Selective cavity merging for isolation regions in a memory die
Methods, systems, and devices for selective cavity merging for isolation regions in a memory die are described. For example, formation of material structures of a memory die may include depositing a stack of alternating layers of a first material and a second material over a substrate of the memory die, forming a pattern of cavities through the stack of alternating material layers, and forming voids between layers of the first material based on removing portions of the second material. An electrical isolation region may be formed between portions of the memory die based on depositing a dielectric material in at least some of the cavities and in at least a portion of the voids between the layers of the first material.
1 . A method, comprising:
depositing a stack of material layers over a substrate of a memory die, the stack of material layers comprising alternating layers of a first material and a second material;
forming a plurality of cavities through the stack of material layers;
forming one or more voids between the layers of the first material based at least in part on removing one or more portions of the second material; and
forming an electrical isolation region between a first portion of the memory die and a second portion of the memory die based at least in part on depositing a dielectric material in the plurality of cavities and in portions of the one or more voids between the layers of the first material that extend between adjacent cavities of the plurality of cavities.
2 . The method of claim 1 , wherein the first portion of the memory die comprises a first block of memory cells and the second portion of the memory die comprises a second block of memory cells.
3 . The method of claim 2 , further comprising:
forming one or more first access lines for the first block of memory cells based at least in part on depositing one or more conductive materials in second portions of the one or more voids between the layers of the first material in the first portion of the memory die; and
forming one or more second access lines for the second block of memory cells based at least in part on depositing the one or more conductive materials in third portions of the one or more voids between the layers of the first material in the second portion of the memory die.
4 . The method of claim 3 , wherein the one or more first access lines and the one or more second access lines are electrically isolated from one another based at least in part on depositing the dielectric material in the plurality of cavities and in the portions of the one or more voids between the layers of the first material.
5 . The method of claim 2 , further comprising:
forming the first block of memory cells based at least in part on depositing a second dielectric material and a semiconductor material in a plurality of second cavities in the first portion of the memory die; and
forming the second block of memory cells based at least in part on depositing the second dielectric material and the semiconductor material in a plurality of third cavities in the second portion of the memory die.
6 . The method of claim 5 , further comprising:
forming the plurality of second cavities and the plurality of third cavities through the stack of material layers concurrently with forming the plurality of cavities through the stack of material layers.
7 . The method of claim 1 , wherein the plurality of cavities are formed via cross-sectional openings that are non-overlapping with one another.
8 . The method of claim 1 , wherein the dielectric material is the same as the first material.
9 . The method of claim 1 , wherein each cavity of the plurality of cavities is formed with an elliptical opening having a minor axis aligned along a length of the electrical isolation region.
10 . The method of claim 1 , wherein the plurality of cavities include an arrangement of multiple rows of cavities along a length of the electrical isolation region.
11 . The method of claim 1 , wherein the plurality of cavities include an arrangement of a first quantity of rows of cavities along a first portion of the electrical isolation region and a second quantity of rows of cavities along a second portion of the electrical isolation region.