TWI396306B - Gallium nitride based light emitting diode structure and its making method - Google Patents

Description

Gallium nitride-based light-emitting diode structure and manufacturing method thereof

The present invention relates to a technical field of a gallium nitride-based light-emitting diode structure and a manufacturing method thereof, and more particularly to a gallium nitride-based light-emitting diode having a high light-emitting efficiency and an interface barrier layer structure before a light-emitting layer. Its production method.

The structure of the gallium nitride-based light-emitting diode element is as shown in the first figure, and includes a sapphire substrate (10), a gallium nitride buffer layer (11), and an n-type doped gallium nitride ohmic contact layer (12). An indium gallium nitride light emitting layer (13), a p-type doped gallium nitride layer (14). Then, a portion of the n-type doped gallium nitride ohmic contact layer (12), the indium gallium nitride light-emitting layer (13), and the p-type doped gallium nitride layer (14) are removed by a yellow light and an etching process to be exposed. Part of the n-doped GaN ohmic contact layer (12) surface, this process is generally referred to as the MESA process. In addition, a transparent conductive layer (15) is formed on the p-type doped gallium nitride contact layer (14); and a p-type metal electrode (16) is located in the transparent conductive layer (15). Upper, an n-type metal electrode (17) is located on the surface of the n-type doped gallium nitride ohmic contact layer (12) to form a so-called conventional gallium nitride-based light-emitting diode lateral electrode structure.

In order to improve the luminous efficiency of a conventional gallium nitride-based light-emitting diode structure according to the prior art, U.S. Patent No. 6,153,894 discloses a nitrogen-containing stacked structure for enhancing the quality of an epitaxial film and improving the luminous efficiency of nitrogen. The structure of a gallium-based light-emitting diode element. Referring to the second figure, the schematic diagram includes a sapphire substrate (20), a gallium nitride buffer layer (21), an n-type doped gallium nitride ohmic contact layer (22), and an n-type doping. Aluminum indium gallium nitride superlattice stacked structure (23), an indium gallium nitride light emitting layer (24), a p-type doped gallium nitride layer (25), a transparent conductive layer (26), a p-type metal Electrode (27), an n-type metal electrode (28). The n-type doped aluminum indium gallium superlattice stack structure (23) is composed of a plurality of layers of aluminum indium gallium nitride of different thicknesses and compositions, and the difference in thickness is less than or equal to 50. .

Moreover, please refer to the third figure, which is a schematic structural view of another gallium nitride-based light-emitting diode element for improving luminous efficiency disclosed in U.S. Patent No. 6,861,663. The utility model comprises an intermediate layer structure composed of a sapphire substrate (30), a gallium nitride buffer layer (31), an n-type doped gallium nitride ohmic contact layer (32), an indium gallium nitride and a gallium nitride. (33), an indium gallium nitride multiple quantum well light emitting layer (34), a p-type doped aluminum gallium nitride coating layer (35), a p-type gallium nitride ohmic contact layer (36), a transparent conductive A layer (37), a p-type metal electrode (38), and an n-type metal electrode (39). Wherein, the intermediate layer structure (33) is composed of an intentionally undoped indium gallium nitride layer and an n-type doped gallium nitride layer, and the n-type doped gallium nitride layer has the most thickness Good between 100~500 And greater than the thickness of the barrier layer of the indium gallium nitride multiple quantum well light-emitting layer (34).

Furthermore, please refer to the fourth figure, which is a schematic structural diagram of another gallium nitride-based light-emitting diode element for improving luminous efficiency disclosed in U.S. Patent No. 688,1983. It comprises a thickness-periodically varying indium gallium nitride multi-quantum well light-emitting layer (200) and is formed over an n-doped gallium nitride layer (100). The n-type doped gallium nitride layer (100) is composed of an n-type doped gallium nitride layer (100a) having an epitaxial growth temperature of 1000 to 1050 ° C and a relative growth temperature of 880 to 920 ° C. The doped gallium nitride layer (100b) is formed by the multi-quantum well light-emitting layer (200) having a thickness variation periodically generated by adding the low-temperature grown n-type doped gallium nitride layer (100b). The preferred thickness of the doped gallium nitride layer (100b) is about 1000 . The advantage of the indium gallium nitride multiple quantum well light-emitting layer (200) whose thickness is periodically changed is that the injection carrier can be prevented from being compounded by the dislocation defect and the luminous efficiency can be effectively improved. However, the luminous efficiency of the conventional light-emitting diodes is still quite limited, and it is necessary to improve.

