Preparation of low defect density of III-V on Si for device fabrication

1. A method of forming a semiconducting material, the method comprising:

depositing a high aluminum content III-V material layer on a substrate, the high aluminum content III-V material layer comprising at least one III element and a V element, the at least one III element comprising Al and being present in an amount of least 50 atomic % (at. %) based on total atomic weight of the at least one III element, and the high aluminum content III-V material layer being partially oxidized to include AlO;

depositing a graded buffer on the high aluminum content III-V material layer to form a graded layer of an indium (In) containing III-V material, the In containing III-V material being indium-gallium-arsenic (InGaAs) or indium-aluminum-arsenic (InAlAs) and comprising In in an increasing atomic gradient up to 35 atomic % (at.%) based on total atomic weight of InGa or InAl; and

forming a layer of InGaAs on the graded layer, the layer of InGaAs comprising about 25 to about 100 at. % In based on total atomic weight of InGa.

2. The method of claim 1 , wherein the substrate comprises silicon (Si), germanium (Ge), or a combination thereof.

3. The method of claim l, wherein the high aluminum content III-V material layer is AlAs.

4. The method of claim 1 , wherein the graded layer has a thickness in a range from about 100 nanometers (nm) to about 10 micrometers.

5. The method of claim 1 , wherein the layer of InGaAs forms a channel layer in a transistor device.

6. The method of claim 1 , wherein the high aluminum content III-V material layer has a thickness in a range from about 1 nm to about 1 micrometer.

7. A method of forming a semiconducting material, the method comprising:

forming a high aluminum content III-V material layer on a substrate, the high aluminum content III-V material comprising at least one III element and a V element, the at least one III element comprising Al and being present in an amount of least 50 at. % based on total atomic weight of the at least one III element;

depositing a graded buffer on the high aluminum content III-V material layer to form a graded layer of an In containing III-V material, the In containing III-V material being InGaAs or InAlAs and comprising In in an increasing atomic gradient up to 35 at. % based on total atomic weight of InGa or InAl;

forming a layer of InGaAs on the graded layer, the layer of InGaAs comprising about 25 to about 100 at. % In based on total atomic weight of InGa; and

oxidizing the high aluminum content III-V material layer to form AlO.

8. The method of claim 7 , wherein the layer of InGaAs has a thickness in a range from about 1 to about 20 nm.

9. The method of claim 7 , wherein the atomic gradient is a linear gradient.

10. The method of claim 7 , wherein the semiconducting material has a dislocation density in a range from about 1×10 2 to about 1×10 9 defects/cm 2 .

11. The method of claim 7 , wherein the atomic gradient is a step-wise gradient.

12. The method of claim 7 , wherein the semiconducting material has an average roughness (RMS) of less than 6 nanometers (nm).

13. The method of claim 7 , wherein the semiconducting material has a defect density of less than 2×10 9 defects/cm 2 .

14. The method of claim 7 , wherein the oxidizing the high aluminum content III-V material layer comprises flowing nitrogen gas and water vapor onto the high aluminum content III-V material layer.