NAND Program Verification Using Temperature-Compensated Pass Bits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Nonvolatile memory devices suffer from low data processing speed and are prone to memory cell deterioration due to temperature variations during program operations.
Innovation Solution
A semiconductor device with temperature-compensated pass permission bits that adjust the number of memory cells to be programmed based on temperature, comparing verification results to determine when to terminate the program operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If program operation is performed without temperature-based verification, then programming speed is maintained, but memory cell distribution deteriorates due to temperature variations
Solution Approach 1:
The patent performs verification operations at multiple stages during the program operation (initial verification after first program pulse, and final verification after second program pulse) to proactively detect and prevent memory cell distribution deterioration before it occurs, rather than waiting for the problem to manifest
Solution Approach 2:
The patent implements a feedback mechanism where verification results are continuously monitored and used to control subsequent program operations. When verification fails indicating distribution deterioration, the system adjusts by applying additional program pulses or modifying program parameters to correct the issue
2Reliability
If verification operation is performed frequently to prevent memory cell distribution deterioration, then reliability is improved, but operation time increases
Solution Approach 1:
The patent employs periodic verification operations at strategically determined intervals during the program process (after initial programming phase and before completion) rather than continuous verification, balancing reliability monitoring with time efficiency
Solution Approach 2:
The patent applies verification at critical partial stages of the program operation rather than exhaustive continuous verification, focusing on key transition points where distribution deterioration is most likely to occur
Data Source
AI summary
A semiconductor device may include memory strings coupled between bit lines, respectively, and a source line, each of memory strings including memory cells coupled to word lines, and page buffers coupled to the bit lines, respectively, each of page buffers configured to output a verification result by sensing data that have been stored in memory cells that are coupled to each selected word line, among the memory strings, after a start of a verification operation of a program operation. The number of memory cells that have been programmed successfully and a pass permission bit may be compared based on a temperature of the semiconductor device and the verification result after the start of the verification operation of the program operation, wherein the pass permission bit corresponds to the temperature.