Dislocation reduction in semiconductor compounds
A solution for fabricating a semiconductor structure and the corresponding semiconductor structure are provided. The semiconductor structure includes a plurality of semiconductor layers grown over a substrate using a set of epitaxial growth periods. During each epitaxial growth period, a first semiconductor layer having one of: a tensile stress or a compressive stress is grown followed by growth of a second semiconductor layer having the other of: the tensile stress or the compressive stress directly on the first semiconductor layer.
1 . A semiconductor structure, comprising:
a substrate; and
a plurality of semiconductor layers located over the substrate, the plurality of semiconductor layers including a set of epitaxial growth periods, each epitaxial growth period including:
a first semiconductor layer formed of a group III nitride material and having one of: a tensile stress or a compressive stress, wherein the first semiconductor layer includes a first surface roughness; and
a second semiconductor layer directly on the first semiconductor layer and formed of the group III nitride material, wherein the second semiconductor layer has the other of: the tensile stress or the compressive stress, wherein at least ten percent of an area of an interface between the first and the second semiconductor layers has a shear stress that is greater than a shear stress between two group III nitride semiconductor layers with a lattice mismatch of at least 0.01%, wherein the second semiconductor layer includes a second surface roughness, and wherein the first surface roughness and the second surface roughness differ by at least 0.02%.
2 . The semiconductor structure of claim 1 , wherein at least one of the first semiconductor layer or the second semiconductor layer is doped with a dopant configured to increase the tensile stress or the compressive stress of the group III nitride material.
3 . The semiconductor structure of claim 2 , wherein a dopant for the at least one of the first semiconductor layer or the second semiconductor layer includes at least one of: Arsenic (As), Beryllium (Be), Carbon (C), Calcium (Ca), Cadmium (Cd), Cerium (Ce), Chromium (Cr), Copper (Cu), Dysprosium (Dy), Iron (Fe), Germanium (Ge), Mercury (Hg), Magnesium (Mg), Lithium (Li), Manganese (Mn), Sodium (Na), Oxygen (O), Phosphorous (P), Sulfur(S), Antimony (Sb), Selenium (Se), Silicon (Si), Tin (Sn), Tellurium (Te), Vanadium (V), and Zinc (Zn).
4 . The semiconductor structure of claim 2 , wherein a dopant concentration for the dopant is between 1×10 15 cm −3 to 1×10 21 cm −3 .
5 . The semiconductor structure of claim 1 , wherein a thickness of each layer is between approximately 10 nanometers and approximately 10 micrometers.
6 . The semiconductor structure of claim 1 , further comprising a buffer layer directly on the substrate, wherein the first semiconductor layer is located directly on the buffer layer.
7 . The semiconductor structure of claim 1 , wherein the first semiconductor layer and the second semiconductor layer have a lattice mismatch of at least 0.02%.
8 . The semiconductor structure of claim 1 , wherein a composition of the first semiconductor layer and a composition of the second semiconductor layer differ by at most approximately five percent.
9 . The semiconductor structure of claim 1 , wherein a thickness of each of the semiconductor layers is greater than a critical thickness to avoid pseudomorphic growth.
10 . A semiconductor structure, comprising:
a substrate; and
a plurality of semiconductor layers on the substrate, the plurality of semiconductors including a plurality of epitaxial growth periods, each epitaxial growth period including:
a first group III nitride semiconductor layer formed of a group III nitride material and having one of: a tensile stress or a compressive stress, the first group III nitride semiconductor layer including a first dopant configured to increase the one of the tensile stress or the compressive stress of the first group III nitride semiconductor layer; and
a second group III nitride semiconductor layer directly contacting the first group III nitride semiconductor layer and formed of the group III nitride material, wherein the second group III nitride semiconductor layer has the other of: the tensile stress or the compressive stress, wherein the second group III nitride semiconductor layer includes a second dopant configured to increase the other of the tensile stress or the compressive stress of the second group III nitride semiconductor layer, wherein at least ten percent of an area of an interface between the first and the second group III nitride semiconductor layers has a shear stress that is greater than a shear stress between two group III nitride semiconductor layers with a lattice mismatch of at least 0.01%.
11 . The semiconductor structure of claim 10 , wherein the first dopant causes the first group III nitride semiconductor layer to expand.
12 . The semiconductor structure of claim 10 , wherein the first dopant causes the first group III nitride semiconductor layer to contract.
13 . The semiconductor structure of claim 10 , wherein the first dopant acts as a surfactant.
14 . The semiconductor structure of claim 10 , wherein a dopant concentration for the first dopant is between 1×10 15 cm −3 to 1×10 21 cm −3 .
15 . A semiconductor device, comprising:
a substrate;
a buffer layer located on the substrate, wherein the buffer layer comprises a semiconductor heterostructure including a plurality of semiconductor layers, the plurality of semiconductor layers including a plurality of epitaxial growth periods, each epitaxial growth period including:
a first semiconductor layer formed of a group III nitride material and having one of: a tensile stress or a compressive stress, the first group III nitride semiconductor layer including a first dopant configured to increase the one of the tensile stress or the compressive stress of the first group III nitride semiconductor layer; and
a second semiconductor layer directly contacting the first semiconductor layer and formed of the group III nitride material, wherein the second semiconductor layer has the other of: the tensile stress or the compressive stress, wherein the second group III nitride semiconductor layer includes a second dopant configured to increase the other of the tensile stress or the compressive stress of the second group III nitride semiconductor layer, wherein at least ten percent of an area of an interface between the first and the second semiconductor layers has a shear stress that is greater than a shear stress between two group III nitride semiconductor layers with a lattice mismatch of at least 0.01%.
16 . The device of claim 15 , further comprising an n-type semiconductor layer located directly on the buffer layer.
17 . The device of claim 15 , further comprising an active layer located on the buffer layer.
18 . The device of claim 17 , wherein the active layer is configured to emit electromagnetic radiation during operation of the device.