Reaction cavity, method for forming protective film thereof, and method for manufacturing light emitting diode

Abstract

The present disclosure provides a reaction cavity, a forming method of a protective film thereof and a preparation method of a light emitting diode, and belongs to the technical field of optoelectronic manufacturing. The forming method comprises: introducing a Ga source into a reaction cavity according to a first flow rate; during the introduction of the Ga source, introducing an MO source into the reaction cavity, wherein the flow rate of the MO source is less than the first flow rate; stopping the introduction of the Ga source and the MO source and waiting for a set time length to form a protective film on the inner wall of the reaction cavity. The embodiments of the present disclosure can form a protective film with good quality in the reaction cavity, and improve the growth quality of the epitaxial stack of the light emitting diode.

Description

Technical Field

[0001] This disclosure relates to the field of optoelectronic manufacturing technology, and in particular to a method for forming a reaction chamber and its protective film, and a method for preparing a light-emitting diode. Background Technology

[0002] MOCVD (Metal-Organic Chemical Vapor Deposition) is a vapor-phase epitaxial growth technique. GaN materials are typically grown inside the MOCVD reaction chamber. However, after the MOCVD reaction chamber has been in operation for a certain period of time, GaN material residue will remain inside the chamber, thus requiring regular cleaning and maintenance.

[0003] In related technologies, after cleaning the GaN material from the inner wall of the reaction chamber, a protective film needs to be formed on the inner wall of the reaction chamber to restore the growth environment before epitaxial growth of the GaN layer, in order to grow high-quality epitaxial wafers. When forming the protective film, only one type of Mo source is introduced into the reaction chamber at a single flow rate, allowing the Mo source material to deposit on the inner wall of the reaction chamber to form the protective film.

[0004] However, the protective film formed on the inner wall of the reaction chamber by this coating method is of poor quality, and a good growth environment is not formed in the reaction chamber, which in turn affects the growth quality of the subsequent epitaxial stack. Summary of the Invention

[0005] This disclosure provides a method for forming a reaction chamber and its protective film, and a method for fabricating a light-emitting diode (LED). The method enables the formation of a high-quality protective film within the reaction chamber, improving the growth quality of the epitaxial layers in the LED. The technical solution is as follows:

[0006] On one hand, embodiments of this disclosure provide a method for forming a protective film in a reaction chamber, the method comprising: introducing a Ga source into the reaction chamber at a first flow rate; introducing an MO source into the reaction chamber during the process of introducing the Ga source, wherein the flow rate of the MO source is less than the first flow rate; stopping the introduction of the Ga source and the MO source and waiting for a set time to form a protective film on the inner wall of the reaction chamber.

[0007] Optionally, the step of introducing the Ga source into the reaction chamber at the first flow rate includes: introducing the Ga source into the reaction chamber at a flow rate of 800 sccm to 1200 sccm for 30 min to 60 min.

[0008] Optionally, before introducing the Ga source into the reaction chamber at the first flow rate, the method further includes raising the temperature inside the reaction chamber to 600°C to 1000°C to bake the reaction chamber for 10 to 20 minutes.

[0009] Optionally, the MO source includes one of an Al source, a Ga source, and a Mg source.

[0010] Optionally, the step of introducing the MO source into the reaction chamber includes introducing the MO source into the reaction chamber at a flow rate of 300 sccm to 800 sccm.

[0011] Optionally, stopping the supply of the Ga source and the MO source and waiting for a set time includes: stopping the supply of the Ga source and the MO source, while raising the temperature inside the reaction chamber to 800°C to 1200°C for 5 to 10 minutes.

[0012] Optionally, after stopping the flow of the Ga source and the MO source and waiting for a set time, the method further includes: introducing the Ga source into the reaction chamber and controlling the flow rate of the Ga source to be lower than the first flow rate.

[0013] Optionally, introducing the Ga source into the reaction chamber and controlling the flow rate of the Ga source to be lower than the first flow rate includes: introducing the Ga source into the reaction chamber at a second flow rate for a first duration, wherein the second flow rate is less than the first flow rate; and introducing the Ga source into the reaction chamber at a third flow rate for a second duration, wherein the third flow rate is less than the second flow rate.

[0014] On the other hand, embodiments of this disclosure provide a reaction chamber, the inner wall of which has a protective film, the protective film being formed using the reaction chamber forming method described above.

