Patent ID: 6930002

Claim:
A method for programming a single-poly electrical programmable read only memory (EPROM) cell, said single-poly EPROM cell comprising a P-channel floating gate transistor on an isolated N-well of a P-type substrate, and an N-channel coupling device, wherein said P-channel floating gate transistor comprises P + drain, P + source, P channel defined between said P + drain and P + source, tunnel oxide on said P channel, and doped polysilicon floating gate on said tunnel oxide, and wherein said N-channel coupling device comprises a polysilicon floating electrode that is electrically connected to said doped polysilicon floating gate and is capacitively coupled to a control doped region formed in said P-type substrate, the method comprising: grounding said P-type substrate; grounding said N-well; biasing said P + drain of said P-channel floating gate transistor to a negative voltage; grounding or floating said P + source of said P-channel floating gate transistor; and applying a positive voltage on said control doped region so that said positive voltage being coupled to said P-doped polysilicon floating gate, wherein said P channel of said P-channel floating gate transistor is in “OFF” state, and a depletion region and electron-hole pairs are created at a junction between said P + drain and said N well, and band-to-band tunneling (BTBT) induced hot electrons will inject into said doped polysilicon floating gate by tunneling through said tunnel oxide.