Memory Programming Voltage Calibration for Word-Line Threshold Variation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing memory technologies face challenges in reducing programming time and improving programming efficiency due to variations in initial threshold voltages across different word lines, leading to inconsistent programming times and reliability issues.
Innovation Solution
An operating method that applies a first start program voltage to target word lines, followed by incremental step voltage adjustments, and performs multiple verify operations to determine a precise second start program voltage based on verification results, ensuring accurate programming by adjusting for initial threshold voltage differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a fixed start program voltage is applied to all word lines, then the programming process is simple, but programming time varies due to initial threshold voltage differences
Solution Approach 1:
The patent applies different start program voltages to different word line groups based on their initial threshold voltage characteristics. The memory device determines initial threshold voltages for multiple word line groups and assigns different start program voltages accordingly, making each word line group receive a customized voltage that matches its specific characteristics, thereby reducing programming time variation.
Solution Approach 2:
The patent dynamically adjusts the start program voltage parameter based on measured initial threshold voltages. By changing the voltage parameter according to the actual state of each word line group, the system optimizes programming efficiency and reduces time variation without complicating the overall programming process.
2Manufacturing precision
If incremental step voltage adjustments are performed with multiple verifications, then programming accuracy is improved, but programming time increases
Solution Approach 1:
The patent performs preliminary determination of initial threshold voltages for all word line groups before the actual programming operation. This preliminary measurement allows the system to pre-calculate optimal start program voltages for each word line group, so that when programming occurs, the process is faster and more accurate without requiring extensive real-time adjustments and verifications.
Solution Approach 2:
The patent divides word lines into multiple groups and determines initial threshold voltages and start program voltages for each group separately. This segmentation allows parallel processing of voltage determination for different groups, reducing the overall time penalty while maintaining high programming accuracy through customized voltage application to each group.
3Productivity
If customized start program voltages are determined for each word line group, then programming efficiency is improved, but device complexity increases
Solution Approach 1:
The memory device performs self-characterization by automatically determining its own initial threshold voltages for different word line groups during manufacturing or initialization. This self-service approach eliminates the need for external complex measurement equipment and simplifies the overall system complexity while enabling customized voltage application for improved programming efficiency.
Solution Approach 2:
The control logic within the memory device is designed to perform multiple functions: determining initial threshold voltages, calculating optimal start program voltages, and controlling the programming operation. This multi-functionality consolidates what could be separate complex systems into a single integrated controller, improving efficiency without proportionally increasing overall device complexity.
Data Source
AI summary
An operating method for a memory, a memory, and a memory system are provided in the present application. The memory includes at least a plurality of word lines and a plurality of strings, and the plurality of word lines include a target word line, and each word line is coupled to a plurality of strings. Each string includes a plurality of memory cells. In accordance with the operating method provided by the present application, the first verification and the second verification are performed on a plurality of target memory cells with first and second verify voltages during performing a first programming operation on a plurality of target memory cells in target string coupled to the target word line, and the second start program voltage is determined based on at least the second verification result, ensuring the accuracy of the second start program voltage.