3D Word Line Structure With Protruding Extension for Charge Trapping
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Solution Overview
Problem
Current 3D semiconductor devices face limitations in charge trapping ability due to the narrow electric field between the word line structure and the channel layer, which affects data storage and erasure reliability.
Innovation Solution
The introduction of a word line structure with a body portion and an extension portion, where the extension portion has a greater vertical width than the body portion, protruding both upward and downward, enhances the electric field and improves charge trapping by increasing the vertical width difference, thereby increasing the amount of charges trapped in the charge trap layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional word line structure with uniform width is used, then the device structure is simple, but the electric field width is narrow and charge trapping ability is insufficient
Solution Approach 1:
The word line structure is segmented into two distinct portions: a body portion with a first width and an extension portion with a second width greater than the first width. This segmentation allows the extension portion to protrude into the channel layer and widen the electric field for improved charge trapping, while the body portion maintains the basic structural framework, thus resolving the contradiction between enhanced functionality and structural simplicity.
Solution Approach 2:
The extension portion is designed with a different width (second width) compared to the body portion (first width) to create a localized region of enhanced electric field. This local quality change allows the electric field to be widened specifically where needed for charge trapping without requiring the entire word line structure to be complex, thereby improving charge trapping ability while maintaining overall structural simplicity.
2Reliability
If the vertical width of the word line structure is increased to widen the electric field, then charge trapping ability improves, but the manufacturing precision requirements increase
Solution Approach 1:
The extension portion protrudes vertically into the channel layer, utilizing the vertical dimension to widen the electric field. By extending in the vertical direction rather than increasing horizontal dimensions, the design achieves improved charge trapping capability while avoiding the need for extremely precise horizontal width control, thus addressing the manufacturing precision challenge.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration widens the electric field between the word line structure and the channel layer, enhancing charge trapping capability and improving data storage and erasure reliability in 3D semiconductor devices.
Implementation Method 1
The 3D semiconductor device can store data by trapping charges according to an electric field between a word line structure and a channel layer
Data Source
AI summary
A three-dimensional semiconductor device is provided. The three-dimensional device may include substrate; a common electrode layer on the substrate; a word line stack disposed on the common electrode layer, the word line stack having interlayer insulating layers and word lines structures alternately stacked and; and a vertical channel pillar penetrating the word line stack, the vertical channel pillar being electrically connected to the common electrode layer. Each of the word line structures includes a body portion having a first vertical width and an extension portion having a second vertical width greater than the first vertical width. The extension portion abuts the vertical channel pillar.