Method for cleaning a chamber of a mocvd apparatus

Abstract

The present disclosure provides a cavity cleaning method of MOCVD equipment, and belongs to the field of semiconductor manufacturing. The method comprises the following steps: after epitaxial growth is completed, reaction products on the surface of a graphite disc are etched by Cl2 circulation; Al x Ga y In 1‑x‑y N is deposited in a reaction cavity under an Mg-rich H2 atmosphere to form a Mg-doped Al x Ga y In 1‑x‑y N microstructure on the inner wall of the reaction cavity and the surface of the graphite disc, wherein 0≤x≤1 and 0≤y≤1. The present disclosure re-establishes the Mg environment in the cavity by growing a high-Mg-doped Al x Ga y In 1‑x‑y N structure in the cavity after Cl2 etching of the cavity, thereby improving the effective doping of Mg in the epitaxial layer during epitaxial growth in the cavity, and improving the quantum efficiency of the quantum well light-emitting layer.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor manufacturing, and in particular to a method for cleaning the cavity of an MOCVD apparatus. Background Technology

[0002] Metal-organic chemical vapor deposition (MOCVD) equipment is a type of equipment used for epitaxial layer growth and has wide applications in the semiconductor manufacturing industry.

[0003] During epitaxial layer growth, a substrate is placed on a graphite disk within the cavity of an MOCVD (Multi-access Edge Computing) device, and a gas for epitaxial growth is introduced to grow the desired epitaxial layer on the substrate. However, during epitaxial layer growth, reaction products are left on the cavity of the MOCVD device and on the graphite workpiece. These reaction products can cause parasitic reactions during subsequent epitaxial layer growth. To avoid parasitic reactions, after epitaxial growth, related technologies perform Cl2 etching inside the MOCVD cavity to remove the reaction products.

[0004] In related technologies, Cl2 etching is performed after each epitaxial growth cycle. During Cl2 etching of the reaction chamber, diluted Cl2 etches the reaction products remaining on the chamber walls and graphite components. The reaction products are then carried out of the chamber by purging. During the etching and removal of these reaction products, MgO and Mg-doped GaN within the chamber also react with Cl2 and are carried out, disrupting the Mg-rich environment within the chamber. This affects the effective doping of Mg in the epitaxial layer during epitaxial growth, thereby impacting the quantum efficiency of the MQW quantum well's light-emitting layer. Summary of the Invention

[0005] On one hand, a method for cleaning the cavity of an MOCVD device is provided, the method comprising:

[0006] After epitaxial growth is completed, the reaction products on the surface of the graphite disk are etched by Cl2 cycles.

[0007] Al was deposited in the reaction chamber under a Mg-rich H2 atmosphere. x Ga y In 1-x-y N, to form Mg-doped Al on the inner wall of the reaction chamber and the surface of the graphite disk. x Ga y In 1-x-y N microstructures, where 0≤x≤1 and 0≤y≤1.

[0008] Optionally, the reaction products generated by cyclically etching the surface of the graphite disk with Cl2 include:

[0009] The reaction chamber is then heated and purged.

[0010] The reaction products were obtained by etching the surface of the graphite disk with Cl2;

[0011] The reaction chamber was purged with N2 and NH3 and then baked.

[0012] Repeat the above steps.

[0013] Optionally, the reaction products generated by etching the surface of the graphite disk with Cl2 include:

[0014] A mixture of Cl2 and N2 gas is introduced into the reaction chamber, and the concentration of Cl2 is gradually increased. Within a set time period, the reaction products are etched onto the surface of the graphite disk.

[0015] Optionally, Al is deposited in the reaction chamber under a Mg-rich H2 atmosphere. x Ga y In 1-x-y N includes:

[0016] Under the H2 atmosphere at 900-1050℃, a MO source and a nitrogen source are introduced to deposit Mg-doped Al. x Ga y In 1-x- y N.

[0017] Optionally, in the H2 atmosphere at 900-1050°C, a MO source and a nitrogen source are introduced to deposit Mg-doped Al. x Ga y In 1-x-y N includes:

[0018] Under the H2 atmosphere at 900-1000℃, the first valve of Cp2Mg is open and the second valve is closed; the first valve of TMGa is open and the second valve is closed; the first valve of TMIn is open and the second valve is closed; the first valve of TMAl is open and the second valve is closed; the first valve of NH3 is open and the second valve is closed; this process continues for 2-3 minutes.

[0019] Open the second valves for Cp2Mg, TMGa, and TMIn for 2-5 minutes;

[0020] Keep the second valves of Cp2Mg, TMGa and TMIn open, and simultaneously open the second valve of TMAl for 5-10 minutes.

[0021] Close the second valve of TMA1, open the second valve of NH3, and introduce NH3 for 5-30 minutes;

[0022] Close the second valve and the first valve of Cp2Mg, TMGa, TMIn, TMAl and NH3, and raise the temperature to 1000-1050℃ for 2-5 minutes.

[0023] Optionally, the flow rate of Cp2Mg is 2500-3500 sccm, the flow rate of TMGa is 40-60 sccm, the flow rate of TMIn is 700-900 sccm, the flow rate of TMAl is 50-70 sccm, and the flow rate of NH3 is 20000-30000 sccm.

[0024] Optionally, the Al x Ga y In 1-x-y The pressure in the reaction chamber during N deposition is 500-700 mbar.

[0025] Optionally, the method further includes:

[0026] In the deposition of Al x Ga y In 1-x-y After N, the pressure and temperature of the reaction chamber are reduced.

