Capacitive Coupling Sense Amplifier for 3D Memory Cell Arrays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor memory technologies face challenges in efficiently reading and writing multi-level data due to limitations in signal amplification and capacitance, particularly in small memory cell capacitance, which affects data retention and reliability.
Innovation Solution
The implementation of a capacitive coupling type sense amplifier circuit with a specific capacitance ratio between interconnect capacitances, including a source line capacitance, to enhance signal amplification and data rewriting, utilizing a transfer gate to adjust the source line capacitance and improve data retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multi-level technology is implemented to improve memory density, then memory capacity increases, but signal amplification and data retention become more difficult
Solution Approach 1:
The patent implements a three-dimensional memory structure where memory cells are stacked vertically across multiple layers. Word lines extend in the row direction within each layer, bit lines extend in the column direction, and source lines are positioned below each layer. This 3D arrangement increases memory capacity by utilizing vertical stacking while maintaining reliable signal amplification through the capacitive coupling sense amplifier design that compensates for small cell capacitance.
2Area of stationary object
If memory cell capacitance is reduced to increase density, then memory cell size decreases, but signal amplification capability deteriorates
Solution Approach 1:
The patent introduces a capacitive coupling sense amplifier that uses interconnect capacitance as an intermediary element. The sense amplifier leverages the capacitance of bit lines, word lines, and source lines to amplify signals from small memory cells. By utilizing the inherent capacitance of interconnect structures rather than relying solely on large cell capacitance, the system achieves effective signal amplification despite reduced memory cell size and capacitance.
Solution Approach 2:
The sense amplifier circuit performs multiple functions: it amplifies read signals from small memory cells, enables data rewriting operations, and maintains signal integrity across the three-dimensional memory structure. The capacitive coupling mechanism serves both as a signal amplification tool and as a means to maintain data retention, providing multi-functional support for operations on high-density memory cells with small capacitance.
3Quantity of substance
If three-dimensional structure is implemented to increase memory density, then memory capacity increases, but manufacturing complexity increases
Solution Approach 1:
The patent divides the three-dimensional memory structure into discrete layers, each containing memory cells, word lines, bit lines, and source lines. This segmentation allows for systematic manufacturing where each layer can be processed and assembled in a standardized sequence. The modular layer structure simplifies the fabrication of complex 3D memory by breaking it down into manageable repeating units that can be manufactured using standard semiconductor processing techniques.
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 configuration allows for effective reading and rewriting of multi-level data, even with small memory cell capacitance, enhancing memory reliability and characteristics without complex layout designs.
Implementation Method 1
a capacitive coupling type sense amplifier circuit which reads the read signal
Implementation Method 2
utilizing a transfer gate to adjust the source line capacitance
Data Source
AI summary
According to one embodiment, a semiconductor memory includes a first bit line; a second bit line; a source line; a first memory cell electrically connected between the first bit line and the source line and including a first transistor and a first capacitor; a second memory cell electrically connected between the second bit line and the source line and including a second transistor and a second capacitor; a third transistor electrically connected to the source line; and a sense amplifier circuit including a first node electrically connected to the first bit line and a second node electrically connected to the second bit line.