Semiconductor structure and a method of forming the same
Some embodiments show a semiconductor structure including a substrate with a {100} crystal surface plane which includes a plurality of adjacent structured regions at a top side of the substrate. The plurality of adjacent structured regions includes adjacent substrate surfaces with {111} crystal planes and a III-V semiconductor material layer above the top side of the substrate. A semiconductor device region includes at least one semiconductor device structure. The semiconductor device region is arranged above the plurality of adjacent structured regions at the top side of the substrate.
1. A semiconductor structure comprising:
a substrate with a {100} crystal surface plane comprising a plurality of adjacent structured regions at a top side of the substrate, wherein the plurality of adjacent structured regions comprise adjacent substrate surfaces with {111} crystal planes; and
a III-V semiconductor material layer above the top side of the substrate with a semiconductor device region, which comprises at least one semiconductor device structure, wherein the semiconductor device region is arranged above the plurality of adjacent structured regions at the top side of the substrate; and
a sawing frame region surrounding the plurality of adjacent structured regions, wherein the sawing frame region comprises a plurality of adjacent structured regions having adjacent substrate surfaces with {111} crystal planes and substrate surfaces with crystal planes different from {111} crystal planes.
2. The semiconductor structure according to claim 1 , wherein the plurality of adjacent structured regions comprise exclusively adjacent substrate surfaces with {111} crystal planes.
3. The semiconductor structure according to claim 1 , wherein the adjacent substrate surfaces with {111} crystal planes form trench structures.
4. The semiconductor structure according to claim 1 , further comprising a buffer layer, arranged between the substrate and the III-V semiconductor material layer.
5. The semiconductor structure according to claim 4 , wherein the buffer layer and the substrate comprise less crystal lattice mismatch than the III-V semiconductor material layer and the substrate.
6. The semiconductor structure according to claim 1 , wherein a material of the substrate and a material of the III-V semiconductor material layer comprise a coincidence site lattice.
7. The semiconductor structure according to claim 1 , wherein the III-V semiconductor material layer comprises gallium nitride (GaN).
8. The semiconductor structure according to claim 1 , wherein the at least one semiconductor device structure is a field-effect transistor (FET) structure, a high electron mobility transistor (HEMT) structure, a diode structure or an electric circuit.
9. The semiconductor structure according to claim 1 , wherein a first region of the III-V semiconductor material layer which overlaps the plurality of adjacent structured regions, comprises a lower crystal defect density than a second region of the III-V semiconductor material layer, which overlaps the sawing frame region.
10. The semiconductor structure according to claim 1 , wherein a first region of the III-V semiconductor material layer, which overlaps the plurality of adjacent structured regions, comprises a higher crystal lattice tension or crystal lattice compression strength than a second region of the III-V semiconductor material layer, which overlaps the sawing frame region.
11. The semiconductor structure according to claim 1 , wherein the III-V semiconductor material layer further comprises alignment marks.
12. The semiconductor structure according to claim 1 , wherein the substrate further comprises lattice stress compensation regions and the III-V semiconductor material layer comprises a thickness between 1 nm and 50 μm.
13. A method of forming the semiconductor structure of claim 1 , the method comprising:
forming the plurality of adjacent structured regions at the top side of the substrate;
forming the III-V semiconductor material layer above the top side of the substrate; and
forming the at least one semiconductor device structure in the semiconductor device region of the III-V semiconductor material layer.
14. The method according to claim 13 , wherein forming of the plurality of adjacent structured regions comprises depositing a masking layer at the top side of the substrate, removing locally the masking layer from the top side of the substrate, so that the top side of the substrate with the {100} crystal surface plane is locally exposed and etching the locally exposed top side of the substrate, so that the plurality of adjacent structured regions which comprise the adjacent substrate surfaces with {111} crystal planes are formed.
15. The method according to claim 13 , further comprising arranging a buffer layer between the top side of the substrate and the III-V semiconductor material layer.
16. The method according to claim 13 , wherein the forming of the III-V semiconductor material layer comprises performing an epitaxial growth of the III-V semiconductor material layer.
17. The method according to claim 13 , wherein forming the plurality of adjacent structured regions, further comprises forming the sawing frame region surrounding the plurality of adjacent structured regions.
18. The method according to claim 17 , wherein forming the sawing frame region is performed, so that the sawing frame region comprises substrate surfaces with crystal planes different from {111} crystal planes.
19. The method according to claim 17 , wherein forming the III-V semiconductor material layer is performed so that a first region, which is formed above the plurality of adjacent structured regions, comprises a lower crystal defect density than a second region, which is formed above the sawing frame region.
20. The method according to claim 13 , further comprising removing the substrate below the semiconductor device structure.
21. The method according to claim 13 , wherein forming the plurality of adjacent structured regions further comprises forming a lattice stress compensation region and wherein the III-V semiconductor material layer is formed so that the III-V semiconductor material layer comprises a thickness between 1 nm and 50 μm.
22. The method according to claim 13 , wherein forming the plurality of structured regions and/or forming the III-V semiconductor material layer is performed so that an alignment mark is formed comprising either a different height, or a different structure or a different defect density compared to a III-V semiconductor region adjacent the alignment mark.
23. A semiconductor structure comprising:
a substrate with a {100} crystal surface plane comprising a plurality of adjacent structured regions at a top side of the substrate, wherein the plurality of adjacent structured regions comprise adjacent substrate surfaces with {111} crystal planes;
a III-V semiconductor material layer, above the top side of the substrate with a semiconductor device region, wherein the semiconductor device region is arranged above the plurality of adjacent structured regions,
a sawing frame region surrounding the plurality of adjacent structured regions, wherein the sawing frame region comprises a plurality of adjacent structured regions having adjacent substrate surfaces with {111} crystal planes and substrate surfaces with crystal planes different from {111} crystal planes,
a buffer layer between the substrate and the III-V semiconductor material layer; and
a field-effect transistor (FET) structure, a diode structure, a high-electron-mobility transistor (HEMT) structure or an electric circuit arranged in the semiconductor device region.