3D Memory Source Structure Segmentation for Stable Cell Stacking

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Solution Overview

Problem

The stability of the manufacturing process for 3D semiconductor memory devices deteriorates as the number of stacked memory cells increases, leading to challenges in maintaining process stability and reliability.

Innovation Solution

A semiconductor memory device design that includes a semiconductor substrate with source structures and a filling pattern, discharge contacts penetrating the substrate, and a channel layer penetrating interlayer dielectrics and conductive patterns, along with a trench and slit configuration to improve manufacturing stability and prevent source sacrificial layer removal during the manufacturing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the number of stacked memory cells is increased to improve integration degree, then the degree of integration is improved, but the stability of the manufacturing process deteriorates

Engineering Contradiction:

Improvenumber of stacked memory cellsVSAvoidstability of manufacturing process

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The source structures are divided into multiple separate source structures (first source structure, second source structure, third source structure) spaced apart from each other. This segmentation prevents the source sacrificial layer from being completely removed during manufacturing processes, thereby maintaining process stability while allowing increased stacking of memory cells

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A filling pattern is introduced as an intermediary element disposed between the separated source structures. This filling pattern maintains structural integrity and spacing between source structures during manufacturing, preventing harmful removal of the source sacrificial layer while enabling higher memory cell stacking

Inventive Principle:

Principle #24Intermediary (Mediator)

2Quantity of substance

If the number of stacked memory cells is increased to improve integration degree, then the degree of integration is improved, but the precision of source structure formation deteriorates

Engineering Contradiction:

Improvenumber of stacked memory cellsVSAvoidprecision of source structure formation

Core Design Contradiction:

Quantity of substanceVSManufacturing precision

Solution Approach 1:

By dividing the source structures into multiple separate structures with spacing between them, the precision of forming each individual source structure is improved. The separated structures are easier to form accurately using standard manufacturing processes compared to a single continuous source structure

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The filling pattern acts as a spacer and structural support between source structures, maintaining precise spacing and positioning. This intermediary element ensures that source structures remain properly positioned during subsequent manufacturing steps, improving overall formation precision

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If the source sacrificial layer is completely removed to simplify structure, then the structure is simplified, but the manufacturing process stability deteriorates due to oxidation and contamination

Engineering Contradiction:

Improvestructure simplicityVSAvoidmanufacturing process stability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The harmful portion of the source sacrificial layer is selectively removed while leaving beneficial portions intact. The source sacrificial layer is removed from regions where it would cause problems, but retained in regions where it protects against oxidation and contamination, thus taking out only the harmful elements

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The source sacrificial layer is selectively removed from specific regions while being retained in other regions. This local quality approach allows the structure to have different properties in different locations: removed where simplification is needed, retained where protection is needed, optimizing both simplicity and stability

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20230328983A1Semiconductor memory device and manufacturing method of a semiconductor memory device

Publication Date: 2023.10.12 SK HYNIX INC

AI summary

There are provided a semiconductor memory device and a manufacturing method of the semiconductor memory device. The semiconductor memory device includes a first source structure and a second source structure spaced apart from each other over a semiconductor substrate, a filling pattern between the first source structure and the second source structure, a memory cell array overlapping with the first source structure, and a discharge contact penetrating the second source structure and connected to the semiconductor substrate.