Patent ID: 6165898
Filing Date: 2000-12-26
Classification: H01L

Abstract:
A method for forming a via through a dielectric layer within a microelectronics fabrication comprising:providing a substrate employed within a microelectronics fabrication, the substrate having a contact region formed therein;forming upon the substrate and covering the contact region a blanket first dielectric layer, the blanket first dielectric layer being formed of a first dielectric material which is not susceptible to etching with an oxygen containing plasma;forming upon the blanket first dielectric layer a blanket second dielectric layer, the blanket second dielectric layer being formed of a second dielectric material which is susceptible to etching within the oxygen containing plasma;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 first photoresist layer, the patterned first photoresist layer leaving 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;etching, 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 while employing the patterned first photoresist layer as a first etch mask layer, the first plasma etch method employing a first etchant gas composition appropriate to the hard mask material from which is formed the blanket hard mask layer;etching, while employing a second plasma etch method and at least the patterned hard mask layer as a second etch mask layer, the blanket second dielectric layer, and simultaneously stripping the patterned first photoresist layer, to form a patterned second dielectric layer having a second trench formed therethrough at a location corresponding with the first trench formed through the blanket hard mask layer, the second plasma etch method employing the oxygen containing plasma; the second plasma etch not etching the blanket first dielectric layer;forming 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, the a real dimension of the via being contained within the a real dimension of the second trench; andetching, 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, the third plasma etch method employing a third etchant gas composition appropriate to the first dielectric material.