SRAM and flash memory

In charge-trap cells, widely used in 3D NAND, which material is commonly used for the layer that stores charge?

  1. ACopper
  2. BSilicon nitride (SiN)
  3. CAluminum
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Answer: B. Silicon nitride (SiN)

Instead of a conductive floating gate, a charge-trap cell stores electrons in trap levels within silicon nitride, an insulator. Because the charge is localized in the film, interference with neighboring cells is small, and it is well suited to the vertically stacked structure of 3D NAND.

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More SRAM and flash memory questions

  1. Under which condition does the data retention of flash memory tend to degrade?
  2. In recent advanced processes, what is the most appropriate reason SRAM cell area has become harder to shrink than logic?
  3. Which technique do NAND flash controllers use to cope with the increase in read errors that comes with storing more bits per cell?
  4. What is a typical use of NOR flash memory?
  5. Which correctly describes garbage collection in an SSD?