Semiconductor device and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-9601420-B2
Application number	US-201314018709-A
Country	US
Kind code	B2
Filing date	Sep 5, 2013
Priority date	Sep 6, 2012
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

A semiconductor device includes a stack structure of a conductive line and an insulating capping line extending in a first direction on a substrate, a plurality of contact plugs arranged in a row along the first direction and having sidewall surfaces facing the conductive line with air spaces between the sidewall surfaces and the conductive line, and a support interposed between the insulating capping line and the contact plugs to limit the height of the air spaces. The width of the support varies or the support is present only intermittently in the first direction. In a method of manufacturing the semiconductor devices, a sacrificial spacer is formed on the side of the stack structure, the spacer is recessed, a support layer is formed in the recess, the support layer is etched to form the support, and then the remainder of the spacer is removed to provide the air spaces.

First claim

What is claimed is:

1. A semiconductor device comprising:
a substrate;
a linear stack structure disposed on the substrate and extending longitudinally in a first direction on the substrate, the first direction being parallel to a top surface of the substrate,
the stack structure including a conductive line extending longitudinally in the first direction, and an insulating capping line disposed on an upwardly facing top surface of the conductive line and extending longitudinally in the first direction;
a row of contact plugs spaced from each other in the first direction, the contact plugs each having first and second sidewall surfaces, the first sidewall surfaces of the contact plugs facing one side of the conductive line with air spaces between the first sidewall surfaces and the conductive line, respectively, the second sidewall surface of each of the contact plugs facing a said second sidewall surface of another of the contact plugs in the row with air gaps extending in the first direction between adjacent ones of the second sidewall surfaces in the row;
a support interposed between one side of the insulating capping line and the row of contact plugs and topping the air spaces, the width of the support in a second direction orthogonal to the first direction and parallel to the upper surface of the substrate varying along the first direction or the support being discontinuous in the first direction; and
an interlayer insulating layer disposed on the stack structure, the interlayer insulating layer having a bottom surface extending contiguously across an upwardly facing top surface of the insulating capping line and into regions between upper portions of adjacent ones of the contact plugs in the row,
wherein the bottom surface of the interlayer insulating layer extends in said regions below the level of the upwardly facing top surface of the insulating capping line,
the bottom surface of the interlayer insulating layer tops and is exposed by the air gaps, and
the air gaps, mid-way between the adjacent ones of the second sidewall surfaces of the contact plugs in the row, are confined below the level of upwardly facing top surfaces of the contact plugs.

2. The device of claim 1 , wherein the support has a first support portion facing the first sidewall surfaces of the contact plugs and a second support portion that is offset from the first sidewall surfaces in the first direction so as to not face the sidewall surfaces, and
the width of the second support portion in the second direction is smaller than the width of the first support portion in the second direction.

3. The device of claim 2 , wherein the support includes a plurality of first support portions which are spaced from each other at regular intervals along the first direction, and face the first sidewall surfaces of the contact plugs, respectively.

4. The device of claim 2 , wherein the second support portion of the support has one sidewall surface disposed in said regions between upper portions of the contact plugs, and another sidewall surface that faces the capping line,
the bottom surface of the interlayer insulating layer covers said one sidewall surface of the second support portion, and
an uppermost boundary of each of the air gaps is located below the level of upwardly facing top surfaces of the contact plugs and above the level of a downwardly facing bottom surface of the second support portion.

5. The device of claim 2 , wherein the support is a single layer of material selected from the group consisting of SiCN, SiOC, SiON, SiOCN, and metal oxides.

6. The device of claim 1 , wherein the support extends continuously in the first direction over the entire length of the stack structure.

7. The device of claim 1 , wherein the support is discontinuous in the first direction over the entire length of the stack structure.

8. The device of claim 1 , further comprising an insulating liner interposed between the insulating capping line and the support, the insulating liner covering sides of the conductive line.

9. The device of claim 1 , further comprising insulating spacers covering the first sidewall surfaces of the contact plugs, and wherein the insulating spacers are exposed.

10. The device of claim 1 , wherein the first and second sidewall surfaces of the contact plugs are exposed.

11. The device of claim 1 , wherein the support includes at least one material selected from the group consisting of silicon nitride (SiN), silicon carbon nitride (SiCN), silicon oxide carbide (SiOC), silicon oxynitride (SiON), silicon oxide carbon nitride (SiOCN), titanium oxide (TiO), tantalum oxide (TaO), tantalum titanium oxide (TaTiO), tantalum silicon oxide (TaSiO), and aluminum oxide (AlO).

12. The device of claim 1 , wherein the support has a multilayered structure including a plurality of support layers of different materials.

13. The device of claim 1 , wherein an uppermost boundary of each of the air gaps is located below the level of upwardly facing top surfaces of the contact plugs and above the level of the upwardly facing top surface of the conductive line of the stack structure.

14. The device of claim 1 , wherein no part of the support is interposed in the first direction between the contact plugs adjacent one another in the row.

15. A semiconductor device comprising:
a substrate having a plurality of active regions;
a linear stack structure including a bit line and an insulating capping line disposed on an upwardly facing surface of the bit line, and wherein the stack structure extends longitudinally on the substrate across the plurality of active regions in a first direction parallel to a top surface of the substrate;
contact plugs each contacting one of the active regions and each having first and second sidewall surfaces, the first sidewall surfaces of the contact plugs facing the bit line with air spaces between the first sidewall surfaces and the bit line, respectively, the second sidewall surface of each of the contact plugs facing a said second sidewall surface of another of the contact plugs with air gaps extending in the first direction between adjacent ones of the second sidewall surfaces of the contact plugs;
a support having a bottom surface and opposite sidewall surfaces, the bottom surface topping and exposed by the air spaces, one of the opposite sidewall surfaces facing the insulating capping line and the other of the opposite sidewall surfaces facing the contact plugs, the width of the support in a second direction orthogonal to the first direction and parallel to the top surface of the substrate varying along the first direction or the support is discontinuous in the first direction; and
an interlayer insulating layer disposed on the stack structure, the interlayer insulating layer having a bottom surface extending contiguously across an upwardly facing top surface of the insulating capping line and into regions between upper portions of the contact plugs,
wherein the bottom surface of the interlayer insulating layer extends in said regions below the level of the upwardly facing top surface of the insulating capping line,
the bottom surface of the interlayer insulating layer tops and is exposed by the air gaps, and
the air gaps, mid-way between the adjacent ones of the second sidewall surfaces of the contact plugs in the row, are confined below the level of upwardly facing top surfaces of the contact plugs.

16. The device of claim 15 , further comprising a word line buried in the substrate, the word line extending in a direction different from the first direction.

17. The device of cla

Assignees

• Hwang Yoo-Sang
• Chung Hyun-Woo
• Kim Dae-Ik
• Samsung Electronics Co Ltd

Inventors

• Hwang Yoo-Sang
• Chung Hyun-Woo
• Kim Dae-Ik

Classifications

• H10W20/495

  Capacitive arrangements or effects of, or between wiring layers · CPC title

• H10W20/072

  of dielectric parts comprising air gaps · CPC title

• H10W20/069

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

• H10W20/063

  by forming conductive members before forming protective insulating material · CPC title

• H10W20/47

  comprising two or more dielectric layers having different properties, e.g. different dielectric constants · CPC title