Memory Device Program Disturbance Reduction via Self-Boosting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor devices scale down, increasing integration in non-volatile memory leads to undesired coupling and interference between memory cells during programming, causing program disturbance and reducing data reliability.
Innovation Solution
A method for operating a memory device that involves applying specific voltage waveforms and recovery processes to reduce program disturbance by discharging excessive electrons from channel regions, establishing a self-boosting channel to minimize unintended programming of unselected cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the degree of integration of non-volatile memory is increased to enhance device performance and price competitiveness, then device performance and price competitiveness are improved, but undesired coupling and interference between memory cells during programming increases, causing program disturbance and reducing data reliability
Solution Approach 1:
The patent applies preliminary action by performing a recovery operation before the program operation. This recovery operation discharges excessive electrons from the channel region of unselected memory cells, preparing them in advance to prevent program disturbance during the subsequent programming process. The recovery voltage is applied to the bit line and word line to create a potential well that repels electrons from unselected cells before programming occurs.
2Ease of manufacture
If voltage is applied to the selected word line to program the selected cell, then the selected cell is programmed, but other unselected cells on the same word line and other word lines are inadvertently programmed
Solution Approach 1:
The patent applies local quality by creating different voltage conditions in different regions of the memory array during programming. A recovery voltage is applied locally to unselected word lines and bit lines to create a potential well in the channel regions of unselected cells, while the selected cell receives the full program voltage. This localized voltage differentiation ensures that only the selected cell is programmed while unselected cells are protected through the recovered state.
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 program disturbance, enhancing data reliability by maintaining a maximal self-boosting voltage in program inhibited strings, thereby preventing inadvertent programming of unselected memory cells.
Implementation Method 1
applying specific voltage waveforms and recovery processes to reduce program disturbance by discharging excessive electrons from channel regions
Implementation Method 2
establishing a self-boosting channel to minimize unintended programming of unselected cells
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method of operating a memory device, the memory device includes a top select cell, a top dummy cell and a string of memory cells. The top select cell has a first terminal coupled to a bit line and a control terminal coupled to a top select line. The top dummy cell has a control terminal coupled to a top dummy word line. The string of memory cells has control terminals coupled to respective word lines, the method comprising: applying a pre-pulse voltage to the top dummy word line, the top select line and the bit line while applying a low voltage to the word lines, and then sequentially applying the low voltage to the top dummy word line, the top select line and the bit line while applying the low voltage to the word lines.