Silicon-rich block copolymers to achieve unbalanced vias

A method of forming an integrated circuit comprising:

• forming on a substrate a first conductive layer having conductive elements separated by a trench;
• forming a first insulating layer within the trench that has a low dielectric constant and that is convertible at least in part into a layer that is resistant to a plasma that may be used for a photoresist ashing step or to a solvent that may be used for a via clean step;
• forming a second insulating layer on top of the first insulating layer;
• patterning a photoresist layer over the second insulating layer to define a via formation region;
• etching an unlanded via, defined by the via formation region, that extends from the surface of the second insulating layer to the first conductive layer;
• removing the photoresist layer to convert at least part of the first insulating layer into a third insulating layer that is resistant to a plasma used for the photoresist ashing step or to a solvent used for a via clean step, the third insulating layer protecting the remaining portion of the first insulating layer from the photoresist removal step;
• forming a conductive plug that fills the unlanded via etched through the second insulating layer;
• and
• forming a second conductive layer on top of the second insulating layer that is connected to the first conductive layer with the conductive plug.

A method of forming an integrated circuit comprising:

• forming on a substrate a first conductive layer having conductive elements separated by a trench;
• forming an insulating layer within the trench that comprises a silicon containing block copolymer;
• forming a first layer of silicon dioxide on top of the insulating layer;
• patterning a photoresist layer over the first silicon dioxide layer to define a via formation region;
• etching an unlanded via, defined by the via formation region, that extends from the surface of the first silicon dioxide layer to the first conductive layer;
• removing the photoresist layer converting at least part of the insulating layer into a second silicon dioxide layer, the second silicon dioxide layer protecting the remaining portion of the insulating layer from the photoresist removal step;
• forming a conductive plug that fills the unlanded via etched through the first silicon dioxide layer;
• and
• forming a second conductive layer on top of the first silicon dioxide layer that is connected to the first conductive layer with the conductive plug.