[0027] Optionally, reducing the pressure and temperature of the reaction chamber includes:

[0028] Reduce the pressure in the reaction chamber to 140-160 mbar;

[0029] When the temperature of the reaction chamber drops below 500°C, the atmosphere inside the reaction chamber is switched from H2 to N2.

[0030] When the temperature of the reaction chamber drops below 450°C, the purging setting in the reaction chamber is set to 10% of the maximum value, and the temperature of the reaction chamber is waited for to drop below 400°C.

[0031] On the other hand, an LED manufacturing method is provided, which includes the method described in any one of the above.

[0032] The beneficial effects of the solution provided in this disclosure are as follows:

[0033] During Cl2 etching of the reaction chamber, Cl2 reacts with the reaction products within the chamber, which are then carried out of the chamber by internal purging. During this etching and removal of the reaction products, MgO and Mg-doped GaN within the chamber also react with Cl2 and are carried out, disrupting the Mg environment within the chamber. By using a carrier gas to transport the MO and nitrogen sources into the reaction chamber after Cl2 etching of the chamber's interior, highly Mg-doped Al is grown inside the chamber. x Ga y In 1-x- y The N-structure reconstructs the Mg environment inside the cavity, enhancing the effective doping of Mg in the epitaxial layer during epitaxial growth within the cavity, thereby improving the quantum efficiency of the quantum well light-emitting layer. Attached Figure Description

[0034] 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.

[0035] Figure 1 This is a flowchart of a method for cleaning the cavity of an MOCVD device according to an embodiment of the present disclosure;

[0036] Figure 2 This is a cross-sectional view of the cavity of an MOCVD device provided in an embodiment of this disclosure;

[0037] Figure 3 This is a top view of a graphite disk provided in an embodiment of this disclosure;

[0038] Figure 4 This is a schematic diagram of a stacked air outlet provided in an embodiment of the present disclosure;

[0039] Figure 5 This is a flowchart of another method for cleaning the cavity of an MOCVD device provided in this embodiment;

[0040] Figure 6 This is a schematic diagram of experimental data provided in the embodiments of this disclosure. Detailed Implementation

[0041] 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.

[0042] Figure 1 This is a flowchart illustrating a method for cleaning the cavity of an MOCVD device according to an embodiment of this disclosure. See also... Figure 1 The method includes:

[0043] 101. After epitaxial growth is completed, the reaction products on the surface of the graphite disk are etched by cyclic etching with Cl2.

[0044] In one implementation of this disclosure, step 101 may include:

[0045] Step 1: Perform heating and purging within the reaction chamber;

[0046] Step 2: Use Cl2 to etch the reaction products on the surface of the graphite disk;

[0047] Step 3: Purge the reaction chamber with N2 and NH3 and then bake it;

[0048] Step 4: Repeat the above steps.

[0049] In this implementation, the reaction products (byproducts) are carried away from the chamber by cyclic Cl2 etching and purging.

[0050] In this embodiment of the disclosure, the graphite disk includes a graphite carrier disk and a large graphite disk.

[0051] By introducing Cl2 into the reaction chamber, the Cl2 inside the chamber reacts with the reaction products (byproducts) on the graphite disk, and then the reaction products on the surface of the graphite disk are removed by purging them out of the chamber.

[0052] Multiple Cl2 etching processes are performed to avoid incomplete removal of reaction products due to incomplete first Cl2 etching.

[0053] In one example, steps 1-3 can be repeated twice, and in another example, steps 1-3 can be repeated more times, such as three times.

[0054] Figure 2 This is a cross-sectional view of the cavity of an MOCVD device provided in an embodiment of this disclosure. See also... Figure 2 The MOCVD cavity includes an RF coil 201, a large graphite disk 202, a first graphite element 203 (middle type edge graphite cover), a graphite carrier disk 204 (planetary disk), a second graphite element 205 (center graphite cover), a stacked air outlet 206, a Cl2 air outlet 207, a top cover 208, a cavity sidewall 209, and an exhaust port 210.

[0055] The radio frequency coil 201 is located below the graphite disk 202, and the first graphite component 203, the graphite carrier disk 204, and the second graphite component 205 are located above the graphite disk 202, and are on the same layer. The stacked air outlet 206 is located above the graphite disk 202, and corresponds to the center of the graphite disk 202.

[0056] The upper end of the stacked vent 206 is connected to the top cover 208, and there are Cl2 vents 207 on both sides of the stacked vent 206, which are connected to the top cover 208. A cavity sidewall 209 is provided on the outer side of the graphite disk 202, and an exhaust port 210 is provided between the cavity sidewall 209 and the graphite disk 202.

[0057] The graphite disk 202 is used to support the graphite carrier disk 204, and the surface of the graphite disk 202 has multiple uniformly distributed graphite carrier disks 204. The graphite carrier disk 204 is used to support the substrate, the RF coil 201 is used to increase the cavity temperature, the stacked gas outlet 206 is used to deliver carrier gas, MO source, and NH3 (nitrogen source), and the Cl2 gas outlet 207 is used to deliver Cl2. Figure 2 As shown, the gas generated by the stacked gas outlet 206 and Cl2 gas outlet 207 diffuses (radiates) outward from the center.

[0058] In this embodiment of the disclosure, a gas purging device is provided at the top cover 208, the radio frequency coil 201, the edge exhaust port 210, the stacked exhaust port 206, and other locations. Figure 2 (Not shown in the image).

