FRAM (Ferroelectric RAM) is a non-volatile memory, which has the features of high-speed writing, low-power consumption and high endurance. Fujitsu Semiconductor can provide you the various kinds of FRAM products such as FRAM standalone memory, FRAM Microcontroller and FRAM RFID.

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What is FRAM?

FRAM(Ferroelectric Random Access Memory) is also known as FeRAM. It is a type of memory that uses a ferroelectric film as a capacitor to store data. FRAM has the characteristcs of both ROM(Read Only Memory) and RAM(Random Access Memory), and advantages in high-speed writing,high endurance, low power consumption and tamper resistance.

About Ferroelectric

The figure below explains PZT crystal structure, which is commonly used as a typical ferroelectric material. There are zirconium and titanium in the lattice, which have two stabilization points. They can move between the points according to the external electric field. Once the position is settled, it will not move anymore even the absence of electric filed. Top and bottom electrodes structure a capacitor. Then, the capacitor plots bottom electrode voltage and polarization, which yields a hysteresis loop. Data is stored in the form of "1" or "0".

PZT Crystal Structure and Principles of FRAM

1. Polarization occurs when an electric field is applied. (Zr/Ti ions move upward or downward in the crystal)
2. Electric polarization remains even in the absence of an applied electric field.
3. Two stabilized states are stored in the form of "0" or "1" data.

FRAM in Memory Classification

Non-volatility

• Battery-free (ecology product)

Higher speed writing

• Over-writable just like SRAM Rewrite command is not required
• No waiting time for erase/write operation Write cycle time = Read cycle time Writing time: 1/30,000 of E²PROM

Higher endurance

• Guarantee the endurance of 10¹⁰cycles (10billion cycles) per bit Endurance: more than 10,000 times of E²PROM

Lower power consumption

• Charge Pump Circuit is not required Power consumption: below 1/400 of E²PROM

Table1 is a comparison table for specification differences between FRAM and other memory devices.

*1) T=Transistor. C=Capacitor *2) Specs of 256Kb stand-alone FRAM memory*3) Total cycles of read and write operation

Fujitsu FRAM Integrated Products

Stand-alone Memory (I²C/SPI/Parallel interface products)

Fujitsu Semiconductor provides stand-alone memory which has FRAM's advantages including non-volatility, high-speed writing, lowe power consumption and high endurance. You can use it for various applications such as mobile, OA equipment, digital appliance, banking terminal.

LSI for RFID

Fujitsu Semiconductor develops and produces LSI for RFID, which covers both HF(High-Frequency:13.56MHz) and UHF(Ultra High-Frequency:860 to 960MHz). Embedded FRAM is the one of its best features; FRAM enables higher speed writing, lower power consumption and higher endurance. Our passive RFID with large memory size is massively used worldwide.

Key Features of Fujitsu's LSI for RFID tag

• High-speed write performance: throughput of writing operation is enhanced by high speed performance of embedded FRAM
• Stable communication distance: writing in low power consumption enables the same communication distance both at writing and reading operation. In contrast, tag with E2PROM consumes large amout of power at writing operation,makes communication distance becomes shorter.
• High-density memory: hight speed writing feature enables large-size memory on the tag.But tag embedded E2PROM is not fast enough to adopt large-size memory.
• High endurance:10 billion cycles of read/write operation is guaranteed. the feature enables long-term use or reuse of tag to be possible.
• High radiation resistance: even after having been irradiated or sterilized with gamma ray, data is kept.Meanwhile, tag embedded E2PROM has weak radiation resistance in principle.
• Applicable International Standards: Fujitsu RFID LSI products lineup are based on ISO15693, ISO18000-3, 6.

Application of FRAM RFID Tag could provide

Image of RF tag's High-speed Performance with FRAM

FRAM Microcontroller

Advantages of FRAM Microcontroller

• Higher speed writing than conventional Flash Microcontrollers
• Data overwrited by Byte is available without erase operation
• Lower power consumption is available when data rewrite operation, not requiring high-voltage being applied
• FRAM memory area is available for both data storage and code storage
• Data is safe even under the electromagnetic wave or radiation

Application example: Power-supply Voltage Supervision System with Microcontroller

Custom LSI

FRAM is suitable for one-chip solution with logic or analogue circuit, and it does not bring CMOS specification down. Fujitsu Semiconductor uses this advantage, and produces FRAM embedded products such as LSI for RFID and IC card. We can customise these products according to your request, or provide the customised LSI with FRAM. Because FRAM has both RAM and ROM advantages, using FRAM reduces your development frustration, and increases your convenience. Moreover, as the design environment is much like of ASIC, you can put a range of IPs.

Custom IC with FRAM

Application using FRAM macro

Custom IC with FRAM can be used for various applications, and give extra features such as security function, cognitive information and environmental variable strage to home appliances, office machines and mobile terminals.

Products Lineup

Stand-alone MemoryDetails 

Serial/ Parallel FRAM are in the lineup, which are able to support a wide range of application.

Reliability

The ferroelectric materials used for FRAM affects the reliability issue. Data retention and fatigue characteristics can lead polarization charge decrease. Fujitsu Semiconductor shows the resistance reliability of FRAM throgh evaluating Test Element Group (TEG) and products. For more detailed FRAM reliability issue, please refer to "FUJITSU FRAM Quality & Reliability"

Technology of Production and Development

IDM(Integrated Device Manufacturer) organization faciliates high-quanlity

Fujitsu controls whole processes of FRAM: research, development and mass production. Since the first mass production in 1999, we have been producing and shipping a great number of FRAM products. Controlling the whole FRAM production within the group including wafer and assembly processes, makes stable supply possible. This also achieves the delivery of high quality FRAM products with our own technology such as Fujitsu original ferroelectric film forming technology, ferroelectric capacitor processing technology and degradation(canused by wiring and ILD<Inter Layer Dielectrics>film deposition) control technology of ferroelectric capacitor.

Plants

Wafer process: Mie plant, Fujitsu Semiconductor Limited

Established in October 1984. Mie plant is one of the leading plants of Fujitsu Semiconductor, which works for Logic LSI production (Front-end process). Its property in Kuwana, MIE, spreads over 307,000m3. There are 200mm and 300mm line for wafer production since April 2005 and another 300mm line since 2007. Also, the Mie plant is voluntarily working for "green" activities such as hybrid seismic isolation structure, NAS batteries and Zero emission.

Assembly process: Kyushu plant, Fujitsu Integrated Microtechnology Limited

Established in October 1978. Kyushu plant has been running for assembly and testing. It provides server computers, high-end network models and assembly with a full lineup of packages from standard to special packages for digital AV, mobile phones and automotive-related products.

Assembly process: Nantong Fujitsu Microelectronics Co., Ltd.

Established in October 1997. The Nantong plant is a Fujitsu's joint company in China. It focuses on assembly and testing for general-use microcontrollers and linear integrated circuit for analogue.