Epitaxial device and epitaxial layer forming method

Abstract

The invention relates to an epitaxial device and a forming method of an epitaxial layer. The epitaxial device comprises a growth assembly which at least comprises a plurality of growth chambers which are mutually independent, and the plurality of growth chambers are used for accommodating a substrate; the transmission structure is positioned outside the plurality of growth chambers and is used for transmitting the substrate among the plurality of growth chambers; the reaction gas transmission pipeline is communicated with the plurality of growth chambers and is used for transmitting reaction gas to the plurality of growth chambers, and the reaction gas is used for forming an epitaxial layer on the surface of the substrate; and the doping assembly comprises a plurality of doping structures located outside the growth assembly, the plurality of doping structures are communicated with the plurality of growth chambers one by one, and the plurality of doping structures are respectively used for transmitting a plurality of doping gases with different concentrations. According to the invention, multiple epitaxial layers with different electrical resistivity can be grown in the same machine, the epitaxial process is simplified, the epitaxial growth efficiency is improved, and the epitaxial cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing, and in particular to an epitaxial device and a method for forming an epitaxial layer. Background Art

[0002] Currently, the semiconductor integrated circuit (IC) industry has experienced exponential growth. Technological advances in IC materials and design have produced generations of ICs, each with smaller and more complex circuits than the previous generation. In the course of IC development, functional density (i.e., the number of interconnected devices per chip area) has generally increased, while geometry size (i.e., the smallest component that can be produced using a manufacturing process) has decreased. In addition to IC components becoming smaller and more complex, the wafers on which ICs are manufactured have become larger and larger, which places increasingly higher demands on the quality of the wafers.

[0003] As the demand for special device manufacturing continues to increase, the substrate formed by the epitaxial process has the advantages of low cost and low defects, and is therefore increasingly being used in the manufacture of special devices. Forming multiple epitaxial layers by epitaxial processes, and at least two of the multiple epitaxial layers have different resistivities, at least two of the epitaxial layers have different resistivity climbing curves, or at least two of the epitaxial layers have different resistivity transition zone curves, in order to meet the manufacturing needs of a variety of special devices, is a hot topic of current research. However, the current generation of multiple epitaxial layers with different resistivities requires multiple epitaxial processes, and requires switching different epitaxial growth machines for growth, which not only has low growth efficiency, but also high growth cost, which is not conducive to improving semiconductor process production efficiency and reducing production costs.

[0004] Therefore, how to simplify the process of generating multiple epitaxial layers with different resistivities, improve the growth efficiency of growing multiple epitaxial layers with different resistivities and reduce the production cost is a technical problem that needs to be solved urgently. Summary of the invention

[0005] The present invention provides an epitaxial device and a method for forming an epitaxial layer, which are used to simplify the process of generating multiple epitaxial layers with different resistivities, improve the growth efficiency of growing multiple epitaxial layers with different resistivities and reduce the production cost, so as to meet the manufacturing requirements of special devices.

[0006] According to some embodiments, the present invention provides an epitaxial device, comprising:

[0007] A growth assembly, comprising at least a plurality of growth chambers that are independent of each other, and each of the plurality of growth chambers is used to accommodate a substrate;

[0008] a transport structure, located outside the plurality of growth chambers, for transporting the substrate between the plurality of growth chambers;

[0009] A reaction gas transfer pipeline, which is connected to each of the plurality of growth chambers and is used to transfer reaction gases to the plurality of growth chambers respectively. The reaction gases are used to form an epitaxial layer on the surface of the substrate.

[0010] A doping component, including a plurality of doping structures located outside the growth component. The plurality of doping structures are in one-to-one communication with the plurality of growth chambers, and the plurality of doping structures are respectively used to transfer doping gases with various different concentrations.

[0011] In some embodiments, the growth component further includes:

[0012] A buffer chamber, located outside the plurality of growth chambers, and the buffer chamber is used to store and cool the substrate.

[0013] In some embodiments, one of the plurality of growth chambers is a first growth chamber, another one of the plurality of growth chambers is a second growth chamber, and yet another one of the plurality of growth chambers is a third growth chamber;

[0014] One of the plurality of doping structures is a first doping structure connected to the first growth chamber, another one of the plurality of doping structures is a second doping structure connected to the second growth chamber, and yet another one of the plurality of doping structures is a third doping structure connected to the third growth chamber. The concentration of the doping gas transferred by the first doping structure is greater than the concentration of the doping gas transferred by the second doping structure, and the concentration of the doping gas transferred by the second doping structure is greater than the concentration of the doping gas transferred by the third doping structure.

