Diffusion method and diffusion device

Abstract

A diffusion method, comprising: a pre-step, involving: feeding a plurality of carrying apparatuses into a process chamber, each carrying apparatus carrying a plurality of devices to be processed, and executing a pre-operation; a blowing step, involving: introducing a set gas to blow the inside of the process chamber, so as to maintain an atmosphere inside the process chamber; a deposition step, involving: introducing a reaction gas to perform a reaction inside the process chamber, and controlling a pressure change inside the process chamber, with a change amount being ΔP; a cyclic determination step, involving: cyclically executing the blowing step and the deposition step, and determining whether the number of cycles of the blowing step and the deposition step is greater than or equal to a set number of times, and if the number of cycles of the blowing step and the deposition step is greater than or equal to the set number of times, executing a post-step below, wherein the set number of times is greater than 1; and the post-step, involving: executing a post-operation on the deposited devices to be processed. The solution can improve the diffusion uniformity of devices to be processed of carrying apparatuses on at least some positions inside a process chamber. To this end, further provided in the present application is a diffusion device.

Description

Diffusion method and diffusion device

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on November 20, 2023, with application number 2023115428124 and invention name “A Diffusion Method and Diffusion Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of photovoltaic cells, and in particular to a diffusion method and a diffusion device. Background Art

[0003] In the manufacturing field of Thin Oxide Passivated Contact (TOPCon) cells, the manufacturing process can be roughly divided into texturing, boron diffusion, and alkaline polishing. Among them, the purpose of boron diffusion is to make a PN junction, which is also called the heart of the solar cell and has an important impact on the performance of the solar cell.

[0004] The main process of boron diffusion occurs in a high-temperature furnace tube. When the temperature is raised to the reaction temperature, a reaction gas (a certain proportion of boron source, oxygen, and nitrogen) can be introduced into the high-temperature furnace tube. The reaction gas reacts to generate a single boron substance, which adheres to the surface of the device to be processed. As the temperature continues to rise, the single boron substance on the surface can be pushed into the interior of the device to be processed to form a PN junction. In conventional technology, in order to improve production efficiency, multiple rows of devices to be processed are usually set up in the high-temperature furnace tube so that boron diffusion can be carried out on multiple rows of devices to be processed simultaneously. However, due to the high temperature inside the high-temperature furnace tube, boron oxide exists in liquid form, which can easily lead to uneven distribution. In particular, the uniformity of boron diffusion to the devices to be processed near the outlet of the air inlet pipe and the inlet of the exhaust pipe will be low, resulting in performance differences among the devices to be processed in the same batch. Not only is it difficult to meet the requirements of use, but it also affects product quality and increases production costs.

[0005] Therefore, how to provide a solution to overcome or alleviate the above-mentioned defects is still a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0006] The purpose of this application is to provide a diffusion method that can improve the diffusion uniformity of the device to be processed at least partially within the process chamber, thereby improving the product consistency of the device to be processed after the diffusion process. To this end, this application also provides a diffusion device.

[0007] In order to solve the above technical problems, the present application provides a diffusion method, including: a pre-step, sending multiple carrying devices into the process chamber, each of the carrying devices carries multiple devices to be processed, and performing pre-operation; a purge step, introducing a set gas to purge the inside of the process chamber to maintain the atmosphere inside the process chamber; a deposition step, introducing a reaction gas to react inside the process chamber and control the pressure change inside the process chamber, the change amount is ΔP; a cyclic judgment step, cyclically executing the purge step and the deposition step, and judging whether the number of cycles of the purge step and the deposition step is greater than or equal to the set number, if so, executing the following post-step, the set number is greater than 1; a post-step, performing post-operation on the devices to be processed after deposition.

