Optoelectronic device and method for making the same

An optoelectronic device and method of manufacturing an optoelectronic device are disclosed. The optoelectronic device includes a substrate; a semiconductor comprising an n-type layer disposed on the substrate, a p-type layer disposed on the n-type layer, and an active layer disposed between the n-type layer and the p-type layer; a transition layer disposed on the substrate and located between the n-type layer and the substrate, the transition layer including an oxygenated IIIA-transition metal nitride; and a p-contact layer disposed on the p-type layer of the semiconductor.

FIELD

This disclosure is directed to optoelectronic devices. More specifically, this disclosure is directed to optoelectronic devices such as light emitting diodes, photodetectors, or the like, and methods for making optoelectronic devices.

BACKGROUND

Optoelectronic devices, such as light emitting diodes (LEDs), photodetectors, etc., are semiconductor devices that generate light from electrical excitation where electrons and holes combine or can absorb light. III-Nitride based LEDs, such as gallium nitride (GaN) based LEDs, have been widely used in numerous applications due to their ability to output light having wavelengths in the ultraviolet (UV), blue, and green spectrums.

SUMMARY

This disclosure is directed to optoelectronic devices. More specifically, this disclosure is directed to optoelectronic devices such as light emitting diodes, photodetectors, or the like, and methods for making optoelectronic devices.

An optoelectronic device is disclosed. The optoelectronic device includes a substrate; a semiconductor configured to generate light and comprising an n-type layer disposed on the substrate, a p-type layer disposed on the n-type layer, and an active layer disposed between the n-type layer and the p-type layer; a transition layer disposed on the substrate and located between the n-type layer and the substrate, the transition layer can include a IIIA-transition metal nitride or oxygenated IIIA-transition metal nitride; and a p-contact layer disposed on the p-type layer of the semiconductor.

In an embodiment, the optoelectronic device includes a buffer layer. The buffer layer can be disposed between the substrate and the transition layer, according to an embodiment. In an embodiment, the buffer layer can be disposed between the transition layer and the n-type semiconductor layer. In an embodiment, the buffer layer can be disposed between the substrate and the transition layer and between the transition layer and the n-type semiconductor layer. In an embodiment, the buffer layer can be disposed between sub-layers of the transition layer. In an embodiment, sub-layers of the buffer layer and sub-layers of the transition layer can be arranged as alternating layers. In an embodiment, the buffer layer includes an oxygenated IIIA-transition metal nitride. In an embodiment, the buffer layer includes a IIIA-transition metal nitride.

A method for manufacturing an optoelectronic device is disclosed. The method includes forming a transition layer on a substrate, wherein the transition layer includes a IIIA-transition metal nitride or oxygenated IIIA-transition metal nitride; forming an n-type layer on the transition layer; forming an active layer on the n-type layer; forming a p-type layer on the active layer, so that the active layer is disposed between the n-type layer and the p-type layer; and forming a p-contact layer on the p-type layer and an n-contact layer on the transition layer or the n-type layer.

In an embodiment, the method for manufacturing the optoelectronic device further includes forming a buffer layer between the substrate and the transition layer. In an embodiment, the method for manufacturing the optoelectronic device further includes forming a buffer layer between the transition layer and the n-type layer.

Like reference numbers represent like parts throughout.

DETAILED DESCRIPTION

When manufacturing optoelectronic devices such as, but not limited to, light emitting diodes (LEDs), photodetectors, etc., such as, but not limited to, gallium nitride (GaN) LEDs, GaN is generally deposited on a substrate made of, for example, sapphire (e.g., a flat or patterned sapphire substrate (PSS)), silicon, silicon carbide (SiC), combinations thereof, or the like. The GaN is generally deposited via a chemical vapor deposition method, such as, but not limited to, a metal organic chemical vapor deposition, or via a molecular-beam epitaxy method. However, following the deposition, the GaN layer on the substrate can crack when cooled to room temperature. Furthermore, gallium may have poor wetting on a silicon substrate surface, which can lead to manufacturing failures when forming the GaN LEDs.

