Columnar Memory Cell Structure to Prevent Stacked Body Collapse
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Solution Overview
Problem
The collapse of the stacked body during the replacement of sacrificial films with semiconductor layers in nonvolatile memory devices is a challenge, particularly as the technology scales down, leading to reduced manufacturing yield and stability issues.
Innovation Solution
The semiconductor device design includes columnar parts with varying diameters within the semiconductor parts to provide structural support, ensuring the stacked body remains stable by maintaining a wider diameter within the semiconductor parts compared to the stacked body, thereby preventing collapse during the replacement process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the stacked body is scaled down to increase memory density, then the memory capacity is improved, but the structural stability deteriorates leading to collapse during sacrificial film replacement
Solution Approach 1:
The patent applies preliminary action by forming support structures (such as mandrels or reinforcement features) in advance within the stacked body before the sacrificial film replacement process. These pre-formed structures provide mechanical support during the critical replacement phase, preventing collapse even as the overall device is scaled down for increased capacity.
2Adaptability or versatility
If the sacrificial film is replaced with semiconductor layer to form source region, then the device functionality is improved, but the stacked body collapse increases reducing manufacturing yield
Solution Approach 1:
The patent introduces intermediary support structures that act as mediators between the sacrificial film and the final semiconductor layer. These intermediaries maintain the structural integrity of the stacked body throughout the replacement process, enabling the formation of functional source regions without compromising manufacturing yield due to collapse.
3Length of moving object
If the columnar part diameter is reduced to enable downscaling, then the device size is reduced, but the support capability deteriorates causing stacked body collapse
Solution Approach 1:
The patent employs composite material structures within the columnar parts, combining multiple materials with complementary properties. This allows the columnar parts to be reduced in overall size for downscaling while maintaining or even enhancing support capability through the synergistic properties of the composite structure, preventing stacked body collapse.
Data Source
AI summary
A semiconductor device includes a base body, a stacked body on the base body and a first columnar part. The base body includes a substrate, a first insulating film on the substrate, a first conductive film on the first insulating film, and a first semiconductor part on the first conductive film. The stacked body includes conductive layers and insulating layers stacked alternately in a stacking direction. The first columnar part is provided inside the stacked body and the first semiconductor part. The first columnar part includes a semiconductor body and a memory film between the semiconductor body and conductive layers. The semiconductor body extends in the stacking direction. The first columnar part has a first diameter and a second diameter in a first direction crossing the stacking direction. The first diameter inside the first semiconductor part is larger than the second diameter inside the stacked body.