Multi-purpose composite mask for dual damascene patterning

Claim 1

A method of forming a multi-purpose composite mask for dual damascene patterning comprising the steps of: providing a substrate having a stack of dielectric layers comprising a barrier layer, a first dielectric layer, an etch-stop layer, a second dielectric layer and a cap layer formed thereon in said order wherein said first dielectric layer comprises a low-k material including black diamond; forming a via opening in said stack of dielectric layers; forming a polymeric dielectric layer over said substrate, including over said via opening; forming a silicon based dielectric layer over said polymeric dielectric layer; patterning said silicon based and polymeric dielectric layers to define a trench opening, and partially removing said polymeric dielectric layer from said via opening; using said polymeric dielectric as a via protector, etching further said trench opening until said etch-stop layer is reached; and cleaning any remaining polymeric dielectric in said via to complete the forming of said dual damascene structure.

Claim 2

A method of forming a multi-purpose composite mask for dual damascene patterning comprising the steps of: providing a substrate having a stack of dielectric layers comprising a barrier layer, a first dielectric layer, an etch-stop layer, a second dielectric layer and a cap layer formed thereon in said order wherein said first dielectric layer comprises a low-k material including black diamond; forming a via opening in said stack of dielectric layers; forming a polymeric dielectric layer over said substrate, including over said via opening; forming a silicon based dielectric layer over said polymeric dielectric layer; patterning said silicon based and polymeric dielectric layers to define a trench opening, and partially removing said polymeric dielectric layer from said via opening; using said polymeric dielectric as a via protector, etching further said trench opening until said etch-stop layer is reached; and cleaning any remaining polymeric dielectric in said via to complete the forming of said dual damascene structure.

Claim 19

A method of forming a multi-purpose composite mask for dual damascene patterning comprising the steps of: providing a substrate having a first metal layer formed thereon; forming a first dielectric layer over said first metal layer; forming a second dielectric layer over said first dielectric layer wherein said second dielectric layer comprises a low-k material including black diamond; forming a third dielectric layer over said second dielectric layer; forming a fourth dielectric layer over said third dielectric layer; forming a fifth dielectric layer over said fourth dielectric layer; forming a via opening starting from said fifth dielectric layer until reaching to and stopping on said first dielectric layer on said substrate; forming a polymeric dielectric layer over said substrate, including over said via opening; forming a silicon based dielectric layer over said polymeric dielectric layer; patterning said silicon based dielectric layer to define a hard mask for trench opening; using said silicon based dielectric layer as a hard mask, etching to transfer said trench opening into said polymeric dielectric layer, while at the same time leaving a portion of said polymeric dielectric in said via opening; using said silicon based and polymeric dielectric layers as a mask, further trench etching the underlying said fifth and fourth dielectric layers until stopping on said third dielectric layer; and removing said portion of said polymeric dielectric from the bottom of said via opening until said first dielectric via is reached, and said dual damascene structure is formed.

Claim 20

A method of forming a multi-purpose composite mask for dual damascene patterning comprising the steps of: providing a substrate having a first metal layer formed thereon; forming a first dielectric layer over said first metal layer; forming a second dielectric layer over said first dielectric layer wherein said second dielectric layer comprises a low-k material including black diamond; forming a third dielectric layer over said second dielectric layer; forming a fourth dielectric layer over said third dielectric layer; forming a fifth dielectric layer over said fourth dielectric layer; forming a via opening starting from said fifth dielectric layer until reaching to and stopping on said first dielectric layer on said substrate; forming a polymeric dielectric layer over said substrate, including over said via opening; forming a silicon based dielectric layer over said polymeric dielectric layer; patterning said silicon based dielectric layer to define a hard mask for trench opening; using said silicon based dielectric layer as a hard mask, etching to transfer said trench opening into said polymeric dielectric layer, while at the same time leaving a portion of said polymeric dielectric in said via opening; using said silicon based and polymeric dielectric layers as a mask, further trench etching the underlying said fifth and fourth dielectric layers until stopping on said third dielectric layer; and removing said portion of said polymeric dielectric from the bottom of said via opening until said first dielectric via is reached, and said dual damascene structure is formed.