[0015] In another aspect, embodiments of this disclosure provide a method for fabricating a light-emitting diode, the method comprising: growing an epitaxial wafer of a light-emitting diode in a reaction chamber as described above.

[0016] The beneficial effects of the technical solutions provided in this disclosure include at least the following:

[0017] The method for forming a protective film in the reaction chamber according to an embodiment of this disclosure firstly introduces a Ga source into the reaction chamber at a first flow rate. Since the first flow rate is greater than the flow rate of the MO source, the flow rate of the Ga source is relatively large, allowing for rapid formation of a protective film on the inner wall of the reaction chamber through this high flow rate. Furthermore, a MO source is introduced simultaneously with the Ga source. Because the components in the MO source readily adhere to the smooth surface of the reaction chamber, allowing the easily adhering MO source to deposit first makes it easier for the introduced Ga source to adhere within the reaction chamber, thus forming the protective film. Next, the introduction of both the Ga and MO sources is stopped for a set time to allow sufficient time for both sources to adhere within the reaction chamber, forming a more stable protective film. This results in a more stable protective film that adheres more tightly to the surface of the reaction chamber, yielding a high-quality protective film, which is beneficial for improving the growth quality of subsequent epitaxial layers. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart of a method for forming a protective film in a reaction chamber according to an embodiment of this disclosure;

[0020] Figure 2 This is a flowchart of another method for forming a protective film in a reaction chamber according to an embodiment of this disclosure;

[0021] Figure 3 This is a schematic diagram of the structure of a light-emitting diode provided in an embodiment of this disclosure.

[0022] The markings in the diagram are explained as follows:

[0023] 10. Substrate;

[0024] 20. Buffer layer;

[0025] 30. Undoped GaN layer;

[0026] 40. n-type layer;

[0027] 50. Emissive layer; 51. Quantum well layer; 52. Quantum barrier layer;

[0028] 60. p-type layer; 61. Low-temperature p-type GaN layer; 62. p-type AlGaN layer; 63. High-temperature p-type GaN layer; 64. p-type ohmic contact layer. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0030] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” “third,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar terms mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” “right,” “top,” and “bottom,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0031] Figure 1 This is a flowchart illustrating a method for forming a protective film in a reaction chamber according to an embodiment of this disclosure. Figure 1 As shown, the forming method includes:

[0032] Step 101: Introduce the Ga source into the reaction chamber at the first flow rate.

[0033] For example, the Ga source can be a TMGa source or a TEGa source.

[0034] Step 102: During the process of introducing the Ga source, introduce the MO source into the reaction chamber.

[0035] Among them, the traffic from the MO source is less than the traffic from the first source.

[0036] Step 103: Stop the supply of Ga and MO sources and wait for the set time to form a protective film on the inner wall of the reaction chamber.

[0037] The method for forming a protective film in the reaction chamber according to an embodiment of this disclosure firstly introduces a Ga source into the reaction chamber at a first flow rate. Since the first flow rate is greater than the flow rate of the MO source, the flow rate of the Ga source is relatively large, allowing for rapid formation of a protective film on the inner wall of the reaction chamber through this high flow rate. Furthermore, a MO source is introduced simultaneously with the Ga source. Because the components in the MO source readily adhere to the smooth surface of the reaction chamber, allowing the easily adhering MO source to deposit first makes it easier for the introduced Ga source to adhere within the reaction chamber, thus forming the protective film. Next, the introduction of both the Ga and MO sources is stopped for a set time to allow sufficient time for both sources to adhere within the reaction chamber, forming a more stable protective film. This results in a more stable protective film that adheres more tightly to the surface of the reaction chamber, yielding a high-quality protective film, which is beneficial for improving the growth quality of subsequent epitaxial layers.

[0038] In this embodiment of the disclosure, ammonia gas is continuously introduced during the formation of the protective film to supplement the N source, which is used to react with the Ga source and the MO source to form the AlGaN protective film.

[0039] For example, the ammonia flow rate is 10 L / min to 100 L / min.

[0040] In this embodiment of the disclosure, the reaction chamber is the reaction chamber of an MOCVD (Multi-access Edge Computing) device, and the MOCVD reaction chamber is used for the epitaxial growth of GaN material. For example, the MOCVD reaction chamber can be used to grow GaN-based epitaxial wafers.

[0041] Figure 2 This is a flowchart of another method for forming a protective film in a reaction chamber according to an embodiment of this disclosure.

