Low ohmic contact nitride light emitting diode chip and method of fabricating the same

Abstract

The application discloses a preparation method of a low-ohmic contact nitride light-emitting diode chip, which comprises the following steps: growing a buffer layer on a substrate; growing an n-type nitride layer on the buffer layer; growing a nitride light-emitting layer on the n-type nitride layer; growing a p-type nitride layer on the nitride light-emitting layer; growing a first contact functional layer on the p-type nitride layer and growing a second contact functional layer on the first contact functional layer; etching off part of the epitaxial layer between the second contact functional layer and the upper surface of the n-type nitride layer; etching off part of the second contact functional layer to expose part of the first contact functional layer; arranging a transparent conductive layer on the unetched second contact functional layer and the exposed first contact functional layer; and arranging a p-type electrode and an n-type electrode on the transparent conductive layer and the n-type nitride layer, respectively. The application can overcome the difficulty in realizing the ohmic contact of the p-type GaN-based semiconductor material, and improve the photoelectric performance of the nitride light-emitting diode chip.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a low-ohmic contact nitride light-emitting diode chip and its fabrication method. Background Technology

[0002] Wide bandgap GaN-based semiconductor materials possess excellent physical and chemical properties such as high breakdown field strength, high thermal conductivity, and fast electron saturation migration rate, and have attracted much attention due to their broad application prospects in blue-green LEDs, photodetectors, and high-temperature, high-frequency, and high-power devices.

[0003] Since Nakamura fabricated the first GaN-based blue LED, GaN-based wide-bandgap III-V semiconductor devices have been extensively studied and have achieved significant results, showing broad application prospects in optoelectronics and high-temperature, high-frequency, high-power devices. The commercialization of LEDs and the realization of long-life lasers both require good p-type ohmic contacts. Reliable, low-resistance ohmic contacts are fundamental to the fabrication of high-power LEDs and LDs, as high-resistance contacts generate additional voltage drops and heat, affecting the performance of semiconductor devices and directly determining their normal operation. Therefore, high-quality ohmic contacts are crucial for improving device performance, leading to extensive research into low-resistance p-type ohmic contacts. While GaN-based device research has made great progress, many challenges remain. Good ohmic contacts are one of the keys to fabricating high-performance GaN-based devices, especially for high-current-density semiconductor lasers and high-temperature, high-power devices.

[0004] Indium tin oxide (ITO), a transparent conductive material, possesses excellent photoelectric properties and high transmittance in the visible light range, making it the most widely used transparent conductive layer. However, it is difficult to achieve ohmic contacts between ITO and p-type GaN-based semiconductor materials. In contrast, ohmic contacts of n-type GaN-based semiconductor materials are easier to fabricate, while fabricating low-resistance p-type GaN-based semiconductor materials is more challenging. P-type GaN-based semiconductor materials are generally doped with Mg, but the Mg-H passivation effect has become one of the factors that seriously restricts the development of GaN-based material devices. The activation efficiency of Mg is usually less than 1%. In particular, as the Al content of p-type AlInGaN materials increases, the acceptor ionization energy increases, making it difficult to achieve high carrier concentration p-type doping, which increases the difficulty of achieving ohmic contacts in p-type GaN-based semiconductor materials.

[0005] Therefore, there is an urgent need to propose a low-ohmic contact nitride light-emitting diode chip and its fabrication method that can overcome the difficulties in realizing ohmic contacts in existing p-type GaN-based semiconductor materials. Summary of the Invention

[0006] The purpose of this invention is to provide a low-ohmic contact nitride light-emitting diode chip and its fabrication method, which can overcome the technical problem of difficulty in achieving ohmic contacts in existing p-type GaN-based semiconductor materials.

[0007] To solve the above-mentioned technical problems, the present invention provides a method for fabricating a low-ohmic contact nitride light-emitting diode chip, comprising:

[0008] S1: Provide a substrate on which a buffer layer is grown;

[0009] S2: An n-type nitride layer is grown on the buffer layer;

[0010] S3: A nitride luminescent layer is grown on the n-type nitride layer;

[0011] S4: Grow a p-type nitride layer on the nitride luminescent layer;

[0012] S5: A surface treatment functional layer is grown on the p-type nitride layer, wherein the surface treatment functional layer includes a first contact functional layer and a second contact functional layer, the second contact functional layer is grown on the first contact functional layer, and the first contact functional layer is grown on the p-type nitride layer.