[0059] Figure 3 A top view of a graphite disk 202 provided for an embodiment of this disclosure. See also... Figure 3 , Figure 3 The diagram shows a first graphite element 203, a graphite carrier disk 204, a second graphite element 205, a stacked air outlet 206, a third graphite element 301 (Left type edge graphite cover), and a fourth graphite element 302 (Right type edge graphite cover).

[0060] like Figure 3As shown, the graphite disk 202 has eight circular graphite carrier disks 204, which are evenly spaced. At the edge of the graphite disk 202 and between the graphite carrier disks 204, there are first graphite elements 203, third graphite elements 301, and fourth graphite elements 302, with the first graphite element 203 located between the third graphite element 301 and the fourth graphite element 302. A circular, stacked vent 206 is located in the central region of the graphite disk 202, and a second graphite element 205 is located between the stacked vent 206 and the plurality of graphite carrier disks 204. The shapes of the components shown in the figure are examples of top views of the components and are not intended to limit the embodiments of this disclosure.

[0061] Figure 4 This is a schematic diagram of a stacked air outlet structure provided in an embodiment of this disclosure. See also... Figure 4 The stacked air outlets 206 include G1 air outlet 401, G2 air outlet 402, G3 air outlet 403, G4 air outlet 404, and G5 air outlet 405.

[0062] The G2 air outlet 402 is located above the G1 air outlet 401, the G3 air outlet 403 is located above the G2 air outlet 402, the G4 air outlet 404 is located above the G3 air outlet 403, the G5 air outlet 405 is located above the G4 air outlet 404, and there is a gap 406 between each layer of air outlets in the stacked air outlets 206.

[0063] The G1 outlet 401, G3 outlet 403, and G5 outlet 405 are used to transport carrier gas and NH3, and the G2 outlet 402 and G4 outlet 404 are used to transport MO source and carrier gas.

[0064] Combination Figure 3 , Figure 4 It can be seen that the shape of the stacked air outlet 206 can be cylindrical.

[0065] 102, Al was deposited in the reaction chamber under a Mg-rich H2 atmosphere. x Ga y In 1-x-y N, to form Mg-doped Al on the inner wall of the reaction chamber and the surface of the graphite disk. x Ga y In 1-x-y N microstructures, where 0≤x≤1 and 0≤y≤1.

[0066] In one implementation of this disclosure, step 102 may include: depositing Mg-doped Al by introducing a MO source and a nitrogen source in an H2 atmosphere at 900-1050°C. x Gay In 1-x-y N.

[0067] Where 0 ≤ x ≤ 1 and 0 ≤ y ≤ 1. For example, x can be 0.5 and y can be 0.5, or x can be 0 and y can be 1, etc.

[0068] In this implementation, a H2 atmosphere at 900-1050℃ is more conducive to the development of highly Mg-doped Al. x Ga y In 1-x-y N growth.

[0069] In this embodiment of the disclosure, the method may further include: depositing Al x Ga y In 1-x-y After N, the pressure and temperature of the reaction chamber are reduced.

[0070] During Cl2 etching of the reaction chamber, Cl2 reacts with the reaction products within the chamber. These products are then carried out of the chamber by purging. During this process, Cl2 reacts with MgO and Mg-doped GaN, carrying them out of the chamber and thus disrupting the Mg environment within the chamber. This disclosure, after Cl2 etching of the chamber interior, utilizes a carrier gas to transport the MO source and nitrogen source into the reaction chamber, and grows highly Mg-doped Al within the chamber. x Ga y In 1-x-y The N-structure reconstructs the Mg environment inside the cavity, enhancing the effective doping of Mg in the epitaxial layer during epitaxial growth within the cavity, thereby improving the quantum efficiency of the quantum well light-emitting layer.

[0071] Figure 5 This disclosure provides a method for cleaning the cavity of an MOCVD device. See also: Figure 5 The method includes:

[0072] 501. After the epitaxial layer growth is completed, execute the cavity cleaning procedure.

[0073] Among them, cavity clean out refers to the process after the epitaxial layer growth is completed, in which the MOCVD equipment removes the epitaxial wafer from the machine and returns the SiC (silicon carbide) ring that fixes and moves the epitaxial wafer back to the cavity, so that it is in an empty cavity state (Pocket not loaded with substrate) to wait for the execution of the Cl2 cycle etching program and the Mg-rich environment pre-deposition (Coating) program.

[0074] In this embodiment of the disclosure, the cleaning method is used for Aixtron's G5+C model equipment.

[0075] In another embodiment, the cleaning method is used for other models of MOCVD equipment from Aixtron or other companies' MOCVD equipment.

[0076] 502, heating and purging are performed inside the reaction chamber.

[0077] In this embodiment of the disclosure, step 502 can be performed in the following manner:

[0078] The first step is to control the power of the radio frequency coil in an N2 atmosphere to raise the temperature inside the reaction chamber to the first temperature range.

[0079] The initial atmosphere inside the reaction chamber was set to N2, and the rotation speed of the graphite disk 202 inside the reaction chamber was set to 5-5.5 rpm / min.

[0080] Automatic control of the gas output from the stacked gas outlet 206 is activated, and the pressure in the reaction chamber is set within the first pressure range.

[0081] Start the radio frequency coil 201 and control the power of the radio frequency coil 201 to increase from 0% to 25% of the rated power. Wait 1-2 minutes until the temperature inside the reaction chamber is within the first temperature range before proceeding to the next step.

