Bonded Semiconductor Substrates for Void-Resistant Metal Interfaces
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Solution Overview
Problem
The reliability of semiconductor devices manufactured using wafer bonding techniques is limited by the formation of voids at the bonding interface, which reduces electromigration resistance and increases contact resistance, leading to potential disconnection and reduced device reliability.
Innovation Solution
Incorporating a conductive body within the second metal layer that extends towards the first metal layer, along with barrier metal films containing titanium, to enhance the feed rate of titanium atoms to the bonding interface, thereby improving electromigration resistance and device reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If wafer bonding technique is used to bond two substrates, then device functionality and integration are improved, but voids form at the bonding interface reducing reliability
Solution Approach 1:
A conductive body is formed within the second metal layer before bonding, extending toward the first metal layer. This preliminary structure prepares the bonding interface to prevent void formation and maintain electromigration resistance, addressing reliability issues before they occur during the bonding process.
Solution Approach 2:
The conductive body acts as an intermediary element between the first and second metal layers at the bonding interface. It facilitates reliable electrical connection and prevents void formation by providing a continuous conductive path, thereby improving bonding interface reliability while maintaining device functionality.
2Ease of manufacture
If conventional bonding structure is used, then manufacturing is simpler, but electromigration resistance is reduced due to void formation
Solution Approach 1:
The conductive body is formed in advance within the second metal layer using standard semiconductor fabrication processes. This preliminary action ensures electromigration resistance is built into the structure before bonding, without adding significant manufacturing complexity to the overall process.
3Device complexity
If no conductive body extension is provided, then device structure is simpler, but contact resistance increases and disconnection may occur
Solution Approach 1:
The conductive body is strategically positioned within the second metal layer, extending locally toward the bonding interface where it is most needed. This localized enhancement improves contact stability and prevents disconnection at the critical bonding region without unnecessarily complicating the overall device structure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively increases the electromigration resistance and reliability of the semiconductor device by providing a higher feed rate of titanium to the bonding interface, reducing void formation and maintaining stable connections between metal pads.
Implementation Method 1
enhance the feed rate of titanium atoms to the bonding interface
Implementation Method 2
barrier metal films containing titanium
Data Source
AI summary
According to one or more embodiments, a semiconductor device includes a first substrate and a second substrate. The first substrate includes a first metal layer and a first insulating layer. The first insulating layer surrounds the first metal layer. The second substrate includes a second metal layer, a second insulating layer, and a first conducive body. The second metal layer is in contact with the first metal layer. The second insulating layer surrounds the second metal layer and is in contact with the first insulating layer. A part of the first conductive body is in the second metal layer and extends in a first direction toward the first metal layer.