Semiconductor device and method of manufacturing the same
In a method of forming a semiconductor device including a fin field effect transistor (FinFET), a first sacrificial layer is formed over a source/drain structure of a FinFET structure and an isolation insulating layer. The first sacrificial layer is patterned, thereby forming an opening. A first liner layer is formed on the isolation insulating layer in a bottom of opening and at least side faces of the patterned first sacrificial layer. After the first liner layer is formed, a dielectric layer is formed in the opening. After the dielectric layer is formed, the patterned first sacrificial layer is removed, thereby forming a contact opening over the source/drain structure. A conductive layer is formed in the contact opening.
1. A semiconductor device including fin field effect transistors (FinFETs) disposed over a substrate, comprising:
a first FinFET including a first fin structure extending in a first direction, a first source/drain structure and a first source/drain contact in contact with the first source/drain structure;
a dielectric layer disposed around the first source/drain contact; and
a first liner layer, made of a different dielectric material than the dielectric layer, disposed between the dielectric layer and the first source/drain contact.
2. The semiconductor device of claim 1 , further comprising a residual piece of a semiconductor material disposed at a bottom portion of an interface between the dielectric layer and the first source/drain contact.
3. The semiconductor device of claim 2 , wherein the residual piece of the semiconductor material includes amorphous silicon or polysilicon.
4. The semiconductor device of claim 1 , wherein the first liner layer is made of silicon nitride.
5. The semiconductor device of claim 1 , further comprising an isolation insulating layer in which a bottom portion of the first fin structure is embedded,
wherein a part of the first liner layer is disposed between the dielectric layer and the isolation insulating layer.
6. The semiconductor device of claim 5 , further comprising a second liner layer between the part of the first liner layer and the isolation insulating layer.
7. The semiconductor device of claim 6 , wherein the second liner layer is made of silicon nitride.
8. The semiconductor device of claim 1 , wherein a width of the first source/drain contact along a second direction crossing the first direction varies along a vertical direction perpendicular to a surface the substrate.
9. The semiconductor device of claim 8 , wherein the width decreases as a distance from the substrate increases.
10. The semiconductor device of claim 9 , wherein:
the first source/drain contact includes a lower portion and an upper portion having a funnel shape, and
a width of the upper portion is greater than a width of the bottom portion.
11. The semiconductor device of claim 10 , wherein the width of the bottom portion is constant.
12. The semiconductor device of claim 10 , wherein a difference between the width of the upper portion and the width of the bottom portion is less than 6 nm.
13. The semiconductor device of claim 10 , wherein a vertical length of the bottom portion is greater than a vertical length of the upper portion.
14. The semiconductor device of claim 10 , wherein the vertical length of the bottom portion is twice or more the vertical length of the upper portion.
15. The semiconductor device of claim 10 , wherein:
the first FinFET further includes a gate electrode, and
an interface between the bottom portion and the upper portion is located at a level higher than an upper surface of the gate electrode.
16. The semiconductor device of claim 12 , wherein a width of the second liner layer along a second direction crossing the first direction is smaller than a width of the dielectric layer along the second direction.
17. The semiconductor device of claim 12 , wherein a width of the second liner layer along a second direction crossing the first direction is greater than a width of the dielectric layer along the second direction.
18. The semiconductor device of claim 1 , wherein the first source/drain structure includes an epitaxial layer formed around a source/drain region of the first fin structure.
19. The semiconductor device of claim 18 , wherein the first source/drain structure further includes a silicide layer disposed between the epitaxial layer and the first source/drain contact.
20. The semiconductor device of claim 1 , further comprising a second FinFET separated by the dielectric layer from the first FinFET,
wherein the first FinFET is a p-type and the second FinFET is an n-type.