Nonpolar or semipolar group III-nitride substrates
Aspects of the disclosure provide for mechanisms for producing group III-nitride substrates. In accordance with some embodiments, a method for producing a group III-nitride substrate is provided. The method may include: providing a growth template comprising a semiconductor layer of a group III-nitride material with a nonpolar orientation or a semipolar orientation; fabricating a mask on the semiconductor layer for preventing defects in the growth template from propagating into group III-nitride materials grown on the growth template; and forming, on the mask, an epitaxial layer of the group III-nitride with the nonpolar orientation or semipolar orientation. The mask may include a stripe pattern comprising SiO 2 and/or SiN. Forming the epitaxial layer of the group III-nitride material may include growing the group III-nitride material in the semipolar orientation or the nonpolar orientation in nitrogen carrier gas.
1. A method, comprising:
fabricating a mask on a semiconductor layer comprising a group III-nitride material with a first crystallographic orientation, wherein the first crystallographic orientation comprises at least one of a nonpolar orientation or a semipolar orientation, wherein the first crystallographic orientation comprises at least one of (20 2 1), (20 21 ), (30 3 1), (30 31 ), (10 1 1), (11 2 2), (11 2 0), or (10 1 0), wherein the group III-nitride material with the first crystallographic orientation is coalesced, and wherein the mask comprises a plurality of stripes comprising a masking material; and
forming, on the mask, an epitaxial layer of the group III-nitride material with the first crystallographic orientation, comprising:
growing, using nitrogen carrier gas, the group III-nitride material in the first crystallographic orientation to a thickness that is approximately 100 microns or greater than 100 microns.
2. The method of claim 1 , wherein the masking material comprises at least one of SiN or SiO 2 .
3. The method of claim 1 , wherein fabricating the mask on the semiconductor layer comprising the group III-nitride material with the first crystallographic orientation comprises:
depositing, on a planar surface of the semiconductor layer comprising the group III-nitride material with the first crystallographic orientation, the plurality of stripes comprising the masking material, wherein the planar surface of the semiconductor layer comprising the group III-nitride material with the first crystallographic orientation is approximately parallel to a crystallographic plane with the first crystallographic orientation, and wherein a diameter of the semiconductor layer is equal to or greater than 2 inches.
4. The method of claim 3 , wherein a first dimension of at least one of the plurality of stripes is between 1 μm and 100 μm.
5. The method of claim 4 , wherein a second dimension of the at least one of the plurality of stripes is between 10 nm and 2 μm.
6. The method of claim 1 , wherein forming, on the mask, the epitaxial layer of the group III-nitride material comprises growing the group III-nitride material utilizing at least one of a hydride vapor phase epitaxy (HVPE) process, a molecular beam epitaxy (MBE) process, or a metalorganic chemical vapor deposition (MOCVD) process.
7. The method of claim 1 , further comprising:
removing the epitaxial layer to produce a free-standing substrate for growing the group III-nitride material.
8. A growth template, comprising:
a semiconductor layer comprising a group III-nitride material with a first crystallographic orientation, wherein the first crystallographic orientation comprises at least one of a nonpolar orientation or a semipolar orientation, wherein the first crystallographic orientation comprises at least one of (20 2 1), (20 21 ), (30 3 1), (30 31 ), (10 1 1), (11 22 ), (11 2 0), or (10 1 0), and wherein the group III-nitride material with the first crystallographic orientation is coalesced; and
a mask fabricated on the semiconductor layer of the group III-nitride material with the first crystallographic orientation, wherein the mask comprises a plurality of stripes comprising a masking material that is deposited on a planar surface of the semiconductor layer comprising the group III-nitride material with the first crystallographic orientation, wherein the planar surface of the semiconductor layer comprising the group III-nitride material is approximately parallel to a crystallographic plane with the first crystallographic orientation.
9. The growth template of claim 8 , wherein the group III-nitride material comprises gallium.
10. The growth template of claim 8 , wherein a diameter of the semiconductor layer of the group III-nitride material is greater than 2 inches.
11. The growth template of claim 8 , wherein a first dimension of at least one of the plurality of stripes is between 1 μm and 100 μm.
12. The growth template of claim 11 , wherein a second dimension of the at least one of the plurality of stripes is between 10 nm and 2 μm.
13. The growth template of claim 8 , further comprising an epitaxial layer of the group III-nitride material formed on the mask.
14. The growth template of claim 13 , wherein a surface of the epitaxial layer is a planar surface approximately parallel to a crystallographic plane with the first crystallographic orientation.
15. The growth template of claim 14 , wherein a diameter of the epitaxial layer of the group III-nitride material is equal to or greater than 2 inches.