Three-dimensional memory device containing phosphorus-doped silicon oxide ion-gettering structures and methods of forming the same
A three-dimensional memory device includes a pair of alternating stacks of insulating layers and electrically conductive layers, where the pair of alternating stacks are laterally spaced from each other by a lateral isolation trench, memory openings vertically extending through a respective alternating stack of the pair of alternating stacks, memory opening fill structures located in a respective one of the memory openings and including a respective vertical semiconductor channel and a respective vertical stack of memory elements, and a lateral isolation trench fill structure located in the lateral isolation trench. Phosphorus-doped silicon oxide portions are located within or on sidewalls of the lateral isolation trench at levels of the insulating layers.
1 . A three-dimensional memory device, comprising:
a pair of alternating stacks of insulating layers and electrically conductive layers, wherein the pair of alternating stacks are laterally spaced from each other by a lateral isolation trench;
memory openings vertically extending through a respective alternating stack of the pair of alternating stacks;
memory opening fill structures located in a respective one of the memory openings and comprising a respective vertical semiconductor channel and a respective vertical stack of memory elements;
a lateral isolation trench fill structure located in the lateral isolation trench, wherein phosphorus-doped silicon oxide portions are located within or on sidewalls of the lateral isolation trench at levels of the insulating layers; and
further comprising at least one feature selected from:
(a) the phosphorus-doped silicon oxide portions are doped with carbon atoms at an atomic percentage of at least 0.001%; or
(b) the phosphorus-doped silicon oxide portions are located within the lateral isolation trench; or
(c) the lateral isolation trench fill structure comprises an insulating spacer and a conductive fill structure.
2 . The three-dimensional memory device of claim 1 , wherein the at least one feature comprises the feature (a).
3 . The three-dimensional memory device of claim 1 , wherein the at least one feature comprises the feature (b).
4 . The three-dimensional memory device of claim 3 , wherein the phosphorus-doped silicon oxide portions comprise portions of a single continuous insulating structure located in the lateral isolation trench and vertically extending from bottommost layers of the pair of alternating stacks to topmost layers of the alternating stacks.
5 . The three-dimensional memory device of claim 1 , wherein the at least one feature comprises the feature (c).
6 . A three-dimensional memory device, comprising:
a pair of alternating stacks of insulating layers and electrically conductive layers, wherein the pair of alternating stacks are laterally spaced from each other by a lateral isolation trench;
memory openings vertically extending through a respective alternating stack of the pair of alternating stacks;
memory opening fill structures located in a respective one of the memory openings and comprising a respective vertical semiconductor channel and a respective vertical stack of memory elements; and
a lateral isolation trench fill structure located in the lateral isolation trench, wherein phosphorus-doped silicon oxide portions are located within or on sidewalls of the lateral isolation trench at levels of the insulating layers;
wherein:
the vertical semiconductor channel comprises p-type silicon;
a n-type silicon source region doped with phosphorus atoms is located below the lateral isolation trench fill structure; and
the n-type silicon source region is also doped with carbon atoms.
7 . The three-dimensional memory device of claim 6 , further comprising a carbon doped silicon region located below the n-type silicon source region.
8 . A three-dimensional memory device, comprising:
a pair of alternating stacks of insulating layers and electrically conductive layers, wherein the pair of alternating stacks are laterally spaced from each other by a lateral isolation trench;
memory openings vertically extending through a respective alternating stack of the pair of alternating stacks;
memory opening fill structures located in a respective one of the memory openings and comprising a respective vertical semiconductor channel and a respective vertical stack of memory elements;
a lateral isolation trench fill structure located in the lateral isolation trench, wherein phosphorus-doped silicon oxide portions are located within or on sidewalls of the lateral isolation trench at levels of the insulating layers, wherein the phosphorus-doped silicon oxide portions are located on the sidewalls of the lateral isolation trench; and
a contact-level dielectric layer overlying the alternating stacks,
wherein:
the lateral isolation trench extends through the contact-level dielectric layer; and
an additional phosphorus-doped silicon oxide portion is located at a level of the contact-level dielectric layer within or around the lateral isolation trench.
