US-20260129947-A1 - SEMICONDUCTOR DEVICE INCLUDING TRANSISTOR STRUCTURES AND WORK-FUNCTION FILM

US20260129947A1US 20260129947 A1US20260129947 A1US 20260129947A1US-20260129947-A1

Abstract

A semiconductor device includes a substrate, a plurality of transistor structures disposed on the substrate and spaced apart from each other in a first direction parallel to a surface of the substrate, each of the plurality of transistor structures including a lower portion active pattern and an upper portion active pattern spaced apart from the lower portion active pattern in a second direction intersecting the first direction, a gate cut film disposed between two adjacent transistor structures of the plurality of transistor structures, for each lower portion active pattern, a first layer that surrounds a portion of the lower portion active pattern, and a second layer disposed on each first layer. Each of the plurality of transistor structures includes a first work-function film surrounding the first portion of the lower portion active pattern and a second work-function film that surrounds a portion of the upper portion active pattern.

Inventors

Byungho Moon
Minwoo Kim
Donghoon HWANG
Seongkwang Kim
Hyunsoo Kim
Wonchang LEE
Jaeho JEON

Assignees

SAMSUNG ELECTRONICS CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20250919
Priority Date: 20241101

Claims (20)

1 . A semiconductor device comprising: a substrate; a plurality of transistor structures disposed on the substrate and spaced apart from each other in a first direction parallel to a surface of the substrate, each of the plurality of transistor structures comprising a lower portion active pattern and an upper portion active pattern spaced apart from the lower portion active pattern in a second direction intersecting the first direction; a gate cut film disposed between two adjacent transistor structures of the plurality of transistor structures; for each lower portion active pattern, a first layer that surrounds at least a first portion of the lower portion active pattern; and a second layer disposed on each first layer, wherein each of the plurality of transistor structures comprises a first work-function film surrounding the first portion of the lower portion active pattern and a second work-function film that surrounds at least a first portion of the upper portion active pattern and extends in the first direction, and wherein the gate cut film penetrates through the second work-function film to form a gap between a first part of the second work-function film and a second part of the second work-function film.
2 . The semiconductor device of claim 1 , wherein the gate cut film has a length in the first direction that gradually decreases as the gate cut film gets closer to the substrate.
3 . The semiconductor device of claim 1 , wherein the first work-function film includes a gap formed therein at a location between the plurality of transistor structures.
4 . The semiconductor device of claim 1 , further comprising a separating insulating film disposed in each transistor structures between the lower portion active pattern and the upper portion active pattern, wherein the separating insulating film contacts the second work-function film.
5 . The semiconductor device of claim 1 , wherein at least a common gate transistor structures of the plurality of transistor structures includes a region in which the first work-function film and the second work-function film contact each other.
6 . The semiconductor device of claim 5 , wherein: in the common gate transistor structure, a surface area of an entire contact region where the second work-function film and the second layer contact each other is greater than a surface area of an entire contact region where the first work-function film and the second work-function film contact each other.
7 . The semiconductor device of claim 5 , wherein: in the common gate transistor structure, the second work-function film comprises a bottommost surface in the second direction that is closer to the substrate than an uppermost surface of the first work-function film is to the substrate.
8 . The semiconductor device of claim 1 , wherein at least a split gate transistor structure of the plurality of transistor structures includes a region in which the first work-function film comprises an uppermost surface in the second direction that is closer to the substrate than a bottommost surface of the second work-function film is to the substrate.
9 . The semiconductor device of claim 8 , wherein: in the split gate transistor structure, a length (T 1 ) in the second direction between the uppermost surface of the first work-function film and the bottommost surface of the second work-function film is less than 5.8 nm.
10 . The semiconductor device of claim 8 , wherein the split gate transistor structure further comprises a separating insulating film disposed between the lower portion active pattern and the upper portion active pattern, a ratio (T 1 /T 2 ) of the length (T 1 ) between the uppermost surface of the first work-function film and the bottommost surface of the second work-function surface and a length (T 2 ) of the separating insulating film in the second direction is 0.5 or less.