The main object of the present invention is to provide a gallium nitride-based light-emitting diode structure having high luminous efficiency, comprising an interface isolation layer comprising at least one n-type doped superlattice structure layer and an n-type doped nitrogen The composition of the gallium layer can effectively reduce the density of the non-radiative recombination center, thereby improving the luminous efficiency.

Another object of the present invention is to provide a gallium nitride-based light-emitting diode structure having high light-emitting efficiency, comprising an interface isolation layer comprising at least one n-type doped superlattice structure layer and an n-type doping layer The gallium nitride layer is composed of and is located below the light-emitting layer.

Another object of the present invention is to provide a gallium nitride-based light-emitting diode structure with high luminous efficiency, comprising a substrate, a low-temperature gallium nitride buffer layer, an undoped gallium nitride layer, and an n-type doping. A gallium nitride and aluminum gallium nitride superlattice structure layer, an n-type doped gallium nitride ohmic contact layer, an n-type doped gallium nitride and an aluminum gallium nitride superlattice structure layer, an n-type doping a hetero-GaN layer, a light-emitting layer, a p-type doped gallium nitride and an aluminum gallium nitride superlattice structure layer, and a p-type doped gallium nitride ohmic contact layer. The isolated non-radiative recombination formed by the n-type doped superlattice structure and the n-type doped gallium nitride layer increases the quantum efficiency of the interior.

Furthermore, the present invention mainly provides a gallium nitride-based light-emitting diode structure and a method for fabricating the same, comprising: a substrate; at least one gallium nitride layer disposed above the substrate; and the gallium nitride system Above the layer, an interface isolation structure composed of an n-type gallium nitride-based superlattice structure and an n-type gallium nitride layer and a gallium nitride-based light-emitting layer are sequentially formed; a p-type gallium nitride layer, It is formed above the gallium nitride-based light-emitting layer. In the invention, by lowering the temperature and adjusting the environment of the epitaxial reaction chamber, the interface isolation structure and the luminescent layer are epitaxially grown under pure nitrogen and low temperature, thereby improving the efficiency of the radiation recombination.

In addition, the present invention mainly provides a gallium nitride-based light-emitting diode structure, comprising: a substrate, at least one gallium nitride layer, a light-emitting layer, a p-type gallium nitride layer and at least one isolation layer. Wherein the gallium nitride layer is located above the substrate; the light emitting layer is located above the gallium nitride layer; the p-type gallium nitride layer is located above the light emitting layer; Between the gallium nitride layer and the light emitting layer.

The isolation layer is composed of an n-type gallium nitride-based superlattice structure and an n-type gallium nitride layer stack.

Wherein, the epitaxial growth temperature of the isolation layer is between 835 ° C and 950 ° C.

Wherein the thickness of the n-type gallium nitride layer in the composition of the isolation layer is less than 1400 .

The n-type gallium nitride superlattice structure in the composition of the isolation layer is composed of an aluminum nitride indium gallium layer and a gallium nitride layer alternately stacked.

Wherein, the optimal thickness range of the n-type gallium nitride layer is 300 ~1400 .

Wherein, the thickness of the n-type gallium nitride superlattice structure is between 600 ~800 .

The aluminum nitride indium gallium layer of the n-type gallium nitride superlattice structure has an aluminum composition ratio of 5% to 10%.

Wherein, the n-type gallium nitride-based superlattice structure further comprises an indium gallium nitride layer connected to the gallium nitride layer and then stacked alternately.

Wherein, the indium gallium nitride layer has an indium composition ratio of less than 10% and a thickness of not more than 15 .

