NONVOLATILE SEMICONDUCTOR MEMORY DEVICE, THREE-DIMENSIONAL SEMICONDUCTOR DEVICE, AND METHOD OF MANUFACTURING THE SAME
First Claim
1. A three-dimensional semiconductor device, comprising:
- a semiconductor substrate;
a plurality of conductive layers and insulating layers stacked alternately above the semiconductor substrate; and
a plurality of contacts extending in a stacking direction of the plurality of conductive layers and insulating layers,the plurality of conductive layers forming a stepped portion having positions of ends of the plurality of conductive layers gradually shifted from an upper layer to a lower layer,the plurality of contacts being connected respectively to each of steps of the stepped portion, andthe stepped portion being formed such that, at least from an uppermost conductive layer to a certain conductive layer, the more upwardly the conductive layer is located, the broader a width of the step is.
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Accused Products
Abstract
A three-dimensional semiconductor device includes a semiconductor substrate, a plurality of conductive layers and insulating layers, and a plurality of contacts. The plurality of conductive layers and insulating layers are stacked alternately above the semiconductor substrate. The plurality of contacts extend in a stacking direction of the plurality of conductive layers and insulating layers. The plurality of conductive layers form a stepped portion having positions of ends of the plurality of conductive layers gradually shifted from an upper layer to a lower layer. The plurality of contacts are connected respectively to each of steps of the stepped portion. The stepped portion is formed such that, at least from an uppermost conductive layer to a certain conductive layer, the more upwardly the conductive layer is located, the broader a width of the step is.
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Citations
20 Claims
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1. A three-dimensional semiconductor device, comprising:
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a semiconductor substrate; a plurality of conductive layers and insulating layers stacked alternately above the semiconductor substrate; and a plurality of contacts extending in a stacking direction of the plurality of conductive layers and insulating layers, the plurality of conductive layers forming a stepped portion having positions of ends of the plurality of conductive layers gradually shifted from an upper layer to a lower layer, the plurality of contacts being connected respectively to each of steps of the stepped portion, and the stepped portion being formed such that, at least from an uppermost conductive layer to a certain conductive layer, the more upwardly the conductive layer is located, the broader a width of the step is. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A nonvolatile semiconductor memory device, comprising:
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a semiconductor substrate; and a memory string provided on the semiconductor substrate and including a plurality of memory cells connected in series, the memory string comprising; a semiconductor layer extending in a perpendicular direction to a main surface of the semiconductor substrate and functioning as a body of the memory cells; a charge storage layer provided on a side surface of the semiconductor layer and configured to store a charge; a plurality of conductive layers extending in the perpendicular direction to the main surface of the semiconductor substrate via insulating layers, each of the conductive layers sandwiching the charge storage layer between the conductive layer and the semiconductor layer and functioning as a gate of the memory cells; and a plurality of contacts extending in the perpendicular direction to the main surface of the semiconductor substrate and connected to ends of the conductive layers, the plurality of conductive layers including a stepped portion having positions of ends of the plurality of conductive layers gradually shifted from an upper layer to a lower layer, the plurality of contacts being connected respectively to each of steps of the stepped portion, and the stepped portion being formed such that, at least from an uppermost conductive layer to a certain conductive layer, the more upwardly the conductive layer is located, the broader a width of the step is. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. A method of manufacturing a three-dimensional semiconductor device, comprising:
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stacking a plurality of conductive layers and insulating layers alternately on a semiconductor substrate; forming a resist on a stacked body of the conductive layers and the insulating layers; executing sequentially a selective etching of the conductive layers and the insulating layers by the resist while reducing the resist, thereby forming a stepped portion having positions of ends of the plurality of conductive layers gradually shifted from an upper layer to a lower layer; and connecting contacts respectively to each of steps of the stepped portion, the contacts extending in a stacking direction, formation of the stepped portion being executed while adjusting a reduction width of the resist such that, at least from an uppermost layer to a certain conductive layer, the more upwardly the conductive layer is located, the broader a width of the step is. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification