CN111341645B - Method for manufacturing aluminum nitride semiconductor film and structure thereof - Google Patents

Abstract

This application discloses a manufacturing method and structure of an aluminum nitride semiconductor thin film, which relates to the field of film formation of semiconductor equipment, including: providing a sapphire substrate; forming an aluminum metal layer on one side of the sapphire substrate; nitriding the aluminum metal layer processing, generating the first aluminum nitride film; generating the second aluminum nitride film on the side away from the sapphire substrate of the first aluminum nitride film; for the sapphire substrate with the first aluminum nitride film and the second aluminum nitride film The bottom is subjected to high-temperature annealing treatment outside the reaction chamber; the third aluminum nitride film is formed on the side of the second aluminum nitride film away from the sapphire substrate. In this application, before the second aluminum nitride film is formed, the first aluminum nitride film is first formed on the sapphire substrate, and the first aluminum nitride film and the second aluminum nitride film effectively reduce the damage caused by subsequent aluminum nitride films. The stacking stress can reduce the crack density and hole defect density, and generate high-quality aluminum nitride semiconductor thin films.

Description

Fabrication method and structure of aluminum nitride semiconductor thin film

technical field

The present application relates to the field of film formation of semiconductor devices, in particular, to a method for manufacturing an aluminum nitride semiconductor thin film and its structure.

Background technique

With the continuous advancement of light-emitting diode technology, in recent years, light-emitting diodes in the ultraviolet band have also received high attention. Usually, when making ultraviolet light-emitting diodes, especially in the deep ultraviolet range with a luminous wavelength below 320nm, an aluminum nitride semiconductor film will be epitaxially grown on a sapphire substrate, so that the aluminum nitride semiconductor film can be used as a sapphire substrate and ultraviolet light. The buffer layer between the structures of the light emitting diode, the crystalline quality of the buffer layer of the aluminum nitride semiconductor thin film is critical to the luminous efficiency of the subsequent epitaxial growth of the light emitting diode structure.

Due to the lattice constant mismatch between the aluminum nitride semiconductor film and the sapphire substrate, and the large difference in thermal expansion coefficient, if the aluminum nitride semiconductor film is directly epitaxially grown on the sapphire substrate at high temperature, it is easy to produce cracks and high-density holes. Defects, thereby reducing the output yield and internal quantum efficiency of UV LEDs.

Contents of the invention

In view of this, the present application provides a method for manufacturing an aluminum nitride semiconductor film and its structure. Before forming the second aluminum nitride film, the first aluminum nitride film is first formed on the sapphire substrate, and the first aluminum nitride film is passed through the first nitrogen film. The aluminum nitride film and the second aluminum nitride film can effectively reduce the stacking stress caused by subsequent aluminum nitride films, thereby reducing crack density and hole defect density, and producing high-quality aluminum nitride semiconductor films.

In order to solve the above technical problems, the application has the following technical solutions:

In one aspect, the present application provides a method for manufacturing an aluminum nitride semiconductor thin film, comprising:

Provide sapphire substrate;

placing the sapphire substrate in a metalorganic chemical vapor deposition reaction chamber;

Introducing an aluminum-containing precursor into the metalorganic chemical vapor deposition reaction chamber to form an aluminum metal layer on one side of the sapphire substrate;

Introducing an ammonia precursor into the metalorganic chemical vapor deposition reaction chamber, and performing nitriding treatment on the aluminum metal layer to form a first aluminum nitride film;

placing the sapphire substrate with the first aluminum nitride film into a radio frequency sputtering deposition reaction chamber, and forming a second aluminum nitride film on the side of the first aluminum nitride film away from the sapphire substrate;

Performing high-temperature annealing treatment outside the reaction chamber on the sapphire substrate having the first aluminum nitride film and the second aluminum nitride film;

Place the sapphire substrate with the first aluminum nitride film and the second aluminum nitride film after the annealing treatment

into the metalorganic chemical vapor deposition reaction chamber;

Introduce the aluminum-containing precursor and the ammonia precursor into the metalorganic chemical vapor deposition reaction chamber simultaneously; generate a third nitride film on the side of the second aluminum nitride film away from the sapphire substrate Aluminum film.

