Method for restoring a grill after maintenance

Abstract

The present application relates to the field of semiconductor equipment, in particular to a kind of oven maintenance after reinstallation method.The reinstallation method, the reaction cavity of high-temperature oven is adjusted to the following state in turn: temperature is 360 ℃, 20 ~ 40 min N2 is introduced into the reaction cavity;Temperature is 560 ~ 600 ℃, 100 ~ 140 min N2 is introduced into the reaction cavity;Programmed temperature is raised to 820 ~ 860 ℃, after each temperature rise, 8 min N2 is introduced into the reaction cavity;Temperature is 1100 ~ 1200 ℃, 40 ~ 50 min N2 / H2 Mixed gas is introduced into the reaction cavity;Temperature is 1200 ~ 1300 ℃, 30 ~ 40 min N2 / H2 Mixed gas is introduced into the reaction cavity;Temperature is 1400 ~ 1450 ℃, 4 ~ 5 h N2 / H2 Mixed gas is introduced into the reaction cavity;N2 is introduced to reduce temperature, and the duration of temperature reduction process is 1 ~ 1.5 h.The reinstallation method is processed by water vapor first, then Al-Ga and the rest of organic complex are processed, and the first oven after maintenance can realize baking tray production.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor equipment, and in particular to a method for restoring a baking oven after maintenance. Background Art

[0002] During the epitaxial wafer production process, the wafer is often placed on a graphite disk and grown using the MOCVD method. During epitaxial growth, chemicals are deposited on both the epitaxial wafer and the disk. To remove these deposits, a high-temperature oven is used to bake the disk, making it recyclable and preventing surface deposits from affecting epitaxial growth. However, as baking progresses, impurities such as Ga complexes and dust are generated in the oven. Therefore, regular cleaning and maintenance of the oven are necessary to ensure cleanliness during baking.

[0003] Currently, the most common cleaning method is to clean every ten ovens. After cleaning and maintenance of high-temperature ovens, two empty ovens (without graphite trays) are usually required. This empty oven removes moisture, Al-Ga, and other organic matter generated during maintenance. However, this empty oven process often wastes a lot of manpower and electricity, increasing production costs. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a method for resuming a baking oven for baking graphite discs after maintenance, which can effectively reduce production costs.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for resuming the operation of an oven after maintenance, comprising the following steps:

[0006] S1: Set the reaction chamber temperature of the oven to 360°C and introduce N2 into the reaction chamber for 20 to 40 minutes;

[0007] S2: Set the reaction chamber temperature to 560-600°C and introduce N2 into the reaction chamber for 100-140 minutes;

[0008] S3: gradually increase the temperature of the reaction chamber to 820-860°C, and introduce N2 into the reaction chamber for 8 minutes after each temperature increase;

[0009] S4: Set the reaction chamber temperature to 1100-1200°C and introduce N2 / H2 mixed gas into the reaction chamber for 40-50 minutes;

[0010] S5: Set the reaction chamber temperature to 1200-1300°C and introduce N2 / H2 mixed gas into the reaction chamber for 30-40 minutes;

[0011] S6: Setting the reaction chamber temperature to 1400-1450°C, and introducing N2 / H2 mixed gas into the reaction chamber for 4-5 hours;

[0012] S7: N2 is introduced into the reaction chamber to cool it down, and the cooling process lasts for 1 to 1.5 hours. The beneficial effects of the present invention are as follows: The functions of the steps in the method for restoring a baking oven after maintenance are as follows: S1: creating a vacuum in the furnace; S2 and S3: removing moisture from the furnace; S4: removing 60% of the Al-Ga organic complex; S5: eliminating the Al-Ga organic complex in the clean chamber; and S6: improving the surface cleanliness of the graphite disk. This method of first treating moisture and then removing the Al-Ga organic complex allows baking tray production to begin in the first batch after maintenance, eliminating the need for two dry bakes to remove moisture and organic matter generated during maintenance, which wastes significant manpower and electricity, effectively reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Shown is an oven according to a specific embodiment of the present invention. DETAILED DESCRIPTION

[0014] To illustrate the technical content, achieved objectives and effects of the present invention in detail, the following is a description of the embodiments and accompanying drawings.

