Depletion-mode single-poly eeprom cell

Abstract

A method for forming a depletion-mode single-poly electrically erasable programmable read-only memory (EEPROM) cell is provided. The method includes providing a substrate having a floating region and a control region. Then, an isolation deep well and a deep well are formed in the floating region and the control region of the substrate respectively. A well region is formed in the isolation deep well simultaneously with forming an isolation well region between the isolation deep well and the deep well in the substrate. A depletion doped region and a cell implant region are formed at the well region of the substrate and the deep well of the substrate respectively. A floating gate structure is formed across over the floating region and the control region. An implantation process is performed to form a source/drain region and a heavily doped region in the depletion doped region and the cell implant region respectively.