Integrated Circuit Individualization Zone Using Random Via Degradation
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Solution Overview
Problem
Existing methods for individualizing integrated circuits are sensitive to environmental variations and aging, leading to decreased robustness and potential misidentification of legitimate circuits as counterfeit.
Innovation Solution
A method is developed to create a unique individualization zone on microelectronic chips by randomly degrading interconnection levels through the use of particles that block etching mask openings, resulting in malfunctional vias, which are either inactive or have reduced conductivity, making each integrated circuit's response unique and stable over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If functional dispersions (resistance variations, signal propagation times) are used for individualization, then unique identification is achieved, but robustness decreases due to sensitivity to environmental variations and aging
Solution Approach 1:
The patent converts the harmful effect of random particle distribution (which causes manufacturing variability) into a beneficial feature by using it to create a stable, unique fingerprint. The random blockage of vias by particles during the CMP process generates inherent variability that is then used as the basis for individualization, while the physical structure itself provides stability against environmental variations.
Solution Approach 2:
The patent divides the chip into two distinct zones: a functional zone with standard manufacturing and an individualization zone with random via blockage. This segmentation allows the individualization characteristics to be isolated in a specific region, enabling unique identification without affecting the overall functionality and stability of the device.
2Manufacturing precision
If diblock polymer particles are used to block etching mask openings, then some mask openings are blocked, but the blockage is insufficient and not random enough
Solution Approach 1:
The patent changes the parameters of the particle system by using colloidal particles with controlled size distributions and applying them through a recirculating buffer system. By adjusting particle concentration, size, and recirculation conditions, the process achieves both effective blockage of mask openings and sufficient randomness for individualization.
Solution Approach 2:
The patent uses a recirculating buffer system to transport and distribute particles across the mask surface. The fluid dynamics of the recirculating buffer ensure uniform particle distribution and random placement, improving both the effectiveness and randomness of the blockage compared to static particle deposition.
3Reliability
If particles are deposited on the etching mask to create random blockage, then individualization is achieved, but the process complexity increases
Solution Approach 1:
The patent employs a self-organizing process where particles naturally distribute themselves across the mask surface during recirculation, creating random patterns without requiring complex control systems. The physical processes of particle deposition and fluid recirculation automatically generate the desired randomness, reducing the need for additional manufacturing steps.
Solution Approach 2:
The patent integrates the individualization process into the existing CMP manufacturing flow, using the same equipment and materials for both standard fabrication and individualization. The recirculating buffer system serves multiple functions: particle transport, surface coverage, and random pattern generation, thereby minimizing additional process complexity.
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 method produces a stable and unique response diagram for each integrated circuit, resistant to cloning, thus enhancing authentication and reducing costs by leveraging existing microelectronic technologies like CMP, making the integrated circuit physically unclonable.
Implementation Method 1
applying a recirculating buffer on said exposed face such that the recirculating buffer moves the particles over the exposed face
Implementation Method 2
some of said particles at least partially block some of the mask openings, called blocked openings
Implementation Method 3
etching the at least one dielectric layer through the mask openings, so as to form via openings, opening out onto the first electrical track level
Implementation Method 4
filling the via openings with an electrically conductive material, so as to form at least the vias of the interconnection level
Data Source
AI summary
A method for producing an individualization zone of a microelectronic chip having a first and a second electrical track level, and an interconnection level comprising vias, includes providing the first level and a dielectric layer, forming an etching mask having openings on the dielectric layer, and randomly depositing particles in the openings, by deposition then recirculating the particles on the surface of the etching mask. The dielectric layer is etched through mask openings, so as to obtain functional via openings and degraded via openings. The via openings are filled so as to form the vias of the interconnection level, the vias including functional vias at the functional openings and malfunctional vias at the degraded openings.