[0008] In the above scheme, the deposition step is specifically performed under the condition of pressure change, which can change the flow characteristics of the reaction gas inside the process chamber, and thus improve the diffusion uniformity of the components to be processed of the carrier device at at least part of the position inside the process chamber. In particular, the diffusion uniformity of the components to be processed of the carrier device near the outlet of the air inlet pipe or near the inlet of the air outlet pipe is greatly improved, which is conducive to improving the product consistency of the components to be processed after the diffusion process.

[0009] A pressure change includes a pressure increase or a pressure decrease.

[0010] When the pressure is increased, the reaction gas will accumulate at the outlet when flowing from the outlet of the air inlet pipe to the inlet of the air outlet pipe, and then slowly diffuse to other positions in the process chamber, so that the components to be processed of the carrier device near the outlet of the air inlet pipe and the reaction gas can get more sufficient contact, and then more sufficient reaction deposition and diffusion can be carried out, which is beneficial to improving the diffusion effect of the components to be processed of the carrier device near the outlet of the air inlet pipe.

[0011] When the pressure drops, the air flow resistance inside the process chamber is relatively small, the reaction gas can flow to the inlet of the outlet pipe more quickly, and the reaction gas and the components to be processed of the carrier device near the inlet of the outlet pipe can also react more fully, which is beneficial to improving the diffusion effect of the components to be processed of the carrier device near the inlet of the outlet pipe.

[0012] Optionally, the process chamber is provided with an air inlet pipe and an air outlet pipe, and the control of the pressure change inside the process chamber is specifically achieved by adjusting the flow rate of the air inlet pipe and / or the air outlet pipe.

[0013] Optionally, the ΔP is 15 mbar-30 mbar.

[0014] Optionally, the set number of times is 2-4 times.

[0015] Optionally, in at least two adjacent deposition steps, the temperature of the next deposition step is higher than that of the previous deposition step.

[0016] Optionally, the post-operation includes: a pushing step, controlling the process chamber to maintain a set pushing temperature and a set pushing pressure for a set time.

[0017] Optionally, the post-operation further includes: a post-oxidation step, controlling the temperature in the process chamber to rise to a post-oxidation temperature, controlling the pressure in the process chamber to rise to a post-oxidation pressure, and introducing an oxidant, such as oxygen.

[0018] Optionally, the post-operation further includes a cooling process, a pressure return process and a boat discharge process.

[0019] Optionally, the pre-operation includes a pressure pumping process, a leak detection process, a temperature rising process, a constant temperature process and a pre-oxidation process.

[0020] Optionally, the diffusion method is used for boron diffusion.

[0021] A diffusion device includes a process chamber, an air inlet pipe and an air outlet pipe, and is characterized in that it also includes a processor and a memory storing a computer program, and the processor implements the diffusion method described above when executing the computer program. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG1 is a schematic structural diagram of a process chamber;

[0023] FIG2 is a schematic diagram of the process of the diffusion method provided in this application;

[0024] FIG. 3 is a schematic diagram of a specific diffusion process of FIG. 2 .

[0025] The following are the descriptions of the reference numerals:

[0026] 100 process chamber, 110 carrying device, 111 device to be processed, 120 air inlet pipe, 130 air outlet pipe. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the technical solution of the present application, the present application is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] In the description of the embodiments of the present application, the term "plurality" refers to two or more than two. Furthermore, when "plurality" is used to describe the number of different components, it does not indicate the relationship between the quantities of these components.

[0029] In the description of the embodiments of the present application, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0030] In the embodiments of this application, "and / or" is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0031] Please refer to FIG1 , which is a schematic structural diagram of a process chamber.

[0032] As shown in FIG. 1 , a diffusion process such as boron diffusion is usually performed inside a process chamber 100 , which is a reaction container, such as a quartz furnace tube.

[0033] The process chamber 100 may contain multiple carriers 110, each of which is used to carry multiple devices 111 to be processed, so that multiple devices 111 to be processed can be processed simultaneously, thereby improving the efficiency of the diffusion process. The devices 111 to be processed can specifically be devices to be subjected to the diffusion process, such as silicon wafers.