[0082] For example, the first temperature range can be 150-170°C. For instance, by controlling the power of the radio frequency coil 201, the temperature inside the reaction chamber can be raised to above 150°C within 2 minutes.

[0083] For example, the first pressure range can be 100-110 mbar, such as 100 mbar.

[0084] The second step is to increase the power of the radio frequency coil in an H2 atmosphere to raise the temperature inside the reaction chamber to the second temperature range.

[0085] The atmosphere inside the reaction chamber is switched from N2 to H2. At the same time, the gas output ratio of each gas outlet in the stacked gas outlet 206, G5:G4:G3:G2:G1, is adjusted from the default value to 39%:25%:16%:12%:8%. The total gas output of the stacked gas outlet 206 is set to 12000-13000 sccm, for example, 12000 sccm.

[0086] Increase the power of the control radio frequency coil 201 from 25% to 40% of the rated power, wait 1-2 minutes, and proceed to the next step when the temperature inside the reaction chamber is within the second temperature range.

[0087] For example, the second temperature range can be 300-320°C. For instance, by controlling the power of the radio frequency coil 201, the temperature inside the reaction chamber can be raised to above 300°C within 2 minutes.

[0088] When heating the cavity, the purging flow rate of the gas purging device inside the cavity is set as follows: 1000-1100 sccm (e.g., 1000 sccm) at the top cover 208, 1000-1100 sccm (e.g., 1000 sccm) at the edge exhaust port 210, 2000-2100 sccm (e.g., 2000 sccm) at the radio frequency coil 201, 500-600 sccm (e.g., 500 sccm) at the stacked exhaust port 206, and the total gas volume of the planetary disk is set as 5000-6000 sccm (e.g., 5500 sccm).

[0089] It is worth noting that the total gas volume of the planetary disk refers to the sum of the airflow that supports and drives the graphite carrier disk 204 to rotate, and the airflow is located below the graphite carrier disk 204.

[0090] In this embodiment of the disclosure, there are 8 graphite carrier disks 204. Therefore, the total gas volume of the planetary disk is the sum of the airflow flow that drives and rotates the 8 graphite carrier disks 204.

[0091] The third step is to keep the atmosphere inside the cavity constant and increase the power of the radio frequency coil to raise the temperature inside the reaction cavity to the third temperature range.

[0092] The power of the control radio frequency coil 201 is increased from 40% to 50% of the rated power. The heating time is not fixed, and the internal temperature of the reaction chamber is waited for to rise to the third temperature range.

[0093] During this heating period, the purge flow rates of each gas purging device in the cavity are as follows: the purge flow rate at the edge exhaust port 210 increases to 3600-3700 sccm (e.g., 3600 sccm), and the purge flow rate at the radio frequency coil 201 increases to 5000-5100 sccm (e.g., 5000 sccm).

[0094] For example, the third temperature range can be 500-520°C. For instance, by controlling the power of the radio frequency coil 201, the temperature inside the reaction chamber can be raised to above 500°C.

[0095] Fourth step: Keeping the atmosphere inside the cavity unchanged, increase the power of the radio frequency coil to raise the temperature inside the reaction cavity to the fourth temperature range.

[0096] The power of the control radio frequency coil 201 is increased from 50% to 70% of the rated power. The heating time is not fixed, and the cavity temperature is waited for to rise to the fourth temperature range.

[0097] During this heating process, the purging flow rate of the gas purging device inside the cavity remains constant.

[0098] For example, the fourth temperature range can be 850-870°C. For instance, by controlling the power of the radio frequency coil 201, the temperature inside the reaction chamber can be raised to above 850°C.

[0099] Fifth step: Keeping the atmosphere inside the cavity constant, increase the power of the radio frequency coil to raise the temperature inside the reaction cavity to the fifth temperature range.

[0100] The power of the control radio frequency coil 201 is increased from 70% to 80% of the rated power. The heating time is not fixed, and the cavity temperature is waited for to rise to the fifth temperature range.

[0101] During this heating process, the purging flow rate of each gas purging device in the cavity remains constant.

[0102] For example, the fifth temperature range can be 970-990°C. For instance, by controlling the power of the radio frequency coil 201, the temperature inside the reaction chamber can be raised to above 970°C.

[0103] Step 6: Keeping the internal atmosphere constant, increase the power of the radio frequency coil to raise the temperature inside the reaction cavity to the sixth temperature range; then continue to increase the power of the radio frequency coil to raise the temperature inside the reaction cavity to the seventh temperature range.

[0104] The power of the control radio frequency coil 201 is increased from 80% to 88% of the rated power. The heating time is not fixed. Wait for the cavity temperature to rise to the sixth temperature range.

[0105] During this heating process, the purging flow rate of each gas purging device in the cavity remains constant.

[0106] For example, the sixth temperature range is 1020-1040°C. For instance, by controlling the power of the radio frequency coil 201, the temperature inside the reaction chamber can be raised to above 1020°C.

[0107] After the cavity temperature reaches the sixth temperature range, reduce the gas purge flow rate at RF coil 201 to 2000-2100 sccm (e.g., 2000 sccm), while keeping the purge flow rate constant at other purge locations. Continue heating and wait 1-2 minutes.

[0108] When the temperature inside the cavity is in the seventh temperature range, proceed to the next step.

[0109] For example, the seventh temperature range is 1040-1060°C. For instance, by controlling the power of the radio frequency coil 201, the temperature inside the reaction chamber can be raised to above 1040°C within 1 minute.

