Non-Volatile Memory Programming via Dummy Cell Channel Boosting
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Solution Overview
Problem
Non-volatile memory devices experience program speed disparities and uniformity issues due to the coupling effect, particularly at outermost cells adjacent to select transistors, leading to program disturbance.
Innovation Solution
The method involves applying a high-level voltage to dummy cells' pass word lines before applying pass or program voltages to other cells, ensuring dummy cells are turned on earlier to facilitate proper channel boosting and prevent program disturbance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a dummy cell is added between the outermost cell and each select transistor to solve coupling effect, then cell uniformity is improved, but the dummy cell itself experiences slow program speed and generates disturbance problems
Solution Approach 1:
The patent applies a high level voltage to the pass word line of the dummy cell before applying pass voltage to unselected word lines and program voltage to the selected word line. This preliminary action turns on the dummy cell earlier, allowing it to complete its program operation before other cells, thereby preventing program disturbance while maintaining cell uniformity
2Reliability
If high level voltage is applied to pass word line before program operation, then bit line precharging is enhanced, but additional voltage application steps are required
Solution Approach 1:
The patent performs preliminary action by applying high level voltage to the pass word line before the main program operation begins. This ensures the dummy cell is turned on in advance, allowing proper bit line precharging and preventing program disturbance in program-inhibited cells
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 approach enhances the precharging of bit lines, preventing program disturbance by ensuring sufficient voltage rise in program-inhibited cells, thereby maintaining program inhibition and improving overall cell uniformity.
Implementation Method 1
ensuring dummy cells are turned on earlier to facilitate proper channel boosting and prevent program disturbance
Data Source
AI summary
A method of programming a non-volatile memory device includes applying a power supply voltage to a drain select line, applying a high level voltage to a drain-side pass word line or a source-side pass word line, and applying a pass voltage to unselected word lines and a program voltage to a selected word line. The high level voltage is applied to the drain-side pass word line or the source-side pass word line before applying the pass voltage to the unselected word lines and the program voltage to the selected word line.