Method for restarting pvd-aln machine after maintenance

Abstract

The present application relates to physical vapor deposition process, especially to the PVD-AlN machine maintenance after the method of re-computer. The re-computer method, including the following steps S1: setting the cavity temperature is 780~820 DEG C and 630~670 DEG C in turn for baking;S2: keep the cavity temperature is 630~670 DEG C, two times into argon and nitrogen, the second time into argon and nitrogen when setting Source DC is 2800~3200;S3: continue to pass into argon and nitrogen, the temperature drops to 450~550 DEG C. The re-computer method, let the cavity of PVD-AlN machine in 780~820 DEG C and 630~670 DEG C in turn for baking, two times of baking removes the moisture and impurities of the cavity respectively;Again continue to pass into argon and nitrogen to remove the organic compounds in the cavity and cooling to 450~550 DEG C.

Description

Technical Field

[0001] This invention relates to physical vapor deposition processes, and more particularly to a method for reactivating a PVD-AlN equipment after maintenance. Background Technology

[0002] Gallium nitride (GaN) has become a representative of third-generation semiconductor materials due to its stable chemical properties, good thermal stability, and high-temperature resistance. Various substrate materials are used to fabricate light-emitting diodes (LEDs), with sapphire being the earliest and most widely used substrate. However, there is a significant lattice and thermal mismatch between sapphire and GaN. Using an aluminum nitride (AlN) buffer layer can greatly reduce interstructional dislocations and enhance the crystal structure. Therefore, in LED structures, a sapphire substrate needs to be placed in a physical vapor deposition (PVD) device, and an AlN buffer layer needs to be grown on it using magnetron sputtering technology.

[0003] During the operation of PVD-AlN equipment, regular maintenance is required to ensure normal system function. Chinese invention patent CN101328571B discloses a physical vapor deposition apparatus and its maintenance method. During maintenance, the equipment is first cleaned, then baked at >100℃ in a nitrogen atmosphere. Currently, common PVD-AlN machine maintenance requires every two weeks. Each maintenance requires opening the cover to clean the Al target and cleaning and replacing the process components in the reaction chamber. After maintenance, one to two batches of dummy wafers (test-grade silicon wafers) are needed for restarting the machine. This restart method wastes manpower and resources, incurring significant costs. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a method for resuming PVD-AlN machine maintenance, which can effectively reduce production costs.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for resuming operation of a PVD-AlN machine after maintenance, comprising the following steps:

[0006] S1: Set the cavity temperature to 780~820℃ and 630~670℃ sequentially for baking;

[0007] S2: Maintain the cavity temperature at 630-670℃, and introduce argon and nitrogen gas in two separate cycles. When introducing argon and nitrogen gas for the second time, set the Source DC (base elevation height) to 2800-3200.

[0008] S3: Continuously introduce argon and nitrogen gas to lower the temperature to 450-550℃.

[0009] The beneficial effects of this invention are as follows: The PVD-AlN machine re-processing method of this invention involves sequentially baking the chamber at 780–820°C and 630–670°C to remove moisture and impurities from the chamber. Then, argon and nitrogen are continuously introduced to remove organic compounds and other deposits from the chamber, followed by cooling to 450–550°C. Using this re-processing method, AlN growth can be performed in the first batch after maintenance. Compared to the conventional one- to two-time dummy wafer deposition re-processing method, this effectively saves manpower, electricity, and time, and reduces production costs. Attached Figure Description

[0010] Figure 1 The image shown is a physical diagram of the PVD-AlN machine used in Embodiment 1 and Comparative Example 1 of the present invention. Detailed Implementation

[0011] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0012] The most crucial concept of this invention is that the cavity is baked at 780–820°C and 630–670°C in sequence, with the two baking processes removing moisture and impurities from the cavity respectively; then argon and nitrogen are continuously introduced to remove organic compounds and other deposits from the cavity and cool it down to 450–550°C.

[0013] The method for resuming operation of a PVD-AlN machine after maintenance according to the present invention includes the following steps:

[0014] S1: Set the cavity temperature to 780~820℃ and 630~670℃ sequentially for baking;

[0015] S2: Maintain the chamber temperature at 630-670℃, and introduce argon and nitrogen in two separate cycles. When introducing argon and nitrogen for the second time, set the Source DC to 2800-3200.

[0016] S3: Continuously introduce argon and nitrogen gas to lower the temperature to 450-550℃.

[0017] As described above, the beneficial effects of this invention are as follows: The PVD-AlN machine re-processing method of this invention involves sequentially baking the cavity at 780–820°C and 630–670°C to remove moisture and impurities. Then, argon and nitrogen are continuously introduced to remove organic compounds and other deposits from the cavity, followed by cooling to 450–550°C to prevent moisture from the air from re-entering the cavity. A robotic arm can then be used to handle tray placement and removal, allowing for vapor deposition. Using this re-processing method, AlN growth can be performed in the first batch after maintenance. Compared to the conventional one- to two-time dummy wafer deposition re-processing methods, this effectively saves manpower, electricity, and time, reducing production costs.