[0042] like Figure 2 As shown, the forming method includes:

[0043] Step 201: Raise the temperature inside the reaction chamber to 600°C to 1000°C to bake the reaction chamber for 10 to 20 minutes.

[0044] By raising the temperature of the reaction chamber to over 600°C, the material in the Ga source can more easily adhere to the reaction chamber in a high-temperature environment, thus achieving the purpose of rapid film deposition.

[0045] Furthermore, by baking the reaction chamber, the moisture inside is removed, thus preventing moisture from affecting the quality of the protective film.

[0046] For example, the temperature of the reaction chamber is raised to 800°C to bake the reaction chamber for 15 minutes. Maintaining the temperature of the reaction chamber at this temperature ensures that the temperature inside the reaction chamber is kept at a high temperature when the Ga source and MO source are introduced, which is beneficial for the rapid deposition of the protective film.

[0047] Step 202: Introduce the Ga source into the reaction chamber at the first flow rate.

[0048] For example, the Ga source can be a TMGa source or a TEGa source.

[0049] The introduction of the Ga source may include: introducing the Ga source into the reaction chamber at a flow rate of 800 sccm to 1200 sccm for 30 min to 60 min.

[0050] By controlling the flow rate of the Ga source within the above range, a large flow rate of Ga source is introduced into the reaction chamber, which can quickly form a protective film on the inner wall of the reaction chamber. Furthermore, the duration of Ga source introduction is maintained between 30 and 60 minutes, providing sufficient time for Ga source deposition, which is conducive to the formation of a more stable protective film.

[0051] Step 203: During the process of introducing the Ga source, the MO source is also introduced into the reaction chamber.

[0052] Specifically, this may include introducing an Al source into the reaction chamber at a flow rate of 300 sccm to 800 sccm.

[0053] By controlling the inflow rate of the MO source within the above range, and maintaining an appropriate flow rate of the MO source into the reaction chamber, the easily deposited MO source can be deposited first, thereby making it easier for the introduced Ga source to adhere into the reaction chamber to form a protective film.

[0054] Optionally, the MO source includes one of the Al source, Ga source, and Mg source.

[0055] For example, the MO source is an Al source. An Al source is introduced simultaneously with the Ga source. Since Al from the Al source adheres more readily to the surface of the reaction chamber than other MO sources, allowing the easily adherent Al source to deposit first makes it easier for the introduced Ga source to adhere within the reaction chamber, forming an AlGaN protective film. This results in a more stable protective film that adheres more tightly to the surface of the reaction chamber, yielding a high-quality protective film, which in turn improves the growth quality of subsequent epitaxial layers.

[0056] Step 204: Stop the supply of Ga and MO sources and wait for a set time to form a protective film on the inner wall of the reaction chamber.

[0057] Specifically, this may include raising the temperature inside the reaction chamber to 800°C to 1200°C, maintaining it for 5 to 10 minutes, and stopping the flow of Ga and Al sources.

[0058] Before stopping the supply of Ga and Al sources, the temperature inside the reaction chamber is raised to 800°C to 1200°C. This high temperature environment enhances the activity of Al and improves reaction efficiency. Stopping the supply of Ga and Al sources at this point allows the more readily adhering Al source in the remaining Ga and Al sources to deposit first, and also allows the Ga source to adhere to the inner wall of the reaction chamber along with the Al source, thus improving the stability of the protective film.

[0059] Step 205: Introduce a Ga source into the reaction chamber and control the flow rate of the Ga source to be lower than the first flow rate.

[0060] Since the reaction will gradually saturate after reaching a certain point, if a large amount of Ga source is continuously introduced, an over-reaction will occur, which is not conducive to the formation of a protective film. Therefore, under the premise of introducing a large amount of Ga source in the aforementioned steps, Ga source is introduced into the reaction chamber at a reduced flow rate during the reaction end period. In this way, the material in the Ga source continues to adhere to the protective film during the reaction end process, so as to gradually stabilize the protective film.

[0061] Specifically, this can include the following two steps:

[0062] The first step is to introduce a Ga source into the reaction chamber at the second flow rate for a first duration.

[0063] The second flow rate is less than the first flow rate.

[0064] For example, the second flow rate is 300 sccm to 500 sccm. The first duration is 20 min to 40 min.

[0065] The second step is to introduce a Ga source into the reaction chamber at the third flow rate for a second duration.

[0066] The third flow rate is less than the second flow rate.