In addition, the present invention provides a gallium nitride-based light-emitting diode structure, comprising: a substrate, a gallium nitride-based buffer layer, a first n-type gallium nitride-based superlattice structure layer, and a first n a gallium nitride based layer, a second n-type gallium nitride based superlattice structure layer, a third n-type gallium nitride based layer, a light emitting layer and a p-type gallium nitride based layer. Wherein the gallium nitride buffer layer is located above the substrate; the first n-type gallium nitride-based superlattice layer is located above the gallium nitride buffer layer; the first n-type gallium nitride The layer is located above the first n-type gallium nitride-based superlattice structure layer; the second n-type gallium nitride-based superlattice layer is located above the first n-type gallium nitride layer; The third n-type gallium nitride layer is located above the second n-type gallium nitride-based superlattice structure layer; the light-emitting layer is located above the third n-type gallium nitride layer; the p-type A gallium nitride layer is located above the light emitting layer.

The second n-type gallium nitride-based superlattice structure and the third n-type gallium nitride layer are stacked to form an interface isolation layer.

The p-type gallium nitride layer is composed of a p-type cladding layer and a p-type ohmic contact layer.

Wherein, the p-type cladding layer is a superlattice structure composed of a p-type gallium nitride layer.

Furthermore, the present invention provides a method for fabricating a gallium nitride-based light-emitting diode structure, which comprises the following steps:

a. providing a substrate;

b. forming a gallium nitride buffer layer above the substrate;

c. forming a first n-type gallium nitride-based structural layer above the gallium nitride-based buffer layer;

d. interrupting the growth and reducing the epitaxial growth temperature while simultaneously converting the reaction chamber to a pure nitrogen atmosphere;

e. forming an n-type interface isolation layer and a light-emitting layer above the first n-type gallium nitride-based structural layer; and

f. interrupting the growth and adding hydrogen to convert the reaction chamber into a nitrogen and hydrogen mixed environment and forming a p-type gallium nitride layer, the p-type gallium nitride layer being above the light-emitting layer.

The first n-type gallium nitride-based structural layer is formed by an epitaxial growth temperature of 980 ° C to 1030 ° C and the n -type interface isolation layer is formed by an epitaxial growth temperature of 835 ° C to 950 ° C. .

Where the thickness is between 600 ~800 The superlattice structure is formed by alternately stacking an n-type aluminum indium gallium nitride layer and an n-type gallium nitride layer with an aluminum composition ratio of 5% to 10%, and then forming a thickness of 300 ~1400 The n-type gallium nitride layer forms an n-type interface isolation layer to achieve the effect of improving luminous efficiency.

The above-mentioned objects, structures and features of the present invention will be described in detail with reference to the preferred embodiments of the present invention. .