[0015] In some embodiments, the first doping structure includes a first transfer pipeline. One end of the first transfer pipeline is connected to a first doping source, and the other end is connected to the first growth chamber. The first doping source is used to store and supply a first doping gas;

[0016] The second doping structure includes a second transfer pipeline and a first mixer. The first mixer includes a first air inlet, a second air inlet, and a first air outlet. One end of the second transfer pipeline is connected to the first air outlet in the first mixer, and the other end is connected to the second growth chamber. The first air inlet in the first mixer is connected to a second doping source, and the second air inlet in the first mixer is connected to a dilution source. The second doping source is used to store and supply a second doping gas, and the dilution source is used to store and supply a dilution gas;

[0017] The third doping structure includes a third transfer pipeline, a second mixer, and a third mixer. The second mixer includes a third air inlet, a fourth air inlet, and a second air outlet. The third mixer includes a fifth air inlet, a sixth air inlet, and a third air outlet. One end of the third transfer pipeline is connected to the third air outlet and the other end is communicated with the third growth chamber. The fifth air inlet in the third mixer is connected to the second air outlet. The sixth air inlet in the third mixer is connected to a dilution source. The third air inlet in the second mixer is connected to a third doping source. The fourth air inlet in the second mixer is connected to the dilution source. The third doping source is used to store and supply a third doping gas.

[0018] In some embodiments, the types of the first doping gas, the second doping gas, and the third doping gas are the same, and the concentrations of the first doping gas in the first doping source, the second doping gas in the second doping source, and the third doping gas in the third doping source are the same.

[0019] In some embodiments, the doping assembly further includes a main dilution pipeline connected to the dilution source;

[0020] The second doping structure further includes a second doping source input pipeline and a first dilution branch pipeline. The second doping source input pipeline is connected to the first air inlet in the first mixer. One end of the first dilution branch pipeline is connected to the second air inlet in the first mixer and the other end is connected to the main dilution pipeline.

[0021] In some embodiments, the third doping structure further includes:

[0022] A third doping source input pipeline, connected to the third air inlet in the second mixer;

[0023] A second dilution branch pipeline, with one end connected to the fourth air inlet in the second mixer and the other end connected to the main dilution pipeline;

[0024] A third dilution branch pipeline, with one end connected to the sixth air inlet in the third mixer and the other end connected to the main dilution pipeline.

[0025] According to some other embodiments, the present invention further provides a method for forming an epitaxial layer, including the following steps:

[0026] Provide the epitaxial device as described above;

[0027] Select one of the plurality of growth chambers as a first growth chamber, and place a substrate into the first growth chamber through the transfer structure;

[0028] Transfer the reaction gas to the first growth chamber through the reaction gas transfer pipeline, and control the doping structure communicated with the first growth chamber to transfer the doping gas to the first growth chamber, so as to form a first epitaxial layer on the substrate;

[0029] Select another one of the plurality of growth chambers as the second growth chamber, and transfer the substrate with the first epitaxial layer formed thereon to the second growth chamber through the transfer structure;

[0030] Transfer the reaction gas to the second growth chamber through the reaction gas transfer pipeline, and control the doping structure communicated with the second growth chamber to transfer the doping gas to the second growth chamber, so as to form a second epitaxial layer above the first epitaxial layer, and the resistance value of the second epitaxial layer is different from that of the first epitaxial layer.

[0031] In some embodiments, the growth assembly further includes a buffer chamber located outside the plurality of growth chambers; before transferring the substrate with the first epitaxial layer formed thereon to the second growth chamber through the transfer structure, the following steps are further included:

[0032] Transfer the substrate with the first epitaxial layer formed thereon to the buffer chamber through the transfer structure, and cool the substrate in the buffer chamber.

[0033] In some embodiments, the resistance value of the second epitaxial layer is greater than that of the first epitaxial layer; after forming the second epitaxial layer above the first epitaxial layer, the following steps are further included:

[0034] Select another one of the plurality of growth chambers as the third growth chamber, and transfer the substrate with the first epitaxial layer and the second epitaxial layer formed thereon to the third growth chamber through the transfer structure;

[0035] Transfer the reaction gas to the third growth chamber through the reaction gas transfer pipeline, and control the doping structure communicated with the third growth chamber to transfer the doping gas to the third growth chamber, so as to form a third epitaxial layer above the second epitaxial layer, and the resistance value of the third epitaxial layer is greater than that of the second epitaxial layer.

