Dummy Conductive Members for Stronger Wafer Bonding
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Solution Overview
Problem
The challenge in semiconductor manufacturing is to enhance the bonding strength between wafers to manage the increased complexity and prevent delamination during processing, particularly in smaller package structures with higher integration density.
Innovation Solution
A semiconductor structure is designed with dummy conductive members between two wafers, which are bonded to each other through bonding layers, ensuring a predetermined density that increases the bonding strength and minimizes delamination during subsequent processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If integration density is increased by reducing minimum feature size, then more components can be integrated into a given area, but manufacturing process complexity increases
Solution Approach 1:
The patent applies preliminary action by forming dummy conductive members in advance within bonding layers before wafer bonding. These pre-formed structures serve as bonding enhancement features that simplify the overall manufacturing process by preventing delamination issues that would otherwise require complex post-bonding repairs or rework.
Solution Approach 2:
The dummy conductive members act as intermediaries between the bonding layers of different wafers. These intermediate structures provide additional bonding sites and mechanical support that facilitate reliable wafer bonding while managing the complexity of high-density integration processes.
2Area of stationary object
If package structures are made smaller with smaller footprints, then formation and integration of components of different sizes is facilitated, but bonding strength between wafers decreases
Solution Approach 1:
The patent applies local quality by concentrating bonding enhancement features (dummy conductive members) at specific locations within the bonding layers where they provide maximum benefit. Rather than uniformly distributing all features, the dummy conductive members are strategically placed to locally strengthen the bonding interface in critical areas, maintaining overall bonding strength despite reduced package footprint.
Solution Approach 2:
The bonding structure uses composite materials by combining bonding layers with embedded dummy conductive members made of different materials (e.g., copper, aluminum, or tungsten). This composite structure provides both the dielectric properties needed for insulation and the conductive properties needed for bonding enhancement, achieving strong bonding in compact packages.
3Reliability
If dummy conductive members are added to increase bonding strength, then wafer delamination is prevented, but device structure becomes more complex
Solution Approach 1:
The dummy conductive members serve multiple functions: they act as bonding enhancement features, provide mechanical support, and can serve as electrical ground references or shielding structures. This multi-functionality reduces the need for separate dedicated structures, thereby limiting the increase in overall device complexity while achieving improved bonding strength and reliability.
Solution Approach 2:
The dummy conductive members are formed using the same fabrication processes and materials as the functional conductive structures in the device. This homogeneity in formation methods and materials minimizes additional process complexity and allows the dummy structures to be integrated seamlessly into the existing manufacturing flow.
Data Source
AI summary
The present application provides a semiconductor structure having a dummy conductive member, and a manufacturing method of the semiconductor structure. The semiconductor structure includes a first wafer including a first substrate, a first dielectric layer over the first substrate, a first bonding layer over the first dielectric layer, a first via extending through the first bonding layer, and a first dummy conductive member disposed adjacent to the first via and extending partially through the first bonding layer; and a second wafer including a second bonding layer over the first bonding layer, a second via extending through the second bonding layer, a second dummy conductive member disposed adjacent to the second via and extending partially through the second bonding layer, a second dielectric layer over the second bonding layer, and a second substrate over the second dielectric layer.