[0034] Each carrier 110 can enter and exit the process chamber 100 to facilitate the entry and exit of the device 111 to be processed in and out of the process chamber 100. The manner in which each carrier 110 enters and exits the process chamber 100 is not limited herein. In practical applications, those skilled in the art may configure it based on specific circumstances, as long as it meets the requirements of use. For example, the carrier 110 may be a quartz boat, which enters and exits the process chamber 100 via a quartz boat support and a silicon carbide paddle.

[0035] The process chamber 100 is further equipped with an air inlet pipe 120 and an air outlet pipe 130. The air inlet pipe 120 is used to introduce gas into the process chamber 100, while the air outlet pipe 130 is used to extract gas from the process chamber 100. Both the air inlet pipe 120 and the air outlet pipe 130 are equipped with pumps for adjusting the opening and closing of the air inlet pipe 120 and the air outlet pipe 130 and adjusting the flow rate.

[0036] In the implementation shown in FIG1 , ten carriers 110 are disposed within the process chamber 100. From left to right, the ten carriers 110 can be designated as ①, ②, ③, ④, ⑤, ⑥, ⑦, ⑧, ⑨, and ⑩. Device ① is located near the outlet of the inlet pipe 120, and device ⑩ is located near the inlet of the outlet pipe 130. The side of device ① can be referred to as the rear end of the process chamber 100, and the side of device ⑩ can be referred to as the head end of the process chamber 100.

[0037] Taking boron diffusion as an example, the main characteristics of boron diffusion are square resistance, junction depth and passivation effect. The latter two are rarely tested in normal mass production. Therefore, the quality of the diffusion performance mainly depends on square resistance. As the name suggests, square resistance is the square resistance. Strictly speaking, a battery cell has only one square resistance. However, in actual production, only a small square resistance of a certain area can be tested. Therefore, multiple points on the device to be processed 111 can be tested, and the uniformity (or convergence) of the square resistance values ​​of multiple points can be judged to characterize the effect of boron diffusion.

[0038] In actual production, affected by the air intake and exhaust, the boron oxide droplets generated by the reaction gas stay for a short time at the outlet of the air inlet pipe 120 and the inlet of the air outlet pipe 130, and cannot fully diffuse to the device to be processed 111, resulting in poor uniformity of the square resistance of the device to be processed 111 on device No. ① or device No. 10. In particular, compared with the devices to be processed 111 on other supporting devices 110, the square resistance uniformity of the devices to be processed 111 at the upper and lower ends of devices No. ① and No. 10 is significantly different.

[0039] Table 1: Square resistance values ​​of devices to be processed in the upper, middle and lower areas of device ①

[0040] As shown in Table 1 above, in conventional technology, the intra-chip uniformity of the devices 111 to be processed in the upper, middle and lower regions of device No. ① is basically around 19%, and the device uniformity reaches 11.10%.

[0041] It should be noted that the "mean" in the table refers to the average value of the square resistance measured at each test point, that is, (square resistance at test point 1 + square resistance at test point 2 + square resistance at test point 3 + square resistance at test point 4 + square resistance at test point 5) / 5; "intra-chip uniformity" refers to [(the maximum square resistance measured at each test point - the minimum square resistance measured at each test point) / (2*mean)]*100%; "device mean" refers to the average value of the upper, middle and lower means, that is, (mean of the upper part + mean of the middle part + mean of the lower part) / 3; "device uniformity" refers to [(the maximum value among the means - the minimum value among the means) / (2*device mean)]*100%.

[0042] To this end, an embodiment of the present application provides a diffusion method, which changes the flow characteristics of the reaction gas inside the process chamber 100 by changing the pressure inside the process chamber 100 during the deposition step, thereby significantly improving the square resistance uniformity of each device to be processed 111 in the aforementioned device No. ① or device No. 10, thereby improving the diffusion effect and the product consistency of the device to be processed after the diffusion process.

