Support Contact Structures for Stable 3D Memory Stack Formation
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Solution Overview
Problem
Conventional methods of forming vertical memory arrays in non-volatile memory devices, such as NAND Flash memory devices, result in undesirable damage and delamination of features during and after formation, leading to bending and lift-off issues.
Innovation Solution
A method of forming microelectronic devices with support contact structures that includes simultaneously forming slots and contact openings in a preliminary stack structure, followed by filling these openings with different materials, which helps stabilize the structure and prevent damage during processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional methods are used to form vertical memory arrays, then memory density is increased through 3D architecture, but structural damage and delamination occur during processing
Solution Approach 1:
The method performs preliminary actions by forming support contact structures and filling slots with dielectric material before completing the vertical memory array formation. This preliminary structural reinforcement prevents subsequent damage and delamination during processing, while still achieving the desired high memory density through 3D architecture.
Solution Approach 2:
The invention applies beforehand cushioning by introducing support contact structures and dielectric filling material into slots prior to completing the memory array formation. These structures act as cushioning elements that prevent structural damage and delamination during subsequent processing steps, ensuring structural integrity while maintaining high memory density.
2Reliability
If support structures are added to prevent damage, then structural integrity is improved, but device complexity increases
Solution Approach 1:
The method merges the formation of support contact structures and dielectric slot filling into the existing memory array fabrication process sequence. By integrating these support structures into the standard processing flow rather than adding separate steps, the structural integrity is improved without proportionally increasing device complexity.
Solution Approach 2:
The support contact structures and dielectric filling material serve multiple functions: they provide structural support to prevent damage, act as placeholders for subsequent processing steps, and maintain structural integrity during fabrication. This multi-functionality reduces the need for additional dedicated support structures, thereby limiting the increase in device complexity.
Data Source
AI summary
Methods of forming a microelectronic device includes forming a preliminary stack structure including blocks separated by slots, each block including: tiers each including insulative material and sacrificial material; and live contact openings and support contact openings extending completely through the tiers. A first liner and a second liner are formed over surfaces of the preliminary stack structure. Portions of the second liner and the first liner within the support contact openings are removed without removing additional portions of the second liner and the first liner within the slots and the live contact openings. Fill material is formed within the slots, the live contact openings, and the support contact openings to form sacrificial slot structures, sacrificial contact structures, and support contact structures. The sacrificial contact structures are replaced with conductive contact structures. The sacrificial slot structures are removed, and the sacrificial material of the tiers is replaced with conductive material.