Geometric effects of nanocrystals in nonvolatile memory using block copolymer nanotemplate

This study describes geometric characteristics of a nonvolatile memory (NVM) device with a designed chromium (Cr) nanocrystal (NC) floating gate. By using a block copolymer (BCP) nanotemplate as a mask layer, cone-shaped NCs and disc-shaped NCs were formed. It was found that the NVM device using the cone-shaped NC had a better program efficiency than that of the device using the disc-shaped one. This trend was verified by a theoretical model, which considered an effect of the capacitive-coupling ratio between a control gate and a NC floating gate.