Process for Making Conductive Lines of Two Different Materials Within a Level of Wiring
Original Publication Date: 1988-Jul-01
Included in the Prior Art Database: 2005-Feb-15
A differential photomask is used to form some tapered and some vertical walled images in photoresist. These images are subsequently projected into underlying insulating material by reactive ion etching (RIE). When the images in the insulator are coated with a conformal coating of a first conductor and then etched by an anisotropic process, e.g., RIE, the vertical walled images retain conductor while the conductor is totally removed from the tapered walled images. After a second, thicker conformal coating of a second conductor is deposited and planarized, the tapered images retain the second conductor while leaving only the first conductor in the vertical walled images. Referring to Fig.