CN-122002899-A - Integrated circuit device and method of manufacturing an integrated circuit device

Abstract

Integrated circuit devices and methods of forming integrated circuit devices are provided. The integrated circuit device may include a first transistor on a substrate, and a second transistor on the first transistor, wherein the first transistor is between the substrate and the second transistor in a vertical direction perpendicular to an upper surface of the substrate, wherein the first transistor includes a first channel layer spaced apart from each other in the vertical direction, and a first work function layer on the first channel layer, wherein the second transistor includes a second channel layer spaced apart from each other in the vertical direction, and a second work function layer on the second channel layer, wherein the second work function layer is spaced apart from the first channel layer.

Inventors

• Pu Junmo
• Xu Kangyi

Assignees

• 三星电子株式会社

Dates

Publication Date

20260508

Application Date

20251103

Priority Date

20250430

Claims (20)

1. 1. An integrated circuit device, comprising: a first transistor on the substrate, and A second transistor on the first transistor, Wherein the first transistor is between the substrate and the second transistor in a vertical direction perpendicular to an upper surface of the substrate, Wherein the first transistor includes: first channel layers spaced apart from each other in the vertical direction, and A first work function layer on the first channel layer, Wherein the second transistor includes: second channel layers spaced apart from each other in the vertical direction, and A second work function layer on the second channel layer, and Wherein the second work function layer is spaced apart from the first channel layer.
2. 2. The integrated circuit device of claim 1, wherein the first work function layer is between the first channel layer and the second work function layer.
3. 3. The integrated circuit device of claim 2 wherein the second work function layer comprises a second inner work function layer and a second outer work function layer, Wherein the second internal work function layer is between adjacent ones of the second channel layers, Wherein the second external work function layer extends around the second channel layer and the second internal work function layer, and Wherein the second work function layer has an interface between the second inner work function layer and the second outer work function layer.
4. 4. The integrated circuit device of claim 3 wherein the first work function layer comprises a first inner work function layer and a first outer work function layer, Wherein the first internal work function layer is between adjacent ones of the first channel layers, Wherein the first external work function layer extends around the first channel layer and the first internal work function layer, and Wherein the first work function layer has no interface between the first inner work function layer and the first outer work function layer.
5. 5. The integrated circuit device of claim 4, wherein the first inner work function layer and the first outer work function layer are configured to form a unitary structure.
6. 6. The integrated circuit device of claim 4, wherein the interface of the second work function layer overlaps the second channel layer in the vertical direction.
7. 7. The integrated circuit device of claim 6, wherein a width of at least one of the second channel layers is greater than a width of the second internal work function layer in a horizontal direction parallel to the upper surface of the substrate.
8. 8. The integrated circuit device of claim 6, wherein the first inner work function layer and the first outer work function layer comprise a first material.
9. 9. The integrated circuit device of claim 8, wherein the second internal work function layer and the second external work function layer comprise a second material different from the first material.
10. 10. The integrated circuit device of claim 8 wherein the second internal work function layer comprises a second material, Wherein the second external work function layer comprises a third material, and Wherein the second material is different from the first material and the third material.
11. 11. An integrated circuit device, comprising: a first transistor on the substrate; a second transistor on the first transistor, and An insulator between the first transistor and the second transistor in a vertical direction perpendicular to an upper surface of the substrate, Wherein the first transistor includes: first channel layers spaced apart from each other in the vertical direction, and A first work function layer on the first channel layer, Wherein the second transistor includes: second channel layers spaced apart from each other in the vertical direction, and A second work function layer on the second channel layer, and Wherein the second work function layer is spaced from the first channel layer by the first work function layer.
12. 12. The integrated circuit device of claim 11, wherein the first work function layer is in contact with the insulator.
13. 13. The integrated circuit device of claim 11 wherein the second work function layer comprises a second inner work function layer and a second outer work function layer, Wherein the second internal work function layer is between adjacent ones of the second channel layers, Wherein the second external work function layer extends around the second channel layer and the second internal work function layer, and Wherein the second work function layer has an interface between the second inner work function layer and the second outer work function layer.
14. 14. The integrated circuit device of claim 13 wherein the first work function layer comprises a first inner work function layer and a first outer work function layer, Wherein the first internal work function layer is between adjacent ones of the first channel layers, Wherein the first external work function layer extends around the first channel layer and the first internal work function layer, and Wherein the first work function layer has no interface between the first inner work function layer and the first outer work function layer.
15. 15. The integrated circuit device of claim 14, wherein the first inner work function layer and the first outer work function layer are configured to form a unitary structure.
16. 16. The integrated circuit device of claim 11, wherein the first work function layer comprises a first material, and Wherein the second work function layer comprises a second material different from the first material.
17. 17. A method of forming an integrated circuit device, the method comprising: Forming a first stack including a first channel layer on a substrate and a second stack including a second channel layer on the first stack, wherein the first channel layers are spaced apart from each other in a vertical direction perpendicular to an upper surface of the substrate, and the second channel layers are spaced apart from each other in the vertical direction; Forming an insulator between the first stack and the second stack in the vertical direction; Forming a dummy layer extending around the first channel layer, the second channel layer, and the insulator; Replacing an upper portion of the dummy layer on the second channel layer with a first internal work function layer; replacing a lower portion of the dummy layer on the first channel layer with a second work function layer, and Forming a first external work function layer on the first internal work function layer, the insulator and the second work function layer, Wherein the first external work function layer is spaced from the first channel layer by the second work function layer.
18. 18. The method of claim 17, wherein the first external work function layer is in contact with the first internal work function layer.
19. 19. The method of claim 18, wherein the integrated circuit device comprises an interface between the first external work function layer and the first internal work function layer.
20. 20. The method of claim 19, wherein the first external work function layer and the first internal work function layer comprise a first material, and Wherein the second work function layer comprises a second material different from the first material.