[0015] The most critical concept of the present invention is to first treat the water vapor and then treat the Al-Ga and other organic complexes, so that the first furnace can produce baking trays after maintenance.

[0016] A method for restoring an oven after maintenance according to the present invention comprises the following steps:

[0017] S1: Set the reaction chamber temperature of the oven to 360°C and introduce N2 into the reaction chamber for 20 to 40 minutes;

[0018] S2: Set the reaction chamber temperature to 560-600°C and introduce N2 into the reaction chamber for 100-140 minutes;

[0019] S3: gradually increase the temperature of the reaction chamber to 820-860°C, and introduce N2 into the reaction chamber for 8 minutes after each temperature increase;

[0020] S4: Set the reaction chamber temperature to 1100-1200°C and introduce N2 / H2 mixed gas into the reaction chamber for 40-50 minutes;

[0021] S5: Set the reaction chamber temperature to 1200-1300°C and introduce N2 / H2 mixed gas into the reaction chamber for 30-40 minutes;

[0022] S6: Setting the reaction chamber temperature to 1400-1450°C, and introducing N2 / H2 mixed gas into the reaction chamber for 4-5 hours;

[0023] S7: N2 is introduced into the reaction chamber to cool it down. The cooling process lasts for 1 to 1.5 hours.

[0024] As can be seen from the above description, the beneficial effects of the present invention are as follows: first, a low-temperature bake in S1 is performed to create a vacuum in the furnace environment, then a continuous bake is performed at 560-600°C for approximately 1 hour, and the reaction chamber temperature is gradually raised to 820-860°C, during which N2 is intermittently introduced to remove moisture in the furnace; an N2 / H2 mixed gas is introduced twice, at 1100-1200°C and 1200-1300°C, to decompose the Al-Ga organic complex; and then the plate is baked at a high temperature of 1400-1450°C to improve the surface cleanliness of the graphite plate. This method of first treating moisture and then removing the Al-Ga organic complex allows the first batch of baking to be started after maintenance, eliminating the problem of having to perform two empty bakes to remove moisture and organic matter generated during maintenance, which wastes a lot of manpower and electricity, and effectively reduces production costs.

[0025] If the cooling annealing time of S7 is too short, it will lead to excessive thermal stress and structural stress. The slow cooling process of 1 to 1.5 hours can not only ensure the stability of the performance of the graphite disk during the cooling process, but also ensure that the gas in the cavity is consumed.

[0026] The baking oven referred to in the present invention is a baking oven used to remove deposits on the surface of a graphite disk.

[0027] Furthermore, S3 includes the following steps:

[0028] S31: The temperature of the reaction chamber is raised to 680-720°C, and N2 is introduced into the reaction chamber for 8 minutes;

[0029] S32: The temperature of the reaction chamber is raised to 720-760°C, and N2 is introduced into the reaction chamber for 8 minutes;

[0030] S33: The temperature of the reaction chamber is raised to 820-860°C, and N2 is introduced into the reaction chamber for 8 minutes;

[0031] As can be seen from the above description, each gradient of the temperature rising stage S3 lasts for 8 minutes, which is used to further remove water vapor from the cavity.

[0032] Furthermore, the flow rate of N2 is 18 to 22 L / min.

[0033] From the above description, it can be seen that the flow rate of nitrogen will affect the gas flow field in the cavity and determine the intensity of the disk being purged per unit time. N2 plays the role of a reactant that purges the disk surface and also acts as a protective gas.

[0034] Furthermore, the flow rate of the N2 / H2 mixed gas is 30 to 40 L / min.

[0035] Furthermore, the volume percentage of N2 in the N2 / H2 mixed gas is 20 to 50%.