[0013] S6: Anneal and etch the epitaxial structure formed in S1 to S5 to etch away part of the epitaxial layer between the second contact functional layer and the upper surface of the n-type nitride layer to form a mesa structure.

[0014] S7: Etch the mesa structure formed in S6 to etch away part of the second contact functional layer and expose part of the first contact functional layer.

[0015] S8: A transparent conductive layer is disposed on the unetched second contact functional layer after the etching process of S7 and on the exposed first contact functional layer.

[0016] S9: P-type electrodes and n-type electrodes are respectively disposed on the transparent conductive layer and the n-type nitride layer.

[0017] In one embodiment of the present invention, S1-S5 are grown using MOCVD epitaxial technology to form an epitaxial structure.

[0018] In one embodiment of the present invention, the first contact functional layer is a metal oxide layer, wherein the metal selected for the metal oxide layer is a hydrogen storage element and / or a hydrogen storage alloy.

[0019] In one embodiment of the present invention, the metal of the metal oxide layer is one or a combination of two or more of Mg, Ni, V, Cr, Mn, Fe, Co, Al, Ga, La, Ce, Sm, Cu, In, Sn, B, Pt, Pd, Cr, Ag, Ir, Ti, Zr, and Ta.

[0020] In one embodiment of the present invention, the second contact functional layer is grown using alternating layers of insulating material.

[0021] In one embodiment of the present invention, the second contact functional layer is a combination of two or more of SiO2, TiO2, Al2O3, MgO, Ta2O5, Fe3O4, Nb2O5, HfO2, and ZrO2.

[0022] In one embodiment of the present invention, the second contact functional layer is a combination of two or more of SiO2, TiO2, and Al2O3.

[0023] In one embodiment of the present invention, the thickness of the first contact functional layer is 5-15 nm, and the thickness of the second contact functional layer is 50-100 nm.

[0024] Furthermore, the present invention also provides a low-ohmic contact nitride light-emitting diode chip, which is prepared by the method for preparing a low-ohmic contact nitride light-emitting diode chip as described above, comprising:

[0025] Substrate;

[0026] A buffer layer is formed on the substrate;

[0027] An n-type nitride layer is formed on the buffer layer, and an n-type electrode is disposed on the n-type nitride layer;

[0028] A nitride luminescent layer is formed on the n-type nitride layer;

[0029] A p-type nitride layer is formed on the nitride luminescent layer;

[0030] A surface treatment functional layer includes a first contact functional layer and a second contact functional layer, wherein the second contact functional layer is formed on the first contact functional layer and the first contact functional layer is formed on the p-type nitride layer;

[0031] A transparent conductive layer is formed on the second contact functional layer, and a p-type electrode is disposed on the transparent conductive layer.

[0032] In one embodiment of the present invention, the first contact functional layer is a metal oxide layer, wherein the metal selected for the metal oxide layer is a hydrogen storage element and / or a hydrogen storage alloy; the second contact functional layer is a structure formed by alternating growth of insulating materials.

[0033] The technical solution of the present invention has the following advantages compared with the prior art:

[0034] 1. The present invention provides an in-situ growth surface treatment functional layer, which includes a first contact functional layer and a second contact functional layer. On the one hand, the hydrogen storage metal material of the first contact functional layer is used to remove H in the p-type nitride surface layer, reduce the passivation of H on the acceptor, improve the doping efficiency, and achieve good ohmic contact between the p-type nitride layer and the transparent conductive layer, thereby reducing the ohmic contact resistance. On the other hand, the insulating properties of the second contact functional layer can limit the carrier injection area, reduce the sidewall damage caused by etching in the existing chip fabrication process, reduce the probability of carrier capture on the sidewall, improve the carrier injection of the nitride light-emitting layer, and improve the chip luminous efficiency, which is especially suitable for Micro-LED fabrication process (size less than 100μm).