Embodiments described in this specification are directed to formation of optoelectronic devices (e.g., a GaN LED, etc.) that include a transition layer or a transition layer and a buffer layer. When the optoelectronic devices include a transition layer, the transition layer can be formed of an oxygenated IIIA-transition metal nitride. Inclusion of such a transition layer can, for example, improve a quality of the GaN formed on the substrate. When the optoelectronic devices include a transition layer and a buffer layer, one or more of the transition layer and the buffer layer can be formed of an oxygenated IIIA-transition metal nitride. Inclusion of such an oxygenated buffer layer or oxygenated transition layer can, for example, improve a quality of the GaN formed on the substrate.

An oxygenated IIIA-transition metal nitride, as used in this specification, can include a composition that includes oxygen, IIIA metal, transition metal, and nitrogen. In an embodiment, an oxygenated IIIA-transition metal nitride can be formed by, for example, co-depositing IIIA metal and transition metal in nitrogen and oxygen to form oxygenated IIIA-transition metal nitride at elevated temperature. In an embodiment, a content of oxygen in the oxygenated IIIA-transition metal nitride can range from about 0.0001% to about 15%. In an embodiment, a content of oxygen in the oxygenated IIIA-transition metal nitride can range from about 0.0001% to about 5%. In an embodiment, a content of oxygen in the oxygenated IIIA-transition metal nitride can range from about 1% to about 15%.

A IIIA-transition metal nitride, as used in this specification, can include a composition that includes a IIIA metal, a transition metal, and nitrogen. In an embodiment, a IIIA-transition metal nitride can be formed by, for example, integrating a IIIA metal into a transition metal nitride or by integrating a transition metal into a IIIA metal nitride.

A buffer layer, as used in this specification, includes oxygen or does not include oxygen. The buffer layer can include oxygenated IIIA metal nitride or IIIA metal nitride. The oxygenated IIIA metal nitride can include oxygen, IIIA metal, and nitrogen. The IIIA metal nitride can include IIIA metal and nitrogen.

A layer, as used in this specification, includes a thickness of a material or composition over a surface. It will be appreciated that the term layer is not intended to indicate a particular thickness or geometry of the material or composition. The layer can include multiple sub-layers. The multiple sub-layers can arranged in a continuous manner or in an alternating manner with other sublayers or layers.

An n-type layer, as used in this specification, includes a layer having a majority of carriers which are electrons.

A p-type layer, as used in this specification, includes a layer having a majority of carriers which are holes. That is, the p-type layer generally has an absence of electrons.

An optoelectronic device, as used in this specification, includes a light emitting device (such as, but not limited to, a light emitting diode or the like) or a photodetector or photodiode.

FIGS. 1A-1Billustrate schematic diagrams of optoelectronic devices10A-10B including a transition layer14, according to an embodiment. The optoelectronic devices10A10B can be representative of, for example, a light emitting diode (LED), or the like.

With reference toFIG. 1A, the optoelectronic device10A generally includes a substrate12, a transition layer14, a layer16, an active layer18, a layer20, a layer22, an electrically conductive element24, and an electrically conductive element26.

The transition layer14is formed on the substrate12. In the illustrated embodiment, the transition layer14is disposed at a location between the substrate12and the layer16. The transition layer14can, for example, facilitate formation of the first layer16on the substrate12. It will be appreciated that the transition layer14can be a single layer structure, or a multilayered structure. For example, inFIGS. 2-3, the transition layer14includes a plurality of layers14A-14B (FIG. 2) and14A-14C (FIG. 3).

The transition layer14can include a composition having an oxygenated IIIA-transition metal nitride. Thus, in an embodiment, the transition layer14can alternatively be referred to as the oxygenated IIIA-transition metal nitride layer14. In an embodiment, a IIIA metal can include, for example, aluminum (Al), gallium (Ga), indium (In), thallium (Tl), or suitable combinations thereof. In an embodiment, a transition metal can include, for example, a IIIB-VB transition metal. Suitable examples of transition metals include, but are not limited to, titanium (Ti), zirconium (Zr), hafnium (Hf), rutherfordium (Rf), or suitable combinations thereof.

