Scalable high density non-volatile memory cells in a contactless memory array
AssigneeMicron Technology, Inc.
InventorArup Bhattacharyya
Life of this patent
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Abstract
A plurality of split gate non-volatile memory cells are formed vertically in a trench along the sidewalls. Each cell is comprised of a bistable element and an adjacent fixed gate threshold element that share a common respective control gate/access gate. The bistable element has a gate insulator stack that is comprised of either a floating gate or a charge trapping layer over a tunnel insulator. A plurality of silicon rich nitride layers are formed over the floating gate or charge trapping layer and separated by a high dielectric constant layer.
Claims20
A method for fabricating an integrated non-volatile memory device, the method comprising:
- forming a plurality of trenches in a substrate material, each pair of trenches defining a mesa and each trench having a top section and a bottom section;
- forming a bistable element along each sidewall of the trenches;
- forming a fixed threshold element along each sidewall of the trenches and substantially adjacent to the bistable element;
- forming diffusion areas in the tops of the mesas and in the substrate at the bottoms of the trenches;
- and
- forming a shared source line substantially in the middle of each trench.
A method for fabricating an integrated non-volatile memory device, the method comprising:
- forming a plurality of trenches in a substrate material, each pair of trenches defining a mesa;
- forming a planar bistable element on each mesa;
- forming a fixed threshold element along each sidewall of the trenches and substantially adjacent to the bistable element;
- forming a shared source line diffusion area in substrate at the bottom of each trench;
- and
- forming a shared source line substantially in the middle of each trench.
A method for fabricating an integrated non-volatile memory integrated circuit, the method comprising:
- forming a plurality of mesas in a p-type substrate material, each pair of mesas defining a trench and each mesa having a top section and a bottom section;
- forming a bistable element at the top section along opposing sidewalls of each mesa;
- forming a fixed threshold element along opposing sidewalls at the bottom section and substantially adjacent to the bistable element along the sidewall;
- doping n+ diffusion areas in the top of each mesa between and substantially adjacent two bistable elements and in the substrate at the bottom of each trench;
- and
- forming a shared source line in each trench between each pair of mesas.
Dependencies are inferred from the claim text.