Abstract: A flash memory device includes a substrate having first and second wells. The first well is defined within the second well. A plurality of trenches defines the substrate into a plurality of sub-columnar active regions. The trenches is formed within the first well and extends into the second well. A plurality of flash memory cells are formed on each of the sub-columnar active regions.

Abstract: Structures and methods for flash memory transistors are formed with self-aligned drain/source contacts. The flash transistors are formed with a plurality of gate layers. An etch resistant layer(s) are deposited on top of the gate layers in the memory array transistors and on the gate layers of peripheral transistors. An additional oxide layer/spacer may be formed on the etch resistant layer to control the resulting transistor junction configuration. As a result within the same process various transistors may be formed satisfying various requirements. Contact holes to the drain and source regions of the memory and peripheral transistors are then formed. The etch resistant layer prevents the contact etchants from completely etching away the protective etch resistant layer surrounding the gate layers. The spacing between the drain/source contacts and the gate layers can be greatly reduced increasing the density of the memory array transistors and reducing chip size.

Abstract: Non-volatile memory transistors are provided that include a floating gate formed from first and second layers of material such as polysilicon. The second floating gate layer is selectively grown or deposited on top of the first gate layer, eliminating the need to mask for positioning of the second floating gate layer. The memory transistors are separated by isolation regions. The second floating gate layer overlaps portions of the isolation regions to provide a high control gate-to-floating gate coupling ratio. The process enables smaller memory transistors. Floating gate to isolation overlap, and therefore floating gate to floating gate spacing, is controlled by selective deposition or selective epitaxial growth of the second polysilicon layer.

Abstract: Non-volatile memory transistors are provided that include a floating gate formed from first and second layers of material such as polysilicon. The second floating gate layer is selectively grown or deposited on top of the first gate layer, eliminating the need to mask for positioning of the second floating gate layer. The memory transistors are separated by isolation regions. The second floating gate layer overlaps portions of the isolation regions to provide a high control gate-to-floating gate coupling ratio. The process enables smaller memory transistors. Floating gate to isolation overlap, and therefore floating gate to floating gate spacing, is controlled by selective deposition or selective epitaxial growth of the second polysilicon layer.

Abstract: Non-volatile memory transistors are provided that include a floating gate formed from first and second layers of material such as polysilicon. The second floating gate layer is selectively grown or deposited on top of the first gate layer, eliminating the need to mask for positioning of the second floating gate layer. The memory transistors are separated by isolation regions. The second floating gate layer overlaps portions of the isolation regions to provide a high control gate-to-floating gate coupling ratio. The process enables smaller memory transistors. Floating gate to isolation overlap, and therefore floating gate to floating gate spacing, is controlled by selective deposition or selective epitaxial growth of the second polysilicon layer.

Abstract: Non-volatile memory transistors are provided that include a floating gate formed from first and second layers of material such as polysilicon. The second floating gate layer is selectively grown or deposited on top of the first gate layer, eliminating the need to mask for positioning of the second floating gate layer. The memory transistors are separated by isolation regions. The second floating gate layer overlaps portions of the isolation regions to provide a high control gate-to-floating gate coupling ratio. The process enables smaller memory transistors. Floating gate to isolation overlap, and therefore floating gate to floating gate spacing, is controlled by selective deposition or selective epitaxial growth of the second polysilicon layer.

Abstract: Structures and methods for flash memory transistors are formed with self-aligned drain/source contacts. The flash transistors are formed with a plurality of gate layers. An etch resistant layer(s) are deposited on top of the gate layers in the memory array transistors and on the gate layers of peripheral transistors. An additional oxide layer/spacer may be formed on the etch resistant layer to control the resulting transistor junction configuration. As a result within the same process various transistors may be formed satisfying various requirements. Contact holes to the drain and source regions of the memory and peripheral transistors are then formed. The etch resistant layer prevents the contact etchants from completely etching away the protective etch resistant layer surrounding the gate layers. The spacing between the drain/source contacts and the gate layers can be greatly reduced increasing the density of the memory array transistors and reducing chip size.

Abstract: An abrupt drain junction and a graded source junction are fabricated using a common diffusion step, wherein the common diffusion step is used to create both the drain junction-and the source junction. The common diffusion step is accomplished while an oxide spacer is present over a gate stack, prior to the common diffusion step, resulting in faster source diffusion and a graded source junction, while the slower diffusion in the drain region results in an abrupt drain junction. The oxide spacer moves the drain junction further away from the gate stack to allow for greater cell densities.