Memory Device Adaptive Programming Voltage Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As the number of vertically stacked memory cells in memory devices increases, interference between cells becomes a significant issue, leading to characteristic differences that can result in overlapping threshold voltage distributions and reduced data accuracy if the same program voltage is applied without consideration for these differences.
Innovation Solution
A memory device that includes a controller to perform sequential first and second programming operations, adjusting the program voltage based on information about each memory cell's location and characteristics to ensure accurate data storage and reading, with different voltages applied to different memory cells to maintain distinct threshold voltage distributions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the number of vertically stacked memory cells is increased to achieve higher capacity, then the storage capacity increases, but interference between cells increases causing threshold voltage overlap and reduced data accuracy
Solution Approach 1:
The patent applies local quality by determining and applying different program voltages to different memory cells based on their specific locations and characteristics. The controller identifies memory cells experiencing interference and provides tailored program voltages to those specific cells, making the programming process adaptive to local conditions rather than uniform across all cells.
Solution Approach 2:
The patent changes the program voltage parameter dynamically based on memory cell characteristics and location. By adjusting the program voltage level according to interference conditions and cell-specific properties, the system maintains distinct threshold voltage distributions even as the number of stacked cells increases, thereby preserving data accuracy while scaling capacity.
2Ease of operation
If the same program voltage is applied to all memory cells, then the programming operation is simplified, but threshold voltage distributions overlap due to interference between vertically stacked cells
Solution Approach 1:
The patent introduces dynamics into the programming operation by making the program voltage adaptive rather than static. The controller dynamically determines appropriate program voltages based on real-time assessment of memory cell locations, interference conditions, and cell characteristics, allowing the system to maintain precision while managing complexity through intelligent control.
Solution Approach 2:
The patent implements feedback by having the controller determine program voltages based on information about memory cell characteristics and locations. This feedback mechanism allows the system to adjust programming parameters according to actual cell conditions, preventing threshold voltage overlap while maintaining operational efficiency through informed decision-making.
3Reliability
If different program voltages are applied to different memory cells to prevent interference, then data accuracy is maintained, but the programming complexity increases
Solution Approach 1:
The patent applies preliminary action by having the controller determine appropriate program voltages before executing the programming operation. By assessing memory cell characteristics and locations in advance and pre-determining the necessary voltage levels, the system prepares the optimal programming strategy upfront, reducing complexity during the actual programming execution while maintaining data accuracy.
Data Source
AI summary
A memory device includes a memory cell array including a plurality of word lines, at least one select line provided above the plurality of word lines, and a channel region passing through the plurality of word lines and the at least one select line, the plurality of word lines and the channel region providing a plurality of memory cells, and a controller. The controller is to store data in a program memory cell among the plurality of memory cells by sequentially performing a first programming operation and a second programming operation, and to determine a program voltage input to a program word line connected to the program memory cell, in the first programming operation, based on information regarding the program memory cell.