IC Substrate Thinning Detection via Trench Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrated circuits, particularly those with sensitive information, face security threats from attacks that involve thinning the substrate from the back face, which can compromise the integrity of the components on the front face, and existing methods lack effective detection mechanisms.
Innovation Solution
A detection system is integrated into the integrated circuit that includes a semiconductor substrate with a trench structure within semiconductor wells, allowing for the measurement of electrical resistance changes to detect substrate thinning, which can be implemented in a compact form using decoupling capacitors and trench configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the substrate is thinned from the back face to bring components closer, then the attack effectiveness increases, but the substrate integrity and security protection decreases
Solution Approach 1:
The patent implements preliminary detection mechanisms by embedding sensors and monitoring systems within the substrate structure before any thinning attack occurs. These sensors can detect changes in substrate thickness, structural integrity, and electrical properties in real-time, allowing the system to identify and respond to thinning attacks before they compromise security.
Solution Approach 2:
The patent employs feedback mechanisms where sensor data about substrate conditions is continuously monitored and fed back to a control system. This enables real-time detection of abnormal thinning patterns and triggers security responses such as alerting authorities or disabling sensitive functions, creating a closed-loop security system that adapts to threats.
2Measurement precision
If detection devices are added to detect substrate thinning, then security detection capability improves, but device complexity and surface area occupied increases
Solution Approach 1:
The patent designs detection structures that serve multiple functions: the same trench structures used for electrical isolation also serve as channels for sensor placement, and the substrate layers themselves act as both functional circuit carriers and sensing elements. This multi-functionality reduces the need for separate dedicated detection components.
Solution Approach 2:
The patent embeds detection sensors and monitoring circuits within existing substrate layers and structures rather than adding external components. Sensors are nested within trench structures, and detection circuits are integrated into available substrate areas, creating a compact hierarchical arrangement that minimizes surface area occupation.
3Ease of manufacture
If trenches are formed within semiconductor wells for detection, then detection implementation simplicity improves, but manufacturing process complexity increases
Solution Approach 1:
The patent divides the substrate into discrete regions with trenches formed at specific locations within semiconductor wells. This segmentation allows for localized detection zones that can be independently manufactured and tested, reducing the overall manufacturing complexity while maintaining detection effectiveness.
Solution Approach 2:
The patent utilizes changes in electrical parameters (such as resistance, capacitance, or conductivity) that occur when trenches are formed in the substrate. By monitoring these parameter changes, the system can detect substrate thinning without requiring complex mechanical measurement systems, simplifying both manufacturing and operation.
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 enables simple and compact detection of substrate thinning, enhancing security by increasing electrical resistance as the substrate is thinned, thereby alerting to potential attacks while also allowing for the formation of decoupling capacitors within the integrated circuit.
Implementation Method 1
measuring a physical quantity representative of the electrical resistance of the well
Implementation Method 2
integrated circuits may also be equipped with decoupling capacitors between the supply voltage and ground
Data Source
AI summary
A semiconductor substrate has a back face and a front face and includes a semiconductor well that is electrically isolated from the semiconductor substrate. A device is configured to detect a thinning of the semiconductor substrate from the back face. The device includes at least one trench that extends within the semiconductor well between two peripheral locations from the front face down to a location situated at a distance from a bottom of the semiconductor well. The trench is electrically isolated from the semiconductor well. A detection circuit is configured to measure a physical quantity representative of well electrical resistance between two contact areas respectively situated on either side of the at least one first trench.