Optionally, where:

Before feeding the aluminum-containing precursor into the metalorganic chemical vapor deposition reaction chamber, the method further includes: feeding hydrogen gas into the reaction chamber to clean the surface of the sapphire substrate.

Optionally, where:

The aluminum-containing precursor includes at least one of trimethylaluminum and triethylaluminum.

Optionally, where:

The ammonia precursor includes at least one of ammonia gas and dimethylhydrazine.

Optionally, where:

Generate a second aluminum nitride film on the side of the first aluminum nitride film away from the sapphire substrate, specifically:

Using polycrystalline aluminum nitride powder as a target material, a predetermined ratio of argon gas and nitrogen gas is introduced into the radio frequency sputtering deposition reaction chamber, and the first aluminum nitride film is formed on the side away from the sapphire substrate. The second aluminum nitride film; the value range of the predetermined ratio is 1:2-1:4.

Optionally, where:

The annealing treatment of the sapphire substrate having the first aluminum nitride film and the second aluminum nitride film is specifically:

Place the sapphire substrate with the first aluminum nitride film and the second aluminum nitride film in a high-temperature annealing furnace outside the reaction chamber, set the temperature of the annealing furnace to be greater than or equal to 1500°C and less than or equal to 1800°C, and to Nitrogen gas is introduced into the annealing furnace for annealing for 1-3 hours.

Optionally, where:

Before performing the high-temperature annealing treatment outside the reaction chamber on the sapphire substrate having the first aluminum nitride film and the second aluminum nitride film, it also includes:

The sapphire substrate with the first aluminum nitride film and the second aluminum nitride film is placed on the carrying base, so that the second aluminum nitride film is located between the sapphire substrate and the carrying base.

On the other hand, the present application also provides a structure of an aluminum nitride semiconductor thin film, including:

Sapphire substrate;

a first aluminum nitride film, the first aluminum nitride film is located on one side of the sapphire substrate;

a second aluminum nitride film, the second aluminum nitride film is located on the side of the first aluminum nitride film away from the sapphire substrate;

A third aluminum nitride film, the third aluminum nitride film is located on a side of the second aluminum nitride film away from the sapphire substrate.

Compared with the prior art, the manufacturing method and structure of the aluminum nitride semiconductor thin film described in this application have achieved the following effects:

The manufacturing method and structure of the aluminum nitride semiconductor thin film provided in this application, before depositing the second aluminum nitride thin film by radio frequency sputtering and annealing, an aluminum metal layer is first formed on the sapphire substrate by using the organic metal chemical vapor deposition method , and nitriding the aluminum metal layer to form the first aluminum nitride film, the annealed first aluminum nitride film and the second aluminum nitride film effectively reduce the stacking stress caused by the subsequent layers of aluminum nitride film, thereby The crack density and hole defect density can be reduced, and a high-quality aluminum nitride semiconductor film can be produced. The aluminum nitride semiconductor film with low hole defect density and high quality is conducive to improving the internal quantum efficiency of the aluminum nitride-based deep ultraviolet light-emitting diode; the low crack density and high-quality aluminum nitride semiconductor film is conducive to improving the nitrogen The uniformity of the photoelectric characteristics of the aluminum-based deep ultraviolet light-emitting diode epitaxial wafer can also reduce the fragmentation rate of the thinning process in the chip manufacturing process, thereby improving the production yield.

Description of drawings

The drawings described here are used to provide a further understanding of the application and constitute a part of the application. The schematic embodiments and descriptions of the application are used to explain the application and do not constitute an improper limitation to the application. In the attached picture:

Fig. 1 shows a kind of structural representation of the aluminum nitride film in the prior art;

FIG. 2 is another structural schematic diagram of an aluminum nitride semiconductor thin film in the prior art;

FIG. 3 is another structural schematic diagram of an aluminum nitride semiconductor thin film in the prior art;

FIG. 4 is a flowchart of a method for manufacturing an aluminum nitride semiconductor thin film provided in an embodiment of the present application;

FIG. 5 is another flow chart of the method for manufacturing an aluminum nitride semiconductor thin film provided in the embodiment of the present application;

FIG. 6 is a flow chart for generating a second aluminum nitride film provided in the embodiment of the present application;

FIG. 7 is another flow chart of the method for manufacturing an aluminum nitride semiconductor thin film provided in the embodiment of the present application;

FIG. 8 is a schematic diagram of the structure of the aluminum nitride semiconductor thin film provided by the embodiment of the present application;

FIG. 9 is a comparison diagram of diffraction intensities of aluminum nitride semiconductor thin films of the present application and the prior art.

