Passivation Layer Openings for Reliable Semiconductor Bump Connections

The patent applies local quality by creating a ledge structure at specific locations within the passivation layer. This ledge provides localized stress relief at the interface between different passivation layers, particularly at corners and high-stress regions, without requiring changes to the overall device architecture or component layout. The ledge acts as a localized feature that addresses stress concentration problems while maintaining the high integration density achieved through reduced minimum feature sizes.

The patent introduces a dimensional change by creating a ledge that extends in the vertical dimension within the passivation layer structure. This ledge provides an additional stress relief pathway by creating a stepped configuration that distributes stress across multiple vertical levels, rather than concentrating it in a single plane. This dimensional approach allows stress management without increasing the horizontal footprint, thereby maintaining high integration density.

The patent applies segmentation by dividing the passivation layer into multiple segments with different thicknesses. Instead of using a single thick passivation layer throughout, the structure includes a first passivation layer and a second passivation layer with a ledge, creating segmented thickness zones. This segmentation provides stress relief at critical interfaces while maintaining thinner overall dimensions in non-critical areas, thereby reducing manufacturing complexity compared to uniformly thick passivation layers.

The patent employs parameter changes by varying the thickness parameter of the passivation layer at different locations. The ledge structure creates a localized thickness variation where the second passivation layer is thicker at the ledge region compared to other areas. This parameter change optimizes stress relief at high-stress locations while avoiding the need to increase the overall passivation layer thickness everywhere, thus reducing manufacturing complexity and process difficulty.

The patent applies the curvature principle by forming flared openings with angled sidewalls instead of vertical sidewalls. The flared geometry creates a gradual transition in the opening shape, which distributes stress more evenly across the passivation layer interface. The curved or angled configuration reduces stress concentration at sharp corners and edges, improving stress distribution while the specific angle requirements can be controlled through standard lithography and etching processes.

The patent employs asymmetry by creating flared openings with non-uniform sidewall angles. The openings have different angles at different heights, creating an asymmetric geometry that optimizes stress distribution. The ledge structure itself represents an asymmetric feature that breaks the symmetry of the passivation layer, providing stress relief at critical locations. These asymmetric features can be manufactured with standard precision by controlling the etch profile and lithography parameters.