[0035] 2. The present invention provides an in-situ growth surface treatment functional layer, which can form a surface protection for the p-type nitride epitaxial layer, avoid surface organic contamination, and eliminate the need for organic solvent surface cleaning process in chip fabrication process, thereby reducing organic impurity contamination and improving device fabrication efficiency. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the structure of a low-ohmic contact nitride light-emitting diode chip provided by the present invention.

[0038] Figure 2 This is a schematic diagram of the light emitted from the nitride light-emitting layer of a low-ohmic contact nitride light-emitting diode chip provided by the present invention.

[0039] Figure 3 This is a schematic diagram of p-type nitride hole injection for a low-ohmic contact nitride light-emitting diode chip provided by the present invention.

[0040] Figure 4 This is a schematic flowchart illustrating a method for fabricating a low-ohmic contact nitride light-emitting diode chip provided by the present invention.

[0041] The reference numerals in the attached figures are explained as follows: 10, substrate; 20, buffer layer; 30, n-type nitride layer; 31, n-type electrode; 41, nitride barrier layer; 42, nitride trap layer; 50, p-type nitride layer; 61, first contact functional layer; 62, second contact functional layer; 70, transparent conductive layer; 71, p-type electrode. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. Based on the embodiments of the present invention, those skilled in the art should understand that modifications can still be made to the technical solutions of each embodiment, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. All other embodiments obtained without creative effort are within the scope of protection of the present invention.

[0043] Please see Figure 4 As shown, this embodiment of the invention provides a method for fabricating a low-ohmic contact nitride light-emitting diode chip, specifically including:

[0044] S1: Provide a substrate on which a buffer layer is grown;

[0045] S2: An n-type nitride layer is grown on the buffer layer;

[0046] S3: A nitride luminescent layer is grown on the n-type nitride layer;

[0047] S4: Grow a p-type nitride layer on the nitride luminescent layer;

[0048] S5: A surface treatment functional layer is grown on the p-type nitride layer, wherein the surface treatment functional layer includes a first contact functional layer and a second contact functional layer, the second contact functional layer is grown on the first contact functional layer, and the first contact functional layer is grown on the p-type nitride layer.

[0049] S6: Anneal and etch the epitaxial structure formed in S1-S5 to etch away part of the epitaxial layer between the second contact functional layer and the upper surface of the n-type nitride layer to form a mesa structure.

[0050] S7: Etch the mesa structure formed in S6 to etch away part of the second contact functional layer and expose part of the first contact functional layer.

[0051] S8: A transparent conductive layer is disposed on the unetched second contact functional layer after the etching process of S7 and on the exposed first contact functional layer.

[0052] S9: P-type electrodes and n-type electrodes are respectively disposed on the transparent conductive layer and the n-type nitride layer.

[0053] In the method provided in this embodiment, S1-S5 uses MOCVD epitaxial growth to form an epitaxial structure. The entire growth of this invention is completed by MOCVD equipment, that is, the entire process does not require transfer, which significantly improves the process efficiency.

[0054] In the method provided in this embodiment, the nitride light-emitting layer is a quantum well structure, which includes a nitride well layer and a nitride barrier layer, wherein the thickness of the nitride well layer is 1-6 nm and the thickness of the nitride barrier layer is 3-8 nm.

[0055] In the method provided in this embodiment, the transparent conductive layer is indium tin oxide (ITO).

[0056] The method provided in this embodiment involves in-situ growth of a surface-treated functional layer, which includes a first contact functional layer. This first contact functional layer is a metal oxide layer, wherein the metal selected for the metal oxide layer is a hydrogen storage element and / or a hydrogen storage alloy. The hydrogen storage alloy may include one or more of the following: Mg-based hydrogen storage alloys, rare-earth-based hydrogen storage alloys, Ti-based hydrogen storage alloys, and zirconium-based hydrogen storage alloys. Specifically, the metal selected for the metal oxide layer is one or more of the following: Mg, Ni, V, Cr, Mn, Fe, Co, Al, Ga, La, Ce, Sm, Cu, In, Sn, B, Pt, Pd, Cr, Ag, Ir, Ti, Zr, and Ta. This invention utilizes the hydrogen storage metal material of the first contact functional layer to remove H from the p-type nitride surface layer, reducing H passivation of the acceptor and improving doping efficiency. This achieves good ohmic contact between the p-type nitride layer and the transparent conductive layer (ITO), reducing ohmic contact resistance and overcoming the technical problem of difficulty in achieving ohmic contact in existing p-type GaN-based semiconductor materials.

