Capacitive Deep Trench Isolation Bonding Pad Architecture
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Solution Overview
Problem
The existing methods for forming bonding pads on semiconductor substrates using capacitive deep trench isolation (CDTI) structures face challenges in efficiently connecting electrical contacts from the front side metallization to the back side surface, which affects the electrical connectivity and reliability of integrated circuits.
Innovation Solution
The method involves forming capacitive deep trench isolation structures that extend through the semiconductor substrate, with a conductive region insulated by an insulating liner, and a bonding pad structure is directly physically and electrically connected to the conductive regions at the back side surface by depositing metal materials within apertures exposed at the ends of these structures, ensuring reliable electrical connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If bonding pads are formed using conventional methods on the front side, then electrical connections can be established, but the back side surface remains unavailable for bonding pad formation and electrical connection
Solution Approach 1:
The invention transitions from conventional front-side bonding pad formation to back-side bonding pad formation by extending CDTI structures completely through the substrate thickness. This dimensional change enables utilization of the back side surface area for electrical connections, effectively doubling the available bonding surface while maintaining connection reliability through the through-substrate conductive pathways.
2Area of stationary object
If CDTI structures are used to extend electrical connections through the substrate, then back side bonding pad formation becomes possible, but the structural complexity of the substrate increases
Solution Approach 1:
The CDTI structures serve multiple functions: they provide electrical connections through the substrate, enable back-side bonding pad formation, and maintain substrate isolation. By making the CDTI structures completely through the substrate, a single structural element accomplishes multiple objectives, reducing overall device complexity despite the through-substrate extension requirement.
Solution Approach 2:
The substrate is segmented into distinct regions with CDTI structures providing isolated conductive pathways. Each CDTI structure acts as an independent segment for electrical connection, allowing modular design and simplifying the overall substrate architecture while enabling back-side bonding pad formation.
3Reliability
If conventional bonding pad formation methods are used, then the process is simple, but electrical connections from front side metallization to back side surface cannot be established
Solution Approach 1:
The CDTI structures are formed preliminarily during the substrate fabrication process, extending through the substrate before final bonding pad formation. This preliminary action establishes the electrical connection pathways in advance, simplifying the subsequent bonding pad formation process and ensuring reliable electrical connections without requiring complex post-fabrication modifications.
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 approach enables robust and reliable electrical connections between the front side metallization and the back side surface, enhancing the connectivity and performance of integrated circuits by using capacitive deep trench isolation structures to facilitate bonding pad formation.
Implementation Method 1
capacitive deep trench isolation (CDTI) structures
Implementation Method 2
each capacitive deep trench isolation structure comprising a conductive region
Data Source
AI summary
A semiconductor substrate has a back side surface and a front side surface. Metallization levels are provide at the front side surface. Capacitive deep trench isolation structures extend completely through the semiconductor substrate from the front side surface to the back side surface. Each capacitive deep trench isolation structure includes a conductive region insulated from the semiconductor substrate by an insulating liner. The conductive regions at first ends of the plurality of capacitive deep trench isolation structures are electrically connected to a first metallization level by electrical contacts. A bonding pad structure is located at the back side surface of the semiconductor substrate in direct physical and electrical connection to the conductive regions at second ends of the capacitive deep trench isolation structures.