Semiconductor device including carbon-containing contact fence

Patent metadata

Field	Value
Publication number	US-11980025-B2
Application number	US-202217705991-A
Country	US
Kind code	B2
Filing date	Mar 28, 2022
Priority date	Sep 23, 2021
Publication date	May 7, 2024
Grant date	May 7, 2024

Abstract

A semiconductor device includes; an active region defined by an isolation film on a substrate, a word line in the substrate, the word line extending in a first direction and crossing the active region, a bit line above the word line and extending in a second direction, a contact between bit lines adjacent in the first direction, the contact connecting the active region and extending in a vertical direction, and a contact fence disposed on each of opposing side surfaces of the contact in the second direction and extending in the vertical direction, wherein the active region has a bar shape extending oblique to the first direction, and the contact fence includes a carbon-containing insulating film.

First claim

What is claimed is:

1. A semiconductor device comprising:
an active region defined by an isolation film on a substrate;
a word line in the substrate, the word line extending in a first direction and crossing the active region;
a bit line above the word line and extending in a second direction;
a contact between bit lines adjacent in the first direction, the contact connecting to the active region and extending in a vertical direction; and
a contact fence disposed on each of opposing side surfaces of the contact in the second direction and extending in the vertical direction,
wherein the contact fence has a step in a portion corresponding to a top surface of the contact,
wherein the active region has a bar shape extending oblique to the first direction, and
wherein the contact fence includes a carbon-containing insulating film.

2. The semiconductor device of claim 1 , wherein a horizontal cross-section of the contact fence has a rectangular shape, and
an entirety of the contact fence includes the carbon-containing insulating film.

3. The semiconductor device of claim 2 , wherein, when a trench for formation of the contact fence has substantially a same width in the second direction as a sacrificial film in an outer portion of the trench,
the contact fence is formed by filling the trench with the carbon-containing insulating film,
the contact is formed by filling a conductive film in a portion from which the sacrificial film and a portion of the carbon-containing insulating film are removed, and
a width of the contact is greater than a width of the contact fence in the second direction.

4. The semiconductor device of claim 1 , wherein a horizontal cross-section of the contact fence has a rectangular shape,
the contact fence includes a center fence including a silicon nitride (SiN) film and an outer fence including the carbon-containing insulating film, and
the outer fence is disposed on each of opposing side surfaces of the center fence in the first direction.

5. The semiconductor device of claim 4 , wherein, when a trench for formation of the contact fence has a greater width in the second direction than a sacrificial film in an outer portion of the trench,
the contact fence is formed by filling the trench with the SiN film and the carbon-containing insulating film,
the contact is formed by filling a conductive film in a portion from which the sacrificial film and a portion of the carbon-containing insulating film are removed, and
a width of the contact is substantially same as a width of the contact fence in the second direction.

6. The semiconductor device of claim 1 , wherein a width of an upper portion of the contact fence above the step is greater than a width of a lower portion of the contact fence below the step in the second direction.

7. The semiconductor device of claim 1 , wherein a width of an upper portion of the contact fence above the step is less than a width of a lower portion of the contact fence below the step in the second direction.

8. The semiconductor device of claim 1 , wherein the contact includes a polysilicon film.

9. The semiconductor device of claim 1 , wherein the carbon-containing insulating film includes at least one of silicon oxide carbon (SiOC) or silicon oxide carbon nitride (SiOCN).

10. A semiconductor device comprising:
an active region defined by an isolation film on a substrate;
a word line in the substrate, the word line extending in a first direction and crossing the active region;
a bit line disposed above the word line and extending in a second direction;
a contact between bit lines adjacent in the first direction, the contact being connected to the active region and extending in a vertical direction; and
a contact fence on each of opposing side surfaces of the contact in the second direction and extending in the vertical direction,
wherein the active region has a bar shape extending oblique to the first direction, and
the contact fence includes a center fence including a silicon nitride (SiN) film and an outer fence including a carbon-containing insulating film.

11. The semiconductor device of claim 10 , wherein a horizontal cross-section of the contact fence has a rectangular shape, and
the outer fence is disposed on each of opposing side surfaces of the center fence in the first direction.

12. The semiconductor device of claim 10 , wherein, when a trench for formation of the contact fence has a greater width in the second direction than a sacrificial film in an outer portion of the trench,
the contact fence is formed by filling the trench with the SiN film and the carbon-containing insulating film,
the contact is formed by filling a conductive film in a portion from which the sacrificial film and a portion of the carbon-containing insulating film are removed, and
a width of the contact is substantially same as a width of the contact fence in the second direction.

13. The semiconductor device of claim 10 , wherein the contact fence has a step in a portion corresponding to a top surface of the contact.

14. The semiconductor device of claim 13 , wherein the contact fence includes one of
a first structure in which a width of an upper portion of the contact fence above the step is greater in the second direction than a width of a lower portion of the contact fence below the step,
a second structure in which the width of the upper portion of the contact fence above the step is less in the second direction than the width of the lower portion of the contact fence below the step, and
a third structure in which the width of the contact fence in the second direction increases upwardly in the vertical direction, or is substantially same in upper and lower portions of the contact fence.

15. A semiconductor device comprising:
an active region defined by an isolation film on a substrate;
a word line in the substrate, the word line extending in a first direction and crossing the active region;
a bit line disposed above the word line and extending in a second direction;
a contact between bit lines adjacent in the first direction, the contact being connected to the active region and extending in a vertical direction; and
a contact fence on each of opposing side surfaces of the contact in the second direction and extending in the vertical direction,
wherein the active region has a bar shape extending oblique to the first direction,
wherein the contact fence includes a carbon-containing insulating film,
wherein the contact comprises a conductive film filling a volume from which the carbon-containing insulating film has been removed, and
wherein a width of the contact is greater than a width of the contact fence in the second direction.

16. The semiconductor device of claim 15 , wherein the contact fence has a step in a portion corresponding to a top surface of the contact.

17. The semiconductor device of claim 16 , wherein the contact fence includes one of
a first structure in which a width of an upper portion of the contact fence above the step is greater in the second direction than a width of a lower portion of the contact fence below the step,
a second structure in which the width of the upper portion of the contact fence above the step is less in the second direction than the width of the lower portion of the contact fence below the step, and
a third structure in which the width of the contact fence in the second direction increases upwards in the vertical direction or is substantially same in upper and lower portions of the contact fence.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Ahn Junhyeok
• Kim Huijung
• Lee Kiseok
• Lee Myeongdong

Classifications

• H10D84/0149

  Manufacturing their interconnections or electrodes, e.g. source or drain electrodes · CPC title

• H10B12/485 Primary

  Bit line contacts · CPC title

• H10B12/34

  the transistor being at least partially in a trench in the substrate · CPC title

• H10B12/315 Primary

  with the capacitor higher than a bit line · CPC title

• H10W20/069

  by forming self-aligned vias or self-aligned contact plugs · CPC title