Non-Volatile Memory Partial Programming for Word Line Coupling
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Solution Overview
Problem
Non-volatile memory devices face data writing errors due to word line coupling effects, which cause distribution distortion in threshold voltages, leading to incomplete programming and reading errors.
Innovation Solution
A method of writing data in non-volatile memory devices that employs partial programming with selective additional programming operations, using varying voltages to minimize the maximum change in threshold voltage and reduce coupling effects between adjacent word lines, thereby enhancing data accuracy and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If full programming operation is performed on all memory cells, then data writing completeness is improved, but word line coupling effect increases causing threshold voltage distribution distortion
Solution Approach 1:
The patent divides the programming operation into multiple stages: first programming adjacent word lines before the target word line, then performing verification, and finally performing additional programming only if needed. This segmentation reduces the coupling effect by avoiding simultaneous programming of all word lines while ensuring complete data writing through staged operations.
Solution Approach 2:
The patent performs preliminary programming of adjacent word lines before programming the target word line. This preliminary action allows the system to prepare neighboring cells in advance, reducing the coupling effect when the target word line is programmed, while still ensuring complete data writing through subsequent verification and additional programming steps.
2Reliability
If programming operation is performed to write data, then data storage is achieved, but threshold voltage distribution becomes distorted due to floating gate coupling
Solution Approach 1:
The patent incorporates verification operations between programming stages to check whether the programming was successful. Based on the verification result, the system determines whether additional programming is needed. This feedback mechanism ensures data storage reliability while maintaining threshold voltage distribution accuracy by adjusting programming operations based on actual programming outcomes.
Solution Approach 2:
The patent changes the programming parameters dynamically based on verification results. If verification fails, the system performs additional programming with adjusted parameters (higher voltage, longer duration) to ensure complete data writing. This parameter adjustment maintains both reliability and precision by adapting to actual programming conditions.
3Manufacturing precision
If incremental step pulse programming with verification and reprogramming is performed, then data writing accuracy is improved, but writing time increases
Solution Approach 1:
The patent performs partial programming operations only when necessary. Instead of always performing full verification and reprogramming cycles, the system performs verification after initial programming and only performs additional programming if verification fails. This partial action approach maintains writing accuracy while reducing unnecessary time consumption from repeated verification and reprogramming cycles.
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 method effectively reduces word line coupling effects, improving data writing precision and reliability by allowing for precise control of threshold voltage changes, thus minimizing errors in data storage and retrieval.
Implementation Method 1
performing a first partial programming operation with respect to first memory cells coupled to the first word line; performing a second partial programming operation with respect to second memory cells coupled to a second word line
Implementation Method 2
performing a first verification operation by verifying the first partial programming operation
Data Source
AI summary
A method of writing data in a non-volatile memory device includes receiving a program command and a first row address corresponding to a first word line; performing a first partial programming operation with respect to first memory cells coupled to the first word line; performing a second partial programming operation with respect to second memory cells coupled to a second word line adjacent to the first word line; performing a first verification operation by verifying the first partial programming operation; and selectively performing a first additional programming operation with respect to the first memory cells depending on a result of the first verification operation.