A method for making a nitride read only memory device with buried diffusion spacers is disclosed. An oxide-nitride-oxide (ONO) layer is formed on top of a silicon substrate, and a polysilicon gate is formed over the ONO layer. The polysilicon gate is formed less than a length of the ONO layer. Two buried diffusion spacers are formed beside two sidewalls of the polysilicon gate and over the ONO layer. Two buried diffusion regions are implanted on the silicon substrate next to the two buried diffusion spacers. The two buried diffusion regions are then annealed such that the approximate interfaces of the buried diffusion regions are under the sidewalls of the polysilicon gate. The structure of a nitride read only memory device with buried diffusion spacers is also described.