NAND Flash Page Buffer Capacitance Extension
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current NAND flash memory devices face challenges in efficiently performing read operations due to limitations in sensing and data retrieval mechanisms, which can lead to inaccuracies and reduced performance.
Innovation Solution
The implementation of a page buffer with a sense capacitor and additional capacitance elements, along with a biasing circuit, enhances the sensing operation by increasing total capacitance, allowing for longer sensing times and improved data state determination in memory cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the sensing operation uses a standard sense capacitor without additional capacitance elements, then the circuit complexity is low, but the sensing time is insufficient and measurement precision is reduced
Solution Approach 1:
The patent combines the sense capacitor with additional capacitance elements (such as parasitic capacitance from interconnect structures or deliberately added capacitors) to create a composite sensing capacitor. This merging increases the total capacitance available for sensing operations, thereby extending the sensing time window and improving the precision of memory cell state detection without requiring a completely separate sensing circuit.
Solution Approach 2:
The patent modifies the electrical parameters of the sensing circuit by increasing the total capacitance value through the addition of capacitance elements. This parameter change directly affects the sensing time constant (τ = RC), allowing for longer sensing durations that improve measurement precision while maintaining circuit feasibility.
2Duration of action of moving object
If the sensing operation is performed with limited capacitance, then the device operation is simple, but the sensing time is too short to accurately determine data states
Solution Approach 1:
By merging the sense capacitor with additional capacitance elements, the total capacitance is increased, which directly extends the sensing time duration. This extended time window allows the sensing circuit to accumulate sufficient charge information from the memory cell, thereby improving the reliability of data state determination.
Solution Approach 2:
The patent prepares the sensing capacitor (including additional capacitance elements) in advance during the read operation setup phase, ensuring that the capacitor is properly charged and ready before the actual sensing begins. This preliminary preparation ensures that the extended sensing time can be effectively utilized for accurate measurement.
3Measurement precision
If additional capacitance elements are added to extend sensing time, then the sensing precision is improved, but the device complexity increases
Solution Approach 1:
The patent merges additional capacitance elements with the existing sense capacitor in a way that leverages existing circuit structures. For example, parasitic capacitance from interconnect wires or adjacent transistor gates is utilized, or capacitors are added in parallel with minimal additional circuitry. This approach improves sensing precision while minimizing the increase in overall device complexity.
Solution Approach 2:
The additional capacitance elements are designed to serve multiple functions: they extend sensing time for improved precision, and can also function as part of the read disturb mitigation mechanism or be integrated with existing page buffer structures. This multi-functionality reduces the net increase in device complexity.
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 solution improves the accuracy and efficiency of read operations in NAND flash memory devices by extending sensing time and enhancing the ability to accurately latch the state of memory cells, thereby improving overall device performance.
Implementation Method 1
a page buffer with a sense capacitor and additional capacitance elements, along with a biasing circuit, enhances the sensing operation by increasing total capacitance
Data Source
AI summary
Memory devices might include a capacitor, a first capacitance element, a first transistor, and control logic. The first transistor might be connected between the capacitor and the first capacitance element. The control logic might be connected to a control gate of the first transistor. The control logic might be configured to activate the first transistor to precharge the capacitor and the first capacitance element during a read operation of the memory device. The first capacitance element might be a wire capacitance of a first signal line.