[0057] In the method provided in this embodiment, the second contact functional layer is grown using alternating insulating materials. Specifically, the second contact functional layer is a combination of two or more of SiO2, TiO2, Al2O3, MgO, Ta2O5, Fe3O4, Nb2O5, HfO2, and ZrO2. Preferably, the second contact functional layer is a combination of two or more of SiO2, TiO2, and Al2O3. The second contact functional layer of this invention uses alternating growth of insulating materials with different refractive indices to form a distributed Bragg reflector (DBR) structure. This can alter the light emitted from the nitride light-emitting layer towards the second contact functional layer and reduce the light absorption of the electrodes on the second contact functional layer, further improving the light extraction efficiency of the chip. See [link to relevant documentation]. Figure 2 As shown; simultaneously, the insulating properties of the second contact functional layer can confine the carrier injection region, reduce sidewall damage caused by etching in existing chip fabrication processes, reduce the probability of carrier capture on the sidewalls, and improve carrier injection in the nitride light-emitting layer, which is especially suitable for Micro-LED fabrication processes (size less than 100μm), see Figure 3 As shown.

[0058] In the method provided in this embodiment, if the first contact functional layer is too thin, it will not be able to remove H in the p-type nitride surface layer during annealing; if it is too thick, it will prolong the epitaxial growth time. Therefore, the thickness of the first contact functional layer in this invention is 5-15 nm. This thickness range will neither affect the removal of H in the p-type nitride surface layer nor increase production costs.

[0059] In the method provided in this embodiment, considering that a second contact functional layer that is too thin cannot provide surface protection for the p-type nitride epitaxial layer, the chip's aging performance will deteriorate over time, affecting its application in special environments such as high temperature and high humidity. Conversely, a layer that is too thick will prolong epitaxial growth time and increase production costs. Therefore, the thickness of the second contact functional layer in this invention is 50–100 nm. This thickness range ensures that the second contact function does not reduce the protection of the p-type nitride epitaxial layer while also not prolonging the epitaxial growth time.

[0060] The method provided in this embodiment allows for the in-situ growth of a surface-treated functional layer, which can form a surface protection layer for the p-type nitride epitaxial layer, avoiding surface contamination by organic matter. This eliminates the need for organic solvent surface cleaning processes in the device fabrication process, reduces organic impurity contamination, and improves device fabrication efficiency.

[0061] Corresponding to the embodiments of the above methods, the present invention provides an embodiment of a low-ohmic contact nitride light-emitting diode chip. Please refer to [link to embodiment]. Figure 1As shown, in this embodiment, a low-ohmic contact nitride light-emitting diode chip is fabricated using the method described above for preparing a low-ohmic contact nitride light-emitting diode chip. Its structure specifically includes:

[0062] Substrate;

[0063] A buffer layer is formed on the substrate;

[0064] An n-type nitride layer is formed on the buffer layer, and an n-type electrode is disposed on the n-type nitride layer;

[0065] A nitride luminescent layer is formed on the n-type nitride layer;

[0066] A p-type nitride layer is formed on the nitride luminescent layer;

[0067] A surface treatment functional layer includes a first contact functional layer and a second contact functional layer, wherein the second contact functional layer is formed on the first contact functional layer and the first contact functional layer is formed on the p-type nitride layer;

[0068] A transparent conductive layer is formed on the second contact functional layer, and a p-type electrode is disposed on the transparent conductive layer.