[0067] For example, the third flow rate is 100 sccm to 300 sccm, and the second duration is 30 min to 60 min.

[0068] It should be noted that since the third flow rate is less than the second flow rate, when the third flow rate is 300 sccm, the second flow rate is greater than 300 sccm; and when the second flow rate is 300 sccm, the third flow rate is less than 300 sccm.

[0069] In the above implementation method, the Ga source flow rate is gradually reduced in a stepwise manner, which can avoid directly and drastically reducing the flow rate, causing a sudden decrease in the Ga source content in the reaction chamber and affecting the growth quality of the protective film. This stepwise reduction of the Ga source flow rate allows the Ga source content to decrease more slowly, thereby stabilizing the protective film.

[0070] The method for forming a protective film in the reaction chamber according to an embodiment of this disclosure firstly introduces a Ga source into the reaction chamber at a flow rate of not less than 800 sccm. This high flow rate allows for rapid formation of a protective film on the inner wall of the reaction chamber. Simultaneously, an Al source is introduced. Since Al from the Al source adheres more readily to the surface of the reaction chamber than other MO sources, allowing the easily deposited Al source to settle first facilitates the adhesion of the introduced Ga source within the reaction chamber, thus forming the protective film. Next, the introduction of both the Ga and Al sources is stopped for a set duration to allow sufficient time for them to adhere within the reaction chamber, resulting in a more stable protective film. This method produces a more stable protective film that adheres more tightly to the surface of the reaction chamber, resulting in a high-quality protective film that improves the growth quality of subsequent epitaxial layers.

[0071] This disclosure provides a reaction chamber with a protective film on its inner wall, the protective film being formed using the reaction chamber formation method described above.

[0072] The reaction chamber can be the reaction chamber of an MOCVD device.

[0073] This disclosure provides a method for fabricating a light-emitting diode (LED), which includes growing the LED in a reaction chamber as described above.

[0074] The preparation method includes:

[0075] The first step is to place a substrate inside the reaction chamber.

[0076] The substrate can be a sapphire substrate, a silicon substrate, or a silicon carbide substrate. The substrate can be a flat substrate or a patterned substrate.

[0077] As an example, in this embodiment of the disclosure, the substrate is a sapphire substrate. Sapphire substrates are a commonly used substrate, with mature technology and low cost. Specifically, it can be a patterned sapphire substrate or a flat sapphire substrate.

[0078] Specifically, this may include: performing a high-temperature cleaning treatment on the sapphire substrate in a hydrogen atmosphere at 1000°C to 1200°C for 5 to 20 minutes, followed by nitriding.

[0079] In the first step, the sapphire substrate can be pretreated by placing it in an MOCVD (Metal-organic Chemical Vapor Deposition) reaction chamber and baking it for 12 to 18 minutes. As an example, in this embodiment of the present disclosure, the sapphire substrate is baked for 15 minutes.

[0080] Specifically, the baking temperature can be from 1000℃ to 1200℃, and the pressure inside the MOCVD reaction chamber during baking can be from 100mbar to 200mbar.

[0081] The second step is to grow a buffer layer on the surface of the substrate.

[0082] The buffer layer can be an AlN layer.

[0083] In this embodiment of the disclosure, growing an AlN layer on a substrate may include:

[0084] The power is controlled at 3500W to 5000W, the flow rate of nitrogen is 300sccm to 500sccm, the flow rate of oxygen is 3sccm to 6sccm, the time is 10min to 15min, and the temperature is 450℃ to 550℃ to generate an AlN layer by sputtering an Al target.

[0085] The third step is to grow an undoped GaN layer on the buffer layer.

[0086] Compared to the substrate, since the crystal structure of the undoped GaN layer is similar to that of the n-type layer, setting the undoped GaN layer as a transition layer can improve the crystal quality of the subsequent epitaxial layer.

[0087] The thickness of the undoped GaN layer is 1 μm to 2 μm. For example, the thickness of the undoped GaN layer is 1.5 μm.

[0088] Specifically, after the low-temperature GaN buffer layer is grown, the temperature is adjusted to 1000℃ to 1200℃ to grow an epitaxial undoped GaN layer with a thickness of 1μm to 2μm, the growth pressure is 100Torr to 500Torr, and the V / III ratio is 200 to 3000.

[0089] The fourth step is to grow an n-type layer on the undoped GaN layer.