[0036] The epitaxial device and the method for forming an epitaxial layer provided by the present invention can grow epitaxial layers with different doping concentrations within the same machine tool by providing multiple independent growth chambers, a transfer structure for transferring a substrate between different growth chambers, and multiple doping structures respectively communicating with the multiple growth chambers. That is, it can grow multiple epitaxial layers with different resistivity values within the same machine tool without switching the machine tool. This not only simplifies the epitaxial process, improves the epitaxial growth efficiency, but also reduces the epitaxial cost, and can generate epitaxial layers that meet specific doping concentration or resistivity requirements. At the same time, the epitaxial device provided by the present invention grows multiple epitaxial layers with different resistivity values through multiple independent growth chambers, which can avoid the mutual influence between adjacent two growth processes when growing epitaxial layers with different resistivity values in the same growth chamber, and can maximize the avoidance or reduction of the influence of the self-doping effect of the growth chamber itself on the epitaxial layer growth process, thereby contributing to improving the growth quality of the epitaxial layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic structural diagram of the epitaxial device in the specific embodiment of the present invention;

[0038] Figure 2 is a schematic structural diagram of the doping component in the specific embodiment of the present invention;

[0039] Figure 3 is a schematic diagram of the first doping structure in the specific embodiment of the present invention;

[0040] Figure 4 is a schematic diagram of the second doping structure in the specific embodiment of the present invention;

[0041] Figure 5 is a schematic diagram of the third doping structure in the specific embodiment of the present invention;

[0042] Figure 6 is a flowchart of the method for forming an epitaxial layer in the specific embodiment of the present invention. SPECIFIC EMBODIMENTS

[0043] The following will make a detailed description of the specific embodiments of the epitaxial device and the method for forming an epitaxial layer provided by the present invention with reference to the accompanying drawings.

[0044] This specific embodiment provides an epitaxial device, Figure 1 is a schematic structural diagram of the epitaxial device in the specific embodiment of the present invention, Figure 2 is a schematic structural diagram of the doping component in the specific embodiment of the present invention. As Figure 1 and Figure 2 shown, the epitaxial device includes:

[0045] A growth component, at least including a plurality of mutually independent growth chambers, and all of the plurality of growth chambers are used to accommodate substrates;

[0046] A transfer structure, located outside the plurality of growth chambers, for transferring the substrates between the plurality of growth chambers;

[0047] A reaction gas transfer pipeline, communicating with all of the plurality of growth chambers, for respectively transferring reaction gases to the plurality of growth chambers, and the reaction gases are used to form an epitaxial layer on the surface of the substrate;

[0048] A doping component, including a plurality of doping structures located outside the growth component, the plurality of doping structures are in one-to-one communication with the plurality of growth chambers, and the plurality of doping structures are respectively used to transfer doping gases with various different concentrations.

[0049] Specifically, the growth component includes a plurality of mutually independent growth chambers, and each growth chamber is used to implement an epitaxial growth process to form an epitaxial layer on the surface of the substrate. The plurality of doping structures are in one-to-one communication with the plurality of growth chambers, so that doping gases with different concentrations can be respectively transferred to the plurality of growth chambers through the plurality of doping structures, and the doping gases contain doping elements. If the concentrations of the doping gases transferred into different growth chambers are different, the doping concentrations of the doping elements in the epitaxial layers grown in different growth chambers will be different, and further the resistivity of the epitaxial layers grown in different growth chambers will be different, so that epitaxial layers with different doping concentrations can be grown in the same machine tool, that is, multilayer epitaxial layers with different resistivities can be grown in the same machine tool without switching the machine tool, which not only simplifies the epitaxial process, improves the epitaxial growth efficiency, but also reduces the epitaxial cost, and can generate epitaxial layers that meet specific doping concentration or resistivity requirements. At the same time, the epitaxial device completes the growth of multiple epitaxial layers with different resistivities through the plurality of mutually independent growth chambers, which can avoid the influence of the previous growth process on the next growth process when growing epitaxial layers with different resistivities in the same growth chamber, and can maximize the avoidance or reduction of the influence of the self-doping effect of the growth chamber itself on the epitaxial layer growth process, thereby helping to improve the growth quality of the epitaxial layer. The plurality mentioned in this specific embodiment means more than two. Among them, the epitaxial layer can be a silicon epitaxial layer, a silicon carbide epitaxial layer or a gallium nitride epitaxial layer.

