What is Semiconductor Memory?

Semiconductor memory is a type of semiconductor device tasked with storing data. There are two electronic data storage mediums that we can utilize, magnetic or optical.

Magnetic storage:

  • Stores data in magnetic form.
  • Affected by magnetic fields.
  • Has high storage capacity.
  • Doesn't use a laser to read/write data.
  • Magnetic storage devices are; Hard disk , Floppy disk, Magnetic tape etc.

Optical storage:

  • Stores data optically, uses laser to read/write.
  • Not affected by magnetic fields.
  • Has less storage than a hard disk.
  • Data accessing is high, compared to a floppy disc.
  • Optical storage devices are; CD-ROM,CD-R, CD-RW, DVD etc.

There is also volatile memory. This is memory that loses its data once power is cut off, while non-volatile memory retains data even without power.

Semiconductor Memory Types

Semiconductor Memory Types

* RAM (Random Access Memory) : Enables Read/Write of stored contents

* ROM (Read Only Memory) : Allows only Read operation

Characteristics of Various Types of Memory

Parameter RAM ROM
Volatility Non Volatility
SRAM DRAM FeRAM Mask ROM EPROM EEPROM FLASH
Data Storage Method Voltage Bias Voltage Bias
+
Refresh
Unnecessary
No. of Read Operations 10 billion
to
1 trillion times
No. of Rewrites 0 times 100 times 100,000 to 1 million times 10,000 to 100,000 times
Write on Substrate Possible Possible Possible × × Possible Possible
Read Time
Write Time -
Bit Cost
Larger Capacity
Memory Cell

Stored in a flip flop circuit

Maintains charge in the capacitor

Polarization of the ferroelectric material

Ions implanted in a transistor

Maintains charge in the floating gate

Maintains charge in the floating gate

Maintains charge in the floating gate