Detailed ways

Certain terms are used, for example, in the description and claims to refer to particular components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. The specification and claims do not use the difference in name as a way to distinguish components, but use the difference in function of components as a criterion for distinguishing. As mentioned throughout the specification and claims, "comprising" is an open term, so it should be interpreted as "including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and basically achieve the technical effect. In addition, the term "coupled" herein includes any direct and indirect electrical coupling means. Therefore, if it is described that a first device is coupled to a second device, it means that the first device may be directly electrically coupled to the second device, or indirectly electrically coupled through other devices or coupling means. connected to the second device. The subsequent description of the specification is a preferred implementation mode for implementing the application, but the description is for the purpose of illustrating the general principle of the application, and is not intended to limit the scope of the application. The scope of protection of the present application should be defined by the appended claims.

Fig. 1 shows a kind of structural representation of the aluminum nitride thin film in the prior art, Fig. 2 shows another kind of structural representation of the aluminum nitride semiconductor thin film in the prior art, Fig. 3 shows the prior art Another structural schematic diagram of the aluminum nitride semiconductor thin film in , please refer to FIG. 1-FIG. 3 . At present, there are mainly the following methods for growing aluminum nitride semiconductor thin films on sapphire substrates:

1. First use a low-temperature aluminum nitride nucleation layer 02 as a stress buffer layer between the sapphire substrate 01, and then epitaxially grow a high-temperature aluminum nitride semiconductor film 03. As shown in Figure 1, this structure cannot At the same time, the problems of aluminum nitride semiconductor film cracks and hole defects are solved.

2. First use a layer of low-temperature aluminum nitride nucleation layer 05 as a stress buffer layer between the sapphire substrate 04, and then pass in trimethylaluminum precursors in a continuous manner and ammonia gas in a pulsed manner to epitaxially grow The first high-temperature aluminum nitride thin film layer 06 is then grown by the same method as the second high-temperature aluminum nitride thin film layer 07 and the third high-temperature aluminum nitride thin film layer 08 , as shown in FIG. 2 . Although this structure can effectively solve the cracking phenomenon of aluminum nitride film and reduce the density of hole defects, the growth rate of the pulse method is about one tenth of that of the continuous method, and it is not easy to control the time ratio of the ammonia switch , so it is difficult to obtain the optimum epitaxial condition window for higher quality AlN thin film layers.

3. Form a layer of polycrystalline aluminum nitride film 002 on the sapphire substrate 001 by sputtering, and then use an annealing procedure at a temperature of 1600°C to 1700°C for 1 to 3 hours to form the polycrystalline aluminum nitride film 002 Re-nucleation is transformed into a high-quality single-crystal aluminum nitride film 003, and then, the single-crystal aluminum nitride film 003 is epitaxially grown by MOCVD method, as shown in FIG. 3 . Although this structure can effectively reduce the hole defect density, the high-temperature re-nucleation method cannot effectively solve the cracking phenomenon caused by the lattice constant mismatch and the large difference in thermal expansion coefficient of the subsequent AlN-based film.

In view of this, the present application provides a method for manufacturing an aluminum nitride semiconductor film and its structure. Before forming the second aluminum nitride film, the first aluminum nitride film is first formed on the sapphire substrate, and the first aluminum nitride film is passed through the first nitrogen film. The aluminum nitride film and the second aluminum nitride film can effectively reduce the stacking stress caused by subsequent aluminum nitride films, thereby reducing crack density and hole defect density, and producing high-quality aluminum nitride semiconductor films.

A detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

FIG. 4 is a flowchart of a method for manufacturing an aluminum nitride semiconductor thin film provided in the embodiment of the present application. Please refer to FIG. 4. The method for manufacturing an aluminum nitride semiconductor thin film provided in the embodiment of the present application includes:

Step 10: providing a sapphire substrate;

Step 20: placing the sapphire substrate in the metalorganic chemical vapor deposition reaction chamber;

Step 30: introducing an aluminum-containing precursor into the metalorganic chemical vapor deposition reaction chamber to form an aluminum metal layer on one side of the sapphire substrate;

Step 40: introducing an ammonia precursor into the metalorganic chemical vapor deposition reaction chamber, and nitriding the aluminum metal layer to form a first aluminum nitride film;

Step 50: placing the sapphire substrate with the first aluminum nitride film into the radio frequency sputtering deposition reaction chamber, and forming a second aluminum nitride film on the side of the first aluminum nitride film away from the sapphire substrate;

Step 60: performing high-temperature annealing treatment outside the reaction chamber on the sapphire substrate having the first aluminum nitride film and the second aluminum nitride film;

Step 70: placing the sapphire substrate with the first aluminum nitride film and the second aluminum nitride film after the annealing treatment into the metalorganic chemical vapor deposition reaction chamber;

Step 80: Introducing aluminum-containing precursors and ammonia precursors into the metalorganic chemical vapor deposition reaction chamber simultaneously; forming a third aluminum nitride film on the side of the second aluminum nitride film away from the sapphire substrate.

Specifically, referring to FIG. 4 , the method for manufacturing an aluminum nitride semiconductor thin film provided in the embodiment of the present application provides a sapphire substrate in step 10, and places the sapphire substrate in a metalorganic chemical vapor deposition (Metal -Organic Chemical Vapor Deposition, MOCVD) reaction chamber; in step 30, set the temperature of the MOCVD reaction chamber to 1000°C-1300°C, the temperature range here includes 1000°C and 1300°C, and pass into the reaction chamber containing Aluminum precursor, and control the flow range of aluminum to be 20sccm-200sccm, so that the aluminum-containing precursor is decomposed at high temperature, and a layer of pre-laid aluminum metal layer is formed on the sapphire substrate, wherein the thickness range of the aluminum metal layer is 1-5 atomic layers, where 1-5 includes 1 and 5; since it is necessary to generate an aluminum metal layer, it is necessary to introduce a substance that can be decomposed to generate an aluminum metal layer, which is referred to as an aluminum-containing precursor in this application , can be at least one of trimethylaluminum and triethylaluminum. The aluminum-containing precursor can generate aluminum atoms after pyrolysis and form an aluminum metal layer on the sapphire substrate. After that, through step 40, the ammonia precursor is introduced into the MOCVD reaction chamber, and the flow range of ammonia is controlled to be 300 sccm-2000 sccm, so that the aluminum metal layer can be nitrided to form a first aluminum nitride film with a thickness of h1, Among them, 0um<h1≤2um. Similar to the above-mentioned aluminum-containing precursors, in step 40, the aluminum metal layer needs to be nitrided, and the nitriding treatment is usually carried out with ammonia gas. Therefore, nitrogen atoms that can be generated after pyrolysis need to be introduced into the reaction chamber Substances, which are called ammonia precursors in this application, include at least one of ammonia gas and dimethylhydrazine. After the ammonia precursor is decomposed, the aluminum metal layer can be nitrided to form the first aluminum nitride film.

Please continue to refer to FIG. 4. After the first aluminum nitride film is formed, the temperature of the reaction chamber is lowered to below 100° C., and the sapphire substrate containing the first aluminum nitride film is taken out, and then in step 50, it is placed in a radio frequency In the RF sputtering deposition (RFsputtering) reaction chamber, a mixed gas of argon and nitrogen is introduced into the RF sputtering deposition reaction chamber, with polycrystalline aluminum nitride powder as the target material, on the surface of the first aluminum nitride film A second aluminum nitride thin film having a thickness of h2 is produced, wherein 50nm≤h2≤400nm. Here, the thickness of the first aluminum nitride film and the second aluminum nitride film refers to the thickness in the vertical direction of the plane where the sapphire substrate is located.