Description

Integrated circuit device and method of manufacturing an integrated circuit device Technical Field The present disclosure relates generally to the field of integrated circuit devices, and more particularly, to integrated circuit devices including stacked transistors. Background Various structures of integrated circuit devices and methods of forming the same have been proposed to increase integration density. For example, a stacked transistor structure including a plurality of transistors vertically stacked has been proposed. Disclosure of Invention An aspect of the present disclosure is to provide an integrated circuit device having improved electrical characteristics and reliability characteristics and a method of manufacturing the integrated circuit device. More specifically, it is an aspect of the present disclosure to provide an integrated circuit device that includes a stacked transistor structure that includes multiple transistors and their matching work function layers to improve and optimize performance. However, it will be appreciated that the embodiments, objects, and benefits of the present disclosure are not limited to the above description. According to some embodiments, an integrated circuit device may include a first transistor on a substrate, and a second transistor on the first transistor, wherein the first transistor is between the substrate and the second transistor in a vertical direction perpendicular to an upper surface of the substrate, wherein the first transistor includes a first channel layer spaced apart from each other in the vertical direction, and a first work function layer on the first channel layer, wherein the second transistor includes a second channel layer spaced apart from each other in the vertical direction, and a second work function layer on the second channel layer, wherein the second work function layer is spaced apart from the first channel layer. According to some embodiments, an integrated circuit device may include a first transistor on a substrate, a second transistor on the first transistor, and an insulator between the first transistor and the second transistor in a vertical direction perpendicular to an upper surface of the substrate, wherein the first transistor includes a first channel layer spaced apart from each other in the vertical direction, and a first work function layer on the first channel layer, wherein the second transistor includes a second channel layer spaced apart from each other in the vertical direction, and a second work function layer on the second channel layer, wherein the second work function layer is spaced apart from the first channel layer by the first work function layer. According to some embodiments, a method of forming an integrated circuit device may include forming a first stack including a first channel layer on a substrate and a second stack including a second channel layer on the first stack, wherein the first channel layers are spaced apart from each other in a vertical direction perpendicular to an upper surface of the substrate, the second channel layers are spaced apart from each other in the vertical direction, forming an insulator between the first stack and the second stack in the vertical direction, forming a dummy layer extending around the first channel layer, the second channel layer, and the insulator, replacing an upper portion of the dummy layer on the second channel layer with a first internal work function layer, replacing a lower portion of the dummy layer on the first channel layer with a second work function layer, and forming a first external work function layer on the first internal work function layer, the insulator, and the second channel layer, wherein the first external work function layer is spaced apart from the first channel layer by the second work function layer. Drawings Fig. 1 is a cross-sectional view of an integrated circuit device according to some embodiments. Fig. 2 is a flow chart of a method of forming an integrated circuit device according to some embodiments. Fig. 3-19 are cross-sectional views illustrating methods of forming integrated circuit devices according to some embodiments. Fig. 3 is a cross-sectional view of an intermediate structure in an intermediate process, including forming an inter-gate sacrificial layer over a stack. Fig. 4 is a cross-sectional view of an intermediate structure in an intermediate process including removing a portion of the inter-gate sacrificial layer and a portion of the stack. Fig. 5 and 6 are cross-sectional views of an intermediate structure in an intermediate process including replacing an inter-gate sacrificial layer with an insulator. Fig. 7 is a cross-sectional view of an intermediate structure in an intermediate process (including removal of the sacrificial layer). Fig. 8 is a cross-sectional view of an intermediate structure in an intermediate process including forming a dummy layer. Fig. 9 is a cross-sectional view of an intermediate st