11 . The semiconductor device of claim 1 , wherein the first layer comprises a first insulating material and the second layer comprises a second insulating material, and a portion of the first layer is disposed continuously in the first direction between the plurality of transistor structures.
12 . The semiconductor device of claim 11 , wherein: a first transistor structure of the plurality of transistor structures comprises a region in which the first work-function film and the second work-function film contact each other, and in the first transistor structure, an uppermost surface of the first layer is closer to the substrate than a bottommost surface of the second work-function film is to the substrate.
13 . The semiconductor device of claim 11 , wherein the plurality of transistor structures comprise a first transistor structure that comprises a region in which the first work-function film and the second work-function film contact each other and a second transistor structure that comprises the first work-function film comprising an uppermost surface that is closer in the second direction to the substrate than a bottommost surface of the second work-function film is to the substrate, and wherein a maximum thickness in the second direction of the second work-function film of the first transistor structure is the same as a maximum thickness in the second direction of the second work-function film of the second transistor structure.
14 . The semiconductor device of claim 1 , wherein the first layer comprises a conductive material, and the second layer comprises an insulating material, and wherein a gap is formed in the first layer between the plurality of transistor structures.
15 . The semiconductor device of claim 14 , wherein the plurality of transistor structures include a first transistor structure that comprises a region in which the first work-function film and the second work-function film contact each other, and wherein, in the first transistor structure, the second work-function film comprises a bottommost surface that is closer to the substrate than an uppermost surface of the first layer is to the substrate.
16 . The semiconductor device of claim 14 , wherein the plurality of transistor structures comprise a first transistor structure that comprises a region in which the first work-function film and the second work-function film contact each other and a second transistor structure that comprises the first work-function film comprising an uppermost surface that is closer in the second direction to the substrate than a bottommost surface of the second work-function film is to the substrate, and wherein a maximum thickness in the second direction of the second work-function film of the first transistor structure is greater than a maximum thickness in the second direction of the second work-function film of the second transistor structure.
17 . The semiconductor device of claim 16 , wherein the first transistor structure comprises the first work-function film that comprises a concave portion at an interface with the second work-function film.
18 . A semiconductor device comprising: a substrate; a plurality of transistor structures disposed on the substrate and spaced apart from each other in a first direction parallel to a surface of the substrate, each comprising a lower portion active pattern comprising a plurality of sheets spaced apart from each other in a second direction intersecting the first direction, an upper portion active pattern spaced apart from the lower portion active pattern in the second direction and comprising a plurality of sheets that are spaced apart from each other in the second direction, and a separating insulating film disposed between the lower portion active pattern and the upper portion active pattern; a gate cut film disposed between adjacent transistor structures of the plurality of transistor structures; a first layer that surrounds at least a portion of each of the lower portion active patterns; and a second layer disposed on the first layer, wherein the gate cut film penetrates a work-function film in the second direction to fill a gap in the work-function film.
19 . The semiconductor device of claim 18 , wherein a bottommost surface of the gate cut film is closer to the substrate than an uppermost surface of the separating insulating film is to the substrate.
20 . A semiconductor device comprising: a substrate; a plurality of transistor structures disposed on the substrate and spaced apart from each other in a first direction parallel to a surface of the substrate, each comprising a lower portion active pattern comprising a plurality of sheets spaced apart from each other in a second direction intersecting the first direction, an upper portion active pattern spaced apart from the lower portion active pattern in the second direction and comprising a plurality of sheets spaced apart from each other in the second direction, and a separating insulating film disposed between the lower portion active pattern and the upper portion active pattern; a gate cut film disposed between adjacent transistor structures of the plurality of transistor structures; a first layer that surrounds at least a portion of each of the lower portion active patterns; and a second layer disposed on the first layer, wherein the gate cut film penetrates a second work-function film in the second direction in order for the second work-function film to have a gap therein with respect to the first direction, and a length of the gate cut film with respect to the first direction decreases as the gate cut film gets closer to the substrate, wherein the gate cut film comprises a bottommost surface that is closer to the substrate than an uppermost surface of the separating insulating film is to the substrate, wherein a portion of a first work-function film has a gap formed therein between the plurality of transistor structures, and wherein the separating insulating film contacts the second work-function film.