[0043] Please refer to FIG. 2 and FIG. 3 , FIG. 2 is a flow chart of the diffusion method provided in this application, and FIG. 3 is a process chart of a specific diffusion process of FIG. 2 .

[0044] As shown in FIG. 2 , in the embodiment of the present application, the diffusion method includes a pre-step S1 , a purge step S2 , a deposition step S3 , a cycle determination step S4 , and a post-step S5 .

[0045] The pre-step S1 may also be referred to as a preparation step, which may be to send a plurality of carriers 110 into the process chamber 100 , each carrier 110 carrying a plurality of devices to be processed 111 , and perform pre-operations.

[0046] As shown in FIG3 , in some implementations, the pre-step S1 may include a preparation process, a boat loading process, and pre-operations, and the pre-operations may include a pressure pumping process, a leak detection process, a temperature rising process, a constant temperature process, and a pre-oxidation process.

[0047] The preparation process is a process for adjusting the temperature, pressure and atmosphere in the process chamber 100, wherein the temperature is 800℃~1100℃, the pressure is 100mbar~800mbar, nitrogen or other inert gas, such as argon, is introduced, and the flow rate of nitrogen is 2000~30000sccm.

[0048] In the implementation shown in FIG3 , the temperature can be adjusted to 800°C, and nitrogen can be introduced into the process chamber 100 through the inlet pipe 120 at a flow rate of 5000 sccm, while the outlet pipe 130 is closed. It should be noted that the "1060" in FIG3 indicates that the pressure in the process chamber is 1060 mbar, which is greater than 1 standard atmosphere, and also indicates that the outlet pipe is closed.

[0049] The boat-entering process is a process for the carrier devices 110 to enter, and is used to deliver each carrier device 110 into the process chamber 100; the temperature and nitrogen flow rate of the boat-entering process can be consistent with those of the preparation process.

[0050] The decompression process involves removing gas from process chamber 100 to adjust the pressure within chamber 100. During this process, inlet pipe 120 can be closed. In the implementation shown in FIG3 , after decompression, the pressure within chamber 100 can be 100 mbar, and the temperature within chamber 100 can be controlled to rise to 830°C.

[0051] The leak detection process is a process for checking whether the process chamber 100 has leaks. In this process, the air inlet pipe 120 and the air outlet pipe 130 can be closed, and the temperature can be kept consistent with the pressure reduction process.

[0052] During the aforementioned boat loading process, pressure reduction process, and leak detection process, there may be a temperature drop phenomenon. Therefore, after the leak detection process, a temperature increase process 1 and a constant temperature process may be performed to raise and maintain the temperature inside the process chamber 100. In the implementation method of Figure 3, the temperature inside the process chamber 100 can be maintained at 830°C, the pressure can be maintained at 150mbar, and nitrogen gas can be introduced into the process chamber 100 at a flow rate of 5000sccm to ensure the atmosphere inside the process chamber 100, thereby ensuring the safety of the gas supply system and the purity of the reaction gas used. It can also ensure that the amount of reaction gas used is in an appropriate proportion, such as the proportion of boron trichloride (BCl3) in boron trichloride (BCl3), oxygen (O2), and nitrogen (N2) in boron diffusion, so as to meet the reaction conditions and ensure product quality.

[0053] The pre-oxidation process may occur after the constant temperature process, and specifically involves introducing an oxidant, such as oxygen, into the process chamber 100 to form an oxide layer on the surface of the device to be processed 111. In the implementation shown in FIG3 , oxygen may be introduced into the process chamber 100 in a nitrogen atmosphere, wherein the flow rates of both oxygen and nitrogen may be 4000 sccm.

[0054] As shown in FIG2 , the purge step S2 specifically involves introducing a set gas into the process chamber 100 for purge to maintain the atmosphere inside the process chamber 100 ; and the purge before introducing the reaction gas (e.g., boron trichloride) into the process chamber 100 can also clean the pipeline, and the purge after introducing the reaction gas can blow away the remaining reaction gas in the pipeline and bring the reaction gas out of the process chamber 100 to ensure the effect of the diffusion process and the quality of the product.