[0036] From the above description, it can be seen that in the N2 / H2 mixed gas, N2 is used as a protective gas and H2 is used as a corrosive gas, and the compounds on the surface of the graphite disk are cleaned by high temperature and hydrogen corrosion under high temperature.

[0037] Furthermore, the pressure of the reaction chambers in S1 to S3 is 2.5-3.5 Torr.

[0038] Furthermore, the pressure of the reaction chamber in S4 to S6 is 0.8-1.2 Torr.

[0039] From the above description, it can be seen that the pressure drop in the reaction chamber from S4 to S6 is conducive to further improving the vacuum degree in the chamber and facilitating the entry of hydrogen.

[0040] The first embodiment of the present invention is a method for restoring an oven after maintenance, comprising the following steps:

[0041] S1: Set the reaction chamber temperature of the oven to 360°C and the pressure to 3 Torr, and introduce N2 at 20 L / min into the reaction chamber for 30 minutes.

[0042] S2: Set the reaction chamber temperature to 580°C and the pressure to 3 Torr, and introduce N2 at 20 L / min into the reaction chamber for 120 min.

[0043] S31: The temperature of the reaction chamber is raised to 700°C and the pressure is 3 Torr. N2 is introduced into the reaction chamber at a flow rate of 20 L / min for 8 minutes.

[0044] S32: The temperature of the reaction chamber is raised to 740°C, the pressure is 3 Torr, and N2 is introduced into the reaction chamber at a flow rate of 20 L / min for 8 minutes.

[0045] S33: The temperature of the reaction chamber is raised to 840°C, the pressure is 3 Torr, and N2 is introduced into the reaction chamber at a flow rate of 20 L / min for 8 minutes.

[0046] S4: The reaction chamber temperature was set to 1150°C and the pressure to 1 Torr. A N2 / H2 mixed gas was introduced into the reaction chamber at a rate of 35 L / min for 45 minutes. The volume percentage of N2 in the N2 / H2 mixed gas was 35%.

[0047] S5: The reaction chamber temperature was set to 1250°C and the pressure to 1 Torr. A N2 / H2 mixed gas was introduced into the reaction chamber at a rate of 35 L / min for 35 minutes. The volume percentage of N2 in the N2 / H2 mixed gas was 35%.

[0048] S6: The reaction chamber temperature was set to 1425°C and the pressure to 1 Torr. A N2 / H2 mixed gas was introduced into the reaction chamber at a rate of 35 L / min for 4.5 hours. The volume percentage of N2 in the N2 / H2 mixed gas was 35%.

[0049] S7: N2 is introduced into the reaction chamber to cool it down, and the cooling process lasts for 1.25 hours.

[0050] A second embodiment of the present invention is a method for restoring an oven after maintenance, comprising the following steps:

[0051] S1: Set the reaction chamber temperature of the oven to 360°C and the pressure to 2.5 Torr, and introduce 18 L / min of nitrogen into the reaction chamber for 20 minutes.

[0052] S2: Set the reaction chamber temperature to 560°C and the pressure to 2.5 Torr, and introduce N2 at 18 L / min into the reaction chamber for 100 min.

[0053] S31: The temperature of the reaction chamber is raised to 680°C, the pressure is 2.5 Torr, and 18 L / min of N2 is introduced into the reaction chamber for 8 minutes.

[0054] S32: The reaction chamber temperature is raised to 720°C, the pressure is 2.5 Torr, and N2 is introduced into the reaction chamber at a flow rate of 18 L / min for 8 minutes.

[0055] S33: The temperature of the reaction chamber is raised to 820°C, the pressure is 2.5 Torr, and N2 is introduced into the reaction chamber at a flow rate of 18 L / min for 8 minutes.

[0056] S4: The reaction chamber temperature was set to 1100°C and the pressure to 0.8 Torr. A N2 / H2 mixed gas was introduced into the reaction chamber at a flow rate of 30 L / min for 40 min. The volume percentage of N2 in the N2 / H2 mixed gas was 20%.