[0050] In some embodiments, the growth component further includes:

[0051] A buffer chamber LL, located outside the plurality of growth chambers, and the buffer chamber LL is used to store and cool the substrates.

[0052] Specifically, after the growth process of one layer of the epitaxial layer is completed in one of the growth chambers, the substrate with the grown epitaxial layer is transferred to the buffer chamber LL through a transfer structure WHC such as a manipulator. After cooling to a preset temperature, the substrate is transferred to another growth chamber through the transfer structure WHC for the growth of another layer of the epitaxial layer. When the epitaxial device simultaneously performs the epitaxial growth process on multiple substrates, a partial number of the substrates can also be placed in the buffer chamber LL to wait until the required growth chamber is idle, and then transferred to the required growth chamber through the transfer structure WHC.

[0053] In one example, the epitaxial device further includes a first load / unload chamber LPA and a second load / unload chamber LPB to implement the automatic loading and unloading operations of the substrate and provide a window for human-machine interaction.

[0054] In some embodiments, one of the multiple growth chambers is a first growth chamber PC1, another growth chamber is a second growth chamber PC2, and yet another growth chamber is a third growth chamber PC3;

[0055] One of the multiple doping structures is a first doping structure 11 connected to the first growth chamber PC1, another doping structure is a second doping structure 12 connected to the second growth chamber PC2, and yet another doping structure is a third doping structure 13 connected to the third growth chamber PC3. The concentration of the doping gas transmitted by the first doping structure 11 is greater than the concentration of the doping gas transmitted by the second doping structure 12, and the concentration of the doping gas transmitted by the second doping structure 12 is greater than the concentration of the doping gas transmitted by the third doping structure 13.

[0056] Specifically, the growth assembly includes at least three growth chambers, namely the first growth chamber PC1, the second growth chamber PC2, and the third growth chamber PC3. The doping assembly includes at least three doping structures, namely the first doping structure 11 connected to the first growth chamber PC1, the second doping structure 12 connected to the second growth chamber PC2, and the third doping structure 13 connected to the third growth chamber PC3.

[0057] Figure 3 It is a schematic diagram of the first doping structure in the specific embodiment of the present invention. Figure 4 It is a schematic diagram of the second doping structure in the specific embodiment of the present invention. Figure 5It is a schematic diagram of the third doping structure in the specific implementation manner of the present invention. In some embodiments, the first doping structure 11 includes a first transfer pipeline 111. One end of the first transfer pipeline 111 is connected to a first doping source, and the other end is communicated with the first growth chamber PC1. The first doping source is used to store and supply a first doping gas;

[0058] The second doping structure 12 includes a second transfer pipeline 121 and a first mixer 30. The first mixer 30 includes a first air inlet, a second air inlet, and a first air outlet. One end of the second transfer pipeline 121 is connected to the first air outlet in the first mixer 30, and the other end is communicated with the second growth chamber PC2. The first air inlet in the first mixer 30 is connected to a second doping source, the second air inlet in the first mixer is connected to a dilution source. The second doping source is used to store and supply a second doping gas, and the dilution source is used to store and supply a dilution gas;

[0059] The third doping structure 13 includes a third transfer pipeline 131, a second mixer 41, and a third mixer 47. The second mixer 41 includes a third air inlet, a fourth air inlet, and a second air outlet. The third mixer 47 includes a fifth air inlet, a sixth air inlet, and a third air outlet. One end of the third transfer pipeline 131 is connected to the third air outlet, and the other end is communicated with the third growth chamber PC3. The fifth air inlet in the third mixer 47 is connected to the second air outlet, the sixth air inlet of the third mixer 47 is connected to the dilution source. The third air inlet in the second mixer 41 is connected to a third doping source, the fourth air inlet in the second mixer 41 is connected to the dilution source. The third doping source is used to store and supply a third doping gas.

