Stress memorization film and oxide isolation in fins
A method of straining fins of a FinFET device by using a stress memorization film and the resulting device are provided. Embodiments include providing a plurality of bulk Si fins, the plurality of bulk Si fins having a recessed oxide layer therebetween; forming a stress memorization layer over the plurality of bulk Si fins and the recessed oxide layer; annealing the stress memorization layer, the plurality of bulk Si fins, and the recessed oxide layer; and removing the stress memorization layer.
1. A method comprising:
providing a plurality of bulk silicon (Si) fins, the plurality of bulk Si fins having a recessed oxide layer therebetween;
forming a stress memorization layer over the plurality of bulk Si fins and the recessed oxide layer;
annealing the stress memorization layer, the plurality of bulk Si fins, and the recessed oxide layer by laser anneal or rapid thermal anneal; and
removing the stress memorization layer in its entirety.
2. The method according to claim 1 , comprising forming the stress memorization layer of a material that has a bulk modulus higher than Si and oxide or silicon oxide (SiOx).
3. The method according to claim 1 , comprising forming the oxide layer of high aspect ratio process (HARP) oxide.
4. The method according to claim 1 , comprising forming the stress memorization layer to a thickness of 0.1 nanometer (nm) to 200 nm.
5. The method according to claim 1 , comprising annealing the stress memorization layer, the plurality of bulk Si fins, and the recessed oxide layer at a temperature of 300° C. to 1400° C.
6. The method according to claim 1 , comprising annealing the stress memorization layer, the plurality of bulk Si fins, and the recessed oxide layer at a pressure of 1 milliTorr (mTorr) to 760 Torr.
7. The method according to claim 2 , comprising forming the stress memorization layer of silicon nitride (SiNx), aluminum oxide (Al 2 O 3 ), lanthanum oxide (La 2 O 3 ), boron nitride (BN), aluminum nitride (AlN), or gallium nitride (GaN).
8. A method comprising:
forming a plurality of bulk silicon (Si) fins, each bulk Si fin having a hard mask layer;
forming an oxide layer over the plurality of bulk Si fins;
planarizing the oxide layer down to the plurality of bulk Si fins;
forming a stress memorization layer over the plurality of bulk Si fins and the oxide layer;
annealing the stress memorization layer, the plurality of bulk Si fins, and the oxide layer by laser anneal or rapid thermal anneal (RTA); and
removing the stress memorization layer in its entirety.
9. The method according to claim 8 , comprising planarizing the oxide layer by chemical mechanical polishing (CMP).
10. The method according to claim 8 , comprising forming the stress memorization layer of a material that has a bulk modulus higher than Si and oxide or silicon oxide (SiOx).
11. The method according to claim 8 , comprising forming the stress memorization layer of silicon nitride (SiNx), aluminum oxide (Al 2 O 3 ), lanthanum oxide (La 2 O 3 ), boron nitride (BN), aluminum nitride (AlN), or gallium nitride (GaN).
12. The method according to claim 8 , comprising forming the stress memorization layer to a thickness of 0.1 nanometer (nm) to 200 nm.
13. The method according to claim 8 , comprising annealing the stress memorization layer, the plurality of bulk Si fins, and the oxide layer at a temperature of 300° C. to 1400° C.
14. The method according to claim 8 , comprising annealing the stress memorization layer, the plurality of bulk Si fins, and the oxide layer at a pressure of 1 milliTorr (mTorr) to 760 Torr.
15. The method according to claim 8 , further comprising recessing the oxide layer between the plurality of bulk Si fins after removing the stress memorization layer.