Vertical-Stacked-Array-Transistor (VSAT) for Nonvolatile Memory Devices

Tech ID: 22265 / UC Case 2010-381-0


UCLA researchers in the Department of Electrical Engineering have created a novel Vertical-Stacked-Array-Transistor (VSAT) for ultra-high-density and cost-effective NAND flash memory devices and solid state drives.


The NAND flash memory has a simple cell structure allowing for higher density and more memory capacity. Further, it is ideal for mobile devices because flash memory is highly durable and able to withstand mechanic shock, high pressure, temperature, immersion in water, etc. Solid state drives, based on NAND flash memory, are lower in cost compare to DRAM and are able to retain data without a constant power supply. However, the cost per gigabyte compared to the conventional hard drive is still considerably higher. Flash memory technology will need to evolve in order to continue to scale and to have a stronger presence in the marketplace


Researchers at UCLA have invented a robust and simple 3-D structure, VSAT, on a 100nm node for ultra-high-density NAND flash memory devices while improving sub-threshold performance and channel mobility.


A viable candidate for low cost and high density memory


  • Low cost to manufacture
  • Simplified fabrication process
  • Ultra-high-density
  • Easy integration with peripheral circuits
  • Improved off-current without sacrificing memory density

State Of Development

The 3-D NAND flash memory cell, VSAT, has been successfully developed on the 100nm node. The anticipated storage capacity of VSAT is 128 GB with 16 multiple layers on the 50nm node.

Patent Status

Country Type Number Dated Case
United States Of America Issued Patent 9,048,329 06/02/2015 2010-381
Japan Issued Patent 5566675 06/27/2014 2010-381
United States Of America Issued Patent 8,541,832 09/24/2013 2010-381

Additional Patents Pending


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  • Wang, Kang L.

Other Information


Flash memory, solid state drive, transistor

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