Wafer Bonding Pad Structure With Dielectric Dummy Patterns
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Solution Overview
Problem
The challenge in semiconductor manufacturing is to improve wafer bonding quality by controlling surface level differences after chemical mechanical polishing (CMP) to prevent voids and reduce metal contamination defects during the sawing process.
Innovation Solution
The solution involves creating semiconductor devices with substrate structures that include bonding pads and dummy patterns made of dielectric materials, which are directly bonded to each other, ensuring a flat surface and preventing metal contamination, thereby enhancing bonding quality and reducing defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If dummy patterns of metal are formed to control surface level difference, then wafer bonding quality is improved, but metal contamination defects occur during sawing process
Solution Approach 1:
The patent replaces permanent metal dummy patterns with temporary dielectric material dummy patterns that serve their level-difference-control function during bonding, then can be removed or left inert. This disposable approach with dielectric materials eliminates the contamination risk of metal patterns during subsequent sawing processes while maintaining the necessary surface level control during wafer bonding.
Solution Approach 2:
The patent changes the material parameter of the dummy patterns from metal to dielectric material. This parameter change fundamentally alters the behavior during sawing - dielectric materials do not cause metal contamination defects - while still maintaining the ability to control surface level differences through appropriate dielectric material selection and deposition thickness control.
2Ease of manufacture
If level difference is not controlled after CMP process, then manufacturing process is simpler, but voids are generated in wafer bonding process
Solution Approach 1:
The patent applies preliminary action by forming dielectric dummy patterns in the scribe regions before the wafer bonding process. These pre-formed patterns compensate for level differences that would otherwise cause voids during bonding, ensuring reliable bonding without requiring complex post-CMP level control measures while maintaining process simplicity.
Solution Approach 2:
The patent applies local quality by placing dielectric dummy patterns specifically in the scribe regions where level differences occur after CMP, rather than uniformly across the entire wafer. This localized approach addresses the specific problem area (scribe regions adjacent to die regions) without adding unnecessary complexity to the overall manufacturing process.
Data Source
AI summary
A semiconductor device includes a first substrate structure and a second substrate structure stacked on the first substrate structure. The first substrate structure includes a plurality of first bonding pads in a first die region of a first substrate, a first passivation layer on the first substrate and exposing the first bonding pads, and a plurality of first dummy patterns in the first passivation layer in a first scribe region. The second substrate structure includes a plurality of second bonding pads in a second die region of a second substrate, a second passivation layer on the second substrate and exposing the second bonding pads, and a plurality of second dummy patterns in the second passivation layer in a second scribe region. The first bonding pad and the second bonding pad are directly bonded to each other.