Semiconductor Die ID Imprinting in Photolithography for Traceability
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Solution Overview
Problem
Existing methods for tracing semiconductor dies are unreliable and imprecise, making it difficult to trace individual dies and distinguish between packaging-induced and micro-processing-induced defects, and they do not allow for precise identification during the manufacturing process.
Innovation Solution
Imprinting a unique identifier, such as a two-dimensional bar code, on semiconductor dies during the manufacturing process using digital photomasks, which are dynamically controlled to minimize interference with the circuit design, and associating this identifier with a record that includes fabrication history and other relevant data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional feedback methods from fabrication units are used for supply chain tracking, then existing processes can be maintained, but traceability becomes unreliable and complex systems are required
Solution Approach 1:
The unique identifier is imprinted on the semiconductor die during the fabrication process itself, before the die leaves the fabrication unit. This preliminary action eliminates the need for complex post-fabrication tracking systems, as the identifier is already embedded and can be read throughout the supply chain.
Solution Approach 2:
Instead of using complex physical tracking systems, the patent uses a digital copy of the identifier (unique pattern of pixels) that can be replicated and read optically. This simple optical signature replaces complex tracking infrastructure.
2Measurement precision
If unique identifiers are imprinted on semiconductor dies, then individual die traceability is achieved, but the identifier must not interfere with circuit design
Solution Approach 1:
The unique identifier is placed in a specific local region of the semiconductor die that does not interfere with the functional circuit areas. The identifier occupies only the space necessary for its pattern, leaving the rest of the die dedicated to circuit functionality.
Solution Approach 2:
The die surface is segmented into functional circuit areas and an identifier area. The unique identifier is confined to a discrete region, separating its function from the circuit functionality while maintaining overall die integrity.
3Reliability
If identifiers are added during fabrication, then traceability is improved, but additional process steps may be required
Solution Approach 1:
The unique identifier imprinting is merged with the existing photolithography process used for circuit fabrication. By using the same photolithography equipment and photosensitive materials already present in the fabrication line, no separate dedicated equipment or process steps are needed.
Solution Approach 2:
The photolithography equipment performs dual functions: fabricating the circuit patterns and imprinting the unique identifier. This multi-functionality eliminates the need for additional specialized equipment, maintaining fabrication productivity while achieving traceability.
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
Enhances traceability and authenticity verification of semiconductor dies, improving supply chain management and quality control by providing a durable identifier that can withstand manufacturing processes and tampering, allowing for improved failure detection and regulatory compliance.
Implementation Method 1
receiving the substrate at a photolithography station, the substrate comprising a photosensitive layer and an area for forming a plurality of semiconductor dies; forming a plurality of circuits on the substrate using at least one photolithography mask
Implementation Method 2
the at least one digital photomask comprises dynamically controlled pixels, controllable to define a unique pattern for the unique identifier
Data Source
AI summary
Various systems and methods for imprinting a unique identifier on a semiconductor die are disclosed herein. Example embodiments involve receiving a substrate at a photolithography station, the substrate including a photosensitive layer and an area for forming semiconductor dies, forming circuits on the substrate using a photolithography mask, imprinting a unique identifier on each semiconductor die on the substrate using a digital photomask and removing the substrate containing the semiconductor dies containing the circuits and the unique identifiers from the photolithography station. In some embodiments, each unique identifier is associated with a unique record for recording characteristics of the substrate, of the semiconductor die and of the unique identifier. In some embodiments, the digital photomask includes dynamically-controlled pixels, controllable to define a unique pattern for each unique identifier. In some embodiments, the unique identifier is a two-dimensional code.