3D Memory Stack Contact Structure With Oxide Support Pillars
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Solution Overview
Problem
Increasing the integration density of two-dimensional non-volatile memory devices by stacking memory cells in a vertical direction over a substrate has been challenging, particularly in forming reliable structures with interlayer insulating layers and gate electrodes.
Innovation Solution
A semiconductor device with a stack structure comprising alternating interlayer insulating layers and gate conductive layers, supported by vertical support structures and contact plugs, is manufactured through a method involving etching and filling processes to form stable contact and channel plugs, and vertical structures using oxide layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If memory cells are stacked in a vertical direction to increase integration density, then the integration density is improved, but the manufacturing complexity and reliability of the structure deteriorate
Solution Approach 1:
The stack structure is divided into multiple alternating layers of interlayer insulating layers and gate conductive layers, with channel plugs segmented between them. This segmentation allows for systematic manufacturing of complex 3D structures by breaking down the overall fabrication into manageable sequential steps, thereby enabling high integration density while controlling manufacturing complexity
Solution Approach 2:
The patent transitions from two-dimensional planar memory cell arrangement to three-dimensional vertical stacking. Memory cells are arranged in the vertical direction with multiple gate conductive layers stacked alternately with interlayer insulating layers, achieving higher integration density by utilizing the vertical dimension rather than expanding horizontally
2Stability of the object's composition
If support structures are formed in contact regions, then the structural stability is improved, but the manufacturing process complexity increases
Solution Approach 1:
The support structures are formed by combining multiple functions into a single element: they provide mechanical support to the stack structure, define contact regions, and serve as isolation structures. This merging reduces the number of separate manufacturing steps needed compared to forming separate support, contact, and isolation structures, thereby improving structural stability while limiting manufacturing complexity
Solution Approach 2:
The support structures formed in contact regions serve multiple purposes simultaneously: they provide structural support for the vertically stacked memory cells, define the contact region boundaries, and act as isolation structures between adjacent memory cell strings. This multi-functionality reduces overall device complexity by eliminating the need for separate structures for each function
Data Source
AI summary
There are provided a semiconductor device and a manufacturing method thereof. The semiconductor device includes: a stack structure including a plurality of interlayer insulating layers and a plurality of gate conductive layers, which are stacked in an alternating manner; at least one support structure penetrating the stack structure in a substantially vertical manner, the at least one support structure being formed in a contact region; and a contact plug penetrating the stack structure in a substantially vertical manner, the contact plug being formed in the contact region, the contact plug being connected to a contact pad that is disposed on the bottom of the stack structure. The at least one support structure is formed of an oxide layer.