Through Silicon Via Alignment Mark With Insulating Separator
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Solution Overview
Problem
In Chip on Chip (CoC) semiconductor devices, alignment marks formed of conductive materials can cause deterioration of semiconductor element characteristics due to metal atom diffusion into the substrate, leading to issues like shortened data hold time in memory chips.
Innovation Solution
A semiconductor device design that includes a conductor not electrically connected to the semiconductor element, surrounded by a ring-shaped insulating separator to prevent metal atom diffusion, and a method for fabricating this device by aligning subsequent chips using the non-electrically connected conductor as an alignment mark.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If alignment marks are formed of conductive materials (same as through plugs) to enable identification and alignment, then alignment precision is improved, but metal atom diffusion into the semiconductor substrate causes deterioration of device characteristics
Solution Approach 1:
The patent divides the conductor into two distinct types: through electrodes that are electrically connected to semiconductor elements, and conductors that are not electrically connected and serve solely as alignment marks. This segmentation allows alignment marks to be made of conductive materials for precise alignment while preventing metal atom diffusion from affecting device characteristics, as the non-connected conductors are isolated from the functional semiconductor elements.
Solution Approach 2:
The patent introduces an insulating layer as an intermediary between the conductor serving as an alignment mark and the semiconductor substrate. This insulating layer prevents direct contact and metal atom diffusion from the conductive alignment mark into the semiconductor substrate, while still allowing the alignment mark to be identified and used for precise alignment during the stacking process.
2Ease of manufacture
If the same metal material is used for both through plugs and alignment marks to simplify fabrication, then manufacturing complexity is reduced, but metal impurity causes charge leakage in capacitors
Solution Approach 1:
The patent segments the conductor into two functional categories: through electrodes electrically connected to semiconductor elements and conductors not electrically connected that serve as alignment marks. This segmentation allows both to be made of the same metal material using the same fabrication process, maintaining ease of manufacture, while the non-connected conductors used as alignment marks do not cause charge leakage in capacitors since they are isolated from the functional elements.
Solution Approach 2:
The insulating layer acts as an intermediary that prevents metal atoms from the conductive alignment mark from diffusing into the semiconductor substrate containing capacitors. This eliminates the charge leakage problem caused by metal impurities while maintaining the fabrication simplicity of using the same metal material for both through plugs and alignment marks.
3Manufacturing precision
If conductors are used as alignment marks to enable stacking alignment, then alignment capability is improved, but atom diffusion from the conductor deteriorates semiconductor element characteristics
Solution Approach 1:
The patent introduces an insulating layer as an intermediary between the conductor serving as an alignment mark and the semiconductor substrate. This insulating layer prevents atom diffusion from the conductor into the semiconductor substrate, thereby protecting semiconductor element characteristics while still allowing the conductor to be used for alignment capability during the stacking process.
Solution Approach 2:
The patent segments conductors into those electrically connected to semiconductor elements and those not electrically connected that serve as alignment marks. The non-connected conductors used as alignment marks have their atom diffusion prevented from affecting semiconductor elements, maintaining alignment capability while protecting device characteristics.
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 effectively suppresses the deterioration of semiconductor element characteristics by preventing metal atom diffusion, thereby maintaining the integrity of the semiconductor device performance.
Implementation Method 1
an insulating separator penetrating the semiconductor substrate from the first surface to the second surface and formed in a ring so as to surround the conductor
Data Source
AI summary
A semiconductor device with a semiconductor substrate having a first surface and an opposite-facing second surface, a through electrode electrically connected to the semiconductor element and penetrating the semiconductor substrate from the first surface to the second surface, and a conductor, not electrically connected to the semiconductor element, penetrating the semiconductor substrate from the first surface to the second surface, where the through electrode and the conductor have different shapes in plan view.