Hybrid Bonding Structure for Semiconductor Package Metal Diffusion
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Solution Overview
Problem
The complexity of manufacturing semiconductor devices increases due to the combination of various materials with different thermal properties, necessitating improved manufacturing processes and addressing issues like metal diffusion caused by misalignment or size differences in stacked packages.
Innovation Solution
A semiconductor package structure utilizing a hybrid bonding structure composed of an organic barrier layer, such as benzocyclobutene or polyimide, and an inorganic barrier layer, like silicon nitride, to prevent metal diffusion between dies, even in cases of misalignment or size discrepancies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a stacked package structure is used to increase memory capacity and mounting density, then productivity and memory capacity are improved, but manufacturing complexity increases due to combining multiple materials with different thermal properties
Solution Approach 1:
The bonding structure is segmented into distinct organic and inorganic barrier layers, each performing specific functions. The organic layer (e.g., BCB, polyimide) provides thermal stress buffering, while the inorganic layer (e.g., silicon nitride, silicon oxynitride) provides metal diffusion barrier. This segmentation allows each layer to be optimized independently for its specific function, simplifying the overall manufacturing process despite the multi-material complexity.
Solution Approach 2:
The patent employs a composite barrier structure combining organic and inorganic materials. The organic material layer provides flexibility and thermal stress management, while the inorganic material layer provides rigid metal diffusion protection. This composite approach leverages the complementary properties of different materials to achieve both thermal management and diffusion protection, addressing manufacturing complexity through functional integration.
2Ease of manufacture
If conventional bonding structures are used in stacked packages, then manufacturing is simpler, but metal diffusion occurs due to misalignment or size differences between dies
Solution Approach 1:
The patent changes the material parameters of the bonding structure by introducing both organic and inorganic layers with different thermal and mechanical properties. The organic layer has higher thermal expansion coefficient to compensate for misalignment, while the inorganic layer maintains low permeability to prevent diffusion. This parameter optimization allows the structure to tolerate manufacturing variations without compromising reliability.
Solution Approach 2:
The organic barrier layer acts as a cushioning layer that absorbs thermal expansion differences and misalignment stresses before they can cause metal diffusion. By placing this compliant layer between the rigid inorganic barrier and the dies, the structure pre-compensates for expected manufacturing variations, ensuring reliable diffusion protection even when alignment is not perfect.
3Ease of manufacture
If a single-layer barrier structure is used for bonding, then manufacturing is easier, but it cannot simultaneously prevent metal diffusion and accommodate thermal stress differences
Solution Approach 1:
The barrier structure is divided into two functional segments: an organic barrier layer for thermal stress management and an inorganic barrier layer for metal diffusion prevention. This segmentation allows each layer to be optimized for its specific function rather than requiring a single layer to perform both functions, which would compromise one or the other.
Solution Approach 2:
The patent uses a composite structure of organic and inorganic materials to achieve both thermal stress accommodation and metal diffusion prevention. The organic material (e.g., BCB, polyimide) provides thermal compliance, while the inorganic material (e.g., silicon nitride, silicon oxynitride) provides diffusion barrier. This composite approach enables comprehensive protection that neither material could achieve alone.
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 hybrid bonding structure effectively prevents metal diffusion, ensuring secure bonding and reliable electrical connections between dies, enhancing the manufacturing process and package performance.
Implementation Method 1
The hybrid bonding structure includes an organic barrier layer and an inorganic barrier layer bonded to each other
Data Source
AI summary
The present disclosure provides a semiconductor package structure. The semiconductor package structure includes a first die, a second die and a hybrid bonding structure disposed between the first die and the second die. The first die includes a first front side and a first back side opposite to the first front side. The second die includes a second front side and a second back side opposite to the second front side. The hybrid bonding structure is disposed between the first back side of the first die and the second front side of the second die. The first die and the second die are bonded to each other by the hybrid bonding structure. The hybrid bonding structure includes an organic barrier layer and an inorganic barrier layer bonded to each other.