Blanket EPI super steep retrograde well formation without Si recess
View Patent ↗A method of forming SSRW FETs with controlled step height between a field oxide and epitaxially grown silicon and the resulting devices are provided. Embodiments include providing a SiN layer on a substrate, forming first, second, and third spaced STI regions of field oxide through the SiN layer and into the substrate, removing a top portion of the field oxide for each STI region by a controlled deglaze, removing the SiN layer, forming an n-type region in the substrate between the first and second STI regions and a p-type region in the substrate between the second and third STI regions, and epitaxially growing a Si based layer on the substrate over the n-type and p-type regions.
1. A device comprising:
a substrate;
first, second, and third shallow trench isolation (STI) regions of field oxide formed in the substrate and extending 21 nanometers (nm) above the substrate;
a n-type region in the substrate between the first and second STI regions and an p-type region in the substrate between the second and third STI regions; and
an epitaxially grown silicon (Si) based layer having a thickness of 15 to 20 nm on the substrate over the p-type and the n-type regions.
2. The device according to claim 1 , wherein the epitaxially grown Si based layer comprises epitaxially grown Si:C having a thickness of 5 to 10 nanometers (nm) on the substrate and epitaxially grown Si having a thickness of 10 to 15 nm on the epitaxial grown Si:C.
3. The device according to claim 2 , wherein the Si:C comprises Si having a 0.5 to 2% carbon atomic concentration.
4. The device according to claim 1 , wherein the epitaxially grown Si based layer comprises:
epitaxially grown Si:C having a thickness of 5 to 10 nm over the p-type region and a first epitaxially grown Si having a thickness of 10 to 15 nm over the epitaxially grown Si:C; and
a second epitaxially grown Si having a thickness of 15 to 20 nm over the n-type region.
5. The device according to claim 1 , wherein the P-well is doped with boron (B) and the n-type region is doped with phosphorus (P) or Arsenic (As).
6. The device according to claim 1 , wherein a height of the STI regions above the substrate is formed by a controlled deglaze of the field oxide.
7. A device comprising:
a substrate;
first, second, and third spaced shallow trench isolation (STI) regions of field oxide in the substrate;
an n-type region in the substrate between the first and second STI regions and a p-type region in the substrate between the second and third STI regions;
a carbon doped silicon (Si:C) layer above the substrate in the n-type region but not above the substrate in the p-type region;
a first silicon (Si) based layer on top of the Si:C layer; and
a second silicon (Si) based layer on the substrate over the p-type region.
8. The device according to claim 7 , wherein the first and second Si based layers are epitaxially grown.
9. The device according to claim 7 , wherein the first Si based layer is located between the first and second STI regions.
10. The device according to claim 7 , wherein the second Si based layer is located between the second and third STI regions.
11. The device according to claim 7 , wherein the thickness of the Si:C layer is between 5 nm and 10 nm.
12. The device according to claim 11 , wherein the thickness of the first Si based layer is between 10 nm and 15 nm.
13. The device according to claim 12 , wherein the thickness of the second Si based layer is between 15 nm and 20 nm.
14. The device according to claim 7 , wherein each of the Si:C layer, first Si based layer, and second Si based layer has a thickness and the thickness of the second Si based layer is equal to the combined thicknesses of the Si:C layer and the first Si based layer.
15. The device according to claim 7 , wherein the Si:C layer has a carbon atomic concentration between 0.5 and 2%.
16. The device according to claim 7 , wherein the n-type region comprises phosphorous (P).
17. The device according to claim 7 , wherein the p-type region comprises boron (B).
18. A device comprising:
a substrate;
first, second, and third spaced shallow trench isolation (STI) regions of field oxide in the substrate;
an n-type region in the substrate between the first and second STI regions and a p-type region in the substrate between the second and third STI regions;
a carbon doped silicon (Si:C) layer above the substrate in the p-type region but not above the substrate in the n-type region;
a first silicon (Si) based layer on top of the Si:C layer; and
a second silicon (Si) based layer on the substrate over the n-type region.
19. The device according to claim 18 , wherein the n-type region comprises phosphorous (P).
20. The device according to claim 18 , wherein the p-type region comprises boron (B).