After the second aluminum nitride film is generated, in step 60, the sapphire substrate with the first aluminum nitride film and the second aluminum nitride film is placed in a high-temperature annealing furnace outside the reaction chamber, and the temperature of the annealing furnace is set to be maintained at Between 1500° C. and 1800° C., nitrogen gas is introduced into the annealing furnace to perform annealing treatment on the second aluminum nitride film. During the annealing process, the second aluminum nitride film needs to be protected to a certain extent, so as to prevent the nitrogen atoms on the surface of the second aluminum nitride film from volatilizing due to heating during the annealing process, resulting in failure to obtain good crystal quality in the subsequent steps. Through step 70, the annealed sapphire substrate with the first aluminum nitride film and the second aluminum nitride film is placed in the MOCVD reaction chamber. In step 80, the temperature of the MOCVD reaction chamber is set to be greater than 1200°C, and the aluminum-containing precursor and the ammonia precursor are introduced into the reaction chamber to form a third aluminum nitride film, and the flow range of the aluminum precursor and the ammonia precursor is set 20sccm-200sccm and 300sccm-2000sccm respectively, so that the thickness h3 of the third aluminum nitride film is in the range of 0um<h3≤2um.

In the manufacturing method of the aluminum nitride semiconductor thin film provided by the present application, before utilizing the radio frequency sputtering to deposit the second aluminum nitride thin film, the aluminum metal layer is first formed on the sapphire substrate by the vapor phase deposition method, and the aluminum metal layer is nitrogen-treated. After chemical treatment, the first aluminum nitride film is formed, and the stacking stress caused by the subsequent layers of aluminum nitride film is effectively reduced through the first aluminum nitride film and the second aluminum nitride film, thereby reducing the crack density and hole defect density. Generate high-quality aluminum nitride semiconductor thin films. The aluminum nitride semiconductor film with low hole defect density and high quality is conducive to improving the internal quantum efficiency of the aluminum nitride-based deep ultraviolet light-emitting diode; the low crack density and high-quality aluminum nitride semiconductor film is conducive to improving the nitrogen The uniformity of the photoelectric characteristics of the aluminum-based deep ultraviolet light-emitting diode epitaxial wafer can also reduce the fragmentation rate of the thinning process in the chip manufacturing process, thereby improving the production yield.

Optionally, Fig. 5 shows another flow chart of the method for manufacturing an aluminum nitride semiconductor thin film provided in the embodiment of the present application. Please refer to Fig. 5. Before the precursor, step 21 is also included: injecting hydrogen gas into the reaction chamber to clean the surface of the sapphire substrate. Specifically, please refer to FIG. 5. After the sapphire substrate is placed in MOCVD in this embodiment, the surface of the sapphire substrate is first cleaned through step 21. When cleaning the substrate surface, keep the temperature of the reaction chamber greater than 1050° C., and then Introduce hydrogen gas with a purity level above 6N, heat-treat and clean the surface of the sapphire substrate, use high temperature to volatilize the residual organic matter or oxides on the surface of the sapphire substrate, and take the hydrogen away from the surface of the sapphire substrate and the MOCVD chamber In addition, it can avoid the formation of an incomplete aluminum metal film on the surface of the substrate by the aluminum-containing precursor injected later, resulting in the inability to obtain stable characteristics of the aluminum nitride film in the subsequent process.

Optionally, referring to FIG. 4 , the aluminum-containing precursor includes at least one of trimethylaluminum and triethylaluminum. Specifically, please refer to FIG. 4, in step 30 and step 80, when making the first aluminum nitride film and the third aluminum nitride film, the aluminum-containing precursor uses trimethylaluminum or triethylaluminum as the MOCVD process The raw material is passed into the MOCVD reaction chamber at high temperature, and it is easy to thermally decompose to form aluminum atoms, and then form an aluminum metal layer on the sapphire substrate. It should be noted that the use of trimethylaluminum or triethylaluminum as the aluminum precursor is only an implementation in this embodiment, and in other embodiments, the aluminum precursor can also be other aluminum-containing compounds. Applications are not limited to this.

Optionally, referring to FIG. 4 , the ammonia precursor includes at least one of ammonia gas and dimethylhydrazine. Specifically, referring to FIG. 4, in step 40 and step 80, when the ammonia precursor is introduced to form the first aluminum nitride film and the third aluminum nitride film, the ammonia precursor can be ammonia gas or dimethylhydrazine , after the aluminum metal layer is generated in step 30, the aluminum metal layer needs to be nitrided, and ammonia and dimethylhydrazine are easily decomposed at high temperature to generate nitrogen atoms, which can be nitrided with the aluminum atoms of the aluminum metal layer react to form the first aluminum nitride film. It should be noted that the use of ammonia or dimethylhydrazine as the ammonia precursor is only a schematic implementation in this embodiment, and in other embodiments, the ammonia precursor can also be other compounds. Applications are not limited to this.