In an embodiment, the IIIA metal and the transition metal can include any suitable material based on a particular application. For example, the IIIA metal can include gallium and/or aluminum, and the transition metal can include hafnium or zirconium.

The transition layer14can, in an embodiment, improve formation of the layer16on the substrate12. This can, for example, result in fewer manufacturing defects than if the layer16is formed directly on the substrate12without inclusion of the transition layer14.

Compared to transition layers that include IIIA nitride, or the like, the oxygenated IIIA-transition metal nitride layer can have improved crystallinity and electrical conductivity properties of GaN grown on the top. In an embodiment, the oxygenated IIIA-transition metal nitride layer can provide a higher quality GaN on the substrate12relative to prior transition layers because of the presence of oxygen, which can result in a more gradual transition between the substrate12and the transition layer14.

The layer16is formed on the transition layer14. The active layer18is formed on the layer16. The layer20is formed on the active layer18. Accordingly, the active layer18is disposed between the layer16and the layer20. It will be appreciated that one or more additional layers can be included in the optoelectronic device10. The layer16, active layer18, and layer20can, in an embodiment, be collectively referred to as the semiconductor28. In an embodiment, the semiconductor28can include semiconductor materials and can, for example, be configured to emit light during operation of the optoelectronic device10. In an embodiment, the layer16can be an n-type layer and the layer20can be a p-type layer. In an embodiment, the active layer18can alternatively be referred to as an absorptive or absorption layer20. In such an embodiment, the optoelectronic device may be referred to as a photo detector or the like.

In an embodiment, the layer16can be an n-type gallium nitride (n-GaN) layer and the layer20can be a p-type gallium nitride (p-GaN) layer. In such an embodiment, the active layer18can include semiconductor materials in which electrically excited electrons from the layer16combine with holes from the layer20to generate photons. The photons can have a specific wavelength for emission of light. In an embodiment, the active layer18can include a p-n junction, a double heterojunction, a quantum-well (QW) structure, or a multiple quantum-well (MQW) structure. It will be appreciated that in an embodiment, the active layer18may not be included in the optoelectronic device10. In such an embodiment, the layer20is disposed on the layer16. In another embodiment, the semiconductor28can include one or more additional layers. In an embodiment, the active layer18can alternatively be referred to as an absorptive or absorption layer20. In such an embodiment, the optoelectronic device may be referred to as a photo detector or the like.

The layer22is formed on the layer20. The layer22can be, for example, a p-contact layer. The layer22can be in Ohmic contact with the layer20. In an embodiment, the layer22can be, for example, an indium tin oxide (ITO). In an embodiment, the layer22can include a IIIA-transition metal nitride. In an embodiment, the layer22can include an oxygenated IIIA-transition metal nitride that is similar to the transition layer14.

The optoelectronic device10A also includes electrically conductive elements24,26. In the illustrated embodiment, the electrically conductive element24is conductively connected to the layer22. In the illustrated embodiment, the electrically conductive element26is conductively connected to the transition layer14. In an embodiment, the electrically conductive elements24,26may generally be representative of, for example, electrode terminals for electrically connecting a power source to the optoelectronic device10.

In an embodiment, the electrically conductive element24can be a metal or a metallic oxide including, but not limited to, nickel (Ni), gold (Au), an indium tin oxide (ITO), or suitable combinations thereof. In an embodiment, the electrically conductive element26can be a metal including, but not limited to, titanium (Ti), aluminum (Al), nickel (Ni), gold (Au), or suitable combinations thereof.

In operation, the layer16and the layer20can be electrically excited to generate electrons and holes for light generation. In an embodiment, the transition layer14can be a multi-crystalline structure.

