Methods to Counter the Layer-Dependent Radiation Response of 3D NAND Flash Memory

uah p 21004pan

Docket: UAH-P-21004


Flash memory can be classified into two groups: a traditional 2D geometry and a newer 3D geometry. The need to transition to a 3D architecture stems from the inherent scaling limits of 2D flash technology. 3D NAND technology is fundamentally different from its 2D counterpart because it comprises a series of alternating, differently sized metal and oxide layers rather than memory cells simply sitting on a crystalline silicon wafer. Recent studies have confirmed layer-to-layer variability of endurance and data retention of 3D flash memory, but this unique structure implies a layer-dependent radiation response as well.

Researchers at UAH have developed a new technology that is now able to characterize the layer-dependent total ionization dose (TID) and single event effects (SEEs) response of 3D NAND memory. The response is quantified by the bit error ratio (BER), which compares the number of radiation-corrupted bits to the total number of bits. The results confirm that cells in the top and bottom layers are more vulnerable to TID and that 3D memory exhibits more page-to-page radiation response variation.

This technology’s findings will allow for more efficient data protection since the vulnerability of 3D flash memory to radiation can now be characterized. Knowing how the different layers react to radiation exposure allows the arrangement of more radiation hardness methods to the most vulnerable layers. The result is a 3D flash memory device that is able to resist radiation exposure while minimizing any unneeded protection. 


• 3D NAND flash memory
• High-radiation environments
• Nuclear, aerospace and defense


• First major portrayal of layer-dependent radiation response in 3D flash memory
• Efficient application of radiation-hardening techniques


  • State of Development: Prototype
  • Licensing Status: Available for Licensing
  • Patent Status: Proprietary

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