3D Memory Drain Select Line Precharge for Accurate Programming
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Solution Overview
Problem
Existing 3D semiconductor memory devices face challenges in individually applying voltage to drain select lines, leading to potential cell deterioration due to varying electrical resistances among these lines.
Innovation Solution
A memory device with a program operation control unit that applies precharge voltages to drain select lines based on their resistance, using different magnitudes and durations to ensure synchronized voltage application across lines with varying resistances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If voltage is applied to drain select lines without individual control, then device complexity is reduced, but manufacturing precision deteriorates due to varying electrical resistances causing cell deterioration
Solution Approach 1:
The patent segments the voltage control function by providing separate control paths for different drain select lines. The memory device includes multiple drain select lines (DSL1, DSL2, DSL3, DSL4) that can be individually controlled with different precharge voltages and durations based on their specific resistance characteristics, allowing precise control for each line while maintaining overall system functionality.
Solution Approach 2:
The patent applies local quality by tailoring the precharge voltage characteristics to each specific drain select line's resistance. Lines with higher resistance receive different precharge parameters than lines with lower resistance, ensuring that each line achieves the required voltage level at the appropriate time for accurate program operations, rather than applying a uniform voltage scheme to all lines.
2Speed
If precharge voltage is applied to all drain select lines simultaneously, then operation speed is improved, but reliability deteriorates due to cell deterioration from resistance variations
Solution Approach 1:
The patent implements preliminary action by applying precharge voltages to drain select lines before the main program voltage is applied to word lines. This precharging ensures that all drain select lines reach their required voltage levels in advance, accounting for their different resistance characteristics, so that when the program operation begins, all lines are properly prepared and synchronized, preventing cell deterioration.
Solution Approach 2:
The patent employs dynamics by making the precharge voltage parameters adaptive rather than fixed. Different drain select lines receive different precharge voltages and durations based on their individual resistance values. This dynamic adjustment ensures that despite variations in line characteristics, all lines achieve proper voltage levels simultaneously, maintaining both speed and reliability.
3Manufacturing precision
If different precharge voltages are applied to drain select lines, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The patent applies self-service by enabling the memory device to automatically determine and apply appropriate precharge voltages to different drain select lines based on their resistance characteristics. The control circuitry autonomously manages the different voltage applications without requiring external intervention or complex external control, making the system self-sufficient in compensating for resistance variations.
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 accuracy of program operations by preventing cell deterioration and improving overall memory device performance.
Implementation Method 1
the precharge voltage being applied to the drain select line during a time period having a duration, which is determined from the electrical resistance of the drain select line
Data Source
AI summary
A memory device applies voltage to drain select lines, which are determined individually. A program operation control unit applies a precharge voltage to a drain select line coupled to a cell string selected from the first cell string and the second cell string before a program voltage is applied to the word line, during a time determined depending on a resistance value of the drain select line coupled to the selected cell string.