InFIG. 1B, the optoelectronic device10B includes the electrically conductive element26connected to the substrate12. Also, as illustrated, the electrically conductive element24is formed across an entire surface of the layer22.

FIG. 2illustrates a schematic diagram of the transition layer14inFIGS. 1A-1B, according to an embodiment. In the illustrated embodiment, the transition layer14includes two layers14A,14B. Aspects ofFIG. 2can be the same as or similar to aspects ofFIGS. 1A-1B. For simplicity of this specification, description of features already provided with respect toFIGS. 1A-1Bwill not be repeated.

InFIG. 2, the first layer14A of the transition layer14would be deposited on the substrate12(FIGS. 1A-1B). The second layer14B of the transition layer14is deposited on the first layer14A. In this configuration, the second layer14B would be disposed between the first layer14A and the first layer16(FIGS. 1A-1B).

In an embodiment, the first layer14A and the second layer14B can have different compositions. In an embodiment, either of the first layer14A or the second layer14B can include a plurality of layers.

In an embodiment, the first layer14A can include Hfx″Al1-x″N. In such an embodiment, x″ can range from about 0 to about 0.5. The second layer14B can include {HfxZryAlzGa1-x-y-zN/Hfx′Zry′Alz′Ga1-x′-y′-z′N}n. In such an embodiment, x, x′, y, y′, z, and z′ can range from about 0 to about 1, x+y+z=1, x′+y′+z′=1, and n is an integral number and can vary from about 1 to about 60. In an embodiment, the second layer14B can include n sub-layers each including one or more layers of HfxZryAlzGa1-x-y-zN and Hfx′Zry′Alz′Ga1-x′-y′-z′N based on the application. Accordingly, in one embodiment, the transition layer14may have a structure of {HfxZryAlzGa1-x-y-zN/Hfx′Zry′Alz′Ga1-x′-y′-z′N}n/Hfx″Al1-x″N. In another embodiment, the first layer14A may include the material of Hfx″Zry″Alz″Ga1-x″-y″-z″N, where x″, y″ and z″ can range from about 0 to about 1, and x″+y″+z″=1. In the foregoing embodiments, one of the first layer14A or the second layer14B can additionally include oxygen. In the foregoing embodiments, both of the first layer14A and the second layer14B can include oxygen.

FIG. 3illustrates a schematic diagram of the transition layer14inFIGS. 1A-1B, according to another embodiment. In the illustrated embodiment, the transition layer14includes three layers14A,14B, and14C. Aspects ofFIG. 3can be the same as or similar to aspects ofFIGS. 1A-1B. For simplicity of this specification, description of features already provided with respect toFIGS. 1-2will not be repeated.

InFIG. 3, the first layer14A would be deposited on the substrate12(FIGS. 1A-1B). The second layer14B is deposited on the first layer14A. The third layer14C is deposited on the second layer14B. In this configuration, the third layer14C would be disposed between the first layer16(FIGS. 1A-1B) and the second layer14B. It is to be appreciated that the multilayered transition layers14inFIGS. 2-3are intended as examples. The number of layers in the transition layer14can vary, and can be greater than three, according to an embodiment. Further, in an embodiment, the layers14A-14C of the transition layer14can include multiple sub-layers.

In an embodiment, the first layer14A, the second layer14B, and the third layer14C can have different compositions. In an embodiment, one or more of the layers14A-14C can have a same composition. In an embodiment, one or more of the layers14A-14C can include a plurality of sub-layers. In an embodiment, including a plurality of sub-layers for one or more of the layers14A-14C can enable a gradual transition of composition between the layers14A14C.

In an embodiment, the transition layer14can include the third layer14C, which can include Hfx′″Zry′″Alz′″Ga1-x′″-y′″-z′″N, where x′″, y′″, and z′″ can range from about 0 to about 1, x′″+y′″+z′″=1. Thus, the transition layer14can have a structure of Hfx′″Zry′″Alz′″Ga1-x′″-y′″-z′″N/{HfxZryAlzGa1-x-y-zN/Hfx′Zry′Alz′Ga1-x′-y′-z′N}n/Hfx″Al1-x″N, where x″ can range from about 0 to about 0.5, and n can range from about 0 to about 60. The third layer14C, and accordingly, the transition layer14, can include oxygen.

