Ultra fast write speed, long refresh time, low power F-N operated volatile memory cell with stacked nanocrystalline Si film

A new volatile memory structure with nanocrystalline Si layer and auxiliary floating polysilicon gate is reported. The charges are injected through tunnel oxide and nanocrystalline Si layer by FN tunneling and then stored in this stacked structure. The nanocrystalline Si layer with extended floating gate structure improves the limited charge storage volume, leads to a memory device with distinct threshold voltage window, and improves programming speed during FN operation. Based on the merit of low power F-N operation, high write speed, long refresh time and compatible CMOS process, this device is feasible for DRAM application.