Memory device and method of fabricating the same
AssigneeMacronix International Co., Ltd.
InventorsChih-Lin Chen, Kuang-Wen Liu, Hsin-Huei Chen
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Abstract
A method of fabricating memory devices is provided. First, a charge storage structure including a gate dielectric structure is formed on the substrate in sequence to form a charge trapping layer. Then, a gate conductive layer is formed above the charge storage structure. Afterwards, the gate conductive layer and at least a part of the charge storage structure are patterned. The cross section of the patterned charge storage structure is then become a trapezoid or a trapezoid analogue, which has the shorter side near the gate conductive layer and the longer side near the substrate.
Claims13
A method of fabricating a memory device, comprising:
- forming a charge storage structure including a gate dielectric structure, a charge trapping layer and a second oxide layer from bottom to top;
- forming a gate conductive layer above the charge storage structure;
- and
- patterning the gate conductive layer and at least a part of the charge storage structure, such that the cross section of a patterned charge storage structure including a patterned gate dielectric structure, a patterned charge trapping layer and a patterned second oxide layer becomes approximately a trapezoid or a trapezoid analogue with the shorter side near the gate conductive layer and the longer side near the substrate;
- and
- during an oxidation process, an oxide encroachment is formed located at a region between the longer side of the charge storage structure and the substrate and not covered by the gate conductive layer but not extend under the gate conductive layer.
A memory device, comprising:
- a substrate;
- a gate conductive layer, disposed on the substrate;
- a charge storage structure, comprising a gate dielectric structure, a charge trapping layer and a second oxide layer from bottom to top, the cross section of the gate dielectric structure, the charge trapping layer and the second oxide layer of the charge storage structure becoming approximately a trapezoid or a trapezoid analogue with the longer side near the substrate and the shorter side near the gate conductive layer;
- and
- an oxide encroachment located at a region between the longer side of the charge storage structure and the substrate and not covered by the gate conductive layer,
- wherein the longer side of the trapezoid or the trapezoid analogue has enough length besides the gate conductive layer to avoid the oxide encroachment extending under the gate conductive layer.
Dependencies are inferred from the claim text.