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Korean Patent Application No. 10-2024-0153650, filed on Nov. 1, 2024, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. BACKGROUND 1. Field of the Invention Example embodiments relate to a semiconductor device. 2. Description of the Related Art As technology for integrated circuits with high density devices and high performance, fin field-effect transistor (FinFET) and nano sheet field-effect transistors have been introduced. The FinFET includes a channel layer surrounded by gate structures on at least three sides, and has one or more vertical fin structures disposed to extend in a horizontal direction. With respect to the nano sheet field-effect transistor, gate-all-around (GAA) transistor or multi-bridge channel (MBC) transistor products are known, for example, and the nano sheet field-effect transistor includes one or more nano sheet channel layers vertically stacked on a substrate and a gate structure surrounding the all-around surface of each nano sheet channel layer. Meanwhile, in order to increase the density of the devices, 3D stacked field-effect transistors (3DSFET) have been proposed, in which a lower nano sheet field-effect transistor and an upper nano sheet field-effect transistor are stacked. Recently, the size of standard cells included in integrated circuits has been decreasing due to downscaling of semiconductor devices, and for devices including cross-couple structures, generally, design rules must not be violated in order to implement a standard cell of reduced size. SUMMARY An aspect provides a semiconductor device of which integration may be improved by downscaling, and electrical reliability may be improved. The technical tasks to be achieved by the present example embodiments are not limited to the technical tasks described above or below, and other technical tasks may be inferred from the following example embodiments by those skilled in the art. According to an aspect, a semiconductor device includes a substrate, a plurality of transistor structures disposed on the substrate and spaced apart from each other in a first direction parallel to a surface of the substrate, each of the plurality of transistor structures including a lower portion active pattern and an upper portion active pattern spaced apart from the lower portion active pattern in a second direction intersecting the first direction, a gate cut film disposed between two adjacent transistor structures of the plurality of transistor structures, for each lower portion active pattern, a first layer that surrounds at least a first portion of the lower portion active pattern, and a second layer disposed on each first layer. Each of the plurality of transistor structures includes a first work-function film surrounding the first portion of the lower portion active pattern and a second work-function film that surrounds at least a first portion of the upper portion active pattern and extends in the first direction, and the gate cut film penetrates through the second work-function film to form a gap between a first part of the second work-function film and a second part of the second work-function film. According to an aspect, a semiconductor device includes a substrate, a plurality of transistor structures disposed on the substrate and spaced apart from each other in a first direction parallel to a surface of the substrate, each including a lower portion active pattern including a plurality of sheets spaced apart from each other in a second direction intersecting the first direction, an upper portion active pattern spaced apart from the lower portion active pattern in the second direction and including a plurality of sheets that are spaced apart from each other in the second direction and a separating insulating film disposed between the lower portion active pattern and the upper portion active pattern, a gate cut film disposed between adjacent transistor structures of the plurality of transistor structures, a first layer that surrounds at least a portion of each of the lower portion active pattern, and a second layer disposed on the first layer. The gate cut film penetrates a work-function film in the second direction to fill a gap in the work-function film. According to an aspect, a semiconductor device includes a substrate, a plurality of transistor structures disposed on the substrate and spaced apart from each other in a first direction parallel to a surface of the substrate, each including a lower portion active pattern including a plurality of sheets spaced apart from each other in a second direction intersecting the first direction, an upper portion active pattern spaced apart from the lower portion active pattern in the second direction and including a plurality of sheets spaced apart from each other in the second direction, and a separating insulating film disposed between th