Die-Level Semiconductor Serialization Using Unique Wiring Signatures
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Solution Overview
Problem
The global issue of counterfeit semiconductor devices poses significant economic losses, as existing methods lack effective means to uniquely identify and authenticate devices at the die level, leading to challenges in distinguishing authentic from counterfeit chips, especially after they enter the market.
Innovation Solution
The implementation of direct-write lithography to create unique wiring structures with varied geometries on semiconductor wafers, providing both electrical and optical identifiers, enabling die-level authentication and serialization without the need for costly mask-based photolithography.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If mask-based photolithography is used to create unique identifiers on semiconductor wafers, then identification accuracy is improved, but manufacturing cost increases significantly
Solution Approach 1:
The patent uses direct-write lithography to create unique identifier patterns on semiconductor wafers without requiring physical photomasks. This copying approach replaces expensive mask fabrication and handling with a digital pattern writing system, achieving the same identification function at lower cost. The system writes unique patterns directly onto each wafer or die, eliminating the need for mask-based photolithography while maintaining identification accuracy.
2Ease of manufacture
If conventional serialization methods are used, then manufacturing simplicity is maintained, but die-level unique identification capability is lost
Solution Approach 1:
The patent divides the identification function into separate segments: conventional batch-level tracking remains simple, while die-level unique identification is added through direct-write lithography. This segmentation allows conventional manufacturing processes to continue unchanged while adding individual die identification capability through unique wiring structures or patterns written to each die.
Solution Approach 2:
The unique identifier patterns are written directly onto the wafer or individual dies during the manufacturing process using direct-write lithography. This preliminary action embeds the identification information before subsequent processing steps, ensuring each die has its unique identifier without requiring additional post-manufacturing steps.
3Loss of information
If direct-write lithography is used to create unique wiring structures, then die-level unique identification is achieved, but processing complexity increases
Solution Approach 1:
The patent replaces the mechanical photomask system with a direct-write lithography system that uses digital pattern generation and direct deposition or exposure methods. This substitution eliminates the need for physical mask fabrication, alignment, and handling, reducing mechanical complexity while enabling flexible die-level unique identification through software-controlled patterning.
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 approach allows for economical and efficient unique identification of semiconductor devices at the die level, providing a dual authentication mechanism that combats counterfeiting by offering a combination of electrical and visual signatures, enhancing the ability to verify authenticity and quantify damages.
Implementation Method 1
direct-write lithography is used to place a unique wiring structure, for example, an array of conductive paths, at a specific location on a die of a wafer
Implementation Method 2
A layer of photoresist on the die is developed to generate a relief pattern
Data Source
AI summary
A method for marking a semiconductor substrate at the die level for providing unique authentication and serialization includes projecting a first pattern of actinic radiation onto a layer of photoresist on the substrate using mask-based photolithography, the first pattern defining semiconductor device structures and projecting a second pattern of actinic radiation onto the layer of photoresist using direct-write projection, the second pattern defining a unique wiring structure having a unique electrical signature.