Novel Single Polysilicon EEPROM Cell With Dual Work Function Floating Gate

Abstract

A novel single polysilicon electrically erasable programmable read-only memory cell with dual work function floating-gate (DWFG) structure is presented in this letter. The floating gate of the proposed DWFG cell is doped with p+ on the source side and n+ on the drain side. For DWFG devices, the floating gate on the source side has a higher work function than that on the drain side. The work function difference and the intrinsic doped region at the middle of the floating-gate affect the channel potential distribution and generate a peak lateral electric field inside the channel, improving the channel's hot electron programming characteristics. The experimental results show that the proposed DWFG cell gives faster programming speeds and program operation at lower voltage than conventional cells