[0055] The above-mentioned setting gas can be nitrogen, or other inert gases, such as argon. In the implementation of Figure 3, nitrogen can be introduced into the process chamber 100 at a flow rate of 3000 seem. The temperature of the first purge and the last purge is consistent with the temperature of the previous step, and the temperature of the intermediate purge is consistent with the temperature of the subsequent step. For example, the temperature of the purge step 1 is consistent with the temperature of the previous oxidation step, which is 830°C, and the temperature of the purge step 3 is consistent with the temperature of the deposition step 3, which is 850°C.

[0056] As shown in FIG2 , the deposition step S3 may specifically be to introduce a reactive gas into the process chamber 100, where the reactive gas may react within the process chamber 100. At the same time, the pressure within the process chamber 100 is controlled to change by a value of ΔP, so that deposition is performed by varying the pressure. Preferably, ΔP is varied in an arithmetic gradient, which can improve the uniformity of the sheet resistance and the performance of the product, such as improving the photoelectric conversion efficiency of photovoltaic cells. It should be understood that the deposition performed by “varying the pressure” here means that the pressure changes during the execution of the deposition step S3, rather than performing deposition at a constant pressure.

[0057] Taking boron diffusion as an example, the above-mentioned reaction gases can specifically be a boron source (such as boron trichloride) and oxygen, and the diffusion process is carried out under a nitrogen atmosphere, wherein the flow rate of boron trichloride is 50 to 300 sccm, the flow rate of oxygen is 500 to 30,000 sccm, and the flow rate of nitrogen is 2,000 to 30,000 sccm; the boron source, oxygen, and nitrogen can be configured according to a set ratio. The specific value of the set ratio is not limited here. In the implementation of Figure 3, in the deposition step S3, nitrogen can be introduced into the process chamber 100 at a flow rate of 2,000 sccm, oxygen can be introduced into the process chamber 100 at a flow rate of 500 sccm, and boron chloride can be introduced into the process chamber 100 at a flow rate of 150 sccm, that is, boron source: oxygen: nitrogen = 3:10:40.

[0058] The pressure change inside the process chamber 100 may include a pressure increase or a pressure decrease; preferably, the pressure in the deposition step S3 may be adjusted within a range of 100 to 300 mbar.

[0059] When increasing the pressure, this can be achieved, for example, by reducing the flow rate of outlet pipe 130 or closing it. Referring to Figure 1 , under this operating condition, due to the reduced flow rate or closure of outlet pipe 130, the pressure within process chamber 110 increases from the pressure of the previous step to a pressure increased by ΔP. For example, Deposition 1 pressure = Purge 1 pressure + ΔP, and Deposition 3 pressure = Purge 3 pressure + ΔP. The reactant gas introduced from inlet pipe 120 accumulates at the rear of process chamber 100, i.e., at the outlet of inlet pipe 120, and then slowly diffuses outward. This allows each device 111 to be processed on apparatus 1 to come into contact with more reactant gas, allowing for more complete reactions, thereby improving the diffusion effect on each device 111 to be processed on apparatus 1. It should be understood that the Deposition 1 pressure and Deposition 3 pressure here refer to the pressure at the end of the corresponding deposition step. For each individual deposition step, such as Deposition 1, Deposition 2, or Deposition 3 in Figure 3 , the pressure changes by ΔP during execution.

[0060] When the pressure is reduced, for example, this can be achieved by increasing the flow rate of the gas outlet pipe 130. Referring to FIG1 , under this operating condition, the airflow resistance within the process chamber 100 can be relatively small, allowing the reactant gas to flow more quickly to device 10 and remain there, allowing for a more complete reaction with the components 111 to be processed on device 10.