[0069] For the structure provided in this embodiment, the present invention grows a surface-treated functional layer in situ. The surface-treated functional layer includes a first contact functional layer, which is a metal oxide layer. The metal selected for the metal oxide layer is a hydrogen storage element and / or a hydrogen storage alloy. The present invention utilizes the hydrogen storage metal material of the first contact functional layer to remove H in the p-type nitride surface layer, reducing the passivation of the acceptor by H, improving the doping efficiency, and achieving good ohmic contact between the p-type nitride layer and the transparent conductive layer (ITO), reducing the ohmic contact resistance, and overcoming the technical problem of difficulty in achieving ohmic contact in existing p-type GaN-based semiconductor materials.

[0070] In the structure provided in this embodiment, the second contact functional layer is grown with alternating layers of insulating material to form a distributed Bragg reflector (DBR) structure. This alters the light emitted from the nitride light-emitting layer towards the second contact functional layer and reduces light absorption by the electrodes on the second contact functional layer, further improving the chip's light extraction efficiency. (See...) Figure 2 As shown; simultaneously, the insulating properties of the second contact functional layer can confine the carrier injection region, reduce sidewall damage caused by etching in existing chip fabrication processes, reduce the probability of carrier capture on the sidewalls, and improve carrier injection in the nitride light-emitting layer, which is especially suitable for Micro-LED fabrication processes (size less than 100μm), see Figure 3 As shown.

[0071] In the structure provided in this embodiment, the p-type electrode is disposed on the transparent conductive layer on the second contact functional layer, that is, the p-type electrode is not disposed in the middle region, which avoids the absorption of light emitted by the p-type electrode by the nitride light-emitting layer and improves the luminous efficiency.

[0072] Since the low-ohmic contact nitride light-emitting diode chip of this embodiment is prepared by the low-ohmic contact nitride light-emitting diode chip preparation method described above, the specific implementation of this structure can be found in the embodiment section of the preparation method of the low-ohmic contact nitride light-emitting diode chip described above. Therefore, the specific implementation can be referred to the description of the corresponding embodiments, and will not be elaborated here.

[0073] Based on the above embodiments, the present invention provides a more detailed description and comparison of the methods and structures of the above embodiments using specific examples and comparative examples.

[0074] Example 1

[0075] 1) Provide a substrate, and grow a 3 μm unintentionally doped GaN buffer layer on the substrate at a temperature of 1080℃ and a growth pressure of 200 torr. The required Ga source is a TMG source and the growth atmosphere is H2 atmosphere.

[0076] 2) Under the conditions of 1090℃ and 200 torr growth pressure, a 3μm n-type GaN layer was grown on an unintentionally doped GaN layer. The Ga source required for growth was a TMG source, and the growth atmosphere was H2 atmosphere.

[0077] 3) Under a growth pressure of 200 torr, a nitride luminescent layer is grown on an n-type GaN layer. The nitride luminescent layer consists of a periodically repeating alternating InGaN quantum well layer and a GaN quantum barrier layer. The repeating period of the luminescent layer is 1-3. The thickness of the InGaN quantum well layer is 2 nm and the growth temperature is 750 °C. The thickness of the GaN barrier layer is 6 nm and the growth temperature is 860 °C.

[0078] 4) A 15 nm p-type AlGaN electron blocking layer was grown on the nitride light-emitting layer at a growth temperature of 980℃ and a growth pressure of 100 torr. The required Ga source was a TMG source, the Al source was TMAl, and the growth atmosphere was N2 atmosphere.

[0079] 5) A 100 nm p-type GaN layer was grown on a p-type AlGaN electron blocking layer at a growth temperature of 950 °C and a growth pressure of 400 torr, with a doping concentration of 5 × 10⁻⁶. 19 cm -3 The required Ga source is a TMG source, and the growth atmosphere is an H2 atmosphere;

[0080] 6) Tantalum ethoxide (Ta(C2H5O)5) and oxygen were introduced at a growth temperature of 650℃ and a growth pressure of 200 torr to grow a 10 nm thick metal Ta oxide first contact functional layer on the p-type GaN layer.

