8T SRAM Cell Layout for Read-Write Performance Without Area Growth

Solution Overview

Problem

Existing SRAM cells with six transistors face challenges in improving read and write performance while maintaining a compact size, as they struggle to optimize electrical characteristics without increasing the area.

Innovation Solution

Implementing an SRAM cell with eight transistors, including specific configurations of transistors and shared source regions, to enhance read and write performance without increasing the cell's footprint.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an SRAM cell is implemented with six transistors to maintain compact size, then the area is minimized, but the read and write performance cannot be optimized

Engineering Contradiction:

Improveread and write performanceVSAvoidtransistor configuration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The SRAM cell is segmented into two six-transistor blocks (first and second blocks), each containing a pair of inverters and two pass gate transistors. This segmentation allows the cell to achieve improved read and write performance through the additional transistors while maintaining a compact layout by reusing shared components between blocks.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Adjacent memory cells share common components, specifically the source regions of pass gate transistors are shared between neighboring cells. The first pass gate transistor of one cell shares its source region with the second pass gate transistor of the adjacent cell, reducing the total area and simplifying the overall device structure while maintaining the enhanced six-transistor configuration benefits.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If additional transistors are added to improve electrical characteristics, then read and write performance is enhanced, but the cell area increases

Engineering Contradiction:

Improveelectrical characteristicsVSAvoidmemory cell area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

Adjacent memory cells share common components, specifically the source regions of pass gate transistors are shared between neighboring cells. The first pass gate transistor of one cell shares its source region with the second pass gate transistor of the adjacent cell, reducing the total area and simplifying the overall device structure while maintaining the enhanced six-transistor configuration benefits.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The shared source regions serve multiple functions by being common to adjacent memory cells. A single source region acts as the source for one transistor in one cell and the source for another transistor in the neighboring cell, allowing the structure to perform multiple functions simultaneously and reducing the overall area required for the memory array.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS20260047058A1Semiconductor device

Publication Date: 2026.02.12 SAMSUNG ELECTRONICS CO LTD

AI summary

The present disclosure provides a semiconductor device including an SRAM cell which is implemented with eight transistors capable of improving read and write performance without increasing the area as compared to an SRAM cell which is implemented with six transistors. Each memory cell includes a first inverter, a second inverter, a first pass gate transistor, and a second pass gate transistor. In addition, each memory cell includes a first additional transistor that is connected between the first pass gate transistor and the second inverter, and a second additional transistor that is connected between the second pass gate transistor and the first inverter.