Optionally, FIG. 6 shows a flow chart for forming the second aluminum nitride film provided by the embodiment of the present application. Please refer to FIG. 6, the second aluminum nitride film is formed on the side away from the sapphire substrate The aluminum nitride thin film is specifically as follows: step 51: use polycrystalline aluminum nitride powder as the target material; step 52: feed a predetermined ratio of argon and nitrogen into the radio frequency sputtering deposition reaction chamber; step 53: in the first The second aluminum nitride film is formed on the side of the aluminum nitride film away from the sapphire substrate; the value range of the predetermined ratio is 1:2-1:4, where the ratio range of argon to nitrogen includes 1:2 and 1:2 4.

Optionally, please refer to FIG. 4. In step 60, the sapphire substrate with the first aluminum nitride film and the second aluminum nitride film is annealed, specifically: the first aluminum nitride film and the second nitrogen The sapphire substrate of the aluminum oxide film is placed in a high-temperature annealing furnace outside the reaction chamber, and the temperature of the annealing furnace is set to be greater than or equal to 1500°C and less than or equal to 1800°C, and nitrogen gas is introduced into the annealing furnace for 1-3 hours of annealing. Specifically, referring to FIG. 4 , after the second aluminum nitride film is formed, the sapphire substrate having the first aluminum nitride film and the second aluminum nitride film is taken out from the radio frequency sputtering deposition reaction chamber, and passed through step 60 Perform high-temperature annealing treatment on the sapphire substrate with the first aluminum nitride film and the second aluminum nitride film outside the reaction chamber, first place it in the annealing furnace, and keep the temperature of the annealing furnace between 1500°C and 1800°C Between, and feed the nitrogen gas that purity is 6N, make the sapphire substrate that has the first aluminum nitride thin film and the second aluminum nitride thin film anneal 1-3 hour under nitrogen atmosphere, make the first aluminum nitride thin film and the second aluminum nitride thin film The crystal lattice of the aluminum nitride film is rearranged, which can solve the defects of cracks and holes in the aluminum nitride film caused by the lattice constant mismatch between the aluminum nitride film and the sapphire substrate, which is beneficial to improve the success of subsequent epitaxial growth. The structural quality of ultraviolet light emitting diodes and the output yield rate of chips.

Optionally, FIG. 7 is another flow chart of the manufacturing method of the aluminum nitride semiconductor thin film provided in the embodiment of the present application. Please refer to FIG. 7, for the first aluminum nitride thin film and the second aluminum nitride Before the sapphire substrate of the film is annealed, step 61 is also included: placing the sapphire substrate with the first aluminum nitride film and the second aluminum nitride film on the carrier base, so that the second aluminum nitride film is positioned on the sapphire substrate between the bottom and the supporting base. Specifically, please refer to FIG. 7 , in order to prevent the nitrogen atoms on the surface of the second aluminum nitride film from volatilizing due to heating during the annealing process, in this embodiment, before annealing, through step 61, the first aluminum nitride film and The sapphire substrate of the second aluminum nitride film is placed on a carrier base, and the second aluminum nitride film part is in contact with the carrier base, that is, the sapphire substrate with the first aluminum nitride film and the second aluminum nitride film One side of the second aluminum nitride film in the substrate is placed downwards on the carrier base. Since there is a gap of less than 1 mm between the second aluminum nitride film and the carrier base, in addition to allowing the overall aluminum nitride film to be on the sapphire substrate The bottom has the effect of releasing warping stress and can also maintain the saturated vapor pressure of nitrogen atoms, thereby preventing the problem of volatilization of nitrogen atoms in the second aluminum nitride film from the surface layer, which is conducive to the formation of high-quality aluminum nitride semiconductor films.

