Inverted T-Shaped Floating Gate Memory and Method for Fabricating the Same
AssigneeMacronix International Co., Ltd.
InventorsMing-Hsiang HSUEH, Yen-Hao SHIH, Erh-Kun LAI
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Abstract
A memory device having a floating gate with a non-rectangular cross-section is disclosed. The non-rectangular cross-section may be an inverted T shape, a trapezoid shape, or a double inverted T shape. Methods are disclosed for producing a floating gate memory device having an improved coupling ratio due to an increased surface area of the floating gate. The memory device has a floating gate having a cross-sectional shape, such as an inverted T shape, such that a top contour is not a flat line segment.
Claims21
A method for forming a non-volatile memory device, comprising:
- providing a substrate;
- forming a tunnel layer over the substrate;
- forming a conductive layer over the tunnel layer;
- removing a first portion of the conductive layer such that a cross-section of the conductive layer forms a plurality of conductive structures, wherein each of the conductive structures has a top portion and a bottom portion and wherein the top portion is narrower than the bottom portion;
- forming an insulator layer over the conductive layer;
- and
- forming a conductive line over the insulator layer.
A method for forming a non-volatile memory device, comprising:
- providing a substrate;
- forming a tunnel layer, a conductive layer and a plurality of trenches, wherein the tunnel layer is on the substrate, the conductive layer is on the tunnel layer, and the trenches extend into the substrate to divide the substrate into a plurality of sections;
- filling the plurality of trenches with a dielectric material to form a plurality of filled trench structures having sidewalls wherein each of the sections of the conductive layer is bounded by two adjacent sidewalls;
- removing a portion of a section of the conductive layer such that a cross-section of the section of the conductive layer forms an inverted T shape;
- forming an insulator layer on the conductive layer;
- and
- forming a conductive line on the insulator layer.
A method of forming a memory device comprising:
- forming a tunnel layer in a substrate;
- and
- forming a floating gate over the tunnel layer, wherein the floating gate has a cross-section that is one of an inverted T shape, a trapezoidal shape, and double inverted T shape.
In a memory device having a memory cell with a floating gate with a cross-section that is non-rectangular and a data bit being stored in the floating gate, the memory cell being controlled by a control gate, a method comprising:
- performing at least one of a program, erase, or read operation on the data bit stored in the floating gate by applying a voltage to the control gate.
Dependencies are inferred from the claim text.