Programmable Fuse-Type TSVs for 3D Chip Stack Repair

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Solution Overview

Problem

In 3D chip stacks with through silicon via (TSV) structures, existing interconnects between chips are non-programmable, making it difficult to alter or repair TSV links once assembled, limiting flexibility in programming and rerouting.

Innovation Solution

The implementation of programmable fuse-type TSVs with a region of reduced cross-section of conductive material, allowing control circuitry across adjacent chips to selectively open TSVs by changing the impedance state from low to high through controlled current flow, enabling programmable interconnects between chips.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional TSV structures are used for chip interconnection, then the packaging density and signal transmission performance are improved, but the ability to alter or repair TSV links after assembly is lost

Engineering Contradiction:
Improvepackaging density and signal transmission performanceVSAvoidability to alter or repair TSV links
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The TSV structure is made dynamically reconfigurable by introducing a fuse element that can change its electrical state from conductive to open-circuit based on applied current. This allows the interconnect to transition between different functional states (connected/disconnected) after assembly, enabling post-fabrication programming and repair capabilities while maintaining the original compact TSV architecture

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The electrical parameter (impedance/conductivity) of the TSV is made changeable by incorporating a fuse structure that can be programmed to alter its resistance state. By applying sufficient current through the fuse region of reduced cross-section, the TSV transitions from a low-impedance connected state to a high-impedance disconnected state, enabling dynamic reconfiguration of interconnect paths

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If TSVs are made programmable with fuse structures, then the flexibility for repair and reconfiguration is improved, but the device complexity increases

Engineering Contradiction:
Improveflexibility for repair and reconfigurationVSAvoidstructure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The TSV interconnect is segmented into distinct functional regions: a fuse region with reduced cross-section for programmability, and regular conductive regions for signal transmission. This segmentation allows the fuse portion to be selectively modified while leaving the rest of the TSV structure intact, adding programming capability without requiring complete redesign of the entire interconnect system

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The fuse structure is implemented as a localized region of reduced cross-section within the TSV, concentrating the programmability function in a specific area. This local modification approach allows the TSV to maintain its standard conductive properties in most regions while gaining reconfigurability only where the fuse region exists, minimizing overall structural complexity

Inventive Principle:
Principle #3Local quality

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

This solution allows for the dynamic alteration of TSV links between chips, enhancing the flexibility and adaptability of 3D chip stacks by enabling programmable interconnects, which can be opened or closed as needed, improving repair and reconfiguration capabilities.

Implementation Method 1

a region of reduced cross-section of conductive material in the via opening as formed within a portion of the via of the at least one TSV structure

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Data Source

PatentEP2324497B13D chip-stack with fuse-type through silicon via
Publication Date: 2013.05.01 INTERNATIONAL BUSINESS MACHINE CORPORATION
  • EP2324497B1 patent drawingFigure 1
  • EP2324497B1 patent drawingFigure 2
  • EP2324497B1 patent drawingFigure 3

AI summary

Programmable fuse-type through silicon vias (TSVs) in silicon chips are provided with non-programmable TSVs in the same chip. The programmable fuse-type TSVs may employ a region within the TSV structure having sidewall spacers that restrict the cross-sectional conductive path of the TSV adjacent a chip surface contact pad. Application of sufficient current by programming circuitry causes electromigration of metal to create a void in the contact pad and, thus, an open circuit. Programming may be carried out by complementary circuitry on two adjacent chips in a multi-story chip stack.