Patent ID: 6287961
Filing Date: 2001-09-11
Classification: H01L,Y10S

Abstract:
A method for forming through a dielectric layer a trench contiguous with a via comprising:providing a substrate having a contact region formed therein;forming upon the substrate a patterned first dielectric layer, the patterned first dielectric layer defining a via accessing the contact region, the patterned first dielectric layer being formed of a first dielectric material which is not susceptible to etching with an oxygen containing plasma;forming upon the patterned first dielectric layer a blanket second dielectric layer, the blanket second dielectric layer completely covering the patterned first dielectric layer and filling the via, the blanket second dielectric layer being formed of a second dielectric material which is susceptible to etching within the oxygen containing plasma; there not being employed a hard mask layer formed upon the patterned first dielectric layer;forming upon the blanket second dielectric layer a blanket hard mask layer, the blanket hard mask layer being formed from a hard mask material which is not susceptible to etching within the oxygen containing plasma;forming upon the blanket hard mask layer a patterned photoresist layer, the patterned photoresist layer providing an exposed portion of the blanket hard mask layer greater than an areal dimension of the via and at least partially overlapping the areal dimension of the via;implanting 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;etching, while employing a first plasma etch method, the ion implanted portion of the blanket hard mask layer to form a patterned hard mask layer defining a first trench formed through the patterned hard mask layer while employing the patterned photoresist layer as a first etch mask layer, the first plasma etch method employing a first etchant gas composition appropriate to the ion implanted portion of the blanket hard mask layer; andetching, while employing a second plasma etch method, the blanket second dielectric layer to form a patterned second dielectric layer having an aperture formed therethrough, the aperture comprising:a second trench corresponding with the first trench; andat least a portion of the via, the second plasma etch method employing the oxygen containing plasma.