3D Memory Backside Via Structure With Etch Stop Metal Plates
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Solution Overview
Problem
Existing three-dimensional memory devices face challenges in providing effective electrical connections for backside via structures, which are crucial for supporting write, read, and erase operations in vertical NAND strings.
Innovation Solution
The introduction of etch stop metal plates that serve as electrical connections for backside via structures, integrated with a semiconductor structure comprising alternating stacks of insulating and conductive layers, memory openings, and contact via structures, along with a method of forming these structures through specific fabrication steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional connection methods are used for backside via structures, then the device complexity is reduced, but the electrical connectivity and operational efficiency deteriorate
Solution Approach 1:
The connection structure is divided into multiple functional segments: etch stop metal plates for electrical connection, dielectric material portions for isolation, and contact via structures for vertical connectivity. This segmentation allows each component to perform its specific function optimally, improving electrical connectivity while managing complexity through functional decomposition.
Solution Approach 2:
The patent introduces backside via structures that extend connections to the backside of the device, utilizing the third dimension (vertical depth) to establish electrical pathways. This dimensional approach enables improved electrical connectivity by creating direct pathways through the device thickness, bypassing traditional lateral connection limitations.
2Reliability
If etch stop metal plates are introduced for backside via structures, then the electrical connectivity is improved, but the manufacturing complexity increases
Solution Approach 1:
Etch stop metal plates are formed during the manufacturing process before subsequent etching operations. This preliminary action ensures that the metal plates are already in place to serve as etch stops and electrical connections, preventing manufacturing defects and ensuring reliable electrical connections without requiring additional complex post-processing steps.
Solution Approach 2:
The patent employs composite structures combining etch stop metal plates with dielectric material portions and contact via structures. This composite approach integrates multiple materials (metals, dielectrics, semiconductors) into a unified structure that simultaneously provides mechanical support, electrical connectivity, and etch stopping functionality, managing manufacturing complexity through material integration.
Data Source
AI summary
A semiconductor structure includes an alternating stack of insulating layers and electrically conductive layers that is located on a front side of at least one semiconductor material layer; memory openings vertically extending through the alternating stack; memory opening fill structures; a dielectric material portion contacting sidewalls of the insulating layers of the alternating stack. In one embodiment, a connection via structure can vertically extend through the dielectric material portion, and a metal plate can contact the connection via structure. Alternately or additionally, an integrated via and pad structure may be provided, which includes a conductive via portion vertically extending through the dielectric material portion and a conductive pad portion located on an end of the conductive via portion.