Microelectronic devices with active source/drain contacts in trench in symmetrical dual-block structure, and related systems and methods

Patent metadata

Field	Value
Publication number	US-12166094-B2
Application number	US-202117373258-A
Country	US
Kind code	B2
Filing date	Jul 12, 2021
Priority date	Jul 12, 2021
Publication date	Dec 10, 2024
Grant date	Dec 10, 2024

Abstract

Microelectronic devices include a tiered stack having vertically alternating insulative and conductive structures. A first series of stadiums is defined in the tiered stack within a first block of a dual-block structure. A second series of stadiums is defined in the tiered stack within a second block of the dual-block structure. The first and second series of stadiums are substantially symmetrically structured about a trench at a center of the dual-block structure. The trench extends a width of the first and second series of stadiums. The stadiums of the first and second series of stadiums have opposing staircase structures comprising steps at ends of the conductive structures of the tiered stack. Conductive source/drain contact structures are in the stack and extend substantially vertically from a source/drain region at a floor of the trench. Additional microelectronic devices are also disclosed, as are methods of fabrication and electronic systems.

First claim

What is claimed is:

1. A microelectronic device, comprising:
a stack structure comprising a vertically alternating sequence of insulative structures and conductive structures arranged in tiers;
a pair of slit structures vertically and laterally extending through the stack structure;
a dual-block structure between the pair of slit structures, the dual-block structure comprising:
a first series of stadiums defined in the stack structure within a first block of the dual-block structure; and
a second series of stadiums defined in the stack structure within a second block of the dual-block structure,
the first series of stadiums and the second series of stadiums being substantially symmetrically structured about a trench at a center of the dual-block structure, the trench laterally extending a width of the first series and the second series of stadiums,
the stadiums of the first series and of the second series of stadiums having opposing staircase structures comprising steps at ends of the conductive structures of the stack structure,
within individual of the stadiums, the steps laterally ascending or laterally descending to define the staircase structures of the stadiums; and

conductive source/drain contact structures in the trench, extending substantially vertically from a source/drain region at a floor of the trench.

2. The microelectronic device of claim 1 , further comprising:
conductive step contact structures extending from the steps of the opposing staircase structures; and
conductive routing lines operatively connecting the conductive step contact structures to the conductive source/drain contact structures.

3. The microelectronic device of claim 2 , further comprising at least one crest portion of the stack structure, the at least one crest portion disposed laterally between one stadium of the first series of stadiums and another stadium of the first series of stadiums, the at least one crest portion extending a full height of the stack.

4. The microelectronic device of claim 3 , wherein the at least one crest portion is substantially free of the conductive source/drain contact structures.

5. The microelectronic device of claim 2 , wherein at least some of the conductive routing lines extend substantially longitudinally from above the steps to above the trench.

6. The microelectronic device of claim 1 , further comprising a dielectric material within the first series of stadiums, within the second series of stadiums, and within the trench.

7. The microelectronic device of claim 6 , wherein the conductive source/drain contact structures extend through the dielectric material in direct physical contact with the dielectric material.

8. The microelectronic device of claim 6 , further comprising conductive step contacts extending to the steps through the dielectric material in direct physical contact with the dielectric material.

9. The microelectronic device of claim 1 , wherein the pair of slit structures are along sidewalls of the dual-block structure, the pair of slit structures comprising:
a first slit structure horizontally adjacent the first series of stadiums and extending through a full height of the stack structure; and
a second slit structure horizontally adjacent the second series of stadiums and extending through a full height of the stack structure.

10. The microelectronic device of claim 1 , further comprising:
a first bridge of the stack structure, the first bridge being interposed between the first series of stadiums and a first slit structure, of the pair of slit structures, extending through a full height of the stack structure; and
a second bridge of the stack structure, the second bridge being interposed between the second series of stadiums and a second slit structure, of the pair of slit structures, extending through a full height of the stack structure.

11. The microelectronic device of claim 1 , wherein the trench spaces the first series of stadiums from the second series of stadiums by a distance of less than about 1.3 μm.

12. The microelectronic device of claim 1 , wherein each step of the steps of the opposing staircase structures longitudinally extends directly from a bridge portion of the stack structure to the trench.

13. The microelectronic device of claim 1 , wherein:
some steps, of the steps of the opposing staircase structures, longitudinally extend directly from a bridge portion of the stack structure to a step edge longitudinally recessed from the trench; and
other steps, of the steps of the opposing staircase structures, longitudinally extend directly from the step edge to the trench.

14. A microelectronic device, comprising:
a stack structure comprising insulative structures vertically interleaved with conductive structures and arranged in tiers;
a pair of slit structures vertically extending through the stack structure to a source/drain region below the stack structure;
a trench between a first slit structure and a second slit structure of the pair of slit structures, the trench vertically extending through the stack structure to the source/drain region, the trench horizontally extending in a lateral direction substantially parallel to the first slit structure and the second slit structure;
a first series of staircased stadiums defined in the stack structure between the first slit structure and the trench;
a second series of staircased stadiums defined in the stack structure between the second slit structure and the trench; and
conductive contact structures disposed in the trench and extending from the source/drain region,
the staircased stadiums of the first series and of the second series individually comprising at least one set of steps ascending or descending in the lateral direction substantially parallel to the trench,
the first series of staircased stadiums being substantially symmetrically structured relative to the second series of staircased stadiums.

15. The microelectronic device of claim 14 , wherein the staircased stadiums of the first series and of the second series of staircased stadiums each comprise a pair of opposing staircases with a substantially same elevational profile as other pairs of opposing staircases of the staircased stadiums of the first series and of the second series of staircased stadiums.

16. The microelectronic device of claim 15 , wherein the pair of opposing staircases individually comprises two of the at least one set of steps ascending or descending in the lateral direction, the two consisting of:
one set of the steps descending in the lateral direction; and
one set of the steps ascending in the lateral direction, each of the steps being defined by a surface area of an end of a different one of the conductive structures.

17. The microelectronic device of claim 15 , wherein the pair of opposing staircases individually comprises multiple sets of the at least one set of steps ascending or descending in the lateral direction, each of the steps being defined by a surface area of an end of a different one of the conductive structures.

18. The microelectronic device of claim 14 , further comprising additional conductive contact structures within the staircased stadiums of the first series and the second series of staircased stadiums, the additional conductive contact structures each extending to a different one of the conductive structures of the stack structure.

19. The microelectronic device of claim 18 , further comprising:
dielectric material within horizontal areas of each of the first series of staircased stadiums, the second

Assignees

• Micron Technology Inc

Inventors

• Xu Lifang
• Hill Richard J
• Chary Indra V
• Heineck Lars P

Classifications

• H10W20/081

  by forming openings in the dielectric parts · CPC title

• H10W20/056

  by filling conductive material into holes, grooves or trenches · CPC title

• H10W20/43

  Layouts of interconnections · CPC title

• H10D64/01

  Manufacture or treatment · CPC title

• H10D64/252 Primary

  for vertical or pseudo-vertical devices · CPC title