrically conductive line along a second direction, and the second direction is different than the first direction,
• wherein a first spacing is between the first electrically conductive line and the second electrically conductive line along the second direction, and
• wherein a second spacing is between the first electrically conductive line and the third electrically conductive line along the second direction;
• and
• forming first doped regions in the electrically insulative layer in the first spacing between the first electrically conductive line and the second electrically conductive line and second doped regions in the electrically insulative layer in the second spacing between the first electrically conductive line and the third electrically conductive line, wherein the first doped regions have a first dielectric constant, the second doped regions have a second dielectric constant, and the first dielectric constant and the second dielectric constant are each greater than a third dielectric constant of the electrically insulative layer.

A method comprising:

• forming a dielectric layer;
• forming a transmission line structure in the dielectric layer, the transmission line structure having a first metal line disposed between a second metal line and a third metal line;
• and
• forming dielectric islands in a first region of the dielectric layer between the first metal line and the second metal line and a second region of the dielectric layer between the first metal line and the third metal line, wherein a first composition of the dielectric islands is different than a second composition of the dielectric layer.