Raised-bitline, contactless, trenched, flash memory cell

Abstract

A raised-bitline, contactless flash memory device with trenches on a semiconductor substrate doped with a first conductivity type includes a first well of an opposite conductivity type comprising a deep conductor line to a device, and a second well of the first conductivity type above the first well comprising a body line to the device. Deep trenches extend through the second well into the first well. The trenches are filled with a first dielectric. There are gate electrode stacks for a flash memory device including a gate oxide layer over the device. First doped polysilicon floating gates are formed over the gate oxide layer. An interpolysilicon dielectric layer is formed over floating gate electrodes, and control gate electrodes formed of doped polysilicon layer overlie the interpolysilicon dielectric layer. A dielectric cap overlies the control gate electrodes. Source/drain regions are formed in the second well self-aligned with the stacks as well as spacer dielectric structures formed adjacent to the sidewalls of the stacks. A third doped polysilicon layer patterned into raised bitlines overlies source/drain regions.