[0018] At different set temperatures, impurities of different components can be removed. In S1, the chamber temperature is first set to 780-820°C. Baking at this temperature causes the AlN deposits on the chamber cover to fall off. Then, the chamber temperature is set to 630-670°C to pre-treat the subsequent gas introduction.

[0019] The first introduction of argon and nitrogen into S2 saturates the atmosphere inside the cavity. When argon and nitrogen are introduced for the second time, the Source DC is set to 2800-3200. Under this condition, argon will cause plasma to form inside the cavity. Ions will bombard the target material and knock atoms onto the surface to form a sputtered film, thereby removing the deposits.

[0020] Furthermore, the flow rate of argon in S2 and S3 is 25–35 sccm, and the flow rate of nitrogen is 170–190 sccm.

[0021] As can be seen from the above description, nitrogen can nitrid the atoms on the target surface, and the introduction of argon gas causes the argon to be ionized by electrons and become the target for impact, which is then sputtered out by the target material; changes in the flow rates of argon and nitrogen gas will lead to differences in the quality of ALN film formation.

[0022] Furthermore, S1 specifically involves: first raising the cavity temperature to 780–820°C and maintaining it for 20–30 minutes; then lowering the cavity temperature to 630–670°C and maintaining it for 10–12 minutes.

[0023] As can be seen from the above description, S3 removes moisture from the cavity at 780–820℃ and removes AlN deposits and other impurities from the cavity cover at 630–670℃.

[0024] Furthermore, S2 specifically refers to:

[0025] S21: Maintain the chamber temperature at 630-670℃ and continuously introduce argon and nitrogen gas for 10-12 minutes;

[0026] S22: Set the Source DC to 2800-3200, maintain the chamber temperature at 630-670℃, and continuously introduce argon and nitrogen gas for 30-35 minutes.

[0027] As can be seen from the above description, when argon and nitrogen are introduced into S2 for the second time, the Source DC is set to 2800-3200. Under this condition, argon will cause plasma to form in the cavity, and ions will bombard the target material, knocking atoms onto the surface to form a sputtered film, thereby removing the deposits.

[0028] Furthermore, the cooling time for S3 is 5–10 minutes.

[0029] As can be seen from the above description, slow cooling can prevent moisture from re-entering the cavity.

[0030] Furthermore, before setting the temperature in S1, nitrogen gas is first introduced into the chamber for cyclic purging, and then the chamber is evacuated.

[0031] As can be seen from the above description, the dust inside the cavity is first removed by blowing, and then a vacuum process is performed to confirm the sealed environment of the cavity and ensure the qualification of the hardware.

[0032] Embodiment 1 of the present invention is as follows:

[0033] The method for resuming operation of a PVD-AlN machine after maintenance includes the following steps:

[0034] S1: Nitrogen gas is introduced into the chamber for 3 cycles of purging;

[0035] S2: Open the leak detector to the vacuum valve to evacuate the cavity;

[0036] S3: Without introducing gas, first raise the temperature of the chamber to 800℃ and hold for 25 minutes; then lower the temperature of the chamber to 650℃ and hold for 11 minutes.

[0037] S4: Maintain the chamber temperature at 650℃ and continuously introduce argon and nitrogen gas for 11 minutes;

[0038] S5: Set Source DC to 3000, maintain the chamber temperature at 650℃, and continuously introduce argon and nitrogen gas for 33 minutes;

[0039] S6: Turn off Source DC, continuously introduce argon and nitrogen, and lower the temperature to 500℃ after 7 minutes.

[0040] In the above steps, the flow rate of argon is 30 sccm and the flow rate of nitrogen is 180 sccm.

[0041] Embodiment 2 of the present invention is as follows:

[0042] The method for resuming operation of a PVD-AlN machine after maintenance includes the following steps:

[0043] S1: Nitrogen gas is introduced into the chamber for 3 cycles of purging;

[0044] S2: Open the leak detector to the vacuum valve to evacuate the cavity;

[0045] S3: Without introducing gas, first raise the chamber temperature to 780℃ and maintain it for 30 minutes; then lower the chamber temperature to 630℃ and maintain it for 12 minutes.

[0046] S4: Maintain the chamber temperature at 630℃ and continuously introduce argon and nitrogen gas for 12 minutes;

[0047] S5: Set Source DC to 2800, maintain the chamber temperature at 630℃, and continuously introduce argon and nitrogen gas for 35 minutes;

[0048] S6: Turn off Source DC, continuously introduce argon and nitrogen, and lower the temperature to 550℃ after 5 minutes.

[0049] In the above steps, the flow rate of argon is 25 sccm and the flow rate of nitrogen is 190 sccm.