Referring to FIG. 5 to FIG. 10 , the present invention provides a gallium nitride-based light-emitting diode structure and a manufacturing method thereof. First, please refer to FIG. 5 , which is a preferred reference example of the present invention. A schematic cross-sectional view of a light-emitting diode structure. The light emitting diode structure mainly comprises a substrate (40), a low temperature gallium nitride buffer layer (41), an undoped high temperature gallium nitride layer (42), and an n-type doped high temperature gallium nitride layer. The ohmic contact layer (43), a light-emitting layer (44), a p-type doped aluminum gallium nitride cladding layer (45) and a p-type doped gallium nitride ohmic contact layer (46) are formed. Wherein, the material of the substrate (40) is selected from one of sapphire, tantalum carbide, zinc oxide, zirconium diboride, spinel, lithium gallate, lithium aluminate, gallium trioxide or tantalum. . First, a thickness of about 250 is formed on the substrate (40) by an organometallic vapor phase epitaxy method. After the low temperature gallium nitride buffer layer (41) and the undoped high temperature gallium nitride layer (42) having a thickness of about 1.2 μm, the epitaxial gallium layer (42) is epitaxially formed to form an n-type carrier doping. 4xe ⁺¹⁸ cm ^-3 concentration of about ohmic contact layer of gallium nitride (43), about its growth thickness of 4 m, then, is formed to a thickness of about 25 Indium-doped gallium nitride quantum well without carrier doping and thickness of about 125 The multiple quantum well light-emitting layer (44) composed of the gallium nitride barrier layer grows to a thickness of about 400 when the epitaxial growth of the light-emitting layer (44) is completed. And a p-type carrier doped with a concentration of about 8xe ⁺¹⁹ cm ^-3 of aluminum nitride gallium consisting of a coating layer (45) and a thickness of about 2500 And a p-type gallium nitride ohmic contact layer (46) having a carrier doping concentration of about 1 xe ^{+ 20} cm ^-3 . After the epitaxial growth of the entire light-emitting diode is completed, a portion of the n-type gallium nitride ohmic contact layer surface, a portion of the light-emitting layer, and a portion of the p-type aluminum nitride are then formed by a conventional lateral electrode die process method. The gallium cladding layer and the gallium nitride ohmic contact layer are etched away, and a transparent conductive layer (47) is deposited on the p-type gallium nitride ohmic contact layer, and a p-type metal electrode (48) and a n are fabricated. Type metal electrode (49). After the luminescence diode process is completed, the substrate (40) is ground to a thickness of about 90 um and fabricated into a 325 um x 325 um luminescent diode die by a conventional laser cutting process and a cleaving process. After the LED process is completed, the crystal grains are fixed on the TO-can and the p-type and n-type metal electrodes are respectively connected to the electrodes on the TO-can by gold wires, and then placed in the integrating sphere and applied. Driven by 20 mA DC, the EL intensity is about 4.5 x 10 ^{-7, which} corresponds to an output power of about 4.2 mW.

Please refer to a sixth drawing, which is a schematic cross-sectional view showing a structure of a light emitting diode according to a preferred embodiment of the present invention. The light emitting diode structure is mainly composed of a substrate (50), a low temperature gallium nitride buffer layer (51), an undoped high temperature gallium nitride layer (52), an n-type doped high temperature gallium nitride and nitride. A superlattice structure layer (53) composed of aluminum gallium, an n-type doped gallium nitride ohmic contact layer (54), an n-type doped gallium nitride and an aluminum gallium nitride superlattice structure layer (55) a light-emitting layer (56), a p-type doped aluminum gallium nitride cladding layer (57), a p-type doped gallium nitride ohmic contact layer (58), and a light-transmitting conductive layer (59) A p-type metal electrode (60) and an n-type metal electrode (61) are formed. First, a thickness of about 250 is formed on the substrate (50) by an organometallic vapor phase epitaxy method. After the low temperature gallium nitride buffer layer (51) and the undoped high temperature gallium nitride layer (52) having a thickness of about 1.2 μm, the epitaxial gallium nitride layer (52) is epitaxially formed to form an n-type carrier doping. superlattice structure layer (53) consisting of a concentration of about 6xe ⁺¹⁸ cm ^-3 temperature of gallium nitride and aluminum gallium nitride, each having a thickness of 20 After overlapping and repeating for 15 times, an n-type gallium nitride ohmic contact layer (54) is epitaxially formed on the superlattice structure layer (53), and has a growth thickness of about 4 μm and an n-type carrier doping concentration. About 4xe ⁺¹⁸ cm ^-3 , then repeating epitaxial growth of a superlattice structure layer (53), and changing its n-type carrier doping concentration of about 1xe ⁺¹⁸ cm ^-3 to form another superlattice structural layer (55), continue to form a thickness of about 25 Indium-doped gallium nitride quantum well without carrier doping and thickness of about 125 The multiple quantum well light-emitting layer (56) composed of the gallium nitride barrier layer has a growth carrier doping concentration of about 8xe ⁺¹⁹ cm-3 and a thickness of about 400 when the epitaxial growth of the light-emitting layer is completed. a p-type aluminum gallium nitride cladding layer (57), and finally, a thickness of about 2,500 And a p-type gallium nitride ohmic contact layer (58) having a carrier doping concentration of about 1 xe ^{+ 20} cm ^-3 . According to the grain processing method disclosed in the above preferred reference example, the light-emitting diode dies having a size of 325 um x 325 um are applied, and a direct current of 20 milliamperes is applied to obtain an EL intensity of about 4.9 x 10 ^-7 . The power is about 4.65mw and its output power is increased by about 10%.