[0090] Optionally, the n-type layer can be an n-type GaN layer. The thickness of the n-type layer is 1.5 μm to 3.5 μm. The dopant of the n-type layer is silane.

[0091] Specifically, after the undoped GaN layer is grown, an n-type GaN layer with a stable Si doping concentration is grown, with a thickness of 1.5 μm to 3.5 μm, a growth temperature of 950℃ to 1150℃, a growth pressure of 300 Torr to 500 Torr, and a V / III ratio of 400 to 3000.

[0092] The fifth step is to grow a light-emitting layer on the n-type layer.

[0093] Specifically, after the n-type layer growth is completed, alternating layers of quantum wells and quantum barrier layers are grown.

[0094] Among them, the quantum well layer is an In y Ga 1-y N(0.1 < y < 0.3) layer. The quantum well layer may include a first InGaN layer, a second InGaN layer, and a third InGaN layer stacked in sequence.

[0095] When growing the quantum well layer, ammonia, triethylgallium, and trimethylindium are introduced into the reaction chamber for a duration of 30 s to 60 s, and the growth temperature in the reaction chamber is controlled to be 700 °C to 850 °C, the growth pressure is 100 Torr to 500 Torr, the V / III ratio is 2000 to 20000, and the thickness is 2 nm to 5 nm.

[0096] Exemplarily, the thickness of the quantum well layer may be 3 nm.

[0097] In the embodiments of the present disclosure, the quantum barrier layer may be an n-type GaN quantum barrier layer.

[0098] When growing the quantum barrier layer, the growth temperature in the reaction chamber is controlled to be 850 °C to 950 °C, the growth pressure is 100 Torr to 500 Torr, the V / III ratio is 2000 to 20000, and the thickness is 5 nm to 15 nm.

[0099] Exemplarily, the thickness of the n-type GaN quantum barrier layer is 10 nm.

[0100] Optionally, the number of layers of the quantum well layer and the number of layers of the quantum barrier layer are both 8 to 12 layers. Exemplarily, the number of layers of the quantum well layer and the number of layers of the quantum barrier layer are both 10.

[0101] Step 6, grow a p-type layer on the light-emitting layer.

[0102] Optionally, the thickness of the p-type layer is 30 nm to 120 nm. Among them, the dopant of the p-type layer is magnesium cyclopentadienyl.

[0103] Among them, the p-type layer may include a low-temperature p-type GaN layer, a p-type AlGaN layer, a high-temperature p-type GaN layer, and a p-type ohmic contact layer stacked in sequence on the light-emitting layer. Both the low-temperature p-type GaN layer and the high-temperature p-type GaN layer are Mg-doped.

[0104] Among them, the thickness of the low-temperature p-type GaN layer may be 30 nm to 120 nm. For example, the thickness of the low-temperature p-type GaN layer may be 100 nm.

[0105] Among them, the thickness of the high-temperature p-type GaN layer may be 50 nm to 150 nm. For example, the thickness of the low-high-temperature p-type GaN layer may be 100 nm.

[0106] In this embodiment, the p-type AlGaN layer serves as an electron blocking layer to prevent electrons from entering the p-type layer. Both the p-type AlGaN layer and the p-type ohmic contact layer are Mg-doped.

[0107] Optionally, the thickness of the p-type AlGaN layer can be from 50 nm to 150 nm. As an example, in an embodiment of this disclosure, the thickness of the p-type AlGaN layer is 80 nm.

[0108] Optionally, the thickness of the p-type ohmic contact layer can be from 3 nm to 10 nm. As an example, in an embodiment of this disclosure, the thickness of the p-type ohmic contact layer is 8 nm.

[0109] Specifically, after the light-emitting layer is grown, a low-temperature p-type GaN layer with a thickness of 30 nm to 120 nm is grown at a growth temperature of 700 °C to 800 °C, a growth time of 3 min to 15 min, a pressure of 100 Torr to 600 Torr, and a V / III ratio of 1000 to 4000.

[0110] After the low-temperature p-type GaN layer is grown, a p-type AlGaN layer with a thickness of 50 nm to 150 nm is grown at a growth temperature of 900 °C to 1000 °C, a growth time of 4 min to 15 min, a growth pressure of 50 Torr to 300 Torr, and a V / III ratio of 1000 to 10000.

[0111] After the p-type AlGaN layer is grown, a high-temperature p-type GaN layer with a thickness of 50 nm to 150 nm is grown at a growth temperature of 900 °C to 1050 °C, a growth time of 10 min to 20 min, a growth pressure of 100 Torr to 500 Torr, and a V / III ratio of 500 to 4000.

