Semiconductor arrangement for a FinFET and method for manufacturing the same

1. A semiconductor arrangement, comprising:

a bulk semiconductor substrate;

a fin formed on the substrate;

a first FinFET and a second FinFET formed on the substrate, wherein the first FinFET comprises a first gate stack intersecting the fin and a first gate spacer disposed on sidewalls of the first gate stack, the second FinFET comprises a second gate stack intersecting the fin and a second gate spacer disposed on sidewalls of the second gate stack;

a dummy gate spacer formed between the first FinFET and the second FinFET and intersecting the fin;

an isolation section self-aligned to a space defined by the dummy gate spacer, wherein the isolation section electrically isolates the first FinFET from the second FinFET; and

an insulation layer disposed under a bottom surface of the isolation section and abutting the isolation section, wherein the insulation layer has a width defined between its opposite sidewalls greater than a width of the space defined by the dummy gate spacer, so that portions of the fin directly under the dummy gate spacer have respective bottom surfaces landed at least partially onto the insulation layer.

2. The semiconductor arrangement of claim 1 , wherein the substrate comprises a doped well, and the insulation layer is disposed in an upper portion of the doped well and defined between the first FinFET and the second FinFET.

3. The semiconductor arrangement of claim 2 , wherein the insulation layer extends substantially along the space defined by the dummy gate spacer.

4. The semiconductor arrangement of claim 3 , wherein a sidewall of the insulation layer facing the first FinFET is closer to the first FinFET than a sidewall of the isolation section facing the first FinFET, and a sidewall of the insulation layer facing the second FinFET is closer to the second FinFET than a sidewall of the isolation section facing the second FinFET.

5. The semiconductor arrangement of claim 4 , further comprising a first further localized insulation layer formed under the fin in a region for the first FinFET and/or a second further localized insulation layer formed under the fin in a region for the second FinFET, wherein the first further insulation layer extends substantially along the first gate stack, while limited in size along a longitudinal direction of fin so as not to extend beyond the region for the first FinFET, and/or wherein the second further insulation layer extends substantially along the second gate stack, while limited in size along the longitudinal direction of fin so as not to extend beyond the region for the second FinFET.

6. The semiconductor arrangement of claim 1 , wherein the isolation section comprises a dielectric material layer whose sidewalls extend substantially along inner walls of the dummy gate spacer.

7. The semiconductor arrangement of claim 1 , wherein the first gate stack and the second gate stack are recessed with respect to the first gate spacer and the second gate spacer, respectively, and the semiconductor arrangement further comprises dielectric layers disposed on top of the first gate stack and the second gate stack inside the first gate spacer and the second gate spacer, respectively.

8. The semiconductor arrangement of claim 1 , further comprising a further semiconductor layer which is at least partially embedded into the fin on respective opposite sides of the first gate stack and/or the second gate stack, wherein the first FinFET and/or the second FinFET comprise respective source/drain regions at least partially formed in the further semiconductor layer.