Split-Gate Flash Memory Voltage Control for Leakage Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing flash memory units with a split-gate structure face inefficiencies and inaccuracies in reading and programming operations due to electric leakage caused by potential differences between shared bit lines, affecting the efficiency and accuracy of data storage and retrieval.
Innovation Solution
The method involves configuring specific voltage ranges for the bit lines, word line, and control gate lines to select a storage bit in a split-gate flash memory unit, suspending the second bit line to equalize potentials, and performing reading or programming operations, thereby preventing leakage currents and improving operational efficiency and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple split-gate memory units share a bit line, then area is saved and circuit design is simplified, but electric leakage occurs due to potential differences between shared bit lines
Solution Approach 1:
The patent applies equipotentiality by suspending the second bit line (BL2) during operations on the first bit line (BL1), ensuring both bit lines connected to the same drain are at the same potential. This prevents leakage currents caused by potential differences while maintaining the shared bit line structure for area efficiency.
2Device complexity
If multiple split-gate memory units share a control gate line, then circuit complexity is reduced, but leakage current increases due to potential differences during operations
Solution Approach 1:
The patent applies equipotentiality to control gate lines by suspending the second control gate line (CG1) during operations on the first control gate line (CG0). This ensures both control gate lines are at the same potential, preventing leakage currents while maintaining the shared control gate line structure for reduced circuit complexity.
3Reliability
If the second bit line is suspended during operations, then leakage current is prevented, but additional control steps are required
Solution Approach 1:
The patent applies preliminary action by suspending the second bit line and second control gate line before performing read or program operations on the first bit line. This preliminary equipotentialization prevents leakage currents during subsequent operations, improving reliability despite adding initial control steps.
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 efficiency and accuracy of reading and programming operations by eliminating electric leakage, ensuring precise data storage and retrieval in flash memory units with split-gate structures.
Implementation Method 1
configuring voltages to the first bit line, the third bit line, the word line, the first control gate line and the second control gate line to select a first storage bit in the first split-gate flash memory unit and make the first storage bit in a to-be-read state or a to-be-programmed state
Implementation Method 2
programming is performed by hot electron injection at a source, which enables higher programming efficiency
Implementation Method 3
When an erasing operation is to be performed to the flash memory unit with the split-gate structure, a positive voltage is applied to the source, and electrons injected into the floating gates are attracted to the source using a tunnel effect between the floating gates and the source
Data Source
AI summary
Method of operating flash memory unit is provided. Flash memory unit includes first and second split-gate flash memory units, source and drain of first split-gate flash memory unit are connected with first and third bit lines respectively, source and drain of second split-gate flash memory unit is connected with second and third bit line respectively, first control gates of two split-gate flash memory units are connected with first control gate line, second control gates of two split-gate flash memory units are connected with second control gate line, word line gates of two split-gate flash memory units are connected with word line, method includes configuring voltages to first and third bit lines, word line, first and second control gate lines to select first storage bit in first split-gate flash memory unit and make first storage bit in to-be-read or to-be-programmed state; suspending second bit line; reading or programming first storage bit.