Three-dimensional memory device and methods of making the same using replacement drain select gate electrodes
First Claim
1. A three-dimensional memory device, comprising:
- an alternating stack of insulating layers and electrically conductive layers located over a substrate;
drain-select-level electrically conductive strips located over the alternating stack;
a drain-select-level isolation structure located between a neighboring pair of the drain-select-level electrically conductive strips;
memory stack structures extending through the alternating stack and the drain-select-level electrically conductive strips and comprising a respective vertical semiconductor channel vertically extending through the alternating stack and a respective one of the drain-select-level electrically conductive strips; and
dielectric cores laterally surrounded by a respective one of the vertical semiconductor channels, wherein each of the dielectric cores includes a respective core cavity devoid of any solid state material therein,wherein each vertical semiconductor channel comprises;
a respective first vertically-extending portion extending through levels of the electrically conductive layers and having a first maximum lateral channel dimension; and
a respective second vertically-extending portion located at a level of the drain-select-level conductive strips and having a second maximum lateral channel dimension that is less than the first maximum lateral channel dimension.
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Accused Products
Abstract
A method of forming a three-dimensional memory device includes forming an alternating stack of insulating layers and sacrificial material layers over a substrate, forming a patterned template structure around memory openings in a drain-select-level above the alternating stack, forming drain-select-level isolation structures in trenches in the patterned template structure, forming memory stack structures in the memory openings extending through the alternating stack, where each of the memory stack structures includes a memory film and a vertical semiconductor channel, replacing the sacrificial material layers with word lines, and separately replacing the patterned template structure with a drain select gate electrode.
8 Citations
19 Claims
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1. A three-dimensional memory device, comprising:
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an alternating stack of insulating layers and electrically conductive layers located over a substrate; drain-select-level electrically conductive strips located over the alternating stack; a drain-select-level isolation structure located between a neighboring pair of the drain-select-level electrically conductive strips; memory stack structures extending through the alternating stack and the drain-select-level electrically conductive strips and comprising a respective vertical semiconductor channel vertically extending through the alternating stack and a respective one of the drain-select-level electrically conductive strips; and dielectric cores laterally surrounded by a respective one of the vertical semiconductor channels, wherein each of the dielectric cores includes a respective core cavity devoid of any solid state material therein, wherein each vertical semiconductor channel comprises; a respective first vertically-extending portion extending through levels of the electrically conductive layers and having a first maximum lateral channel dimension; and a respective second vertically-extending portion located at a level of the drain-select-level conductive strips and having a second maximum lateral channel dimension that is less than the first maximum lateral channel dimension. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A three-dimensional memory device, comprising:
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an alternating stack of insulating layers and electrically conductive layers located over a substrate; drain-select-level electrically conductive strips located over the alternating stack; a drain-select-level isolation structure located between a neighboring pair of the drain-select-level electrically conductive strips; and memory stack structures extending through the alternating stack and the drain-select-level electrically conductive strips and comprising a respective memory film and a respective vertical semiconductor channel that vertically extend through the alternating stack and a respective one of the drain-select-level electrically conductive strips; and wherein each vertical semiconductor channel comprises; a respective first vertically-extending portion extending through levels of the electrically conductive layers and having a first maximum lateral channel dimension; a respective second vertically-extending portion located at a level of the drain-select-level conductive strips and having a second maximum lateral channel dimension that is less than the first maximum lateral channel dimension; and a respective annular horizontal connection portion adjoining a top end of the respective first vertically-extending portion and a bottom end of the respective second vertically-extending portion. - View Dependent Claims (14, 15, 16)
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17. A three-dimensional memory device, comprising:
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an alternating stack of insulating layers and electrically conductive layers located over a substrate; drain-select-level electrically conductive strips located over the alternating stack; a drain-select-level isolation structure located between a neighboring pair of the drain-select-level electrically conductive strips; and memory stack structures extending through the alternating stack and the drain-select-level electrically conductive strips and comprising a respective memory film and a respective vertical semiconductor channel that vertically extend through the alternating stack and a respective one of the drain-select-level electrically conductive strips, wherein each memory film comprises a tunneling dielectric including a first vertically-extending portion that vertically extends through the alternating stack, a second vertically-extending portion that vertically extends through the drain-select-level electrically conductive strips, and a horizontal annular portion that connects an upper periphery of the first vertically-extending portion of the tunneling dielectric and a lower periphery of the second vertically-extending portion of the tunneling dielectric; and wherein each vertical semiconductor channel comprises; a respective first vertically-extending portion extending through levels of the electrically conductive layers and having a first maximum lateral channel dimension; and a respective second vertically-extending portion located at a level of the drain-select-level conductive strips and having a second maximum lateral channel dimension that is less than the first maximum lateral channel dimension. - View Dependent Claims (18, 19)
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Specification