[0112] After the high-temperature p-type GaN layer is grown, a p-type ohmic contact layer with a thickness of 3 nm to 10 nm is grown at a growth temperature of 700 °C to 850 °C, a growth time of 0.5 min to 5 min, a growth pressure of 100 Torr to 500 Torr, and a V / III ratio of 10000 to 20000.

[0113] Step 7: Anneal the epitaxial wafer.

[0114] After epitaxial growth, the temperature of the reaction chamber is lowered to 600°C to 900°C and annealed in a PN2 atmosphere for 10 to 30 minutes. Then, it is gradually lowered to room temperature. Subsequently, a single 22×35mil chip is fabricated through subsequent processing steps such as cleaning, deposition, photolithography, and etching.

[0115] In specific implementation, embodiments of this disclosure may use high-purity H2 and / or N2 as carrier gas, TEGa or TMGa as Ga source, TMIn as In source, SiH4 as n-type dopant, TMAl as aluminum source, ammonia as N source, and Cp2Mg as p-type dopant.

[0116] Figure 3 This is a schematic diagram of the structure of a light-emitting diode provided in an embodiment of this disclosure. For example... Figure 3 As shown, the light-emitting diode is fabricated using the light-emitting diode fabrication method described above. The epitaxial wafer of the light-emitting diode includes a substrate 10, a buffer layer 20, an undoped GaN layer 30, an n-type layer 40, a light-emitting layer 50, and a p-type layer 60 stacked sequentially.

[0117] The light-emitting layer 50 includes multiple quantum well layers 51 and multiple quantum barrier layers 52, which are stacked alternately.

[0118] Optionally, the n-type layer 40 can be an n-type GaN layer. The dopant for the n-type layer is silane.

[0119] Optionally, the p-type layer 60 may include a low-temperature p-type GaN layer 61, a p-type AlGaN layer 62, a high-temperature p-type GaN layer 63, and a p-type ohmic contact layer 64 sequentially stacked on the light-emitting layer 50. Both the low-temperature p-type GaN layer 61 and the high-temperature p-type GaN layer 63 are Mg-doped.

[0120] It should be noted that, Figure 3 The diagram only shows a portion of the structure in the light-emitting layer 50 and is not used to limit the number of cycles of the alternating stacking of the quantum well layer 51 and the quantum barrier layer 52.

[0121] by Figure 3 Taking the epitaxial wafer of a schematic light-emitting diode as an example, two different reaction chambers are used for growth. Figure 3 An illustration of an epitaxial membrane.

[0122] A protective film formed within a reaction chamber is formed using the protective film formation method provided in this embodiment.

[0123] The specific formation steps are as follows: First, a Ga source is introduced into the reaction chamber at a flow rate of 1200 sccm; during the introduction of the Ga source, an Al source is introduced into the reaction chamber at a flow rate of 500 sccm; then, the introduction of the Ga and Al sources is stopped and the set time is waited for to form an AlGaN protective film on the inner wall of the reaction chamber; finally, a Ga source is introduced into the reaction chamber at a flow rate of 300 sccm for 30 minutes; then, a Ga source is introduced into the reaction chamber at a flow rate of 200 sccm for 40 minutes.

[0124] Another type of protective film formed within the reaction chamber is formed using conventional methods for forming protective films.

[0125] The specific formation steps are as follows: A MO source is introduced into the reaction chamber, and the Mo source material is deposited on the inner wall of the reaction chamber to form a GaN protective film.

[0126] For example, the MO source is a Ga source.

[0127] The flow rate of the Ga source introduced during the formation of the protective film is 400 sccm to 600 sccm, and the introduction time is 50 min to 80 min.

[0128] The comparison data of various parameters of epitaxial wafers grown in two different reaction chambers are shown in Table 1 below:

[0129] Table 1

[0130]

[0131] As shown in Table 1, the XRD (Diffraction of X-rays) test data for the 102 and 002 planes were consistent with or lower than before PM maintenance. Simultaneously, the higher Mg doping concentration resulted in higher carrier mobility. Because the recovery was rapid, an additional growth process was not required for recovery. Furthermore, the voltage, brightness, and ESD of the epitaxial wafer obtained in the first growth cycle after reaction chamber cleaning and maintenance were consistent with or higher than the levels before reaction chamber cleaning and maintenance.