[0061] It should be understood that the pressure change inside the process chamber 100 can also be achieved by adjusting the flow rate of the air inlet pipe 120, such as increasing the flow rate of the air inlet pipe to increase the pressure, or decreasing the flow rate of the air inlet pipe to reduce the pressure.

[0062] The above-mentioned change amount ΔP can specifically be 15mbar-30mbar, so that the time spent on the pressure change will be relatively short, which is conducive to improving the efficiency of the diffusion process. In the implementation of Figure 3, the above-mentioned change amount ΔP can be 20mbar.

[0063] In a loop determination step S4, the purge step S2 and the deposition step S3 are repeatedly executed, and it is determined whether the number of cycles of the purge step S2 and the deposition step S3 is greater than or equal to a set number. If so, the following post-step S4 is executed; the set number is greater than 1. In other words, the purge step S2 and the deposition step S3 can be repeated multiple times, thereby further improving the deposition effect and ensuring that the reaction proceeds fully.

[0064] The specific value of the above-mentioned set number of times is not limited here. In actual application, those skilled in the art can set it according to specific needs as long as it can meet the requirements of use; for example, the set number of times can be 2 to 4 times. In the implementation of Figure 3, the above-mentioned set number of times can be 3 times.

[0065] In different deposition steps S3, the temperature conditions may also be different. As shown in FIG3 , a temperature raising step 2 may be included after the first deposition step S3 to raise the temperature inside the process chamber 100. For example, during the first deposition, the temperature inside the process chamber 100 may be maintained at 830°C, and during the second and third depositions, the temperature may be 850°C. This is beneficial to improving the deposition effect of the subsequent deposition step S3.

[0066] In the post-processing step S5 , post-processing operations are performed on the device to be processed 111 after deposition.

[0067] In the implementation of FIG3 , the post-operation may include a temperature raising process, a pushing process, a post-oxidation process, a temperature lowering process, a back-pressure process, and a boat discharge process.

[0068] Temperature Rising Step 3 is used to further increase the temperature within process chamber 100 in preparation for subsequent steps. In the implementation shown in FIG3 , Temperature Rising Step 3 can raise the temperature to 980°C and the pressure within process chamber 100 to 600 mbar. Nitrogen is introduced into process chamber 100 at a flow rate of 5000 sccm.

[0069] The push process specifically involves maintaining a set push temperature and a set push pressure for a set time to increase the diffusion depth and push the boron atoms into the device to be processed 111, for example, pushing the boron atoms into the silicon wafer to form a PN junction. The length of the set time is determined according to process requirements and is not limited here. Taking boron diffusion as an example, after the aforementioned multiple deposition steps S3, boron can diffuse to approximately 1.0 micron from the surface of the device to be processed 111. At this point, the above-mentioned push process can further increase the boron diffusion depth. In the implementation of Figure 3, the set push temperature and set push pressure are both the conditions reached in the process chamber 100 after the temperature rise step 3, that is, the push process can be directly performed after the temperature rise step 3. In the implementation of Figure 3, the temperature of the push process can be 980°C, the pressure can be 600 mbar, and the nitrogen flow rate can be 5000 sccm.

[0070] The post-oxidation step involves controlling the temperature within process chamber 100 to a post-oxidation temperature, controlling the pressure within process chamber 100 to a post-oxidation pressure, and introducing oxygen to further enhance the diffusion depth. In the implementation shown in FIG3 , the post-oxidation temperature can be 1050° C., the post-oxidation pressure can be 700 mbar, and the oxygen flow rate can be 20,000 sccm.

[0071] The cooling process and the back-pressurization process are used to reduce the temperature and pressure inside the process chamber 100, and the boat-out process is used to realize the delivery of each carrier device 110 from the inside of the process chamber 100. At this time, the diffusion process is completed. In the implementation method of Figure 3, the temperature of the cooling process can be 800°C, the nitrogen flow rate can be 5000sccm, and the pressure can be 700mbar; the temperature of the back-pressurization process can be 800°C, the nitrogen flow rate can be 30000sccm; the temperature of the boat-out process can be 800°C, and the nitrogen flow rate can be 5000sccm.