[0060] For example, the first doping structure 11, the second doping structure 12, and the third doping structure 13 are all located outside the plurality of growth chambers and are all connected to an injection pipeline 10. The first doping structure 11, the second doping structure 12, and the third doping structure 13 can respectively transmit doping gases to the injection pipeline 10, and the injection pipeline 10 can be respectively communicated with the first growth chamber PC1, the second growth chamber PC2, and the third growth chamber PC3 through structures such as switching valves. A mixer is not provided in the first doping structure 11, so the first doping gas in the first doping source is directly transmitted into the injection pipeline 10 without dilution, and then transmitted into the first growth chamber PC1 by the injection pipeline 10, so that a first epitaxial layer with a relatively high ion doping concentration and a relatively low resistivity can be formed above the substrate located in the first growth chamber PC1. The first mixer 30 is provided in the second doping structure 12, so that the second doping gas from the second doping source and the dilution gas from the dilution source can be mixed in the first mixer 30 to dilute the second doping gas. The diluted second doping gas is then transmitted into the injection pipeline 10 through the second transmission pipeline 121, and then transmitted into the second growth chamber PC2 by the injection pipeline 10, so that a second epitaxial layer can be formed above the substrate located in the second growth chamber PC2. Since the concentration of the second doping gas transmitted from the second doping structure 12 to the injection pipeline 10 is lower than the concentration of the first doping gas transmitted from the first doping structure 11 to the injection pipeline 10, the ion doping concentration of the second epitaxial layer is lower than that of the first epitaxial layer, and the resistivity of the second epitaxial layer is higher than that of the first epitaxial layer. Two-stage mixers, namely the second mixer 41 and the third mixer 47, are provided in the third doping structure 13. The third doping gas from the third doping source and the dilution gas from the dilution source are mixed once in the second mixer 41 to form the diluted third doping gas. The first mixed gas from the second mixer 41 and the dilution gas from the dilution source are mixed again in the third mixer 47 to form the third doping gas after secondary dilution. The third doping gas after secondary dilution is transmitted into the third growth chamber PC3 through the injection pipeline 10, so that a third epitaxial layer can be formed above the substrate located in the third growth chamber PC3.Since the gas transported by the third doping structure 13 to the injection pipeline 10 is diluted twice, the concentration of the third doping gas transported by the third doping structure 13 to the injection pipeline 10 is lower than the concentration of the second doping gas transported by the second doping structure 12 to the injection pipeline 10. The ion doping concentration of the third epitaxial layer is lower than that of the second epitaxial layer, and the resistivity of the third epitaxial layer is higher than that of the second epitaxial layer.

[0061] In another example, the injection pipeline 10 may not be provided in the doping component. Instead, the first transfer pipeline 111 is directly connected to the first growth chamber PC1, the second transfer pipeline 121 is directly connected to the second growth chamber PC2, and the third transfer pipeline 131 is directly connected to the third growth chamber PC3. This can not only further simplify the structure of the epitaxial device, avoid the mutual influence between the doping gases with different concentrations, but also enable multiple growth chambers to perform the epitaxial growth process on different substrates simultaneously, thereby further improving the productivity of the epitaxial device.

[0062] In one example, the resistivity of the first epitaxial layer is less than or equal to 0.01 ohm·cm, the resistivity of the second epitaxial layer is in the range of 20.01 ohm·cm to 300 ohm·cm, and the resistivity of the third epitaxial layer is greater than 300 ohm·cm.

[0063] In this specific embodiment, by providing the mutually independent first doping structure 11, second doping structure 12, and third doping structure 13, and the second doping structure 12 includes the first mixer 30, and the third doping structure 13 includes two - stage mixers (i.e., the second mixer 41 and the third mixer 47), such that the concentrations of the doping gases transported by the first doping structure 11, second doping structure 12, and third doping structure 13 into the injection pipe 10 are different from each other. As a result, epitaxial layers with different doping concentrations (i.e., different resistivities), such as low - resistance to ultra - high - resistance epitaxial layers, can be generated in different growth chambers. When generating epitaxial layers in different resistance - value regions, there is no need to switch the machine platform, which not only simplifies the growth process of the epitaxial layer, reduces the growth cost of the epitaxial layer, but also helps to improve the growth efficiency of the epitaxial layer and can generate epitaxial layers that meet specific doping - concentration or resistivity requirements. By providing the second mixer 41 and the third mixer 47 in the third doping structure 13, doping gases with a lower and stable concentration can be obtained through two - stage dilution. At the same time, it is also convenient to flexibly adjust the concentration of the diluted doping gas, improving the flexibility of the epitaxial process. In addition, since the first doping structure 11, second doping structure 12, and third doping structure 13 are mutually independent, the order of connection between the first doping structure 11, second doping structure 12, and third doping structure 13 and the injection pipe 10 can be freely adjusted to form an epitaxial layer with a specific structure or composition on the substrate, thereby further expanding the application field of the epitaxial device and further improving the flexibility of the epitaxial process.