[0081] 7) With a continuous oxygen source, under growth conditions of 700℃ and 50tor, silane (SiH4) and tetra(dimethylamine)titanium (TDMAT) are alternately introduced to grow an alternating layer of SiO2 and TiO2 on the first contact functional layer to form the second contact functional layer. The alternation time ratio is 2:1. The second contact functional layer is grown with materials of different refractive indices to form a distributed Bragg reflection (DBR) structure, which can change the light emitted from the nitride light-emitting layer to the second contact functional layer and reduce the light absorption of the electrodes on the second contact functional layer, thereby further improving the light extraction efficiency of the chip.

[0082] 8) Etch the epitaxial structure layer from steps 1) to 7) above, and etch away part of the epitaxial layer between the second contact functional layer and the upper surface of the n-type GaN layer to form a mesa structure;

[0083] 9) Etch the masa structure formed in step 8) to remove part of the second contact functional layer and expose part of the first contact functional layer.

[0084] 10) A transparent conductive layer is provided in the area of ​​the second contact functional layer that has not been etched in step 9) and the exposed area of ​​the first contact functional layer;

[0085] 11) P-type electrodes and n-type electrodes are respectively disposed on the transparent conductive layer and the n-type GaN layer.

[0086] Example 2

[0087] The difference between this embodiment and Embodiment 1 is in step 6: tantalum ethoxide (Ta(C2H5O)5), nickel dicene (Cp2Ni), and oxygen are introduced at a growth temperature of 650°C and a growth pressure of 200 torr to grow a 10 nm thick Ta and Ni oxide first contact functional layer on the p-type GaN layer.

[0088] Example 3

[0089] The difference between this embodiment and Embodiment 1 is in step 6: tantalum ethoxide (Ta(C2H5O)5), nickel dicene (Cp2Ni), magnesium dicene (Cp2Mg), and oxygen are introduced at a growth temperature of 600–800°C and a growth pressure of 200 torr to grow a first contact functional layer of Ta, Ni, and Mg oxides with a thickness of 10 nm on the p-type GaN layer.

[0090] Comparative Example 1

[0091] The difference between Comparative Example 1 and Example 1 is that steps 6 and 7 are omitted.

[0092] Chips of the same size were fabricated using Examples 1, 2, 3, and Comparative Example 1, and the test data are shown in Table 1 below:

[0093] Table 1

[0094]

[0095] As can be seen from the data in Table 1, under the same chip size conditions, Examples 1, 2, and 3 have better brightness and voltage performance. On the one hand, the metal oxide surface treatment functional layer of the present invention enables good ohmic contact between the p-type GaN layer and the transparent conductive layer (ITO). On the other hand, hydrogen storage metal materials can be used to remove H in the p-type nitride surface layer, reducing H passivation of the acceptor and improving doping efficiency. Furthermore, combined with the thermal annealing process, oxygen in the oxide is used to remove Ga atoms in the p-type nitride surface layer to form gallium vacancies, further increasing the hole concentration in the p-type nitride surface layer. This can achieve good ohmic contact between the p-type nitride layer and the transparent conductive layer (ITO), reduce ohmic contact resistance, improve chip brightness, and reduce chip voltage.

[0096] In addition, the insulating properties of the in-situ grown second contact functional layer can effectively confine the carrier injection to the area where the second contact functional layer is etched away. This allows the carrier injection to be effectively confined to the middle region of the light-emitting layer, greatly reducing the capture of carriers by sidewall defects, improving carrier injection efficiency and quantum efficiency, and mitigating current leakage and external quantum efficiency decay caused by damage to the device sidewall surface due to cutting. This is suitable for Micro-LED chip fabrication processes.

[0097] Furthermore, the in-situ growth of the metal oxide surface treatment functional layer can form a surface protection for the p-type nitride epitaxial layer, avoiding organic contamination on the surface. This eliminates the need for organic solvent surface cleaning processes in device fabrication, reducing organic impurity contamination and improving device fabrication efficiency.

[0098] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The structures disclosed in the embodiments are described simply because they correspond to the methods disclosed in the embodiments; relevant parts can be found in the method section.

[0099] The present invention provides a detailed description of a low-ohmic contact nitride light-emitting diode chip and its fabrication method. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of these examples are merely illustrative and are intended to help understand the method and core concepts of the invention. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims.

