Self-aligned contact
The present disclosure relates to semiconductor structures and, more particularly, to self-aligned contacts and methods of manufacture. The structure includes: adjacent diffusion regions located within a substrate material; sidewall structures above an upper surface of the substrate material, aligned on sides of the adjacent diffusion regions; and a contact between the sidewall structures and extending to within the substrate material between and in electrical contact with the adjacent diffusion regions.
1. A structure comprising:
adjacent diffusion regions located within a substrate material;
gate structures above the substrate material and located between the adjacent diffusion regions;
sidewall structures above an upper surface of the substrate material and on sidewalls of a trench within interlevel dielectric material, the sidewall structures being aligned on sides of the adjacent diffusion regions and remote from the gate structures; and
a contact between the sidewall structures and extending to within the substrate material between and in electrical contact with the adjacent diffusion regions.
2. The structure of claim 1 , further comprising silicide contacts below the upper surface of the substrate material and in direct contact with the adjacent diffusion regions.
3. The structure of claim 2 , wherein the silicide contacts are an intervening material between the contact and the adjacent diffusion regions.
4. The structure of claim 2 , wherein the contact provides an electrical conduction path to both the adjacent diffusion regions.
5. The structure of claim 4 , wherein the contact is a self-aligned contact.
6. The structure of claim 4 , wherein a portion of the contact below the upper surface of the substrate material is ball shaped.
7. The structure of claim 4 , wherein the portion of the contact below the upper surface of the substrate material is wider than a portion of the contact between the sidewall structures.
8. The structure of claim 1 , further comprising a contact that extends to additional diffusion regions above the upper surface of the substrate material, and the sidewall structures are adjacent to an outer edge of each of the adjacent diffusion regions.
9. The structure of claim 1 , wherein the diffusion regions are source and/or drain regions for adjacent gate structures.
10. The structure of claim 9 , wherein the substrate material is a fin of a finFET device.
11. The structure of claim 10 , wherein the adjacent gate structures include sidewalls which are of a same material as the sidewall structures.
12. A structure comprising:
a source/drain region in a substrate;
interlevel dielectric material above the substrate;
a trench within the interlevel dielectric material and extending into the substrate adjacent to the source/drain region;
a pair of outer spacers above and adjacent to the source/drain region and on sidewalls of the trench of the interlevel dielectric material, and which are remotely positioned from a gate structure; and
a contact to the source/drain region located between the pair of outer spacers and extending to below a surface of the substrate,
wherein the source/drain region is adjacent source/drain regions comprising a first source/drain region and a second source/drain region for a first gate structure and a second gate structure, respectively, the contact abuts both the first source/drain region and the second source/drain region below the surface of the substrate, and the pair of outer spacers above the source/drain region are remote from both the first gate structure and the second gate structure and are adjacent to an outer edge of each of the adjacent source/drain regions.
13. The structure of claim 12 , wherein the contact has a lower portion which is below the first and second gate structures.
14. The structure of claim 12 , wherein the contact has a mid-portion which is between the pair of outer spacers and is at a level of the first and second gate structures.
15. The structure of claim 12 , wherein the contact has an upper portion which is above the pair of outer spacers.
16. A structure comprising:
a substrate;
a first gate structure over the substrate;
a second gate structure over the substrate and spaced apart from the first gate structure;
a first source/drain region adjacent to the first gate structure and between the first gate structure and the second gate structure;
a second source/drain region adjacent to the second gate structure and between the first gate structure and the second gate structure; and
interlevel dielectric material between the first gate structure and the second gate structure;
a trench within the interlevel dielectric material, spaced away from the first gate structure and the second gate structure;
sidewall structures on sidewalls of the trench, spaced away from the first gate structure and the second gate structure;
a contact contacting the sidewall structures, extending into the substrate, and making contact with the first source/drain region and the second source/drain region.
17. The structure of claim 16 , wherein the contact partially extends between opposing sidewalls of the sidewall structures which are above the substrate.
18. The structure of claim 17 , wherein a lower portion of the contact is wider than a portion of the contact that partially extends between the opposing sidewalls above the substrate.
19. The structure of claim 16 , further comprising silicide contacts below an upper surface of the substrate and in direct contact with the first source/drain region and the second source/drain region, and a liner material between the sidewall structures and the contact, and on an upper surface of the interlevel dielectric material.