[0064] In some embodiments, the types of the first doping gas, the second doping gas, and the third doping gas are the same, and the concentrations of the first doping gas in the first doping source, the second doping gas in the second doping source, and the third doping gas in the third doping source are the same. On the one hand, it is convenient to flexibly adjust and combine the concentrations of the doping gases transported by the first doping structure 11, second doping structure 12, and third doping structure 13 into the injection pipe 10, thus simplifying the process of forming epitaxial layers with different resistivities; on the other hand, it also avoids the problem of doping - ion contamination between adjacent epitaxial layers caused by different types of doping gases.

[0065] In other embodiments, at least two of the first doping gas, the second doping gas, and the third doping gas have different types to meet the deposition requirements of epitaxial layers with a specific structure.

[0066] In some embodiments, the doping assembly further includes a dilution main pipe 14 connected to the dilution source;

[0067] The second doping structure 12 further includes a second doping source input pipeline 122 and a first dilution branch pipeline 123. The second doping source input pipeline 122 is connected to the first air inlet in the first mixer 30. One end of the first dilution branch pipeline 122 is connected to the second air inlet in the first mixer 30, and the other end is connected to the dilution main pipeline 14.

[0068] For example, as Figure 2 and Figure 4 shown, the second doping gas in the second doping source enters the first mixer 30 through the second doping source input pipeline 122, and the dilution gas in the dilution source enters the first mixer 30 through the dilution main pipeline 14 and the first dilution branch pipeline 123. After the second doping gas and the dilution gas are uniformly mixed in the first mixer 30, they are transmitted to the injection pipeline 10 through the second transmission pipeline 121, and enter the second growth chamber PC2 through the injection pipeline 10. In one example, the dilution gas is hydrogen.

[0069] In some embodiments, the third doping structure 13 further includes:

[0070] A third doping source input pipeline 132, connected to the third air inlet in the second mixer 41;

[0071] A second dilution branch pipeline 133, with one end connected to the fourth air inlet in the second mixer 41 and the other end connected to the dilution main pipeline 14;

[0072] A third dilution branch pipeline 134, with one end connected to the sixth air inlet in the third mixer 47 and the other end connected to the dilution main pipeline 14.

[0073] For example, as Figure 2 and Figure 5As shown, the third doping gas in the third doping source enters the second mixer 41 through the third doping source input pipeline 132, and the dilution gas in the dilution source enters the second mixer 41 through the dilution main pipeline 14 and the second dilution branch pipeline 133. After the third doping gas and the dilution gas are evenly mixed in the second mixer 41, they enter the third mixer 47. At the same time, the dilution gas in the dilution source also enters the third mixer 47 through the third dilution branch pipeline 134 to further dilute the third doping gas in the third mixer 47. Then, the third mixer 47 transports the evenly mixed gas to the injection pipeline 10 and enters the third growth chamber PC3 through the injection pipeline 10. By providing two - stage mixers in the third doping structure, the problems of instability of low - concentration doping gas and difficulty in obtaining low - concentration doping gas are solved, which further helps to improve the growth quality of the epitaxial layer and expands the function of the epitaxial device.

[0074] In one example, by providing a first switching valve 112 in the first doping structure 11, it is possible to control whether the first doping source is connected to the first transmission pipeline 111. By providing a second switching valve 124 in the second doping source input pipeline 122, it is possible to control whether the second doping source is connected to the second doping source input pipeline 122. By providing a third switching valve 125 in the first dilution branch pipeline 123, it is possible to control whether the dilution source is connected to the first dilution pipeline 123. By providing a fourth switching valve 135 in the third doping source input pipeline 132, it is possible to control whether the third doping source is connected to the third doping source input pipeline 132. By providing a fifth switching valve 136 in the second dilution branch pipeline 133, it is possible to control whether the dilution source is connected to the second dilution branch pipeline 133. By providing a sixth switching valve 137 in the third dilution branch pipeline 134, it is possible to control whether the dilution source is connected to the third dilution branch pipeline 134. By providing a seventh switching valve 46 on the third dilution branch pipeline 134, the problem of dilution gas leakage in the third dilution branch pipeline 134 can be further avoided.