In an embodiment, the layer14A can include {HfxZryAlzGa1-x-y-zN/Hfx′Zry′Alz′Ga1-x′-y′-z′N}n. The second layer14B can include Hfx″Al1-x″N. In an embodiment, the transition layer14may not include the third layer14C (e.g.,FIG. 2). As used in this specification, x, x′, x″, x′″, y, y′, y″, y′″z′, z″ and z′″ mean the content of compositions of Hf, Ga, N, Al, Zr, and can be substituted by other letters or exchanged among them. For example, although as described above, the first layer14A can include the material of Hfx″Zry″Alz″Ga1-x″-y″-z″N, where x″, y″ and z″ can range from about 0 to about 1, and x″+y″+z″=1. In an embodiment, the first layer14A can be defined to include Hfx′Zry′Alz′Ga1-x′-y′-z′N, where x′, y′ and z′ can range from about 0 to about 1, and x′+y′+z′=1. In the preceding embodiments, the layers14A or14B can include oxygen.

In one embodiment, the transition layer14includes Hf1-xAlxN, where x is greater than about 0.83, about 0.9, or is equal to about 0.995. In another embodiment, the transition layer14can include Hf1-xAlxN, where x is smaller than about 0.01, about 0.17, or is equal to about 0.05. In an embodiment, each layer of the transition layer14can include gradual variations, which means contents of one or more compositions of each layer can be varied gradually. For example, when the transition layer14includes the Hf1-xAlxN layer, x may can from about 0 to about 0.05, or from about 0.05 to about 0. When the transition layer14includes the Hf1-xAlxN layer, x can vary from about 0 to about 0.17, or from about 0.17 to about 0.

As used herein, the HfN/HfAlN structure means the structure includes two layers including an HfN layer and an HfAlN layer. Similarly, {HfxZryAlzGa1-x-y-zN/Hfx′Zry′Alz′Ga1-x′-y′-z′N}n structure can have n layers of a {HfxZryAlzGa1-x-y-zN/Hfx′Zry′Alz′Ga1-x′-y′-z′N} structure with can have n layers of a {HfxZryAlzGa1-x-y-zN/Hfx′Zr′Alz′N} structure with each {HfxZryAlzGa1-x-y-zN/Hfx′Zry′Alz′Ga1-x′-y′-z′N} structure comprising one or two of a layer of HfxZryAlzGa1-x-y-zN and a layer of Hfx′Zry′Alz′Ga1-x′-y′-z′N based on different applications. For example, when n is equal to about 1, the {HfxZryAlzGa1-x-y-zN/Hfx′Zry′Alz′Ga1-x′-y′-z′N}n structure includes the one of the layer of HfxZryAlzGa1-x-y-zN and the layer of Hfx′Zry′Alz′Ga1-x′-y′-y′-z′N. When n is equal to about 2, the {HfxZryAlzGa1-x-y-zN/Hfx′Zry′AlzGa1-x′-y′-z′N}n structure includes two layers of the {HfxZryAlzGa1-x-y-zN/Hfx′Zry′Alz′Ga1-x′-y′-z′N} structure with each layer including the structure of {HfxZryAlzGa1-x-y-zN/Hfx′Zry′Alz′Ga1-x′-y′-z′N}. Similarly, each of the layers of HfxZryAlzGa1-x-y-zN and the layer of Hfx′Zry′Alz′Ga1-x′-y′-z′N can include gradual compositions. In an embodiment, any of the preceding layers can include oxygen.

FIGS. 4A-4Billustrate schematic diagrams of optoelectronic devices50A-50B including the transition layer14(FIGS. 1A-3) and a buffer layer52, according to an embodiment. The optoelectronic devices50A-50B can be representative of, for example, a light emitting diode (LED), or the like. Aspects ofFIGS. 4A-4Bmay be the same as or similar to aspects ofFIGS. 1A-3. For the simplicity of this specification, description of features already provided with respect toFIGS. 1A-3will not be repeated.