[0057] S5: The reaction chamber temperature was set to 1200°C and the pressure to 0.8 Torr. A N2 / H2 mixed gas was introduced into the reaction chamber at a rate of 30 L / min for 30 min. The volume percentage of N2 in the N2 / H2 mixed gas was 20%.

[0058] S6: The reaction chamber temperature was set to 1400°C and the pressure to 0.8 Torr. A N2 / H2 mixed gas was introduced into the reaction chamber at a flow rate of 30 L / min for 4 hours. The volume percentage of N2 in the N2 / H2 mixed gas was 20%.

[0059] S7: N2 is introduced into the reaction chamber to cool it down, and the cooling process lasts for 1 hour.

[0060] A third embodiment of the present invention is a method for restoring an oven after maintenance, comprising the following steps:

[0061] S1: Set the reaction chamber temperature of the oven to 360°C and the pressure to 3.5 Torr, and introduce N2 at 22 L / min into the reaction chamber for 40 min.

[0062] S2: Set the reaction chamber temperature to 600°C and the pressure to 3.5 Torr, and introduce N2 at 22 L / min into the reaction chamber for 140 min.

[0063] S31: The temperature of the reaction chamber is raised to 720°C, the pressure is 0.5 Torr, and 22 L / min of N2 is introduced into the reaction chamber for 8 minutes;

[0064] S32: The temperature of the reaction chamber is raised to 760°C, the pressure is 3.5 Torr, and N2 is introduced into the reaction chamber at 22 L / min for 8 minutes.

[0065] S33: The reaction chamber temperature is raised to 860°C, the pressure is 3.5 Torr, and N2 is introduced into the reaction chamber at a flow rate of 22 L / min for 8 minutes.

[0066] S4: The reaction chamber temperature was set to 1200°C and the pressure to 1.2 Torr. A N2 / H2 mixed gas was introduced into the reaction chamber at a rate of 40 L / min for 50 min. The volume percentage of N2 in the N2 / H2 mixed gas was 50%.

[0067] S5: The reaction chamber temperature was set to 1300°C and the pressure to 1.2 Torr. A N2 / H2 mixed gas was introduced into the reaction chamber at a rate of 40 L / min for 40 min. The volume percentage of N2 in the N2 / H2 mixed gas was 50%.

[0068] S6: The reaction chamber temperature was set to 1450°C and the pressure to 1.2 Torr. A N2 / H2 mixed gas was introduced into the reaction chamber at a rate of 40 L / min for 5 hours. The volume percentage of N2 in the N2 / H2 mixed gas was 50%.

[0069] S7: N2 is introduced into the reaction chamber to cool it down, and the cooling process lasts for 1.5 hours.

[0070] Comparative Example 1 of the present invention is: empty baking with two furnaces, the specific steps are:

[0071] S1: Set the reaction chamber of the oven to gradually heat up to 560-600°C;

[0072] S2: Set the reaction chamber temperature to 560-600°C and introduce 22 L / min N2 into the reaction chamber for 100-140 min;

[0073] S3: gradually raising the temperature of the reaction chamber to 700-800°C and introducing N2 into the reaction chamber for 100-120 minutes;

[0074] S5: Set the reaction chamber temperature to 800-850°C and introduce N2 into the reaction chamber for 160-170 minutes;

[0075] S6: Set the reaction chamber temperature to 850-880°C and introduce N2 into the reaction chamber for 6-7 hours;

[0076] S7: Cooling process is performed, and the cooling process lasts for 30 minutes;

[0077] S8: Repeat S1 to S7 to complete the baking of two ovens.

[0078] Ovens 1 to 3 (model HBM-1000G, see Figure 1 After ten ovens were baked, the ovens were opened to inspect the graphite components. The front and rear doors were removed, and the entire oven was cleaned of compound using a metal spatula. After cleaning, ovens 1 and 2 were reassembled using the reassembly methods of Examples 1 and 2, respectively. After cleaning, oven 3 was reassembled using the reassembly method of Comparative Example 1. The costs for the two reassembly methods are shown in Table 1.