[0075] In one example, the first doping structure 11 further includes a first injection valve 117. The inlet of the first injection valve 117 communicates with the first transfer pipeline 111, and the outlet communicates with the injection pipeline 10. The second doping structure 12 further includes a second injection valve 36. The inlet of the second injection valve 36 communicates with the second transfer pipeline 121, and the outlet communicates with the injection pipeline 10. The third doping structure 13 further includes a third injection valve 57. The inlet of the third injection valve 57 communicates with the third transfer pipeline 131, and the outlet communicates with the injection pipeline 10. Through the mutual cooperation of the first switching valve 112 and the first injection valve 117, it is possible to better control whether the first doping source communicates with the injection pipeline 10, and it is possible to prevent the first doping gas from leaking into the injection pipeline 10 when the first doping structure 11 is separated from the injection pipeline 10. The mutual cooperation of the second switching valve 124, the third switching valve 125 and the second injection valve 36 can better control whether the second doping structure 12 communicates with the injection pipeline 10, and can prevent the second doping gas and the dilution gas from leaking into the injection pipeline 10 when the second doping structure 12 is separated from the injection pipeline 10. The mutual cooperation of the fourth switching valve 135, the fifth switching valve 136, the sixth switching valve 137, the seventh switching valve 46 and the third injection valve 57 can better control whether the third doping structure 13 communicates with the injection pipeline 10, and can prevent the third doping gas and the dilution gas from leaking into the injection pipeline 10 when the third doping structure 13 is separated from the injection pipeline 10.

[0076] In some embodiments, the first doping structure 11 further includes a first flow controller 113 located in the first transfer pipeline 111, and the first flow controller 113 is located downstream of the first switching valve 112;

[0077] The second doping structure 12 further includes a second flow controller 126 located in the second doping source input pipeline 122, a third flow controller 127 located in the first dilution branch pipeline 123, and a fourth flow controller 128 located in the second transfer pipeline 121. The second flow controller 126 is located downstream of the second switching valve 124, and the third flow controller 127 is located downstream of the third switching valve 125;

[0078] The third doping structure 13 further includes a fifth flow controller 138 located in the third doping source input pipeline 132, a sixth flow controller 139 located in the second dilution branch pipeline 133, a seventh flow controller 43 located between the second mixer 41 and the third mixer 47, and an eighth flow controller 40 located in the third dilution branch pipeline 134. The fifth flow controller 138 is located downstream of the fourth switching valve 135, the sixth flow controller 139 is located downstream of the fifth switching valve 136, and the eighth flow controller 40 is located downstream of the sixth switching valve 137.

[0079] In one example, the third doping structure 13 further includes a ninth flow controller 49 located in the third transmission pipeline 131, and the ninth flow controller 49 is located downstream of the third mixer 47. Specifically, by providing a plurality of flow controllers (such as the first flow controller 113, the second flow controller 126, the third flow controller 127, the fourth flow controller 128, the fifth flow controller 138, the sixth flow controller 139, the sixth flow controller 139, the seventh flow controller 43, the eighth flow controller 40, and the ninth flow controller 49), it is convenient to adjust the gas flow rates in each pipeline (such as the first transmission pipeline 111, the second doping source input pipeline 122, the first dilution branch pipeline 123, the second transmission pipeline 121, the third doping source input pipeline 132, the second dilution branch pipeline 133, the third dilution branch pipeline 134, and the third transmission pipeline 131), so as to not only accurately control the concentration of the diluted gas, but also avoid excessive air flow affecting the normal operation of the epitaxial device.

[0080] In some embodiments, the epitaxial device further includes an exhaust main pipeline 15;

[0081] The first doping structure 11 further includes the first one-way valve 115. The intake port of the first one-way valve 115 is connected to the first transmission pipeline 111, and the outlet port of the first one-way valve 115 is connected to the exhaust main pipeline 15;

[0082] The second doping structure 12 further includes a second exhaust branch pipeline 129, a second one-way valve 35, and a third one-way valve 34. One end of the second exhaust branch pipeline 129 is connected to the second transmission pipeline 121, and the other end is connected to the intake port of the second one-way valve 35. The outlet port of the second one-way valve 35 is connected to the exhaust main pipeline 15. The intake port of the third one-way valve 34 is connected to the second transmission pipeline 121, and the outlet port of the third one-way valve 34 is connected to the exhaust main pipeline 15;

[0083] The third doping structure 13 further includes a connecting pipe 42, a third exhaust branch pipe 44, a fourth exhaust branch pipe 48, a fourth one-way valve 53, a fifth one-way valve 54, and a sixth one-way valve 56. One end of the connecting pipe 42 is connected to the second air outlet in the second mixer 41, and the other end is connected to the fifth air inlet in the third mixer 47. The third exhaust branch pipe 44 is located upstream of the seventh flow controller 43. One end of the third exhaust branch pipe 44 is connected to the connecting pipe 42, and the other end is connected to the air inlet of the fourth one-way valve 53. The air outlet of the fourth one-way valve 53 is connected to the main exhaust pipe 15. The fourth exhaust branch pipe 48 is located downstream of the seventh flow controller 43. One end of the fourth exhaust branch pipe 48 is connected to the connecting pipe 42, and the other end is connected to the air inlet of the fifth one-way valve 54. The air outlet of the fifth one-way valve 54 is connected to the main exhaust pipe 15. The air inlet of the sixth one-way valve 56 is connected to the third transfer pipe 131, and the air outlet of the sixth one-way valve 56 is connected to the main exhaust pipe 15.