Please refer to the seventh figure, which is a schematic cross-sectional view of a light emitting diode structure according to another preferred embodiment of the present invention. The structure of the light-emitting diode is mainly based on the embodiment shown in the sixth figure, and has a thickness of about 20 a p-type doped aluminum gallium nitride layer (57a) and a thickness of about 20 The p-type doped gallium nitride layer (57b) is overlapped and the p-type superlattice structure is repeated 20 times to replace the p-type doped aluminum gallium nitride cap layer (57). In addition, the epitaxial growth temperature, thickness, and carrier doping concentration of the remaining structures remain the same. According to the preferred reference example disclosed above, the light-emitting diode dies having a size of 325 um x 325 um are applied with a direct current of 20 milliamperes, and an electrical excitation intensity (EL intensity) of about 5.83 x 10 ^{-7 is} equivalent to an output power of about 5.45 mW. The output power is increased by about 30% compared to the embodiment of the fifth figure.

Please refer to FIG. 8 , which is a cross-sectional view showing a structure of a light emitting diode according to another preferred embodiment of the present invention. The structure of the light-emitting diode is mainly improved by the structure disclosed in the seventh embodiment to obtain the preferred result of the present invention. According to the conventional technique, when a gallium nitride-based light-emitting diode structure is grown by an organometallic vapor phase epitaxy method, the so-called high-temperature growth layer means that the temperature of the growth reaction chamber is about 980 to 1050 ° C. When the indium gallium nitride light-emitting layer structure is grown, the growth temperature of the reaction chamber must be lowered to 700-835 ° C to control the composition of the indium atoms in the light-emitting layer to reach a light-emitting diode component capable of emitting a blue to green wavelength range. . In view of this, when the temperature of the growth reaction chamber is lowered from 980 to 1050 ° C to 700 to 835 ° C, additional growth gaps will be formed in the growth interface of the indium gallium nitride light-emitting layer, which is not conducive to subsequent growth and high quality. Indium gallium nitride light emitting layer. Therefore, in this embodiment, a barrier layer is used to block the defects caused by the void bonding, thereby obtaining a preferred indium gallium nitride/gallium nitride multiple quantum well light-emitting layer. A preferred embodiment is as follows: a thickness of about 250 is formed on the substrate (70) by an organometallic vapor phase epitaxy method. After the low temperature gallium nitride buffer layer (71) and the undoped high temperature gallium nitride layer (72) having a thickness of about 1.2 μm, the epitaxial gallium nitride layer (72) is epitaxially formed to form an n-type carrier doping. superlattice structure layer (73) consisting of a concentration of about 6xe ⁺¹⁸ cm ^-3 temperature of gallium nitride and aluminum gallium nitride, each having a thickness of 20 After overlapping and repeating for 15 times, an n-type gallium nitride ohmic contact layer (74) is epitaxially formed on the superlattice structure layer (73), and has a growth thickness of about 4 μm and an n-type carrier doping concentration. About 4xe ⁺¹⁸ cm ^-3 , and then the temperature of the growth reaction chamber is lowered from about 1030 ° C to about 835 ° C, preferably in the range of 835 ° C to 950 ° C, while reducing the hydrogen flow rate and increasing the nitrogen gas during the temperature reduction process. The flow rate to the epitaxial growth environment is completely switched to pure nitrogen. After the flow rate, pressure and temperature of the reaction chamber are stabilized, the epitaxial conditions of the superlattice structure layer (73) are successively repeated, and only the n-type carrier doping concentration is changed to 1xe. ⁺¹⁸ cm ^-3 to form another superlattice structure layer (75), after which another n-type doped gallium nitride layer (300) of different thickness is respectively added to form a so-called interface barrier layer (400), which is continued Forming a thickness of about 25 Indium-doped gallium nitride quantum well without carrier doping and thickness of about 125 The multiple quantum well light-emitting layer (76) composed of the gallium nitride barrier layer, after the epitaxial growth of the light-emitting layer is completed, the epitaxial conditions and structure of the remaining structures are maintained as the same as disclosed in the seventh figure. The light-emitting diode dies having a size of 325 um x 325 um are completed according to the grain processing method disclosed in the above preferred reference example. The experimental results of the n-type doped gallium nitride layer (300) of different thicknesses in this embodiment are shown in the ninth figure. When the thickness is about 700 At the time of applying 20 mA DC, the EL intensity is about 7.1 x 10 ^{-7, which} corresponds to an output power of about 6.64 mW, and the output power is about 20% higher than that of the embodiment of the seventh figure.

