3D Integrated Structure Cavities for Non-Destructive Diffusion Length Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for estimating the diffusion length of metallic species between buried metallic lines in three-dimensional integrated structures are destructive, rendering the structures unusable after measurement.
Innovation Solution
Forming cavities through one integrated circuit to allow a measuring apparatus to be placed in electrical contact with the metallic lines, measuring resistance to estimate diffusion length without damaging the structure, and optionally forming a conductive layer to protect the lines and prevent corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS), secondary ion mass spectrometry (SIMS), or liquid phase decomposition coupled to atomic absorption spectroscopy (LPDAAS) techniques are used to estimate diffusion length, then measurement precision is improved, but the three-dimensional integrated structure is destroyed and becomes unusable
Solution Approach 1:
The patent introduces an intermediary measurement approach using electrical resistance measurement through cavities as a mediator between the metallic lines. Instead of directly analyzing the metal diffusion with destructive techniques, the method uses resistance measurement as an indirect indicator of diffusion length, allowing the structure to remain intact and functional.
Solution Approach 2:
The patent replaces physical/mechanical destructive analysis methods (TEM, EELS, SIMS, LPDAAS) with an electrical measurement system. By substituting mechanical destruction with electrical resistance measurement through formed cavities, the diffusion length can be estimated without destroying the integrated structure.
2Ease of operation
If Through Silicon Via (TSV) connections are formed to enable measurement, then measurement capability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent segments the measurement approach by creating separate cavities that open to the surface, allowing independent access to each metallic line. This segmentation enables simple probe card measurements without requiring complex through-silicon via structures, reducing overall device complexity while maintaining measurement capability.
Solution Approach 2:
The patent uses simple cavity structures instead of expensive TSV connections. The cavities are easier and cheaper to form than TSVs, and the measurement can be performed with simple probe cards rather than complex measurement equipment, reducing both manufacturing cost and device complexity.
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 non-destructive estimation of diffusion length, allowing for the detection of alignment errors and prevention of unwanted contacts between metallic lines, while being less expensive and simpler to implement than traditional methods like TSV connections.
Implementation Method 1
These undesired contacts arise in the event of an alignment error or if the metallic species of at least one of the two lines diffuse towards the other line to form an electrical contact
Implementation Method 2
The method may further include measuring the resistance between the two locations, the value of the resistance providing an estimate of the diffusion length
Implementation Method 3
The two metallic lines are advantageously arranged in the vicinity of the interface between the two integrated circuits and, for example, are arranged on the highest metallization level of each integrated circuit
Data Source
AI summary
A three-dimensional integrated structure may include two assembled integrated circuits respectively including two metallic lines, and at least two cavities passing through one of the integrated circuits and opening onto two locations respectively in electrical contact with the two metallic lines. The cavities may be sized to place a measuring apparatus at the bottom of the cavities, and in electrical contact with the two locations.