[0110] Step 7: Keep the cavity atmosphere unchanged, reduce the power of the radio frequency coil, and lower the cavity temperature to the eighth temperature range.

[0111] The power of the control radio frequency coil 201 is reduced from 88% of the rated power to 50% of the rated power. The heat is carried away by the cooling water in the cavity sidewall, which reduces the cavity temperature until the cavity temperature drops to the eighth temperature range.

[0112] During this cooling process, the gas purge flow rate at RF coil 201 is increased to 4000-4100 sccm (e.g., 4000 sccm), while the purge flow rate remains unchanged at other locations.

[0113] For example, the eighth temperature range is 900-920°C. For instance, by controlling the power of the radio frequency coil 201, the temperature inside the reaction chamber can be reduced to below 920°C.

[0114] Step 8: Switch the cavity atmosphere while keeping the RF coil power unchanged, so that the cavity temperature rises to the ninth temperature range.

[0115] Switch the internal atmosphere from H2 to N2, adjust the ratio of air output from each air outlet in the stacked air outlet 206 to G5:G4:G3:G2:G1 = 20%:20%:20%:20%:20%, and adjust the total air output of the stacked air outlet 206 to 14000-15000 sccm (e.g., 14000 sccm).

[0116] The power of the RF coil 201 is kept constant, the cavity pressure is maintained in the first pressure range, and the cavity temperature is waited for to rise to the ninth temperature range.

[0117] During this heating process, the purge flow rate at the top cover 208 increases to 2500-2600 sccm (e.g., 2500 sccm), the purge flow rate at the RF coil 201 increases to 10000-11000 sccm (e.g., 10000 sccm), and the purge flow rate at the edge exhaust port 210 decreases to 2000-2100 sccm (e.g., 2000 sccm).

[0118] For example, the ninth temperature range is 970-990°C. For instance, the temperature inside the reaction chamber can be increased to 980°C by controlling the power of the radio frequency coil 201.

[0119] For example, the intracavitary pressure can be maintained within a first pressure range of 100-110 mbar, such as 100 mbar.

[0120] After the temperature rises to the ninth temperature range, wait for the atmosphere inside the reaction chamber to be completely switched to N2, and then proceed to step 503.

[0121] 503, the reaction product obtained by etching the surface of a graphite disk with Cl2.

[0122] In this embodiment of the disclosure, step 503 may include: introducing a mixture of Cl2 and N2 gas into the reaction chamber and gradually increasing the concentration of Cl2, and etching the reaction products on the surface of the graphite disk within a set time period.

[0123] By introducing a mixture of Cl2 and N2 gas into the reaction chamber, the reaction products on the surface of the graphite disk are removed by Cl2 etching. At the same time, the concentration of Cl2 is gradually increased to ensure the etching effect on the reaction products.

[0124] For example, the above steps can be completed using the following process:

[0125] Step 1: Keep the internal temperature (e.g., 980℃) and pressure (e.g., 100mbar) constant, and open the first Cl2 valve for pre-flow.

[0126] Open the first Cl2 valve to pre-circulate Cl2 into the gas delivery channel; at this time, Cl2 does not enter the cavity. At this point, the total flow rate in the gas delivery channel at Cl2 outlet 207 is set to 5300-5400 sccm (e.g., 5300 sccm), with Cl2 accounting for 2% and the remainder being N2.

[0127] Among them, the proportion of air volume of each air outlet in the stacked air outlet 206 remains unchanged as G5:G4:G3:G2:G1.

[0128] The second step is to open the second Cl2 valve and introduce Cl2 into the cavity to etch the reaction products on the surface of the graphite disk.

[0129] The second valve for Cl2 is opened, allowing Cl2 to enter the reaction chamber. The flow rate at the Cl2 outlet 207 is 5300-5400 sccm (e.g., 5300 sccm), with Cl2 comprising 2% and the remainder being N2. When the mass flow meter (MFM) detects that the Cl2 concentration in the chamber exceeds the first threshold, the Cl2 flow rate is increased to 5% of the flow rate at the Cl2 outlet 207 within a first time period. Subsequently, within a second time period, the Cl2 in the chamber is used to etch the reaction products on the surface of the graphite disk.

[0130] For example, the first threshold may be 600 ppm.

[0131] For example, the first time interval can be 8-10 seconds, for instance, the first time interval can be 10 seconds.

[0132] For example, the second time can be in the range of 8-10 minutes, for instance, the second time can be 8 minutes.

[0133] In this embodiment, the first valve can be the Vent valve or Line valve of the MOCVD equipment, which is responsible for controlling the gas pre-flow; the second valve can be the Run valve of the MOCVD equipment, which is responsible for controlling the gas inflow.

[0134] The third step is to finish Cl2 etching, increase the temperature inside the cavity, and decrease the pressure inside the cavity.

[0135] The Cl2 flow rate is reduced to 0. At this point, the power of RF coil 201 is maintained at 50% of its rated power. The cavity temperature is increased to the tenth temperature range, and the cavity pressure is decreased to the second pressure range. When the MFM detects that the Cl2 concentration in the cavity is below the second threshold, the second and first valves for Cl2 are closed.

[0136] For example, the tenth temperature range can be 1000-1050°C, for example, raising the cavity temperature to 1000°C.

[0137] For example, the second pressure range can be 65-75 mbar, such as reducing the intracavitary pressure to 70 mbar.

[0138] For example, the second threshold could be 30 ppm.

