Dual damascene patterned conductor layer formation method without etch stop layer

摘要

A method for forming through a dielectric layer a trench contiguous with a via. There is provided a substrate having a contact region formed therein. There is then formed upon the substrate a patterned first dielectric layer defining a via accessing the contact region, where the patterned first dielectric layer is formed of a first dielectric material which is not susceptible to etching with an oxygen containing plasma. There is then formed completely covering the patterned first dielectric layer and filling the via a the blanket second dielectric layer formed of a second dielectric material which is susceptible to etching within the oxygen containing plasma. There is then formed upon the blanket second dielectric layer a blanket hard mask layer formed from a hard mask material which is not susceptible to etching within the oxygen containing plasma. There is then formed upon the blanket hard mask layer a patterned photoresist layer which provides an exposed portion of the blanket hard mask layer greater that an areal dimension of the via and at least partially overlapping the areal dimension of the via. There is then implanted into the exposed portion of the blanket hard mask layer and into a portion of the blanket second dielectric layer aligned beneath the exposed portion of the blanket hard mask layer a dose of an ion to form an ion implanted portion of the blanket hard mask layer and an ion implanted portion of the blanket second dielectric layer, where the ion implanted portion of the blanket second dielectric layer has an enhanced etch rate within the oxygen containing plasma in comparison with a non ion implanted portion of the blanket second dielectric layer. There is then etched while employing a first plasma etch method the ion implanted portion of the blanket hard mask layer to form a patterned hard mask layer. Finally, there is then etched while employing a second plasma etch method employing the oxygen containing plasma the blanket second dielectric layer to form a patterned second dielectric layer having an aperture formed therethrough, where the aperture comprises a trench and at least a portion of the via.