9 . The three-dimensional memory device of claim 8 , wherein the contact-level dielectric layer comprises:
a base contact-level dielectric sublayer that is laterally spaced from the lateral isolation trench fill structure; and
a doped contact-level dielectric sublayer overlying the base contact-level dielectric sublayer and comprising phosphorus atoms at a higher atomic concentration than the base contact-level dielectric sublayer.
10 . A three-dimensional memory device, comprising:
a pair of alternating stacks of insulating layers and electrically conductive layers, wherein the pair of alternating stacks are laterally spaced from each other by a lateral isolation trench;
memory openings vertically extending through a respective alternating stack of the pair of alternating stacks;
memory opening fill structures located in a respective one of the memory openings and comprising a respective vertical semiconductor channel and a respective vertical stack of memory elements; and
a lateral isolation trench fill structure located in the lateral isolation trench, wherein phosphorus-doped silicon oxide portions are located within or on sidewalls of the lateral isolation trench at levels of the insulating layers;
wherein:
the phosphorus-doped silicon oxide portions are located on the sidewalls of the lateral isolation trench;
the insulating layers comprise a silicon oxide material; and
the phosphorus-doped silicon oxide portions comprise portions of the insulating layers that are proximal to the lateral isolation trench fill structure.
11 . The three-dimensional memory device of claim 10 , wherein the phosphorus-doped silicon oxide portions have a higher atomic concentration of phosphorus atoms than portions of the insulating layers located adjacent to the phosphorus-doped silicon oxide portions.
12 . The three-dimensional memory device of claim 10 , wherein the phosphorus-doped silicon oxide portions are located outside the lateral isolation trench and are vertically spaced from each other.
13 . A method of forming a three-dimensional memory device, comprising:
forming two alternating stacks of insulating layers and electrically conductive layers, wherein the two alternating stacks are laterally spaced from each other by a lateral isolation trench,
forming memory openings through each of the two alternating stacks;
forming memory opening fill structures comprising a respective vertical semiconductor channel and a respective vertical stack of memory elements in the respective memory openings;
forming phosphorus-doped silicon oxide portions within or on sidewalls of the lateral isolation trench at levels of the insulating layers; and
forming a lateral isolation trench fill structure in the lateral isolation trench; and
further comprising at least one feature selected from:
(d) the insulating layers comprise silicon oxide; and the step of forming the phosphorus-doped silicon oxide portions on sidewalls of the lateral isolation trench comprises performing at least one ion implantation process that implants phosphorous atoms into surface portions of the insulating layers that are proximal to the lateral isolation trench, wherein the phosphorus-doped silicon oxide portions comprise implanted portions of the insulating layers; or
(e) the step of forming the phosphorus-doped silicon oxide portions within the lateral isolation trench comprises depositing a phosphorus-doped silicate glass spacer at least in a peripheral region of the lateral isolation trench, wherein the phosphorus-doped silicon oxide portions comprise portions of the phosphorus-doped silicate glass spacer; or
(f) the lateral isolation trench fill structure comprises a conductive fill structure that is formed within and is laterally surrounded by the phosphorus-doped silicon oxide portions.
14 . The method of claim 13 , wherein the at least one feature comprises the feature (d).
15 . The method of claim 14 , further comprising performing at least one additional ion implantation process that implants carbon atoms into the phosphorus-doped silicon oxide portions.
16 . The method of claim 15 , wherein a surface portion of the at least one semiconductor material that underlies the lateral isolation trench is doped with the phosphorus atoms during the at least one ion implantation process and is doped with the carbon atoms during the at least one additional ion implantation process.
17 . The method of claim 13 , wherein the at least one feature comprises the feature (e).
18 . The method of claim 13 , wherein the at least one feature comprises the feature (f).