[0139] 504, the reaction chamber is purged with N2 and NH3 and then baked.

[0140] For example, step 504 can be implemented using the following process:

[0141] The first step is to increase the temperature inside the cavity, decrease the pressure inside the cavity, and introduce N2.

[0142] The power of RF coil 201 remains at 50% of its rated power, waiting for the cavity temperature to rise to the eleventh temperature range and for the cavity pressure to rise to the third pressure range.

[0143] For example, the eleventh temperature range can be 1230-1250°C, such as raising the cavity temperature to 1250°C.

[0144] For example, the third pressure range can be 50-55 mbar, such as reducing the pressure to 50 mbar.

[0145] During this heating and pressurization period, the total gas output of the stacked outlet 206 increases to 50,000-51,000 sccm (e.g., 50,000 sccm), the gas output from the stacked outlet is N2, and the proportion of gas output from each outlet in the stacked outlet 206 is adjusted to G5:G4:G3:G2:G1 = 25%:12%:26%:12%:25%.

[0146] During this heating and pressurization period, the purge flow rate at the top cover 208 increases to 5000-5100 sccm (e.g., 5000 sccm), the purge flow rate at the edge exhaust port 210 increases to 3600-3700 sccm (e.g., 3600 sccm), and the purge flow rate at the RF coil 201 decreases to 5000-5100 sccm (e.g., 5000 sccm).

[0147] The second step is to lower the temperature inside the cavity, maintain the pressure inside the cavity within the third pressure range, and then introduce NH3.

[0148] Open the first NH3 valve, increasing the NH3 flow rate from 0 to 30,000-31,000 sccm (e.g., 30,000 sccm) within the third time interval. Lower the chamber temperature to the twelfth temperature range, maintaining the chamber pressure within the third pressure range. Then open the second NH3 valve, introducing NH3 into the chamber. Proceed with the baking process, waiting for the fourth time interval to complete the baking. During this process, the total flow rate at the stacked outlet 206 is 50,000 sccm, and the N2 flow rate, excluding NH3, is controlled at 20,000 sccm.

[0149] For example, the twelfth temperature range is 1130-1150°C, for example, reducing the cavity temperature to 1150°C.

[0150] For example, the range of the third time can be 20-25 seconds, for instance, the third time can be 20 seconds.

[0151] For example, the range of the fourth time can be 5-7 minutes, such as 5 minutes.

[0152] 505, Adjust the cavity environment to prepare for the second Cl2 etching.

[0153] Before performing the second Cl2 etching, the cavity environment needs to be readjusted.

[0154] When adjusting the intracavitary environment, step 502 can be repeated, or only step 8 in step 502 can be repeated to adjust the intracavitary environment to be consistent with the environment described in step 8 of step 502.

[0155] 506, the reaction products generated by the second etching of the graphite disk surface using Cl2.

[0156] Repeat step 503.

[0157] 507. The reaction chamber is then purged with N2 and NH3 and baked for the second time.

[0158] Repeat step 504 to complete the second Cl2 etching.

[0159] It is worth noting that if there are more Cl2 etchings, then the contents of steps 505, 506, and 507 are repeated sequentially after step 507.

[0160] 508, under an H2 atmosphere at 900-1050℃, a MO source and a nitrogen source are introduced to deposit Mg-doped Al. x Ga y In 1-x-y N.

[0161] The MO sources include Mg (Cp2Mg), Ga (TMGa), In (TMIn), and Al (TMAl). The nitrogen source is NH3.

[0162] In an H2 atmosphere at 900-1050℃, it is more conducive to the growth of Mg-doped Al. x Ga y In 1-x-y N growth.

[0163] In this embodiment of the disclosure, step 508 may include:

[0164] The first step is to switch the gas inside the chamber to H2, lower the temperature inside the chamber, and keep the pressure inside the chamber within the third pressure range.

[0165] The atmosphere inside the chamber is switched to H2, the temperature inside the chamber is adjusted to the thirteenth temperature range, and the pressure inside the chamber is increased to the fourth pressure range.

[0166] For example, the thirteenth temperature range can be 900-1000℃, such as 950℃.

[0167] For example, the fourth pressure range can be 500-700 mbar, such as 500 mbar.

[0168] By controlling the intracavitary pressure within the fourth pressure range, it is more beneficial for Al doped with Mg within the cavity. x Ga y In 1-x-y N growth.

[0169] During this process, the air volume ratio of each air outlet in the stacked air outlet 206 is adjusted to G5:G4:G3:G2:G1 = 20%:20%:20%:20%:20%, the flow rate of the stacked air outlet 206 is 20000 sccm, the purge flow rate at the top cover 208 is reduced to 3000-3100 sccm (e.g., 3000 sccm), the purge flow rate at the edge exhaust port 210 is increased to 2500-2600 sccm (e.g., 2500 sccm), and the purge flow rate at the RF coil 201 is reduced to 10000-11000 sccm (e.g., 10000 sccm).

[0170] The atmosphere transition time in the first step can be 2 minutes.

[0171] The second step is to open the first valves of the MO source and nitrogen source for pre-flow.

[0172] Under the cavity environment described in the first step, open the first valves for Cp2Mg, TMGa, TMIn, TMAl, and NH3 for pre-flow. At this time, the MO source and nitrogen source are located in the gas delivery pipeline and are not introduced into the cavity, for 2-3 minutes.

[0173] For example, the Cp2Mg flow rate is in the range of 2500-3500 sccm, for instance, the Cp2Mg flow rate can be 3000 sccm.