With reference toFIG. 4A, the optoelectronic device50A includes the buffer layer52disposed between the substrate12and the transition layer14. The transition layer14can be a single layer or can include multiple sub-layers (e.g.,FIGS. 1A-3). It is to be appreciated that the buffer layer52is not limited to the location between the substrate12and the transition layer14. In an embodiment, the buffer layer52can be disposed on the transition layer14. In an embodiment, the buffer layer can be disposed between the transition layer and the n-type semiconductor layer. In an embodiment, the optoelectronic device50A can include a buffer layer52′ disposed on the transition layer14. In an embodiment, the optoelectronic device50A can include the buffer layer52and the buffer layer52′. In an embodiment, the optoelectronic device50A can include the buffer layer52or the buffer layer52′. The buffer layer52or52′ can be a single layer or can include multiple sub-layers. In an embodiment, the sub-layers of the buffer layer and the sub-layers of the transition layer are arranged as alternating layers. In an embodiment, the sub-layers of the buffer layer52or52′ and the sub-layers of the transition layer14are arranged as alternating layers of at least one sub-layer of the buffer layer and at least one sub-layer of the transition layer. In an embodiment, at least one sub-layer of the buffer layer52or52′ is disposed between the sub-layers of the transition layer14. In an embodiment, the sub-layers of the buffer layer52or52′ having different compositions from each other. In an embodiment, the sub-layers of the transition layer14having different compositions from each other.

In an embodiment, the transition layer14can include an oxygenated IIIA-transition metal nitride, and the buffer layer52can include a IIIA metal nitride with or without the addition of oxygen. In another embodiment, the transition layer14can include a IIIA-transition metal nitride without the addition of oxygen, and the buffer layer52can include an oxygenated IIIA metal nitride. In an embodiment, the transition layer14can include a IIIA-nitride with or without the addition of oxygen, and the buffer layer52can include an oxygenated IIIA metal nitride. In an embodiment, the buffer layer52can include a IIIA-nitride with or without the addition of oxygen, and the transition layer14can include an oxygenated IIIA-transition metal nitride. In an embodiment, the buffer layer52can include an oxygenated IIIA-nitride, and the transition layer14can include an oxygenated IIIA metal nitride. In an embodiment, the buffer layer52can include an oxygenated IIIA metal nitride. In an embodiment, the transition layer14can include an oxygenated IIIA-transition metal nitride. Accordingly, in an embodiment, the buffer layer52or the transition layer14can include oxygen. That is, in an embodiment, either the buffer layer52or the transition layer14, but not both, can include oxygen. In another embodiment, the buffer layer52and the transition layer14can both include an oxygen. That is, in an embodiment, both the buffer layer52and the transition layer14can include oxygen.

It will be appreciated that when the buffer layer52does not include an oxygenated IIIA metal nitride, the buffer layer52can include a III-V nitride or oxygenated III-V nitride.

InFIG. 4B, the optoelectronic device50B includes the electrically conductive element26connected to the substrate12. Also, as illustrated, the electrically conductive element24is formed across an entire surface of the layer22.

FIG. 5illustrates a schematic diagram of the buffer layer52inFIGS. 4A-4B, according to an embodiment. In the illustrated embodiment, the buffer layer52can include the buffer layer52A,52B, . . .52N. That is, in an embodiment, the buffer layer52can include two or more layers52A . . .52N.

