Non-volatile Memory Program Disturb Delayed Ramp Down
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Program disturb occurs in semiconductor memory systems during programming processes, leading to unintended programming of memory locations and data errors due to electrons being accelerated and redirected across word lines, which existing technologies fail to adequately prevent.
Innovation Solution
Implementing countermeasures such as pre-charging channels, applying voltage spikes, and delaying voltage ramp-downs to open and maintain communication between the source and drain sides of channels, thereby preventing electron acceleration and redirection, including the use of a control circuit to manage these processes for selected and unselected memory cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If voltage is applied to selected word line for programming, then programming operation is achieved, but program disturb occurs in adjacent unselected word lines
Solution Approach 1:
The patent applies preliminary actions by pre-charging the channel before programming and performing verify operations before ramping down voltages. These preliminary actions prepare the memory system to prevent program disturb by ensuring proper voltage conditions are established beforehand, allowing the programming operation to proceed without affecting adjacent unselected word lines
2Measurement precision
If verify operation is performed immediately after programming, then programming verification is achieved, but electron acceleration causes program disturb
Solution Approach 1:
The patent performs the verify operation as a preliminary action before ramping down the voltages on selected and unselected word lines. This timing ensures that the channel remains properly charged and electrons are prevented from accelerating into unselected word lines during the verify operation, thus avoiding program disturb while maintaining accurate programming verification
3Speed
If voltage ramp down is performed quickly after verify, then operation speed is improved, but channel communication between source and drain sides is interrupted
Solution Approach 1:
The patent performs the verify operation before ramping down voltages, establishing a preliminary sequence that maintains channel communication. By delaying the voltage ramp down until after verify is complete, the system maintains stable electrical communication between source and drain sides throughout the critical verification period, preventing program disturb while ultimately achieving fast operation through efficient voltage management
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
Effectively prevents program disturb by ensuring electrical communication between channel sides, reducing data errors and maintaining accurate programming across memory cells, with the ability to dynamically choose and implement countermeasures based on temperature conditions.
Implementation Method 1
Program disturb occurs in semiconductor memory systems during programming processes, leading to unintended programming of memory locations and data errors due to electrons being accelerated and redirected across word lines
Data Source
AI summary
Program disturb is a condition that includes the unintended programming of a memory cell while performing a programming process for other memory cells. Such unintended programming can cause an error in the data being stored. In some cases, program disturb can result from electrons trapped in the channel being accelerated from one side of a selected word line to another side of the selected word line and redirected into the selected word line. To prevent such program disturb, it is proposed to open the channel from one side of a selected word line to the other side of the selected word line after a sensing operation for program verify and prior to a subsequent programming voltage being applied.