Metal via structure
A fabrication process including the following steps for making a metal via structure is disclosed. A substrate with at least a metal pad configured thereon is prepared. A first dielectric layer configured on a top surface of the substrate has a first opening exposing a top surface of the metal pad. A patterned first photoresist having a second opening aligned with the first opening is applied on a top surface of the first dielectric layer. A first metal evaporation is performed to form a first adhesive layer conformably distributed on a wall surface of the first opening and on a top surface of the exposed area of the metal pad. A second metal evaporation is performed to form a first metal block. The first photoresist is stripped. The first metal block is flattened to have a top surface coplanar with a top surface of the first dielectric layer.
1. A fabrication process for making a metal via structure, comprising:
preparing a substrate with at least a metal pad configured thereon; a first dielectric layer configured on a top surface of the substrate; the first dielectric layer has a first opening, and the metal pad has a top surface exposed from the first opening of the first dielectric layer;
applying a patterned first photoresist on a top surface of the first dielectric layer, the patterned first photoresist has a second opening aligned with the first opening;
performing a first metal evaporation to form a first adhesive layer, the first adhesive layer is conformably distributed on a wall surface of the first opening and on the top surface of the metal pad exposed from the first opening of the first dielectric layer;
performing a second metal evaporation to form a first metal block on a top surface of the first adhesive layer;
stripping the patterned first photoresist; and
flattening the first metal block so that the first metal block has a top surface coplanar with the top surface of the first dielectric layer.
2. The fabrication process as claimed in claim 1 , further comprising:
applying a patterned second photoresist, the patterned second photoresist has a third opening which covers at least the top surface of the first metal block;
performing a third metal evaporation to form a second adhesive layer on the top surface of the first dielectric layer, the second adhesive layer covers at least the top surface of the first metal block; and
performing a fourth metal evaporation to form a first metal circuit on a top surface of the second adhesive layer.
3. The fabrication process as claimed in claim 2 , further comprising:
forming a second dielectric layer on a top surface of the first metal circuit; the second dielectric layer has an opening aligned with the first metal block; the opening of the second dielectric layer exposes an area of the first metal circuit;
forming a third adhesive layer to cover at least area of the first metal circuit exposed from the opening of the second dielectric layer;
forming a second metal block on a top surface of the third adhesive layer so that the second metal block is aligned with the first metal block; wherein the second metal block has a top surface coplanar with a top surface of the second dielectric layer;
forming a fourth adhesive layer on the top surface of the second dielectric layer, the fourth adhesive layer has a first end extended to cover the top surface of the second metal block; and
forming a second metal circuit on a top surface of the fourth adhesive layer.