Based on the same inventive concept, the present application also provides a structure 100 of an aluminum nitride semiconductor thin film. FIG. 8 shows a schematic diagram of the structure 100 of an aluminum nitride semiconductor thin film provided in an embodiment of the present application. Please refer to FIG. 8 , A structure 100 of an aluminum nitride semiconductor thin film, comprising:

sapphire substrate 110;

The first aluminum nitride film 120, the first aluminum nitride film 120 is located on one side of the sapphire substrate 110;

The second aluminum nitride film 130, the second aluminum nitride film 130 is located on the side of the first aluminum nitride film 120 away from the sapphire substrate 110;

The third aluminum nitride film 140 , the third aluminum nitride film 140 is located on the side of the second aluminum nitride film 130 away from the sapphire substrate 110 .

Specifically, please refer to FIG. 8, the aluminum nitride semiconductor thin film provided by the embodiment of the present application includes a sapphire substrate 110, a first aluminum nitride thin film 120, a second aluminum nitride thin film 130 and a third aluminum nitride thin film 140 , wherein the second aluminum nitride film 130 is located on the side of the first aluminum nitride film 120 away from the sapphire substrate 110, and the third aluminum nitride film 140 is located on the side of the second aluminum nitride film 130 away from the sapphire substrate 110 , wherein the thickness of the first aluminum nitride film 120 is h1, 0um<h1≤2um, the thickness of the second aluminum nitride film 130 is h2, 50nm≤h2≤400nm, and the thickness of the third aluminum nitride film 140 is h3 , 0um<h3≤2um, where the thicknesses of the first aluminum nitride film 120, the second aluminum nitride film 130 and the third aluminum nitride film 140 all refer to the direction perpendicular to the plane where the sapphire substrate 110 is located thickness.

In the structure 100 of the aluminum nitride semiconductor thin film provided in this application, before the second aluminum nitride thin film is deposited by radio frequency sputtering and annealed, an aluminum metal layer is first formed on the sapphire substrate by using an organic metal chemical vapor deposition method, and the The aluminum metal layer is subjected to nitriding treatment to form the first aluminum nitride film. The annealed first aluminum nitride film and the second aluminum nitride film can effectively reduce the stacking stress caused by the subsequent layers of aluminum nitride film, thereby reducing the tortoise. Crack density and hole defect density to generate high-quality aluminum nitride semiconductor thin films. The aluminum nitride semiconductor film with low hole defect density and high quality is conducive to improving the internal quantum efficiency of the aluminum nitride-based deep ultraviolet light-emitting diode; the low crack density and high-quality aluminum nitride semiconductor film is conducive to improving the nitrogen The uniformity of the photoelectric characteristics of the aluminum-based deep ultraviolet light-emitting diode epitaxial wafer can also reduce the fragmentation rate of the thinning process in the chip manufacturing process, thereby improving the production yield.

The following will be explained with the test data:

Figure 9 shows that the present application and the prior art use a low-temperature aluminum nitride nucleation layer as a stress buffer layer, and then epitaxially grow a high-temperature aluminum nitride semiconductor film, such as the aluminum nitride semiconductor film shown in Figure 1 Figure (a) shows the diffraction intensity figure of the 002 surface, and figure (b) shows the diffraction intensity figure of the 102 surface, where the abscissa represents the diffraction angle, the ordinate represents the diffraction intensity, and the dotted line represents the existing The variation trend of the diffraction intensity of the aluminum nitride semiconductor thin film produced in the technology, and the solid line represents the variation trend of the diffraction intensity of the aluminum nitride semiconductor thin film produced in the present application. Referring to FIG. 9, it can be seen that, compared with the prior art, whether it is the 002 plane or the 102 plane, the aluminum nitride semiconductor thin film provided by the present application has stronger diffraction intensity and narrower half-maximum wave width, indicating that the crystal quality is relatively improved. Therefore, using the aluminum nitride semiconductor thin film produced in this application to make a UV light-emitting diode is beneficial to improving the internal quantum efficiency of the UV light-emitting diode.

