Semiconductor Memory Pillar Depth and Insulation for Isolation
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Solution Overview
Problem
Existing semiconductor memory devices face challenges in maintaining structural integrity and electrical isolation of pillars within stacked bodies, leading to potential electrical connections and reliability issues.
Innovation Solution
The semiconductor memory device employs a stacked structure with conductive and insulating films alternately arranged around pillars, where the first pillar extends deeper into the substrate than the second pillar, providing additional support and electrical isolation through specific layer configurations and manufacturing processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If pillars are stacked closely together in a semiconductor memory device, then storage density is improved, but structural integrity and electrical isolation between pillars deteriorate
Solution Approach 1:
The device divides the stacked body into multiple independent pillars, each surrounded by its own insulating film. This segmentation allows pillars to be closely spaced for high density while maintaining electrical isolation through the insulating barriers between them.
Solution Approach 2:
An insulating film is introduced as an intermediary layer between adjacent conductive pillars. This intermediary prevents unwanted electrical connections while allowing the pillars to maintain close proximity for high storage density.
2Reliability
If pillars extend deeper into the substrate, then electrical isolation is improved, but manufacturing complexity increases
Solution Approach 1:
The insulating film is formed preliminarily around the pillars before final stacking and processing. This preliminary action ensures electrical isolation is established early, preventing contamination and short circuits during subsequent manufacturing steps.
Solution Approach 2:
The insulating film is nested around each pillar, creating a concentric structure where the pillar is embedded within the insulating material. This nested configuration provides robust electrical isolation while maintaining a relatively simple manufacturing process.
Data Source
AI summary
According to one embodiment, a semiconductor memory device includes a substrate, a first insulating film, a stacked body, and a first pillar. At least a portion of an upper layer portion of the substrate is conductive. The first insulating film is provided in a portion of the substrate. The stacked body includes conductive films and insulating films stacked alternately in a first direction. The conductive films and the insulating films are provided on the substrate and on the first insulating film. The first pillar pierces the stacked body in the first direction. The first pillar includes a first lower end portion and a first extension portion. The first lower end portion is disposed inside the first insulating film. The first extension portion is disposed inside the stacked body.