[0174] For example, the TMGa flow rate is in the range of 40-60 sccm, for instance, the TMGa flow rate can be 50 sccm.

[0175] For example, the TMIn flow rate is in the range of 700-900 sccm, for instance, the TMIn flow rate can be 800 sccm.

[0176] For example, the TMA1 flow rate is in the range of 50-70 sccm, for instance, the TMA1 flow rate can be 60 sccm.

[0177] For example, the NH3 flow rate is in the range of 20,000-30,000 sccm, for instance, the NH3 flow rate can be 25,000 sccm.

[0178] Using flow rates within the aforementioned range, introducing both the MO and nitrogen sources, is more beneficial for Al doping with Mg within the cavity. x Ga y In 1-x-y N growth.

[0179] The second step of switching and stabilization takes 2 minutes.

[0180] The third step is to open the second valve of part of the MO source and introduce it into the cavity.

[0181] Open the second valves for Cp2Mg, TMGa and TMIn for 2-5 minutes. At this time, the atmosphere in the chamber is H2 and the MO source carrier gas is H2.

[0182] Fourth step: Open the second valve of the remaining MO source and let it into the cavity.

[0183] Keep the second valves of Cp2Mg, TMGa and TMIn open, and simultaneously open the second valve of TMAl for 5-10 minutes.

[0184] Fifth step, close the second valve of TMA1 and open the second valve of NH3.

[0185] Close the second valve of TMA1, open the second valve of NH3, and introduce NH3 into the cavity for 5-30 minutes.

[0186] Step 6: Close the valves of the MO source and nitrogen source to increase the temperature inside the chamber.

[0187] Close the second valve and the first valve for Cp2Mg, TMGa, TMIn, TMAl, and NH3, and wait for the temperature inside the chamber to rise to the fourteenth temperature range for 2-5 minutes.

[0188] For example, the fourteenth temperature range can be 1000-1050°C, such as raising the cavity temperature to 1000°C.

[0189] During this step, the pressure inside the reaction chamber remains constant, that is, it remains within the fourth pressure range.

[0190] In this implementation, introducing the MO source and nitrogen source into the cavity according to the above steps is more conducive to the growth of Mg-doped Al. x Ga y In 1-x-y N.

[0191] 509, in the deposition of Al x Ga y In 1-x-y After N, the pressure and temperature of the reaction chamber are reduced.

[0192] Lowering the temperature and pressure inside the cavity facilitates the subsequent growth of the epitaxial layer.

[0193] For example, step 508 may include:

[0194] The first step is to increase the pressure inside the cavity to the fifth pressure range and decrease the temperature inside the cavity.

[0195] Turn off the RF coil 201, increase the cavity pressure to the fifth pressure range, reduce the cavity temperature, and wait for the cavity temperature to drop below the third threshold.

[0196] For example, the fifth pressure range can be 140-160 mbar, such as increasing the intracavitary pressure to 150 mbar.

[0197] For example, the third threshold can be 500°C.

[0198] During this period, the purge flow rate at top cover 208 is reduced to 1000-1100 sccm (e.g., 1000 sccm), the purge flow rate at edge exhaust port 210 is reduced to 1000-1100 sccm (e.g., 1000 sccm), the purge flow rate at radio frequency coil 201 is reduced to 2000-2100 sccm (e.g., 2000 sccm), the gas output at stacked exhaust port 206 is reduced to 500-600 sccm (e.g., 500 sccm), and the total gas volume of the planetary disk is maintained at 5000-6000 sccm (e.g., 5000 sccm).

[0199] The second step is to switch the atmosphere inside the chamber to N2 and close all gas supply valves.

[0200] Switch the atmosphere inside the chamber from H2 to N2, and close all gas source and MO source valves inside the chamber, waiting for the temperature inside the chamber to drop below the fourth threshold.

[0201] For example, the fourth threshold can be 450°C.

[0202] The third step is to set the purging flow rate of all purging devices in the cavity to 10% of the maximum value and wait for the temperature to drop to the fifteenth temperature range.

[0203] For example, the fifteenth temperature range can be 380-420°C, for instance, reducing the cavity temperature to 400°C.

[0204] Lowering the temperature and pressure inside the reaction chamber by following the above steps is more conducive to stabilizing the internal environment and providing an environment for subsequent epitaxial growth.

[0205] Figure 6 This is a schematic diagram of experimental data provided in an embodiment of this disclosure. See also... Figure 6 Within the same equipment, the parameters of the epitaxial wafers grown after cavity cleaning are determined by using the cavity cleaning method in related technologies and the MOCVD equipment cavity cleaning method in this solution in the preceding and subsequent furnace cycles.

[0206] See Figure 6 It is understood that, in the same equipment, epitaxial wafers are grown after cleaning using the methods provided in this disclosure and related technologies. Among them, Figure 6 The data for the two sets of epitaxial wafers with furnace number EPG01-692 are data for epitaxial wafers grown after using the cavity cleaning method in the relevant technology. The data for the two sets of epitaxial wafers with furnace number EPG01-692 are data for epitaxial wafers grown after using the cavity cleaning method in this scheme.

[0207] exist Figure 6In the comparative experiment shown, to ensure the accuracy of the experimental results, two epitaxial wafers were randomly selected from each furnace for testing. One wafer underwent only X-ray diffraction (XRD) and photoluminescence (PL) testing, while the other wafer underwent X-ray diffraction (XRD), electroluminescence (EL) testing, and photoluminescence (PL) testing.