Can know by above each embodiment, the beneficial effect that the present application exists is:

The manufacturing method and structure of the aluminum nitride semiconductor thin film provided in this application, before depositing the second aluminum nitride thin film by radio frequency sputtering and annealing, an aluminum metal layer is first formed on the sapphire substrate by using the organic metal chemical vapor deposition method , and nitriding the aluminum metal layer to form the first aluminum nitride film, the annealed first aluminum nitride film and the second aluminum nitride film effectively reduce the stacking stress caused by the subsequent layers of aluminum nitride film, thereby The crack density and hole defect density can be reduced, and a high-quality aluminum nitride semiconductor film can be produced. The low-hole defect density and high-quality aluminum nitride semiconductor film is conducive to improving the internal quantum efficiency of aluminum nitride-based deep ultraviolet light-emitting diodes; the low crack density and high-quality aluminum nitride semiconductor film is conducive to improving the nitrogen density. The uniformity of the photoelectric characteristics of the aluminum-based deep ultraviolet light-emitting diode epitaxial wafer can also reduce the fragmentation rate of the thinning process in the chip manufacturing process, thereby improving the production yield.

Those skilled in the art should understand that the embodiments of the present application may be provided as methods, apparatuses, or computer program products. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The above description shows and describes several preferred embodiments of the present application, but as mentioned above, it should be understood that the present application is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various Various other combinations, modifications, and environments can be made within the scope of the inventive concept described herein, by the above teachings or by skill or knowledge in the relevant field. However, modifications and changes made by those skilled in the art do not depart from the spirit and scope of the present application, and should all be within the protection scope of the appended claims of the present application.

Claims (6)

1. A method for manufacturing an aluminum nitride semiconductor film is characterized by comprising the following steps:

providing a sapphire substrate;

placing the sapphire substrate in an organic metal chemical vapor deposition reaction chamber;

introducing an aluminum-containing precursor into the organic metal chemical vapor deposition reaction chamber, and forming an aluminum metal layer on one side of the sapphire substrate;

introducing an ammonia precursor into the organic metal chemical vapor deposition reaction cavity, and performing nitridation treatment on the aluminum metal layer to generate a first aluminum nitride film;

placing the sapphire substrate with the first aluminum nitride thin film into a radio frequency sputtering deposition reaction chamber, and generating a second aluminum nitride thin film on one side of the first aluminum nitride thin film, which is far away from the sapphire substrate;

carrying out high-temperature annealing treatment outside the reaction chamber on the sapphire substrate with the first aluminum nitride film and the second aluminum nitride film, which specifically comprises the following steps: placing the sapphire substrate with the first aluminum nitride film and the second aluminum nitride film in an annealing furnace, setting the temperature of the annealing furnace to be more than or equal to 1500 ℃ and less than or equal to 1800 ℃, introducing nitrogen into the annealing furnace, and annealing for 1-3 hours;

placing the sapphire substrate with the first aluminum nitride film and the second aluminum nitride film after annealing treatment into the organic metal chemical vapor deposition reaction chamber;

simultaneously introducing the aluminum-containing precursor and the ammonia precursor into the organometallic chemical vapor deposition reaction chamber; and generating a third aluminum nitride film on the side of the second aluminum nitride film far away from the sapphire substrate.

2. The method of claim 1, further comprising, prior to introducing an aluminum-containing precursor into the organometallic chemical vapor deposition reaction chamber: and introducing hydrogen into the reaction cavity, and cleaning the surface of the sapphire substrate.

3. The method for producing an aluminum nitride semiconductor film according to claim 1,

the aluminum-containing precursor comprises at least one of trimethyl aluminum and triethyl aluminum.

4. The method for producing an aluminum nitride semiconductor film according to claim 1,

the ammonia precursor comprises at least one of ammonia gas and dimethyl hydrazine.

5. The method for manufacturing an aluminum nitride semiconductor film according to claim 1, wherein a second aluminum nitride film is formed on a side of the first aluminum nitride film away from the sapphire substrate, specifically:

introducing argon and nitrogen in a preset proportion into the radio frequency sputtering deposition reaction cavity by taking polycrystalline aluminum nitride powder as a target material, and forming a second aluminum nitride film on one side of the first aluminum nitride film, which is far away from the sapphire substrate; the value range of the preset proportion is 1:2-1:4.

6. The method of claim 1, wherein before the performing the high temperature annealing outside the reaction chamber on the sapphire substrate having the first and second aluminum nitride films, the method further comprises:

and placing the sapphire substrate with the first aluminum nitride film and the second aluminum nitride film on a bearing base, and enabling the second aluminum nitride film to be located between the sapphire substrate and the bearing base.

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