A method of forming a trace by a damascene process using a contact mask formed hard mask

摘要

A wire line is formed by forming a bit line after forming a second contact used as a storage node contact so that electrical connection between a second contact and a lower semiconductor substrate can be reliably formed. Formation of a wire line by a damascene involves forming a first insulating layer on a semiconductor substrate; etching the first insulating layer to form a contact hole; forming a first conductive layer over the first insulating layer that fills the contact hole; patterning the first conductive layer; forming a storage node contact that fills the contact hole and is electrically connected to the semiconductor substrate; forming a hard mask over the storage node contact; etching the first insulating layer using the hard mask as an etch mask to form a trench in the first insulating layer; forming a bit line that is electrically connected to the semiconductor substrate in the trench; forming a second insulating layer that covers the bit line; planarizing the second insulating layer and the hard mask; and forming a storage node on the storage node contact.