Process of forming a composite diffusion barrier in copper/organic low-k damascene technology

A method of forming a composite barrier layer, comprising the steps of:

• providing a substrate having a dielectric layer formed thereover;
• forming a damascene opening within the dielectric layer;
• the damascene opening exposing a first portion of the substrate;
• forming a dielectric flash layer within the damascene opening and over the first exposed portion of the substrate;
• the dielectric flash layer lining the opening;
• removing the bottommost horizontal portion of the dielectric flash layer to expose a second portion of the substrate;
• forming an aluminium layer over the etched dielectric flash layer and over the second exposed portion of the substrate;
• the etched dielectric flash layer and aluminium layer comprising the composite barrier layer;
• forming a barrier metal layer over the aluminium layer;
• the etched dielectric flash layer, aluminium layer and the barrier metal layer comprising the composite barrier layer and
• forming a planarized metal plug within the barrier metal layer lined damascene opening.

A method of forming a composite barrier layer, comprising the steps of:

• providing a substrate having a dielectric layer formed thereover;
• forming a damascene opening within the dielectric layer;
• the damascene opening exposing a first portion of the substrate;
• forming a dielectric flash layer within the damascene opening and over the first exposed portion of the substrate;
• the dielectric flash layer lining the opening;
• the dielectric flash layer being comprised of SixCyNz—H, SixCyOz—H, SixCy—H or SixOy;
• removing the bottommost horizontal portion of the dielectric flash layer to expose a second portion of the substrate;
• forming an aluminium layer over the etched dielectric flash layer and over the second exposed portion of the substrate;
• the etched dielectric flash layer and aluminium layer comprising the composite barrier layer;
• forming a barrier metal layer over the aluminium layer;
• the etched dielectric flash layer, aluminium layer and the barrier metal layer comprising the composite barrier layer and
• forming a planarized metal plug within the barrier metal layer lined damascene opening.

A semiconductor device having a composite barrier layer comprising:

• a substrate having a dielectric layer formed thereover and having an opening within said dielectric layer;
• said opening exposing a first portion of said substrate;
• a composite barrier layer lining said opening wherein said composite barrier layer comprises:
• a dielectric flash layer within said opening and lining said opening wherein said dielectric flash layer does not cover said first exposed portion of said substrate;
• an aluminium layer over said dielectric flash layer and over said first exposed portion of said substrate;
• and
• a barrier metal layer over said aluminium layer wherein said dielectric flash layer, said aluminium layer and said barrier metal layer comprise said composite barrier layer;
• and
• a planarized metal plug within said barrier metal layer lined opening.