Dual damascene patterned conductor layer formation method without etch stop layer

摘要

A method for forming a via through a dielectric layer within a microelectronics fabrication. There is first provided a substrate having a contact region formed therein. There is then formed upon the substrate and covering the contact region a blanket first dielectric layer formed of a first dielectric material which is not susceptible to etching with an oxygen containing plasma. There is then formed upon the blanket first dielectric layer a 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 first photoresist layer which leaves exposed a portion of the blanket hard mask layer greater than and completely overlapping an a real dimension of a via to be formed through the blanket first dielectric layer to access the contact layer. There is then etched while employing a first plasma etch method the blanket hard mask layer to form a patterned hard mask layer defining a first trench formed through the patterned hard mask layer. There is then etched while employing a second plasma etch method and at least the patterned hard mask layer the blanket second dielectric layer to form a patterned second dielectric layer having a second trench formed therethrough, where the second plasma etch method employs the oxygen containing plasma which preferably simultaneously strips the patterned first photoresist layer. There is then formed over at least the patterned second dielectric layer a patterned second photoresist layer which defines the location of the via to be formed through the blanket first dielectric layer. There is then etched while employing a third plasma etch method and the patterned second photoresist layer as a third etch mask layer the via through the blanket first dielectric layer.