Abstract: A flash memory cell includes a substrate having a surface region and a flash memory cell structure on the surface region. The flash memory cell structure includes a gate dielectric layer on the surface region, a select gate on the gate dielectric layer, a cap oxide layer on the select gate, an oxide spacer on a first edge of the select gate, a tunnel oxide layer on a first region and on a second region of the surface region. The second region is an active region. The flash memory cell structure further includes a poly spacer on the first edge of the oxide spacer and a portion of the tunnel oxide layer on the first region, an ONO layer on at least the poly spacer and a control gate layer on the ONO layer.

Abstract: A polysilicon spacer as a floating gate of a Flash memory device. An advantage of such spacer structure is to reduce a cell size, which is desirable for state-of-the-art Flash memory technology. In a preferred embodiment, the floating gate can be self-aligned to a nearby and/or within a vicinity of the select gate of the cell select transistor. In a preferred embodiment, the present invention preserves a tunnel oxide layer after the removal, using dry etching, a polysilicon spacer structure on the drain side of the select transistor gate. More preferably, the present method provides for a certain amount of tunnel oxide to remain so as to prevent the active silicon area in the drain region of the memory cell from being etched by the dry etching gas.

Abstract: A polysilicon spacer as a floating gate of a Flash memory device. An advantage of such spacer structure is to reduce a cell size, which is desirable for state-of-the-art Flash memory technology. In a preferred embodiment, the floating gate can be self-aligned to a nearby and/or within a vicinity of the select gate of the cell select transistor. In a preferred embodiment, the present invention preserves a tunnel oxide layer after the removal, using dry etching, a polysilicon spacer structure on the drain side of the select transistor gate. More preferably, the present method provides for a certain amount of tunnel oxide to remain so as to prevent the active silicon area in the drain region of the memory cell from being etched by the dry etching gas.

Abstract: A new method is provided for the creation of floating gates of a flash memory array. The floating gates of conventional flash memory devices are formed using a single polysilicon deposition followed by a single polysilicon etch. The invention provides a method that allows for the reduction in the spacing between adjacent floating gates by providing a double polysilicon deposition followed by a double polysilicon etch process. The process of the invention starts with the formation of FOX regions in a semiconductor surface; the channel regions of the devices are implanted. The first half of the floating gates of the device are formed followed by the formation of the second half of the floating gates of the device. The control gate of the device is formed as a last step of the processes of the invention.