Compact Memory Cell Combining SRAM Access and Resistive Retention

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current memory technologies face challenges such as volatility in SRAM, slowness and high voltage requirements in flash memory, and integration difficulties with CMOS, along with the need for compact and fast non-volatile data storage solutions.

Innovation Solution

A memory cell design incorporating a resistance switching element that stores non-volatile data, allowing for quick access and low power consumption by leveraging leakage currents and resistive states, combined with a compact SRAM-like structure for volatile data storage, enabling fast read and write operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If SRAM cell structure is used, then access speed is improved, but data volatility worsens

Engineering Contradiction:
Improveaccess speedVSAvoiddata retention
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent combines SRAM and flash memory into a single hybrid memory cell, merging the fast access capability of SRAM with the non-volatile data retention of flash memory. The cell uses six transistors and two capacitors to implement both volatile storage (in capacitors) and non-volatile storage (in floating gate structures), allowing the same physical structure to provide both rapid access and data persistence without requiring separate memory components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The hybrid memory cell performs multiple functions within a single device structure: it can operate as volatile memory for fast temporary storage, as non-volatile memory for persistent storage, and can maintain data across power cycles. The dual-capacitor design with floating gates enables the cell to function as both SRAM (when powered) and flash memory (when unpowered), eliminating the need for separate volatile and non-volatile memory components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If flash memory is used, then non-volatile data storage is improved, but access speed worsens

Engineering Contradiction:
Improvenon-volatile data storageVSAvoidaccess speed
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The patent combines SRAM and flash memory into a single hybrid memory cell, merging the fast access capability of SRAM with the non-volatile data retention of flash memory. The cell uses six transistors and two capacitors to implement both volatile storage (in capacitors) and non-volatile storage (in floating gate structures), allowing the same physical structure to provide both rapid access and data persistence without requiring separate memory components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The hybrid memory cell performs multiple functions within a single device structure: it can operate as volatile memory for fast temporary storage, as non-volatile memory for persistent storage, and can maintain data across power cycles. The dual-capacitor design with floating gates enables the cell to function as both SRAM (when powered) and flash memory (when unpowered), eliminating the need for separate volatile and non-volatile memory components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If flash memory is used, then non-volatile data storage is improved, but power consumption worsens

Engineering Contradiction:
Improvenon-volatile data storageVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent combines SRAM and flash memory into a single hybrid memory cell, merging the fast access capability of SRAM with the non-volatile data retention of flash memory. The cell uses six transistors and two capacitors to implement both volatile storage (in capacitors) and non-volatile storage (in floating gate structures), allowing the same physical structure to provide both rapid access and data persistence without requiring separate memory components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The hybrid memory cell performs multiple functions within a single device structure: it can operate as volatile memory for fast temporary storage, as non-volatile memory for persistent storage, and can maintain data across power cycles. The dual-capacitor design with floating gates enables the cell to function as both SRAM (when powered) and flash memory (when unpowered), eliminating the need for separate volatile and non-volatile memory components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Quantity of substance

If conventional memory cells are used, then data storage is achieved, but device area increases

Engineering Contradiction:
Improvedata storage capacityVSAvoidmemory cell area
Core Design Contradiction:
Quantity of substanceVSArea of stationary object

Solution Approach 1:

The patent combines SRAM and flash memory into a single hybrid memory cell, merging the fast access capability of SRAM with the non-volatile data retention of flash memory. The cell uses six transistors and two capacitors to implement both volatile storage (in capacitors) and non-volatile storage (in floating gate structures), allowing the same physical structure to provide both rapid access and data persistence without requiring separate memory components.

Inventive Principle:
Principle #5Merging (Combining)

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 solution provides a compact memory cell capable of storing both volatile and non-volatile data with fast access speeds and low power consumption, overcoming the limitations of existing technologies by maintaining data integrity even without a supply voltage and integrating well with CMOS.

Implementation Method 1

A memory cell design incorporating a resistance switching element that stores non-volatile data, allowing for quick access and low power consumption by leveraging leakage currents and resistive states

Methodology Applied
Scientific EffectResistive switching: Electrical Resistance

Data Source

PatentEP2666165B1Compact volatile/non-volatile memory cell
Publication Date: 2019.08.28 CENT NAT DE LA RECH SCI (C N R S)
  • EP2666165B1 patent drawingFigure 1~2
  • EP2666165B1 patent drawingFigure 3~5
  • EP2666165B1 patent drawingFigure 6~7D

AI summary

The invention concerns a memory device comprising at least one memory cell comprising: a first transistor (102) coupled between a first storage node (106) and a first supply voltage (GND, VDD); a second transistor (104) coupled between a second storage node (108) and said first supply voltage, control terminals of the first and second transistors being coupled to the second and first storage nodes respectively; and a single resistance switching element (202), wherein said single resistive switching element is coupled in series with said first transistor and is programmable to have one of first and second resistances (Rmin, Rmax), wherein said first storage node is coupled to a first access line (BL) via a third transistor (110, 810) connected to said first storage node, and said second storage node is coupled to a second access line (BLB) via a fourth transistor (112, 812) connected to said second storage node.