Semiconductor Skeleton Etch for Probing Buried Metal Traces
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Solution Overview
Problem
The increasing complexity of semiconductor chips makes it difficult to physically probe and access transistors and lower-level metal interconnects, hindering failure analysis, debugging, and fault isolation.
Innovation Solution
A partial etch process is used to remove dielectric layers from selected regions of the semiconductor device, exposing metal traces while maintaining structural integrity, allowing for access to sub-surface features and enabling probing and analysis techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If semiconductor chips are made smaller and more complex to increase performance, then device performance and integration density are improved, but accessibility to internal structures for probing and analysis deteriorates
Solution Approach 1:
The patent applies segmentation by dividing the semiconductor chip into multiple layers (conductive layer, dielectric layer, substrate) and selectively removing portions of the dielectric layer to create windows. This allows access to specific internal conductive structures without disrupting the entire device, enabling targeted probing and analysis while maintaining the integrity of the overall complex structure.
Solution Approach 2:
The patent extracts or removes the dielectric layer material from selected regions to create access windows. This extraction process reveals the underlying conductive interconnect structures, allowing physical probing and electrical measurements to be performed on internal structures that would otherwise be inaccessible in the completed integrated circuit.
2Ease of operation
If full etching is used to expose internal structures, then accessibility for probing is improved, but structural integrity and functional operation deteriorate
Solution Approach 1:
The patent applies local quality by selectively removing dielectric material only in specific localized regions where probing access is needed, rather than removing material from the entire structure. This localized approach creates access windows precisely where required while preserving the structural integrity and electrical functionality of the rest of the integrated circuit.
Solution Approach 2:
The patent uses partial action by performing a partial etch that removes only the necessary amount of dielectric material to expose the conductive structures for probing. The etching is controlled to stop before compromising the structural integrity or electrical functionality of the device, achieving sufficient access without excessive material removal.
3Ease of operation
If dielectric layers are removed to access metal traces, then accessibility to sub-surface features is improved, but structural support and trace integrity worsen
Solution Approach 1:
The patent removes dielectric layers only in localized regions to expose metal traces for probing, rather than removing dielectric from the entire structure. This selective removal provides access to sub-surface features while leaving the majority of the dielectric structure intact to maintain structural support and trace integrity.
Solution Approach 2:
The patent segments the dielectric layer removal process, creating discrete access windows at specific locations where probing is needed. The remaining dielectric structure continues to provide structural support and electrical isolation, while the segmented removal areas allow access to underlying metal traces without compromising overall structural integrity.
Data Source
AI summary
Methods for analyzing and altering the operation of a semiconductor device are provided. The methods include exposing an area of a semiconductor device through a selective partial etch process that creates a skeleton-like structure of metal traces. The exposed areas impose minimal invasiveness to the functionality of the device. The exposed area can facilitate probing the semiconductor device with analysis methods that provide information about the operation of the semiconductor device. Additional device functionality alteration is achieved by cutting, connecting, and re-routing interconnect layers.