Memory device with a split pillar architecture
Methods, systems, and devices for memory device with a split pillar architecture are described. A memory device may include a substrate arranged with conductive contacts in a pattern and openings through alternative layers of conductive and insulative material that may decrease the spacing between the openings while maintaining a dielectric thickness to sustain the voltage to be applied to the array. After etching material, an insulative material may be deposited in a trench. Portions of the insulative material may be removed to form openings, into which cell material is deposited. Conductive pillars may extend perpendicular to the planes of the conductive material and the substrate, and couple to conductive contacts. The conductive pillars and cell material may be divided to form a first and second storage components and first and second pillars.
1. A method, comprising:
forming a trench through a first dielectric layer, a first conductive layer, and a second dielectric layer, the trench exposing a substrate and dividing the first conductive layer into a first portion associated with a first word line driver and a second portion associated with a second word line driver;
depositing an insulative material into the trench;
forming a first opening over a contact in contact with the substrate by etching a portion of the insulative material;
depositing, into the first opening, a chalcogenide material in contact with the first portion of the first conductive layer, the first dielectric layer, and the second dielectric layer;
depositing, into the first opening, a conductive material to form a pillar that contacts the chalcogenide material and contacts the substrate; and
forming a second opening through the chalcogenide material and the conductive material to divide the chalcogenide material into a first chalcogenide component and a second chalcogenide component and divide the pillar into a first pillar and a second pillar.
2. The method of claim 1 , further comprising:
depositing, into the second opening, a second insulative material that contacts the first chalcogenide component and the second chalcogenide component.
3. The method of claim 1 , further comprising:
depositing a conformal material that contacts a first sidewall and a second sidewall of the trench, wherein depositing the insulative material into the trench is based at least in part on depositing the conformal material.
4. The method of claim 1 , wherein the first chalcogenide component comprises a first wall contacting the first conductive layer, a second wall contacting a second insulative material, a third wall contacting the first pillar, and a fourth wall contacting a conformal material.
5. The method of claim 1 , wherein forming the second opening through the chalcogenide material and the conductive material comprises:
performing a dry etching process to etch a second insulative material;
performing a selective wet etching process to divide the conductive material into the first pillar and the second pillar; and
performing a selective etching process to divide the chalcogenide material into the first chalcogenide component and the second chalcogenide component.
6. The method of claim 1 , wherein:
the first pillar is formed over the contact extending through the substrate; and
the second pillar is formed over a second contact extending through the substrate.
7. The method of claim 1 , further comprising:
depositing a second substrate over the first dielectric layer, the second substrate in contact with the first pillar and the second pillar, wherein the second substrate comprises a second contact extending through the second substrate and in contact with the first pillar, wherein the second pillar is in contact with the contact of the substrate.
8. The method of claim 1 , further comprising:
forming a plurality of contacts extending through the substrate, the plurality of contacts is associated with a plurality of digit lines;
forming the first dielectric layer on the substrate;
forming the first conductive layer on the first dielectric layer, the first conductive layer configured as at least one word line plate; and
forming the second dielectric layer on the first conductive layer, wherein forming the trench is based at least in part on forming the second dielectric layer.
9. The method of claim 1 , wherein:
the first pillar contacts at least one portion of the first dielectric layer, the second dielectric layer, and the first chalcogenide component; and
the second pillar contacts at least one portion of the first dielectric layer, the second dielectric layer, and the second chalcogenide component.
10. The method of claim 1 , wherein the first pillar and the second pillar are configured as digit lines.
11. The method of claim 1 , wherein forming the trench through the first dielectric layer comprises:
performing a vertical etching process to vertically etch the trench; and
performing a horizontal etching process after the vertical etching process to form at least one recess in the first conductive layer.
12. The method of claim 1 , wherein the trench extends through the first conductive layer in a serpentine shape.
13. The method of claim 1 , wherein the first chalcogenide component and the second chalcogenide component each comprise a storage element for a self-selecting memory cell.