FVBP without backside Si recess

Patent metadata

Field	Value
Publication number	US-12557320-B2
Application number	US-202318327114-A
Country	US
Kind code	B2
Filing date	Jun 1, 2023
Priority date	Jun 1, 2023
Publication date	Feb 17, 2026
Grant date	Feb 17, 2026

Abstract

A microelectronic structure including a nanosheet transistor that includes a source/drain. A frontside contact that includes a first section located on the frontside of the source/drain and a via section that extends to the backside of the nanosheet transistor. A shallow isolation layer located around a portion of the via section the first frontside contact. A backside metal line located on a backside surface of the via section and located on a backside surface of the shallow trench isolation layer. A dielectric liner located along a sidewall of the backside metal line and located along a bottom surface of the backside metal line.

First claim

What is claimed is:

1 . A microelectronic structure comprising:
a nanosheet transistor that includes a source/drain; a frontside contact that includes a first section located on the frontside of the source/drain and a via section that extends to a backside of the nanosheet transistor; a shallow isolation layer located around a portion of the via section the first frontside contact; a backside metal line located on a backside surface of the via section and located on a backside surface of a shallow trench isolation layer; and a dielectric liner located along a sidewall of the backside metal line and located along a bottom surface of the backside metal line, wherein the dielectric liner is in direct contact with a vertical side surface of the shallow trench isolation layer.

2 . The microelectronic structure of claim 1 , wherein the dielectric liner is comprised of at least two separate segments.

3 . The microelectronic structure of claim 2 , wherein each of the at least two separate segments of the dielectric liner have a L-shape, wherein a vertical section of the L-shape dielectric liner is located adjacent to the sidewall of the backside metal line, and wherein a horizontal section of the L-shape dielectric liner is located beneath the bottom surface of the backside metal line.

4 . The microelectronic structure of claim 3 , wherein the horizontal section of the L-shape dielectric liner is located adjacent to a sidewall of the shallow trench isolation layer.

5 . The microelectronic structure of claim 4 , wherein the vertical section of the L-shape dielectric liner has a first width as measured horizontally from a sidewall of the backside metal line across the vertical section of L-shape dielectric liner to an adjacent layer.

6 . The microelectronic structure of claim 5 , wherein the horizontal section of the L-shape dielectric liner has a second width as measure horizontally from the sidewall of the shallow trench isolation layer across the horizontal section of the L-shape dielectric liner to the adjacent layer.

7 . The microelectronic structure of claim 6 , wherein a value of the second width is two times greater than a value of the first width.

8 . The microelectronic structure of claim 6 , wherein the adjacent layer is comprised of a substrate material.

9 . The microelectronic structure of claim 6 , wherein the adjacent layer is comprised of a doped substrate material.

10 . A microelectronic structure comprising:
a first nanosheet transistor that includes a first source/drain; a first frontside contact that includes a first section located on a frontside of the first source/drain and a via section that extends to a backside of the first nanosheet transistor; a second nanosheet transistor that includes a second source/drain; a second frontside contact that includes a first section located on a frontside of the second source/drain and a via section that extends to a backside of the second nanosheet transistor; a shallow isolation layer located around a portion of the via section of the first frontside contact and the located around a portion of the via section of the second frontside contact; a first backside metal line located on a backside surface of the via section of the first frontside contact and located on a backside surface of a shallow trench isolation layer; a second backside metal line located on a backside surface of the via section of the second frontside contact and located on a backside surface of the shallow trench isolation layer; a first dielectric liner located along a sidewall of the first backside metal line and located along a bottom surface of the first backside metal line, and a second dielectric liner is located along a sidewall of the second backside metal line and located along a bottom surface of the second backside metal line; and a substrate layer located between the first dielectric liner and the second dielectric liner.

11 . The microelectronic structure of claim 10 ,
wherein the first dielectric liner is comprised of at least two separate segments and the second dielectric liner is comprise of at least two separate segments, wherein each of the at least two separate segments of the first dielectric liner have a L-shape and the each of the at least two separate segments of the second dielectric liner have a L-shape, wherein a vertical section of the L-shape first dielectric liner is located adjacent to the sidewall of the first backside metal line, and wherein a horizontal section of the L-shape first dielectric liner is located beneath the bottom surface of the first backside metal line, and wherein a vertical section of the L-shape second dielectric liner is located adjacent to the sidewall of the second backside metal line, and wherein a horizontal section of the L-shape second dielectric liner is located beneath the bottom surface of the second backside metal line.

12 . The microelectronic structure of claim 11 , wherein the horizontal section of the L-shape first dielectric liner and the horizontal section of the L-shape second dielectric liner located adjacent to a sidewall of the shallow trench isolation layer.

13 . The microelectronic structure of claim 12 , wherein the vertical section of the L-shape first dielectric liner has a first width as measured horizontally from a sidewall of the first backside metal line across the vertical section of L-shape first dielectric liner to the adjacent substrate layer.

14 . The microelectronic structure of claim 13 , wherein the horizontal section of the L-shape first dielectric liner has a second width as measure horizontally from the sidewall of the shallow trench isolation layer across the horizontal section of the L-shape dielectric liner to the adjacent substrate layer.

15 . The microelectronic structure of claim 14 , wherein a value of the second width is two times greater than a value of the first width.

16 . The microelectronic structure of claim 10 , wherein the substrate layer has an inverted U/V-shaped.

17 . The microelectronic structure of claim 16 , wherein a section of the shallow trench isolation layer is located between vertical sections of the inverted U/V shaped substrate layer.

18 . The microelectronic structure of claim 10 , wherein the substrate layer is in contact with the sidewall of the first dielectric liner, the sidewall of the second dielectric liner, and a sidewall of shallow trench isolation layer.

19 . The microelectronic structure of claim 10 , wherein the substrate layer is comprised of a doped substrate material.

20 . A microelectronic structure comprising:
a first nanosheet transistor that includes a first source/drain; a first frontside contact that includes a first section located on the frontside of the first source/drain and a via section that extends to the backside of the first nanosheet transistor; a second nanosheet transistor that includes a second source/drain; a second frontside contact that includes a first section located on the frontside of the second source/drain and a via section that extends to the backside of the second nanosheet transistor; a shallow isolation layer located around a portion of the via section of the first frontside contact and the located around a portion of the via section of the second frontside contact; a first backside metal line located on a backside surface of the via section of the first frontside contact and located on a backside surface of the shallow trench isolation layer; a second backside metal

Assignees

• IBM

Inventors

• Xie Ruilong
• Choi Kisik
• Hook Terence
• Reznicek Alexander
• Schmidt Daniel
• Kang Tsung-Sheng

Classifications

• H10W20/427

  Power or ground buses · CPC title

• H10W20/435

  Cross-sectional shapes or dispositions of interconnections · CPC title

• H10W20/40

  Interconnections external to wafers or substrates, e.g. back-end-of-line [BEOL] metallisations or vias connecting to gate electrodes · CPC title

• H10W20/023 Primary

  the interconnections being through-semiconductor vias · CPC title

• H10W20/42 Primary

  Vias, e.g. via plugs · CPC title