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Flash memory

technology Maturity 7-9 Next article →

Flash memory is a special way to store digital information. It is used in many things like smartphones and video games.

USB flash drive
USB flash drive

This memory is called "non-volatile." This means it keeps your data even when the power is turned off. It is much better for portable devices than old mechanical drives. Mechanical drives can break easily if they are bumped or dropped. Flash memory is very strong because it has no moving parts.

Flash cell structure
Flash cell structure

How does it work? Most flash memory uses tiny parts called cells. These cells are made of something called a floating-gate MOSFET.

Flash-Programming
Flash-Programming

To save data, electrons are moved into these cells. To erase the data, the electrons are moved out. This can happen through a process called tunneling. In some newer types, a layer called silicon nitride traps the electrons instead. This is called charge trap flash technology.

Flash erase
Flash erase

There are two main types of flash memory. The first is called NOR flash. It allows a computer to read small bits of data very quickly. This makes it great for running the code that starts a computer. The second type is called NAND flash. NAND flash is different because it reads data in large blocks. This makes it much better for storing huge amounts of files. Most USB drives and memory cards use NAND flash because it is cheaper.

Nand flash structure
Nand flash structure

People have been working on this for a long time. A scientist named Fujio Masuoka invented flash memory at Toshiba in 1980. A colleague named Shōji Ariizumi suggested the name "flash." He thought the erasing process looked like a camera flash.

NOR flash layout
NOR flash layout

Toshiba began selling NAND flash in 1987. Later, Intel introduced the first commercial NOR flash chip in 1988. Since then, the technology has changed many times to hold more data.

Today, flash memory can hold a massive amount of information. Scientists use a trick called die stacking to save more data. They stack many layers of memory cells on top of each other. This is called 3D NAND technology. One package can even hold up to 1 tebibyte of data.

NAND Flash Bit Cost from 2D to 3D
NAND Flash Bit Cost from 2D to 3D

However, flash memory does not last forever. Each block can only be erased and rewritten a certain number of times. Eventually, the parts wear out and the memory can no longer hold data.

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🖼️ Images & Media (11)
File:USB flash drive.JPG
USB flash drive.JPG
File:Flash cell structure.svg
Flash cell structure.svg
File:NOR flash layout.svg
NOR flash layout.svg
File:Flash-Programming.svg
Flash-Programming.svg
File:Flash erase.svg
Flash erase.svg
File:Nand flash structure.svg
Nand flash structure.svg
File:NAND_Flash_Bit_Cost_from_2D_to_3D.png
NAND_Flash_Bit_Cost_from_2D_to_3D.png
File:3D NAND minimum cost example.png
3D NAND minimum cost example.png
File:Micron_45_nm_NOR_Flash_Data_Retention.png
Micron_45_nm_NOR_Flash_Data_Retention.png
File:IPhone 3G teardown - Intel 3050M0Y0CE -3303.jpg
IPhone 3G teardown - Intel 3050M0Y0CE -3303.jpg
File:Intel 525 mSATA SSD.jpg
Intel 525 mSATA SSD.jpg
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