Overlapping Electrode Capacitor DC Impedance Testing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing DC tests struggle to detect manufacturing defects or disconnections in capacitors within semiconductor devices due to infinite impedance, making it difficult to identify high-frequency open failures.
Innovation Solution
A semiconductor device configuration with overlapping electrodes and connection wirings, where the impedance between nodes changes with failures, allowing for detection of defects through DC tests by altering the impedance path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a DC test is used to inspect semiconductor devices, then the test is simple and cost-effective, but capacitor defects and wiring disconnections cannot be detected due to infinite impedance
Solution Approach 1:
The capacitor structure is segmented into multiple electrodes (first electrode on first wiring layer, second electrode on second wiring layer) with separate connection wirings. This segmentation allows individual testing of each electrode-wiring connection path, enabling DC tests to detect defects that would otherwise be invisible in a conventional capacitor structure.
Solution Approach 2:
The insulating layer with through-holes acts as an intermediary structure that enables separate electrical access to the first and second electrodes. The through-holes provide pathways for connection wirings to reach each electrode independently, allowing the DC test to measure impedance changes in each path separately without requiring AC signals.
2Adaptability or versatility
If a capacitor is formed with overlapping electrodes on different wiring layers, then the capacitor can be integrated into the circuit, but defects in electrodes or connection wirings become undetectable by conventional DC tests
Solution Approach 1:
The capacitor is segmented into distinct electrodes on separate wiring layers, each with independent connection wirings. This segmentation transforms the capacitor from a single opaque component into a structured assembly where each element can be individually accessed and tested, resolving the detection difficulty while maintaining integration.
Solution Approach 2:
The capacitor structure utilizes the vertical dimension by placing electrodes on different wiring layers (first wiring layer and second wiring layer) separated by an insulating layer. This three-dimensional arrangement, combined with through-holes providing vertical access, enables separate electrical paths that can be tested independently via DC measurements, overcoming the limitations of planar two-terminal capacitors.
3Measurement precision
If two connection wirings are connected to each electrode with low DC impedance only through that electrode, then the impedance between nodes becomes zero when no failure occurs, but galvanic open state is achieved when failure occurs
Solution Approach 1:
Each electrode-wiring connection path is designed with local quality optimization: the connection wirings connected to the first electrode have low DC impedance substantially only through the first electrode, while connection wirings to the second electrode have low DC impedance substantially only through the second electrode. This localized impedance control enables sensitive detection of defects in each path without requiring complex global wiring changes.
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
Enables reliable detection of capacitor failures and disconnections using DC tests, eliminating the need for AC tests and improving detection efficiency and cost-effectiveness.
Implementation Method 1
DC impedance of a path including the electrode and the two connection wirings becomes higher than that in a case where no failure occurs. Hence, any failure in the capacitor can be detected by a DC test, based on a change in DC impedance.
Data Source
AI summary
A semiconductor device includes a first wiring layer, a second wiring layer and an insulating layer provided between the first wiring layer and the second wiring layer. A capacitor has a first electrode formed on the first wiring layer and a second electrode formed on the second wiring layer in such a manner that the second electrode overlaps with the first electrode. To the first electrode, two connection wirings are connected and, to the second electrode, two connection wirings are connected. The two connection wirings are connected to each other with low DC impedance substantially only through the first electrode. Similarly, the two connection wirings are connected to each other with low DC impedance substantially only through the second electrode.