Methods of forming an array of conductive lines and methods of forming an array of recessed access gate lines
View Patent ↗An array of recessed access gate lines includes active area regions having dielectric trench isolation material there-between. The trench isolation material comprises dielectric projections extending into opposing ends of individual active area regions under an elevationally outermost surface of material of the active area regions. The active area material is elevationally over the dielectric projections. Recessed access gate lines individually extend transversally across the active area regions and extend between the ends of immediately end-to-end adjacent active area regions within the dielectric trench isolation material. Other arrays are disclosed, as are methods.
1. A method of forming an array of recessed access gate lines, comprising:
etching isolation trenches into semiconductor material to a first depth to define active area regions;
etching the isolation trenches deeper into the semiconductor material to a second depth, the etching to the second depth projecting the isolation trenches longitudinally into opposing longitudinal ends of individual active area regions below the first depth;
forming dielectric trench isolation material in the extended isolation trenches including projecting portions thereof to form dielectric projections extending into the opposing longitudinal ends of the individual active area regions under an elevationally outermost surface of the semiconductor material of the active area regions, the semiconductor material being elevationally over the dielectric projections; and
forming recessed access gate lines which individually extend transversally across the active area regions and extend between the longitudinal ends of immediately end-to-end adjacent active area regions within the dielectric trench isolation material.
2. The method of claim 1 wherein the deeper etching does not project the isolation trenches into opposing sides of the individual active area regions longitudinally along all of the individual active area regions below the first depth.
3. The method of claim 1 wherein the deeper etching projects the isolation trenches into opposing sides of the individual active area regions longitudinally along all of the individual active area regions below the first depth.
4. The method of claim 1 wherein the deeper etching comprises:
forming masking material over sidewalls and bases of the isolation trenches that have been etched to the first depth, the masking material being thicker centrally over the isolation trench bases that are between immediately side-to-side adjacent active area regions than centrally over the isolation trench bases that are between immediately end-to-end adjacent active area regions;
etching the masking material to centrally expose the isolation trench bases that are between immediately end-to-end adjacent active area regions but not expose the isolation trench bases that are centrally between immediately side-to-side adjacent active area regions;
first etching the semiconductor material to project the isolation trenches longitudinally into opposing longitudinal ends of individual active area regions below the first depth;
after the first etching, removing all of the masking material from the isolation trenches; and
after the removing, second etching the semiconductor material to the second depth.
5. A method of forming an array of conductive lines, comprising:
etching isolation trenches into semiconductor material to a first depth to define active area regions;
etching the isolation trenches deeper into the semiconductor material to a second depth, the etching to the second depth projecting the isolation trenches laterally into opposing sides of individual active area regions below the first depth;
forming dielectric trench isolation material in the extended isolation trenches including projecting portions thereof to form dielectric projections extending laterally into the opposing sides of the individual active area regions under an elevationally outermost surface of the semiconductor material of the active area regions, the semiconductor material being elevationally over the dielectric projections;
etching a contact opening into the semiconductor material at a longitudinally central portion of the individual active area regions to form a longitudinally central semiconductor material elevationally outer surface that is elevationally inward relative to the elevationally outermost surface of the semiconductor material in the individual active area regions; and
forming conductive lines that individually extend transversally across and elevationally over the longitudinally central portions of the active area regions, conductive material being directly against the longitudinally central semiconductor material elevationally outer surface of the individual active area regions and being conductively coupled to the conductive line transversally crossing thereover.
6. The method of claim 5 comprising, prior to etching the contact openings, forming recessed access gate lines which individually extend transversally across the active area regions and extend between the longitudinal ends of immediately end-to-end adjacent active area regions within the dielectric trench isolation material.
7. A method of forming an array of recessed access gate lines and an array of conductive lines, comprising:
etching isolation trenches into semiconductor material to a first depth to define active area regions;
etching the isolation trenches deeper into the semiconductor material to a second depth, the etching to the second depth projecting the isolation trenches longitudinally into opposing longitudinal ends of individual active area regions below the first depth and projecting the isolation trenches laterally into opposing sides of the individual active area regions below the first depth;
forming dielectric trench isolation material in the extended isolation trenches including projecting portions thereof to form dielectric end projections extending into the opposing longitudinal ends of the individual active area regions under an elevationally outermost surface of the semiconductor material of the active area regions and to form dielectric lateral projections extending laterally into the opposing sides of the individual active area regions under the elevationally outermost surface of the semiconductor material of the active area regions, the semiconductor material being elevationally over the longitudinal end and lateral dielectric projections;
forming recessed access gate lines which individually extend transversally across the active area regions and extend between the longitudinal ends of immediately end-to-end adjacent active area regions within the dielectric trench isolation material;
after forming the recessed access gate lines, etching a contact opening into the semiconductor material at a longitudinally central portion of the individual active area regions to form a longitudinally central semiconductor material elevationally outer surface that is elevationally inward relative to the elevationally outermost surface of the semiconductor material in the individual active area regions; and
forming conductive lines that individually extend transversally across and elevationally over the longitudinally central portions of the active area regions, conductive material being directly against the longitudinally central semiconductor material elevationally outer surface of the individual active area regions and being conductively coupled to the conductive line transversally crossing thereover.