[0050] Embodiment 3 of the present invention is as follows:

[0051] The method for resuming operation of a PVD-AlN machine after maintenance includes the following steps:

[0052] S1: Nitrogen gas is introduced into the chamber for 3 cycles of purging;

[0053] S2: Open the leak detector to the vacuum valve to evacuate the cavity;

[0054] S3: Without introducing gas, first raise the chamber temperature to 820℃ and maintain it for 20 minutes; then lower the chamber temperature to 670℃ and maintain it for 12 minutes.

[0055] S4: Maintain the chamber temperature at 670℃ and continuously introduce argon and nitrogen gas for 10 minutes;

[0056] S5: Set Source DC to 3200, maintain the chamber temperature at 670℃, and continuously introduce argon and nitrogen gas for 30 minutes;

[0057] S6: Turn off Source DC, continuously introduce argon and nitrogen, and lower the temperature to 450℃ after 10 minutes.

[0058] In the above steps, the flow rate of argon is 35 sccm and the flow rate of nitrogen is 170 sccm.

[0059] Comparative Example 1 of the present invention is:

[0060] A single dummy-assisted deposition reprocessing method includes the following steps:

[0061] S1: No gas is introduced, allowing the temperature inside the chamber to reach the set temperature of 470℃ and maintain this temperature for 75 minutes;

[0062] S2: Gradual heating is carried out inside the cavity, with each gradient unit being 24°C, raising the temperature to 650°C.

[0063] S3: Maintain the set temperature of 650℃ in the cavity and continuously introduce 200 sccm of argon gas for 10 minutes;

[0064] S4: Keep the temperature inside the chamber constant, introduce 15 sccm of argon and 90 sccm of nitrogen, maintaining the ratio of argon to nitrogen at 6:1, and simultaneously introduce 2 sccm of oxygen for 80 minutes.

[0065] S5: Perform a 7-minute cooling phase to lower the temperature to 500℃.

[0066] Six iTops A320 PVD-AlN machines were used (see...) Figure 1 After running for half a month, the machines were cleaned and maintained. After cleaning, the three PVD-AlN machines were re-run using the re-running method of Example 1, and the three PVD-AlN machines were re-run using the re-running method of Comparative Example 1. Then, the costs were compared.

[0067] The power cost of the re-running method in Example 1 is 45-48% of that in Comparative Example 1, saving at least 52% of the power. The re-running method in Example 1 uses 14% more nitrogen than Comparative Example 1, but consumes 80-85% less argon, resulting in an overall gas cost reduction of approximately 60-75%.

[0068] In summary, the PVD-AlN machine re-engineering method provided by this invention first removes dust from the chamber by purging and then performs vacuuming to ensure a sealed environment and guarantee hardware quality. The chamber is then baked sequentially at 780–820°C and 630–670°C to remove moisture and impurities. Argon and nitrogen are then introduced twice: the first introduction saturates the chamber, and the second removes organic compounds and other deposits. The temperature is then lowered to 450–550°C to prevent moisture from re-entering the chamber, allowing for tray handling by a robotic arm for vapor deposition. This re-engineering method allows AlN growth to begin immediately after maintenance, significantly reducing labor, electricity, and time compared to conventional two-dummy deposition re-engineering methods, thus lowering production costs.

[0069] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for resuming operation of a PVD-AlN machine after maintenance, characterized in that, Includes the following steps: S1: First, raise the cavity temperature to 780~820℃ and maintain it for 20~30 minutes; then lower the cavity temperature to 630~670℃ and maintain it for 10~12 minutes. S2: Maintain the cavity temperature at 630~670℃, and introduce argon and nitrogen gas in two separate steps. When introducing argon and nitrogen gas for the second time, set the base to move upward at a height of 2800~3200. S3: Continuously introduce argon and nitrogen gas to lower the temperature to 450~550℃.

2. The method for resuming operation of a PVD-AlN machine after maintenance according to claim 1, characterized in that, The flow rate of argon in S2 and S3 is 25~35 sccm, and the flow rate of nitrogen is 170~190 sccm.

3. The method for resuming operation of a PVD-AlN machine after maintenance according to claim 1, characterized in that, Specifically, S2 is: S21: Maintain the chamber temperature at 630~670℃ and continuously introduce argon and nitrogen gas for 10~12 minutes; S22: Set the base to move upward to a height of 2800~3200, maintain the cavity temperature at 630~670℃, and continuously introduce argon and nitrogen gas for 30~35 minutes.

4. The method for resuming operation of a PVD-AlN machine after maintenance according to claim 1, characterized in that, The cooling time of S3 is 5~10 minutes.

5. The method for resuming operation of a PVD-AlN machine after maintenance according to claim 1, characterized in that, Before setting the temperature in S1, nitrogen gas is first introduced into the chamber for cyclic purging, and then the chamber is evacuated.

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