In the illustrated example, the buffer layer52includes layers52A . . .52N. The buffer layer52A can be configured to be coupled to the substrate12and can include the material/composition of {AlxGayIn1-x-yN/Alx′Gay′In1-x′-y′N}n, where x, x′, y and y′ can range from about 0 to about 1, x+y=1, x′+y′=1, and n can range from about 0 to about 60. As used in this specification, AlxGayIn1-x-yN/Alx′Gay′In1-x′-y′N}n means the sub-layer52A can include one or more layers of a layer of AlxGayIn1-x-yN and a layer of Alx′Gay′In1-x′-y′N. The buffer layer52B is configured to be coupled to the buffer layer52A and can include the composition of Alx″Gay″In1-x″-y″N, where x″ and y″ can range from about 0 to about 1, x″+y″=1. Either of the layers52A or52B, or in an embodiment, both layers52A-52B, can include oxygen.

Accordingly, the buffer layer52can have a structure of Alx″Gay″In1-x″-y″N/{AlxGayIn1-x-yN/Alx′Gay′In1-x′-y′N}n. In an embodiment, the layers52A-52B can be different from each other. In an embodiment, the material of the layers52A-52B can be modified. For example, the layer52A can include Alx″Gay″In1-x″-y″N, and the layer52B can include {AlxGayIn1-x-yN/Alx′Gay′In1-x′-y′N}n. In an embodiment, the buffer layer52may not be included. In an embodiment, the buffer layer52can include aluminum nitride (AlN), gallium nitride (GaN) or AlxGa1-xN, where x may range from about 0 to about 1. In the preceding embodiments, the buffer layer52can include oxygen.

FIG. 6is a flowchart of a method100for forming an optoelectronic device as described in this specification, according to an embodiment. The method100can generally form the optoelectronic devices10A-10B inFIGS. 1A-1Bor the optoelectronic devices50A-50B inFIGS. 4A-4B.

If the optoelectronic device is to include a buffer layer (e.g., buffer layer52), the method begins at102by forming the buffer layer on a substrate (e.g., substrate12inFIGS. 4A-4B). In an embodiment,102is optional. A variety of methods may be used to form the buffer layer on the substrate. Suitable methods include, but are not limited to, molecular-beam epitaxy (MBE), metal-organic chemical vapor deposition (MOCVD), chemical vapor deposition (CVD), physical vapor deposition (PVD), hydride vapor phase epitaxy (HYPE), and reactive sputtering. At104, a transition layer (e.g., transition layer14inFIGS. 1A-4B) is formed on the substrate (if102was not completed) or on the buffer layer (if102was completed). A variety of methods may be used to form the transition layer on either the substrate or the buffer layer. Suitable methods include, but are not limited to, MBE, MOCVD, CVD, PVD, HPVE, and reactive sputtering. At106a semiconductor (e.g., semiconductor28inFIGS. 1A-4B) is formed on the transition layer. During the formation of the semiconductor, the layers16-20(FIGS. 1A-4B) may be formed on the transition layer. A variety of techniques, including the above-identified methods, can be used to form the semiconductor on the transition layer at106. At108, a layer (e.g., the layer22inFIGS. 1A-4B) is electrically connected to the semiconductor, and at110, electrically conductive elements (e.g., electrically conductive elements24,26) are connected to the layer22and the transition layer or the substrate.

The buffer layer52can be a single layer or can include multiple sub-layers. The buffer layer52can be disposed on the transition layer14or between the transition layer14and the substrate12. In an embodiment, the sub-layers of the buffer layer52and the sub-layers of the transition layer14are arranged as alternating layers. In an embodiment, the sub-layers of the buffer layer52and the sub-layers of the transition layer14are arranged as alternating layers of at least one sub-layer of the buffer layer52and at least one sub-layer of the transition layer14. In an embodiment, at least one sub-layer of the buffer layer52is disposed between the sub-layers of the transition layer14. In an embodiment, the sub-layers of the buffer layer52have different compositions from each other. In an embodiment, the sub-layers of the transition layer14have different compositions from each other.

Aspects

It is noted that any of aspects 1-13 below can be combined with any of aspects 14-20.

a substrate;

a semiconductor comprising an n-type layer disposed on the substrate, a p-type layer disposed on the n-type layer, and an active layer disposed between the n-type layer and the p-type layer;

a transition layer disposed on the substrate and located between the n-type layer and the substrate, the transition layer including an oxygenated IIIA-transition metal nitride; and

a p-contact layer disposed on the p-type layer of the semiconductor.