Please refer to the tenth figure for the TEM image of the cross section of the multiple quantum well light-emitting layer of the present invention. The present invention has no periodic variation in thickness, and thus is different from the conventional technology and has its progress.

The foregoing is a description of the technical features of the present invention, and the present invention can be modified and modified without departing from the spirit and scope of the present invention. And modifications should be covered in the scope defined by the scope of the patent application below.

‧Used part ‧

(10). . . Sapphire substrate

(11). . . Gallium nitride buffer layer

(12). . . N-type doped gallium nitride ohmic contact layer

(13). . . Indium gallium nitride light-emitting layer

(14). . . P-type doped gallium nitride layer

(15). . . Transparent conductive layer

(16). . . P-type metal electrode

(17). . . N-type metal electrode

(20). . . Sapphire substrate

(twenty one). . . Gallium nitride buffer layer

(twenty two). . . N-type doped gallium nitride ohmic contact layer

(twenty three). . . N-type doped aluminum nitride indium gallium superlattice stack structure

(twenty four). . . Indium gallium nitride light-emitting layer

(25). . . P-type doped gallium nitride layer

(26). . . Transparent conductive layer

(27). . . P-type metal electrode

(28). . . N-type metal electrode

(30). . . Sapphire substrate

(31). . . Gallium nitride buffer layer

(32). . . N-type doped gallium nitride ohmic contact layer

(33). . . Intermediate layer structure

(34). . . Indium gallium nitride multiple quantum well light emitting layer

(35). . . P-type doped aluminum gallium nitride coating

(36). . . P-type gallium nitride ohmic contact layer

(37). . . Transparent conductive layer

(38). . . P-type metal electrode

(39). . . N-type metal

(100). . . N-type doped gallium nitride layer

(100a). . . N-type doped gallium nitride layer

(100b). . . N-type doped gallium nitride layer

(200). . . Multiple quantum well luminescent layer

‧This part of the creation

(40). . . Substrate

(41). . . Low temperature gallium nitride buffer layer

(42). . . Undoped high temperature gallium nitride layer

(43). . . N-type doped high temperature gallium nitride ohmic contact layer

(44). . . Luminous layer

(45). . . P-type doped aluminum gallium nitride coating

(46). . . P-type doped gallium nitride ohmic contact layer

(47). . . Light-transmissive conductive layer

(48). . . P-type metal electrode

(49). . . N-type metal electrode

(50). . . Substrate

(51). . . Low temperature gallium nitride buffer layer

(52). . . Undoped high temperature gallium nitride layer

(53). . . Superlattice structure layer

(54). . . N-type doped gallium nitride ohmic contact layer

(55). . . N-type doped superlattice structure layer

(56). . . Multiple quantum well luminescent layer

(57). . . P-type aluminum gallium nitride coating

(57a). . . P-type doped aluminum gallium nitride layer

(57b). . . P-type doped gallium nitride layer

(58)‧‧‧p-type gallium nitride ohmic contact layer

(59) ‧‧‧Light conductive layer

(60)‧‧‧p type metal electrode

(61)‧‧‧n type metal electrodes

(70)‧‧‧Substrate

(71)‧‧‧Low temperature gallium nitride buffer layer

(72) ‧‧‧Undoped high temperature gallium nitride layer

(73) ‧‧‧n-doped superlattice structural layer

(74)‧‧‧n-type doped gallium nitride ohmic contact layer

(75) ‧‧‧n-doped superlattice structural layer

(76) ‧‧‧Multiple quantum well luminescent layers

(300)‧‧‧n-type doped gallium nitride layer

(400) ‧‧‧Barrier

First: A schematic diagram of a light-emitting diode structure of a conventional technique.

