Ferroelectric Random Access Memory (FRAM / F-RAM / FeRAM )

Ferroelectric-RAM (FRAM / F-RAM/ FeRAM )

FRAM is alternative non-volatile memory technologies, it offer the same functionality as Flash memory by recording bits on a magnetic surface.

FRAM is similar in construction to DRAM but uses a ferroelectric layer instead of a dielectric layer to achieve non-volatility. Or a memory that uses ferroelectric film as a capacitor for storing data.

FRAM combines the best of RAM and ROM into a single package that outperforms other nonvolatile memories with remarkably fast writes, high endurance for number of rewrites and ultra-low power consumption. It reduces the burden of OEM (original equipment manufacturer) development because there is no need to differentiate between RAM and ROM

In spite of its name, ferroelectric RAM does not contain iron. The ferroelectric name was chosen because the hysteresis characteristic of the capacitor's charge is similar to ferromagnetic materials. It is somewhat misleading because the capacitor is not made of iron (ferrous), and it is not influenced by magnetic fields. Today’s FRAM uses thin film of Lead Zirconate Titanate [Pb(Zr, Ti) O3], commonly referred to as PZT; other materials are being considered. The main developer of FRAM is Ramtron International.

To date, the commercial FRAM devices have been produced at 350 nm and 130 nm. Early models required two FRAM cells per bit, leading to very low densities, but this limitation has since been removed.

Polarization in a Crystal

FRAM uses a ferroelectric capacitor composed of a crystal made up of lead and oxygen atoms plus zirconium or titanium; these crystals have two stable states. When an electric field is applied, the Zr/Ti (zirconium or titanium) atoms in the PZT change polarity, thereby producing a binary switch. The read circuit detects the polarity of the atom as a difference in voltage, which determines the 0 or 1.

Reliability:

The following tests, per JEDEC industry standard test specifications for non-volatile memory, guarantee 10 years of operation and data retention at 85°C.

Security:

FRAM is more resistant to data corruption via electric fields, radiation, etc. also, the extremely fast write times and the small 130 nm process node make it more resistant to physical attacks. Furthermore, FRAM’s much lower power consumption arguably makes it more difficult to attack with differential power analysis techniques.