Claims

1. A method for fabricating a low-ohmic contact nitride light-emitting diode chip, characterized in that, include: S1: Provide a substrate on which a buffer layer is grown; S2: An n-type nitride layer is grown on the buffer layer; S3: A nitride luminescent layer is grown on the n-type nitride layer; S4: Grow a p-type nitride layer on the nitride luminescent layer; S5: A surface treatment functional layer is grown on the p-type nitride layer, wherein the surface treatment functional layer includes a first contact functional layer and a second contact functional layer, the second contact functional layer is grown on the first contact functional layer, the first contact functional layer is grown on the p-type nitride layer, the first contact functional layer is a metal oxide layer, and the metal selected for the metal oxide layer is a hydrogen storage element and / or a hydrogen storage alloy; the second contact functional layer is insulating. S6: Anneal and etch the epitaxial structure formed in S1 to S5 to etch away part of the epitaxial layer between the second contact functional layer and the upper surface of the n-type nitride layer to form a mesa structure. S7: Etch the mesa structure formed in S6 to etch away part of the second contact functional layer and expose part of the first contact functional layer. S8: A transparent conductive layer is disposed on the unetched second contact functional layer after the etching process of S7 and on the exposed first contact functional layer. S9: P-type electrodes and n-type electrodes are respectively disposed on the transparent conductive layer and the n-type nitride layer; The p-type electrode is disposed on the transparent conductive layer of the second contact functional layer.

2. The method for fabricating a low-ohmic contact nitride light-emitting diode chip as described in claim 1, characterized in that: S1-S5 are epitaxial structures grown using MOCVD epitaxial technology.

3. The method for fabricating a low-ohmic contact nitride light-emitting diode chip as described in claim 2, characterized in that: The metal in the metal oxide layer is one or a combination of two or more of the following: Mg, Ni, V, Cr, Mn, Fe, Co, Al, Ga, La, Ce, Sm, Cu, In, Sn, B, Pt, Pd, Cr, Ag, Ir, Ti, Zr, and Ta.

4. The method for fabricating a low-ohmic contact nitride light-emitting diode chip as described in claim 1, characterized in that: The second contact functional layer is grown using alternating layers of insulating material.

5. The method for fabricating a low-ohmic contact nitride light-emitting diode chip as described in claim 1 or 4, characterized in that: The second contact functional layer is a combination of two or more of SiO2, TiO2, Al2O3, MgO, Ta2O5, Fe3O4, Nb2O5, HfO2, and ZrO2.

6. The method for fabricating a low-ohmic contact nitride light-emitting diode chip as described in claim 5, characterized in that: The second contact functional layer is a combination of two or more of SiO2, TiO2, and Al2O3.

7. The method for fabricating a low-ohmic contact nitride light-emitting diode chip as described in claim 1 or 2, characterized in that: The thickness of the first contact functional layer is 5-15 nm, and the thickness of the second contact functional layer is 50-100 nm.

8. A low-ohmic contact nitride light-emitting diode chip, characterized in that, It is prepared by the method for fabricating a low-ohmic contact nitride light-emitting diode chip as described in any one of claims 1-7, comprising: Substrate; A buffer layer is formed on the substrate; An n-type nitride layer is formed on the buffer layer, and an n-type electrode is disposed on the n-type nitride layer; A nitride luminescent layer is formed on the n-type nitride layer; A p-type nitride layer is formed on the nitride luminescent layer; A surface treatment functional layer includes a first contact functional layer and a second contact functional layer, wherein the second contact functional layer is formed on the first contact functional layer and the first contact functional layer is formed on the p-type nitride layer; A transparent conductive layer is formed on the second contact functional layer, and a p-type electrode is disposed on the transparent conductive layer; The first contact functional layer is a metal oxide layer, and the metal selected for the metal oxide layer is a hydrogen storage element and / or a hydrogen storage alloy; the p-type electrode is disposed on the transparent conductive layer on the second contact functional layer; the second contact functional layer is insulating.

9. The low-ohmic contact nitride light-emitting diode chip as described in claim 8, characterized in that: The second contact functional layer is a structure formed by alternating growth of insulating materials.

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