[0072] As shown in Table 2 below, after the various process steps of the embodiment of the present application, the intra-chip uniformity of device No. ① is approximately 8%, and the device uniformity is 6.65%. Compared with the data in Table 1 above, after adopting the diffusion method provided by the present application, the intra-chip uniformity of the square resistance of device No. ① has been greatly improved.

[0073] Table 2 Square resistance values ​​of devices to be processed in the upper, middle and lower areas of device No. ①

[0074] To this end, the present application also provides a diffusion device, including a process chamber 100, an air inlet pipe 120 and an air outlet pipe 130, both of which are equipped with a pump body. It also includes a processor and a memory storing a computer program. When the processor executes the computer program, the diffusion method described above is implemented.

[0075] It should be understood that although the embodiments of the present application use boron diffusion as an example to illustrate the specific implementation process of the diffusion method provided in the present application, this does not mean that the diffusion method provided in the present application can only be applied to boron diffusion. It does not actually limit the type of reaction gas. In actual use, technical personnel in this field can make adjustments according to actual needs.

[0076] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A diffusion method, characterized in that: include: A pre-processing step, wherein a plurality of carriers are sent into the process chamber, each of the carriers carrying a plurality of devices to be processed, and a pre-processing operation is performed; A purging step, introducing a set gas to purge the interior of the process chamber to maintain the atmosphere inside the process chamber; The deposition step is to introduce a reaction gas to react inside the process chamber, and control the pressure change inside the process chamber, the change amount being ΔP; the pressure change is specifically a pressure increase or a pressure decrease; the deposition step is specifically performed under the condition of pressure change; a cycle determination step, cyclically executing the purging step and the deposition step, and determining whether the number of cycles of the purging step and the deposition step is greater than or equal to a set number, and if so, executing the following post-processing step, wherein the set number is greater than 1; A post-processing step is to perform post-processing operations on the device to be processed after the deposition is completed.

2. The diffusion method according to claim 1, characterized in that: The process chamber is provided with an air inlet pipe and an air outlet pipe, and the control of the pressure change inside the process chamber is specifically achieved by adjusting the flow rate of the air inlet pipe and / or the air outlet pipe.

3. The diffusion method according to claim 1, characterized in that: The ΔP is 15 mbar-30 mbar.

4. The diffusion method according to claim 1, characterized in that: The setting number of times is 2 to 4 times.

5. The diffusion method according to claim 1, characterized in that: In at least two adjacent deposition steps, the temperature of the next deposition step is higher than that of the previous deposition step.

6. The diffusion method according to any one of claims 1 to 5, characterized in that: The post-operation includes: The advancing step controls the process chamber to maintain a set advancing temperature and a set advancing pressure for a set time.

7. The diffusion method according to claim 6, characterized in that: The post-operation also includes: The post-oxidation step controls the temperature in the process chamber to rise to the post-oxidation temperature, controls the pressure in the process chamber to rise to the post-oxidation pressure, and introduces an oxidant.

8. The diffusion method according to claim 7, characterized in that: The post-operation also includes a temperature reduction process, a pressure return process and a boat discharge process.

9. The diffusion method according to any one of claims 1 to 5, characterized in that: The pre-operation includes a pressure extraction process, a leak detection process, a temperature increase process, a constant temperature process and a pre-oxidation process.

10. The diffusion method according to any one of claims 1 to 5, characterized in that: The diffusion method described is used for boron diffusion.

11. A diffusion device, comprising a process chamber, an air inlet pipe and an air outlet pipe, characterized in that: It also includes a processor and a memory storing a computer program, and when the processor executes the computer program, the diffusion method according to any one of claims 1 to 10 is implemented.

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