Method of forming carbon layer and method of forming interconnect structure

A method of forming an interconnect structure, the method comprising:

• providing a substrate including a first metal layer and a first insulating layer;
• forming a surface treatment layer on at least one of the first metal layer and the first insulating layer;
• and
• selectively forming a carbon layer on the first metal layer, the carbon layer having an sp2 bonding structure;
• selectively forming a second insulating layer on the first insulating layer;
• forming a third insulating layer to cover the second insulating layer;
• and
• forming a second metal layer after the forming the third insulating layer, the second metal layer being electrically connected to the first metal layer.