[0208] See Figure 6 As can be seen, the quality of the underlying epitaxial crystal is measured using an X-ray diffraction analyzer, and is expressed as an integrated count value. This is used for cross-sectional comparison between samples; a higher value indicates relatively poorer crystal quality. Here, 002 and 102 refer to different crystal orientations. Electroluminescence brightness is obtained using an electroluminescence analyzer, and is expressed as an integrated intensity. This is also used for cross-sectional comparison between samples. The peak emission intensity and emission strength under photoluminescence testing are obtained by integrating the blackbody radiation formula after measurement using the photoluminescence analyzer, and are also used for cross-sectional comparison between samples.

[0209] based on Figure 6 The data from this disclosure, using the method provided, shows no significant changes in the superlattice thickness, wavelength, and half-width of the epitaxial wafer compared to related technologies. However, the emitted light intensity and peak intensity are somewhat improved, indicating a certain improvement in the quantum efficiency within the MQW. This improved quantum efficiency means an increase in the overlap rate of the acceptor and donor wavefunctions within the MQW. The peak intensity and emitted light intensity under photoluminescence testing are the integral intensity of the light intensity received by the sensor, representing relative values ​​of light intensity. The higher the relative intensity to a reference, the higher the quantum efficiency.

[0210] 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 of cleaning a chamber of a MOCVD apparatus, the method comprising: The method comprises: After the epitaxial growth is completed, the reaction product on the surface of the graphite disc is etched by circulating Cl2, in the process, the Cl2 also reacts with MgO and Mg-doped GaN in the reaction chamber, destroying the Mg environment in the reaction chamber; depositing Al x Ga y In 1-x-y N in the reaction chamber under a Mg-rich H2 atmosphere x Ga y In 1-x-y N microstructure on the inner wall of the reaction chamber and the surface of the graphite disc, reconstructing the Mg environment in the reaction chamber, wherein 0≤x≤1, 0≤y≤1.

2. The method of claim 1, wherein, The reaction product on the surface of the graphite disc is etched by circulating Cl2, in the process, the Cl2 also reacts with MgO and Mg-doped GaN in the reaction chamber, destroying the Mg environment in the reaction chamber; The temperature in the reaction chamber is raised and purged; The reaction product on the surface of the graphite disc is etched by Cl2; The reaction chamber is purged by N2 and NH3 and baked; The above steps are repeated.

3. The method of claim 2, wherein, The reaction product on the surface of the graphite disc is etched by Cl2, in the process, the Cl2 also reacts with MgO and Mg-doped GaN in the reaction chamber, destroying the Mg environment in the reaction chamber; Cl2 and N2 mixed gas is introduced into the reaction chamber, and the concentration of Cl2 is gradually increased, and the reaction product on the surface of the graphite disc is etched within a set time.

4. The method according to any one of claims 1 to 3, characterized in that, Deposition of Al in a reaction chamber under an H2 atmosphere rich in Mg x Ga y In 1-x-y N, comprising: In the H2 atmosphere at 900-1050°C, the MO source and nitrogen source are introduced to deposit Mg-doped Al x Ga y In 1-x-y N.

5. The method of claim 4, wherein, The H2 atmosphere at 900-1050℃, the MO source and nitrogen source are introduced, and the Mg-doped Al is deposited x Ga y In 1-x-y N, comprising: At 900-1000℃ in the H2 atmosphere, the first valve of Cp2Mg is opened, the second valve is closed; the first valve of TMGa is opened, the second valve is closed; the first valve of TMIn is opened, the second valve is closed; the first valve of TMAl is opened, the second valve is closed; the first valve of NH3 is opened, the second valve is closed; for 2-3 minutes; The second valves of Cp2Mg, TMGa and TMIn are opened, for 2-5 minutes; The second valves of Cp2Mg, TMGa and TMIn are kept open, and the second valve of TMAl is opened, for 5-10 minutes; The second valve of TMAl is closed, and the second valve of NH3 is opened, and NH3 is introduced, for 5-30 minutes; The second valves and first valves of Cp2Mg, TMGa, TMIn, TMAl and NH3 are closed, the temperature is raised to 1000-1050℃, and the process is continued for 2-5 minutes.

6. The method of claim 5, wherein, The flow rate of Cp2Mg is 2500-3500sccm, the flow rate of TMGa is 40-60sccm, the flow rate of TMIn is 700-900sccm, the flow rate of TMAl is 50-70sccm, and the flow rate of NH3 is 20000-30000sccm.

7. The method of claim 4, wherein, The Al x Ga y In 1-x-y The pressure in the reaction chamber during N deposition was 500-700 mbar.

8. The method according to any one of claims 1 to 3, characterized in that, The method further comprises: After depositing the Al x Ga y In 1-x-y N, the pressure and temperature of the reaction chamber are reduced.

9. The method of claim 8, wherein, The pressure and temperature of the reaction chamber are reduced, comprising: The pressure of the reaction chamber is reduced to 140-160mbar; When the temperature of the reaction chamber is reduced to below 500℃, the atmosphere in the reaction chamber is switched from H2 to N2; When the temperature of the reaction chamber is reduced to below 450℃, the purge in the reaction chamber is set to 10% of the maximum value, and the temperature of the reaction chamber is reduced to below 400℃.

10. A method for manufacturing an LED, characterized in that, The LED preparation method comprises the method of any one of claims 1 to 9.

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