FinFET devices
FinFET devices and processes to prevent fin or gate collapse (e.g., flopover) in finFET devices are provided. The method includes forming a first set of trenches in a semiconductor material and filling the first set of trenches with insulator material. The method further includes forming a second set of trenches in the semiconductor material, alternating with the first set of trenches that are filled. The second set of trenches form semiconductor structures which have a dimension of fin structures. The method further includes filling the second set of trenches with insulator material. The method further includes recessing the insulator material within the first set of trenches and the second set of trenches to form the fin structures.
1. A method of forming dummy gates in a semiconductor structure, the method comprising:
providing a substrate comprising one or more semiconductor fins and providing a dummy gate material over the substrate;
etching a first set of trenches through the dummy gate material;
filling the first set of trenches with one or more first trench-filling materials; subsequent to filling the first set of trenches, etching a second set of trenches, alternating with the first set of trenches, through the dummy gate material; and
filling the second set of trenches with one or more second trench-filling materials to form dummy gates in regions between the first trench-filling materials and the second trench-filling materials.
2. The method of claim 1 , wherein forming the first set of trenches comprises:
forming a plurality of first mandrels;
forming first sidewall spacers on the plurality of first mandrels; and
removing the plurality of first mandrels.
3. The method of claim 2 , wherein a pitch of the first set of trenches is approximately one-half of a pitch of the plurality of first mandrels.
4. The method of claim 1 , wherein etching the second set of trenches comprises:
using portions of the one or more first trench-filling materials extending above the dummy gate material as second mandrels; and
forming second sidewall spacers on the second mandrels.
5. The method of claim 1 , wherein the second set of trenches are self-aligned to the first set of trenches.
6. The method of claim 1 , wherein filling the first set of trenches with one or more first trench-filling materials comprises epitaxially growing a first epitaxial material at a bottom of each trench of the first set of trenches.
7. The method of claim 6 , wherein the first epitaxial material comprises SiGe.
8. The method of claim 6 , wherein filling the second set of trenches with one or more second trench-filling materials comprises epitaxially growing a second epitaxial material at a bottom of each trench of the second set of trenches, and wherein the second epitaxial material is the same as the first epitaxial material.
9. The method of claim 6 , wherein filling the second set of trenches with one or more second trench-filling materials comprises epitaxially growing a second epitaxial material at a bottom of each trench of the second set of trenches, and wherein the second epitaxial material is different than the first epitaxial material.
10. The method of claim 1 , wherein filling the second set of trenches with one or more second trench-filling materials comprises epitaxially growing a second epitaxial material at a bottom of each trench of the second set of trenches.
11. The method of claim 1 , wherein filling the first set of trenches with one or more first trench-filling materials comprises depositing a first liner on sidewalls of the first set of trenches.
12. The method of claim 11 , wherein the first liner comprises SiOCN.
13. The method of claim 11 , wherein the first liner comprises SiCBN.
14. The method of claim 11 , wherein a thickness of the first liner is between approximately 3 nm and 6 nm.
15. The method of claim 11 , wherein the first liner is a conformal liner.
16. The method of claim 11 , wherein filling the first set of trenches further comprises forming a first oxide layer on the first liner.
17. The method of claim 11 , wherein filling the second set of trenches with one or more second trench-filling materials comprises depositing a second liner on sidewalls of the second set of trenches, and wherein the second liner comprises the same material as the first liner.
18. The method of claim 11 , wherein filling the second set of trenches with one or more second trench-filling materials comprises depositing a second liner on sidewalls of the second set of trenches, and wherein the second liner comprises a different material than the first liner.
19. The method of claim 1 , wherein filling the second set of trenches with one or more second trench-filling materials comprises depositing a second liner on sidewalls of the second set of trenches.
20. The method of claim 19 , wherein filling the second set of trenches further comprises forming a second oxide layer on the second liner.