High speed F-N operated volatile memory cell with stacked plasma enhanced chemical vapor deposition (PECVD) nanocrystalline Si layer structure

A volatile memory structure with nanocrystalline Si (nc-Si) layer and auxil iary floating polysilicon gate is proposed. The charges are injected throug h tunnel oxide and nc-Si layer by Fowler-Nordheim (F-N) tunneling and then stored in the stacked structure. The nc-Si layer improves programming speed during F-N operation and the extended structure with floating gate improve s the limited charge storage volume and makes the memory device with distin ct threshold voltage window. The reliability of this cell is shown to be su fficient for using as dynamic memory.