Second figure: A schematic diagram of another light-emitting diode structure of the prior art.

Third figure: A schematic diagram of another light-emitting diode structure of the prior art.

Figure 4: Schematic diagram of another light-emitting diode structure of the prior art.

Fig. 5 is a schematic view showing the structure of a light-emitting diode according to a preferred reference example of the present invention.

Fig. 6 is a schematic view showing the structure of a light-emitting diode according to an embodiment of the present invention.

Figure 7 is a schematic view showing the structure of a light-emitting diode according to another embodiment of the present invention.

Figure 8 is a schematic view showing the structure of a light-emitting diode according to a preferred embodiment of the present invention.

Figure 9 is a graph comparing the trends of electrical excitation strength of a preferred embodiment of the present invention.

Figure 11 is a TEM image of a light-emitting layer of a preferred embodiment of the present invention.

(70). . . Substrate

(71). . . Low temperature gallium nitride buffer layer

(72). . . Undoped high temperature gallium nitride layer

(73). . . N-type doped superlattice structure layer

(74). . . N-type doped gallium nitride ohmic contact layer

(75). . . N-type doped superlattice structure layer

(76). . . Multiple quantum well luminescent layer

(57). . . P-type doped aluminum gallium nitride coating

(300). . . N-type doped gallium nitride layer

(400). . . Barrier layer

Claims (5)

A gallium nitride-based light-emitting diode structure includes: a substrate; at least one gallium nitride layer, the gallium nitride layer is located above the substrate; and a light-emitting layer, the light-emitting layer is located in the nitride a p-type gallium nitride layer above the light-emitting layer; and at least one isolation layer interposed between the gallium nitride layer And the light-emitting layer is composed of an n-type gallium nitride-based superlattice structure and an n-type gallium nitride layer stack and has a growth temperature of 835 ° C to 950 ° C; wherein the n-type gallium nitride system The superlattice structure is composed of an aluminum nitride indium gallium layer and a gallium nitride layer alternately stacked, and the aluminum composition ratio is between 5% and 10%; wherein the n-type gallium nitride layer has a thickness ranging from 300Å to Å. 1400Å. The gallium nitride-based light-emitting diode structure according to claim 1, wherein the n-type gallium nitride-based superlattice structure has a thickness of 600 Å to 800 Å. The gallium nitride-based light-emitting diode structure according to claim 1, wherein the n-type gallium nitride-based superlattice structure further comprises an indium gallium nitride layer connected to the gallium nitride layer to interact with each other. The composition of the stack. The gallium nitride-based light-emitting diode structure according to claim 3, wherein the indium gallium nitride layer has an indium composition ratio of less than 10% and a thickness of not more than 15 Å. A method for fabricating a gallium nitride-based light-emitting diode structure includes: providing a substrate; forming a gallium nitride-based buffer layer over the substrate; Forming a first n-type gallium nitride-based structural layer above the gallium nitride-based buffer layer, and having an epitaxial growth temperature of 980 ° C to 1030 ° C; interrupting growth and reducing epitaxial growth temperature while simultaneously converting the reaction chamber a pure nitrogen atmosphere; forming an n-type interface isolation layer and a light-emitting layer above the first n-type gallium nitride-based structural layer, and having an epitaxial growth temperature of 835 ° C to 950 ° C; and interrupting growth Hydrogen is added to convert the reaction chamber into a mixed environment of nitrogen and hydrogen to form a p-type gallium nitride layer, and the p-type gallium nitride layer is located above the light-emitting layer.