Flash Memory as the Future for Data Storage
By Mason Kline and Davis Kuhn
THE FLOATING GATE TRANSISTOR
FROM FGT TO FLASH MEMORY
● Developed from the Field Effect Transistor (both pictured to the right)
○ To create a Floating Gate Transistor, the control gate on a Field
Effect Transistor is completely isolated from the rest of the
transistor with a dielectric material
○ Once the original control gate is insulated, a new control gate is
added on top of it
○ The old control gate is now the floating gate and can be used to
store electrons with no worries that the charge inside will be
affected by anything
● Storing electrons in the Floating Gate Transistor translates to data
○ The amount of electrons stored within the floating gate varies but
generally is between one and four
○ These electrons are read as binary code
■ i.e. 1s and 0s
● Floating Gate Transistors are linked together in certain patterns to
create flash memory
● Two types of flash memory are predominant
○ NOR
■ Has Floating Gate Transistors in parallel organized into “blocks”
of memory
● These must be erased together as one entity
■ Fires energized electrons into the control gate, but cannot get
it back out
○ NAND
■ Has Floating Gate Transistors in series connected by bit lines
● This allows each floating gate to be individually erased
■ Uses high/low voltages to direct the electrons into and out of
the control gate
Field Effect Transistor (pictured above)
Floating Gate Transistor (pictured below)
HARD DISK DRIVES (HDD) VS SOLID STATE DRIVES (SSD)
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HDD
Slower computing speeds
○ Represented below
Higher error rate
Less sustainable
Requires more power to function
Moving/mechanical parts
Lower cost per byte of storage
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SSD
Faster computing speeds
○ Represented below
Lower error rate
More sustainable
Requires less power to function
No moving/mechanical parts
Higher cost per byte of storage
SLC, MLC, TLC, QLC
● The floating gate can be used to store multiple electrons, which is
generally between one and four
○ If more than four electrons are stored, the software that reads the
binary code becomes too prone to errors
○ The oxide layer surrounding the transistor will also deteriorate faster
due to more electrons being moved through the oxide layer
● Single, Multi, Triple, and Quad Level Cells hold one, two, three, and four
electrons within them, respectively
○ Single Level Cells have the longest lifespans, but the slowest
read/write speeds
○ Quad Level Cells have the greatest memory density
■ 16x larger than a Single Level Cell
Flash SLC
Flash MLC
Hard Disk Drive
Capacity
64 GB
256 GB
1 TB
Reads
100 Mb/s
220 Mb/s
76.5 Mb/s
Writes
80 Mb/s
200 Mb/s
175 Mb/s
Endurance
100,000 cycles
10,000 cycles
N/A*
Average Time
Between Failures
2,000,000 hours
1,000,000 hours
600,00 hours
*The endurance of a Hard Disk Drive cannot be measured in cycles
APPLICATIONS FOR FLASH MEMORY
● Solid State Drives
○ Utilize flash memory to store information without moving parts
○ Faster and more reliable than Hard Disk Drives
○ No memory fragmentation, allowing for improved access speeds
● Cameras
○ Utilize SD cards to store photos, which utilize flash memory to
store information (similar to a Solid State Drive)
○ Allows for a greater number of higher quality photos to be stored
○ Cuts down on disposable cameras for increased sustainability
● Cell phones
○ Flash memory-based memory storage make smartphones possible
○ No moving parts means sudden movements are not harmful
● Flash Drives
○ Essentially act as small Solid State Drives to store information
○ Greatly increased the ease of access in transferring data files