Copper Block Alpha Particle Shielding in IC Interconnects
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Solution Overview
Problem
Integrated circuit chips are vulnerable to alpha particle-induced soft errors due to alpha particles emitted from lead-based solders and ceramic substrates, which can penetrate and cause failures in sensitive regions of the chips.
Innovation Solution
The implementation of copper blocks in conjunction with interlevel dielectric layers and plating base layers to absorb or slow down alpha particles, providing additional thickness to prevent penetration into the silicon regions of the integrated circuit chips.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If lead-based solders and ceramic substrates are used for connecting integrated circuit chips, then ease of manufacture and ubiquitous compatibility are improved, but alpha particle emission increases causing soft errors in sensitive regions
Solution Approach 1:
A copper block is introduced as an intermediary material between the solder/ceramic substrate and the integrated circuit chip. This copper block serves as a mediator that absorbs or blocks alpha particles emitted from the solder and substrate, preventing them from reaching the sensitive regions of the chip while allowing the connection to remain functional.
Solution Approach 2:
The harmful alpha particle emission is extracted or removed from the system by placing a copper block that specifically targets and absorbs these particles. The copper block is positioned to intercept alpha particles before they can penetrate into the chip, effectively extracting the harmful radiation pathway from the connection structure.
2Reliability
If copper blocks are added to block alpha particles, then reliability against soft errors is improved, but device complexity and structural layers increase
Solution Approach 1:
The copper block serves multiple functions simultaneously: it provides electrical connection through the plating base layer, blocks alpha particles from reaching the chip, and can be integrated into existing solder ball or wire bond structures. This multi-functionality reduces the need for separate components, thereby limiting the increase in device complexity.
Solution Approach 2:
The copper block structure is merged with existing connection methods such as solder balls or wire bonds. The copper block can be formed as part of the solder ball structure or integrated with the wire bond, combining multiple functions into a single integrated component rather than adding separate discrete elements.
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 copper blocks effectively prevent 5.3 MeV and 8.8 MeV alpha particles from reaching the sensitive areas of the integrated circuit chips, significantly reducing the probability of soft errors and ensuring reliable chip function.
Implementation Method 1
The copper blocks effectively prevent 5.3 MeV and 8.8 MeV alpha particles from reaching the sensitive areas of the integrated circuit chips
Data Source
AI summary
An alpha particle blocking structure and method of making the structure. The structure includes: a semiconductor substrate; a set of interlevel dielectric layers stacked from a lowermost interlevel dielectric layer closest to the substrate to a uppermost interlevel dielectric layer furthest from the substrate, each interlevel dielectric layer of the set of interlevel dielectric layers including electrically conductive wires, top surfaces of the wires substantially coplanar with top surfaces of corresponding interlevel dielectric layers; an electrically conductive tot final pad contacting a wire pad of the uppermost interlevel dielectric layer; an electrically conductive plating base layer contacting a top surface of the terminal pad; and a copper block on the plating base layer.