[0132] For the voltage forward (VF) of the epitaxial wafer, the VF of conventional protective film formation methods is slightly higher than that of the protective film formation method provided in this disclosure. Since a more uniform protective film within the reaction chamber indicates a more complete reaction within the chamber, resulting in better lattice quality of the grown epitaxial wafer and facilitating the incorporation of Si, Mg, and ln doping, the forward voltage of the epitaxial wafer is lower. Therefore, the protective film formed using the method provided in this disclosure after chamber cleaning adheres more uniformly and effectively to the inner wall of the reaction chamber, which is more conducive to subsequent chemical reactions within the chamber.

[0133] Regarding the electroluminescence brightness of the epitaxial wafer, the electroluminescence brightness of conventional protective film formation methods is slightly lower than that of the protective film formation method provided in this disclosure. Since a more uniform protective film within the reaction chamber indicates a more complete reaction within the chamber, resulting in better lattice quality of the grown epitaxial wafer and facilitating the incorporation of Si, Mg, and ln doping, the epitaxial wafer exhibits greater electroluminescence brightness. Therefore, the protective film formed using the method provided in this disclosure after chamber cleaning adheres more uniformly and effectively to the inner wall of the reaction chamber, further facilitating subsequent chemical reactions within the chamber.

[0134] For ESD (Electro-Static Discharge) of epitaxial wafers, ESD is used to indicate antistatic capability. The ESD of conventional protective film formation methods is slightly lower than that of the protective film formation method provided in the embodiments of this disclosure. Since the more uniform the protective film in the reaction chamber, the more complete the reaction in the reaction chamber, the better the lattice quality of the grown epitaxial wafer, and the more favorable it is for the incorporation of Si, Mg, and ln doping. Therefore, the epitaxial wafer has a stronger antistatic capability. Thus, the protective film formed using the method provided in the embodiments of this disclosure adheres more uniformly and effectively to the inner wall of the reaction chamber after cleaning, which is more conducive to the subsequent chemical reaction in the reaction chamber.

[0135] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A method for forming a protective film in a reaction chamber, characterized in that, The forming method includes: A Ga source is introduced into the reaction chamber at a first flow rate of 800 sccm to 1200 sccm. During the process of introducing the Ga source, an Al source is introduced into the reaction chamber. The flow rate of the Al source is less than the first flow rate. The Al source is used to allow Al atoms to attach to the inner wall of the reaction chamber, so that the Ga atoms in the Ga source react with the Al atoms on the inner wall of the reaction chamber to form a protective film. Stop supplying the Ga source and the Al source and wait for a set time to form a protective film on the inner wall of the reaction chamber, the protective film being an AlGaN film; A Ga source is introduced into the reaction chamber at a second flow rate for a first duration, wherein the second flow rate is less than the first flow rate and the second flow rate is 300 sccm to 500 sccm. A Ga source is introduced into the reaction chamber at a third flow rate for a second duration, wherein the third flow rate is less than the second flow rate and the third flow rate is 100 sccm to 300 sccm.

2. The forming method according to claim 1, characterized in that, The step of introducing the Ga source into the reaction chamber at the first flow rate includes: A Ga source is introduced into the reaction chamber at the first flow rate for 30 to 60 minutes.

3. The forming method according to claim 2, characterized in that, Before the Ga source is introduced into the reaction chamber at the first flow rate, the method further includes: The temperature inside the reaction chamber is raised to 600°C to 1000°C to bake the reaction chamber for 10 to 20 minutes.

4. The forming method according to any one of claims 1 to 3, characterized in that, The process of introducing an Al source into the reaction chamber includes introducing the Al source into the reaction chamber at a flow rate of 300 sccm to 800 sccm.

5. The forming method according to any one of claims 1 to 3, characterized in that, The step of stopping the flow to the Ga source and the Al source and waiting for a set duration includes: Stop supplying the Ga source and the Al source, and simultaneously raise the temperature inside the reaction chamber to 800°C to 1200°C for 5 to 10 minutes.

6. A reaction chamber, characterized in that, The inner wall of the reaction chamber has a protective film, which is formed using the method for forming the reaction chamber as described in any one of claims 1 to 5.

7. A method for fabricating a light-emitting diode, characterized in that, The preparation method includes: growing an epitaxial wafer of a light-emitting diode in the reaction chamber as described in claim 6.

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