Non-Volatile Memory Side Wall Protective Layer Design
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Solution Overview
Problem
Conventional non-volatile memory devices experience non-uniformity of characteristics in memory elements, leading to instability and inefficiency in switching between low-resistance and high-resistance states, which affects data retention and endurance.
Innovation Solution
A non-volatile memory device configuration that includes a first electrode, a variable resistance layer, a second electrode, and a side wall protective layer with an insulating and oxygen barrier capability, where the electrically-conductive layer covers the second electrode and a portion of the side wall protective layer, and the side wall protective layer extends across the second electrode to ensure consistent coverage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the side wall protective layer is formed to cover the stacked-layer structure, then non-uniformity of memory element characteristics is reduced, but the device structure becomes more complex
Solution Approach 1:
The side wall protective layer is segmented into two distinct parts: a first side wall protective layer covering the lower portion of the stacked-layer structure, and a second side wall protective layer covering the upper portion. This segmentation allows each layer to be optimized independently for its specific function, improving overall uniformity while managing structural complexity through functional division.
Solution Approach 2:
The side wall protective layers act as intermediary barrier layers between the stacked-layer structure and the surrounding environment. These protective layers prevent direct contact between oxygen/moisture and the variable resistance layer, serving as a mediating protective interface that ensures uniform characteristics without requiring the entire device structure to be overly complex.
2Reliability
If the side wall protective layer extends to cover the entire stacked-layer structure, then data retention is improved, but manufacturing precision requirements increase
Solution Approach 1:
The protective coverage is divided into two segments: the first side wall protective layer covers the lower portion extending to the interlayer insulating layer, while the second side wall protective layer covers the upper portion extending to the upper electrode. This segmentation allows each layer to be formed with relaxed precision requirements compared to a single continuous layer, while collectively achieving comprehensive coverage for improved data retention.
Solution Approach 2:
The side wall protective layers are formed preliminarily during the manufacturing process before final assembly, ensuring that the protective barrier is already in place to prevent degradation. The first side wall protective layer is formed to cover the lower portion, and the second side wall protective layer is subsequently formed to cover the upper portion, ensuring comprehensive protection is established early in the manufacturing sequence.
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 reduces non-uniformity of characteristics in memory elements, stabilizes the switching process, and improves data retention and endurance by preventing direct contact between the electrically-conductive layer and the variable resistance layer, thus enhancing manufacturing efficiency and reliability.
Implementation Method 1
a side wall protective layer which covers a side wall of the first electrode, a side wall of the variable resistance layer and a side wall of the second electrode
Implementation Method 2
a variable resistance layer which is interposed between the first electrode and the second electrode and reversibly changes its resistance value in response to electric signals
Data Source
AI summary
A non-volatile memory device of the present invention comprises a first electrode; a variable resistance layer formed on and above the first electrode; a second electrode formed on and above the variable resistance layer; a side wall protective layer having an insulativity and covering a side wall of the first electrode, a side wall of the variable resistance layer and a side wall of the second electrode; and an electrically-conductive layer which is in contact with the second electrode; wherein the electrically-conductive layer covers an entire of the second electrode and at least a portion of the side wall protective layer located outward relative to the second electrode, when viewed from a thickness direction; and the side wall protective layer extends across the second electrode to a position above an upper end of the second electrode such that an upper end of the side wall protective layer is located above the upper end of the second electrode, when viewed from a side.