[0079] Table 1

[0080] Example 1 Example 2 Comparative Example 1 electricity costs 19％ 20％ 100％ Ventilation costs 40％ 41％ 100％

[0081] As shown in Table 1, the cost of the present invention's reconditioning method is only about 30% of that of Comparative Example 1. Compared to the Example, Comparative Example 1 lacks the low-temperature baking stage to create a vacuum in the furnace. Water vapor and Al-Ga complexes are removed together, and no staged separation of the different substances is performed. Only nitrogen is introduced as a protective gas throughout the process. This method requires two empty bakes after reconditioning before the graphite disk can be baked. Otherwise, a small amount of Al-Ga complexes will remain on the surface of the graphite disk, which is costly.

[0082] In summary, the restoration method provided by the present invention first uses a low-temperature bake in S1 to create a vacuum in the furnace environment, then continuously bakes at 560-600°C for approximately 1 hour, gradually raising the reaction chamber temperature to 820-860°C while intermittently introducing N2 to remove moisture from the furnace. An N2 / H2 mixed gas is introduced twice, at 1100-1200°C and again at 1200-1300°C, to decompose the Al-Ga organic complex. The disc is then baked at a high temperature of 1400-1450°C to improve the surface cleanliness of the graphite disc. This method of first treating moisture and then removing the Al-Ga organic complex allows disc production to begin in the first batch after maintenance, eliminating the need for two dry bakes to remove moisture and organic matter generated during maintenance, which wastes significant manpower and electricity, effectively reducing production costs.

[0083] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's description and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for restoring an oven after maintenance, characterized in that: The following steps are involved: S1: Set the reaction chamber temperature of the oven to 360°C and introduce N2 into the reaction chamber for 20 to 40 minutes; S2: Set the reaction chamber temperature to 560-600°C and introduce N2 into the reaction chamber for 100-140 minutes; S3: gradually increase the temperature of the reaction chamber to 820-860°C, and introduce N2 into the reaction chamber for 8 minutes after each temperature increase; S4: Set the reaction chamber temperature to 1100-1200°C and introduce N2 / H2 mixed gas into the reaction chamber for 40-50 minutes; S5: Set the reaction chamber temperature to 1200-1300°C and introduce N2 / H2 mixed gas into the reaction chamber for 30-40 minutes; S6: Setting the reaction chamber temperature to 1400-1450°C, and introducing N2 / H2 mixed gas into the reaction chamber for 4-5 hours; S7: N2 is introduced into the reaction chamber to cool it down. The cooling process lasts for 1 to 1.5 hours.

2. The method for restoring an oven after maintenance according to claim 1, characterized in that: The S3 includes the following steps: S31: The temperature of the reaction chamber is raised to 680-720°C, and N2 is introduced into the reaction chamber for 8 minutes; S32: The temperature of the reaction chamber is raised to 720-760°C, and N2 is introduced into the reaction chamber for 8 minutes; S33: The temperature of the reaction chamber is raised to 820-860°C, and N2 is introduced into the reaction chamber for 8 minutes.

3. The method for restoring an oven after maintenance according to claim 1, characterized in that: The flow rate of N2 is 18-22 L / min.

4. The method for restoring an oven after maintenance according to claim 1, characterized in that: The flow rate of the N2 / H2 mixed gas is 30-40 L / min.

5. The method for restoring an oven after maintenance according to claim 1, characterized in that: The volume percentage of N2 in the N2 / H2 mixed gas is 20-50%.

6. The method for restoring an oven after maintenance according to claim 1, characterized in that: The pressure of the reaction chambers in S1 to S3 is 2.5-3.5 Torr.

7. The method for restoring an oven after maintenance according to claim 1, characterized in that: The pressure of the reaction chambers in S4 to S6 is 0.8-1.2 Torr.

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