Characterization of novel SiO 2 /a-Si/a-SiOx tunnel barrier engineered oxide

We suggested the heterogeneously stacked oxide (HSO) for the future tunnel oxide of high density NAND flash memory. HSO has a structure of SiO 2 /a-Si/a-SiOx using the concept of tunnel barrier engineering. By employing HSO tunnel barrier, it was possible to fabricate the tunnel oxide, which is thicker physically and thinner electrically than the single layer tunnel oxide. The bandgap of a-SiOx can be modified, which made it possible to achieve tunnel barrier engineering without employing high-k material. By reducing the erase voltage, the reliabilities of NAND flash memory was improved.