Infineon Technologies recently launched its 512-Mbit, radiation-hardened (rad-hard) NOR Flash memory, a release it claims is a first in the non-volatile memory for space applications.

Developed with funding from the U.S. Air Force Research Laboratory (AFRL) and Microelectronics Research Development Corporation (Micro-RDC), the device is said to deliver unparalleled radiation performance, speed, and density.

Optimized for Space Applications

Infineon designed its 512 Mbit NOR Flash (product brief linked) to store FPGA configuration images and a standalone boot code for space-grade microprocessors. These systems often require rapid initialization and data retrieval, both of which are facilitated by the device’s 133-MHz quad serial peripheral interface (QSPI). This interface offers fast data transfer rates, allowing the device to load a 200-Mb FPGA bitstream in just 0.42 seconds, according to Infineon.

Infineon sought to combine high performance with enduring reliability in the memory solution. To this end, it offers up to 10,000 program/erase cycles, equating to data retention for a decade, even at elevated temperatures of 125°C. The memory operates at a 3.3-V supply voltage, with additional support for 1.8-V input/output. The 512-Mbit density can store multiple FPGA configurations for system redundancy. Additionally, the dual-image capability provides extra assurance against system failure, allowing for fallback options in the event of corrupted data.

A Look at SONOS Technology

Central to Infineon’s new solution is its Silicon-Oxide Nitride-Oxide-Silicon (SONOS) charge gate trap technology.

At its core, SONOS incorporates a silicon-nitride layer sandwiched between silicon-oxide layers, creating a charge-trapping dielectric within the gate stack of a metal-oxide-semiconductor (MOS) transistor. This structure facilitates charge storage in discrete traps within the nitride, fundamentally altering the memory’s performance and reliability profile.

The operation of SONOS memory relies on charge injection and retention within the nitride layer. During programming, electrons are introduced into the nitride through Fowler-Nordheim tunneling, a process induced by a strong electric field across the gate. To erase, holes are tunneled back into the nitride layer, effectively neutralizing stored charges.

Unlike conventional floating-gate Flash memory, which suffers from charge leakage under high-radiation environments, SONOS devices maintain their charge integrity even after prolonged exposure to ionizing radiation.

Specifically, the SONOS-based devices offer a total ionizing dose (TID) tolerance of up to 300 krad(Si), a metric for devices exposed to cosmic rays and high-energy particles. Furthermore, the new memory solution offers superior single-event effects (SEE) performance to ensure immunity to single-event upsets (SEUs) and robust protection against single-event latchups (SELs) at linear energy transfer (LET) values exceeding 80 MeV.cm²/mg at 125°C. Single-event functional interrupt (SEFI) rates are minimized to less than 2.77 × 10?5 errors per device daily.

A Step Forward for Space Electronics

By partnering with the AFRL and Micro-RDC, Infineon successfully integrated cutting-edge research into a commercially viable product and set a new standard in radiation performance and reliability. The new NOR Flash solution is available now for purchase.

By: DocMemory
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