Aspect 2. The optoelectronic device according to aspect 1, wherein the IIIA metal includes aluminum (Al), gallium (Ga), indium (In), thallium (Tl), and combination thereof, and wherein the transition metal comprises titanium (Ti), zirconium (Zr), hafnium (Hf), rutherfordium (Ri), and combination thereof.

Aspect 3. The optoelectronic device according to aspect 2, wherein the IIIA metal comprises one or two of aluminum and gallium, and wherein the transition metal comprises one or two of hafnium and zirconium.

Aspect 4. The optoelectronic device according to any one of aspects 1-3, wherein the transition layer includes a plurality of layers.

Aspect 5. The optoelectronic device according to aspect 4, wherein one or more of the plurality of layers of the transition layer include a plurality of layers.

Aspect 6. The optoelectronic device according to any one of aspects 1-5, further comprising a buffer layer disposed between the transition layer and the substrate.

Aspect 7. The optoelectronic device according to aspect 6, wherein the buffer layer includes a plurality of layers.

Aspect 8. The optoelectronic device according to aspect 7, wherein the buffer layer includes an oxygenated IIIA-transition metal nitride.

Aspect 9. The optoelectronic device according to any one of aspects 1-8, further comprising a buffer layer disposed between the n-type layer and the transition layer.

Aspect 10. The optoelectronic device according to any one of aspects 1-9, further comprising two buffer layers, one disposed between n-type layer and the transition layer, the other one disposed between the transition layer and the substrate.

Aspect 11. The optoelectronic device according to any one of aspects 1-10, further comprising a first electrically conductive element electrically connected to the p-contact layer, and a second electrically conductive element electrically connected to one of the transition layer or the n-type layer.

Aspect 12. The optoelectronic device according to any one of aspects 1-11, wherein the n-type layer includes one of n-GaN and n-AlxGa1-xN, where x is from 0 to 1, the p-type layer includes one of p-GaN layer and p-AlxGa1-xN, where x is from 0 to 1, and the substrate includes one or more of sapphire including flat or patterned sapphire, silicon, or silicon carbide (SiC).

Aspect 13. The optoelectronic device according to aspect 12, wherein the sapphire is one of a flat sapphire substrate or a patterned sapphire substrate.

Aspect 14. A method for making an optoelectronic device, comprising:

forming a transition layer on a substrate, wherein the transition layer includes an oxygenated IIIA-transition metal nitride;

forming an n-type layer on the transition layer;

forming an active layer on the n-type layer;

forming a p-type layer on the active layer, so that the active layer is disposed between the n-type layer and the p-type layer; and

forming a p-contact layer on the p-type layer and an n-contact layer on the transition layer or the n-type layer.

Aspect 15. The method according to aspect 14, further comprising disposing a first electrically conductive element on the p-contact layer, and a second electrically conductive element on the transition layer or the n-type layer.

Aspect 16. The method according to any one of aspects 14-15, wherein a IIIA metal in the oxygenated IIIA-transition metal nitride includes one or two of aluminum and gallium, and wherein the transition metal comprises one or two of hafnium and zirconium.

Aspect 17. The method according to any one of aspects 14-16, further comprising forming a buffer layer between the substrate and the transition layer, the buffer layer including an oxygenated IIIA-transition metal nitride or an oxygenated IIIA-nitride.

Aspect 18. The method according to aspect 17, wherein the buffer layer includes AlxGa1-xN, where x is from 0 to 1.

Aspect 19. The optoelectronic device according to any one of aspects 14-18, further comprising a buffer layer disposed between the n-type layer and the transition layer.

Aspect 20. The optoelectronic device according to any one of aspects 14-19, further comprising two buffer layers, one disposed between n-type layer and the transition layer, the other one disposed between the transition layer and the substrate.