Vertical RAM Selectors Block Parasitic Currents
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Solution Overview
Problem
Conventional RAM devices with cross-point cell configurations experience parasitic currents through non-selected memory cells, leading to incorrect readings and unwanted writing, which affects the accuracy and reliability of memory operations.
Innovation Solution
The development of vertical RAM devices with selectors, featuring a vertical structure and selector elements like diodes, which help eliminate sneak paths by ensuring precise control over memory operations and increasing memory density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a cross-point cell configuration is used, then memory density is increased, but parasitic currents flow through non-selected memory cells causing incorrect readings and unwanted writing
Solution Approach 1:
A selector element is introduced as an intermediary component between the memory element and the bit line. This selector element acts as a gatekeeper that controls current flow, allowing current to pass only when the selected memory cell is activated by the appropriate word line and bit line combination, thereby blocking parasitic currents from flowing through non-selected cells while maintaining high memory density through the vertical cross-point architecture
2Object-generated harmful factors
If vertical structure with selectors is used, then parasitic currents are reduced, but device complexity increases
Solution Approach 1:
The memory structure transitions from a planar two-dimensional cross-point configuration to a vertical three-dimensional architecture. Memory elements are stacked vertically along the bit line, with word lines extending perpendicular to the bit line at different vertical levels. This vertical stacking allows multiple memory cells to share common bit lines and control circuitry, reducing the overall footprint and potentially offsetting the added complexity of selector elements through improved spatial utilization
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
The vertical RAM design with selectors effectively reduces parasitic currents, enhancing memory accuracy and density while maintaining low energy consumption, thereby improving the performance and reliability of memory devices.
Implementation Method 1
The selector element includes respective first and second selector diodes for the first and second memory elements of each of the one or more cell stacks
Data Source
AI summary
Devices and methods for manufacturing a device are presented. The device includes a substrate and a vertical structure disposed over the substrate. The vertical structure includes one or more memory cell stacks with a dielectric layer between every two adjacent cell stacks. Each of the one or more cell stacks includes first and second first type conductors on first and second sides of the cell stack, respectively; first and second electrodes, the first electrode adjacent the first first type conductor, the second electrode adjacent the second first type conductor; and first and second memory elements, the first memory element disposed between the first first type conductor and the first electrode, the second memory element disposed between the second first type conductor and the second electrode. The device also includes a selector element disposed over the substrate and vertically traversing through a middle portion of the vertical structure. The selector element includes respective first and second selector diodes for the first and second memory elements of each of the one or more cell stacks.