[0084] Specifically, by providing the main exhaust pipe 15 in the epitaxial device, on the one hand, the gas pressure in the epitaxial device can be prevented from being too high; on the other hand, after one epitaxial process is completed, the residual gas in the first doping structure 11, the second doping structure 12, and the third doping structure 13 can be emptied, avoiding affecting the next epitaxial process. In one example, the first doping structure 11 further includes a first exhaust branch pipe 114. One end of the first exhaust branch pipe 114 is connected to the first transfer pipe 111, and the other end is communicated with the air inlet of the first one-way valve 115. The second doping structure 12 may further include a fifth exhaust branch pipe 33. One end of the fifth exhaust branch pipe 33 is connected to the second transfer pipe 121, and the other end is connected to the air inlet of the third one-way valve 34. The third doping structure 13 may further include a sixth exhaust branch pipe 55. One end of the sixth exhaust branch pipe 55 is connected to the third transfer pipe 131, and the other end is connected to the air inlet of the sixth one-way valve 56. By providing one-way valves and exhaust branch pipes in the first doping structure 11, the second doping structure 12, and the third doping structure 13 respectively, the exhaust operation can be performed on each pipe separately, and the control in the external environment can be prevented from entering the first doping structure 11, the second doping structure 12, and the third doping structure 13 through the main exhaust pipe 15.

[0085] In one example, the second doping structure 12 further includes a first pressure gauge 31 and a first pressure regulating valve 32 located in the second exhaust branch pipe 129. The first pressure gauge is used to detect the pressure in the second exhaust branch pipe 129, and the first pressure regulating valve 32 is used to automatically adjust the pressure in the second exhaust branch pipe 129 according to the pressure value detected by the first pressure gauge. Since the second exhaust branch pipe 129 communicates with the second transmission pipe 121, the first pressure gauge 31 and the first pressure regulating valve 32 essentially detect and adjust the pressure in the second transmission pipe 121.

[0086] In one example, the third doping structure 13 further includes a second pressure gauge 45 and a second pressure regulating valve 50 located in the third exhaust branch pipe 44, and a third pressure gauge 51 and a third pressure regulating valve 52 located in the fourth exhaust branch pipe 48. Since the third exhaust branch pipe 44 communicates with the connecting pipe 42, the second pressure gauge 45 and the second pressure regulating valve 50 essentially detect and adjust the pressure in the connecting pipe 42. Since the fourth exhaust branch pipe 48 communicates with the third mixer 47, the third pressure gauge 51 and the third pressure regulating valve 52 essentially detect and adjust the pressure in the third mixer 47.

[0087] This specific embodiment also provides a method for forming an epitaxial layer. Figure 6 is a flowchart of the method for forming an epitaxial layer in the specific embodiment of the present invention. The method for forming the epitaxial layer can be implemented by an epitaxial device as shown in Figures 1 - 5 As shown in Figures 1 - 6 The method for forming the epitaxial layer includes the following steps:

[0088] Step S61: Provide the epitaxial device as described above, see Figures 1 - 5 ;

[0089] Step S62: Select one of the plurality of growth chambers as the first growth chamber PC1, and place the substrate into the first growth chamber PC1 through the transfer structure WHC;

[0090] Step S63: Transmit the reaction gas into the first growth chamber PC1 through the reaction gas transmission pipe, and control the doping structure communicating with the first growth chamber PC1 to transmit the doping gas to the first growth chamber PC1, and form a first epitaxial layer on the substrate;

[0091] Step S64: Select another one of the plurality of growth chambers as the second growth chamber PC2, and transmit the substrate formed with the first epitaxial layer into the second growth chamber PC2 through the transfer structure WHC;

[0092] Step S65: Transmit the reaction gas through the reaction gas transmission pipeline into the second growth chamber PC2, and control the doping structure communicated with the second growth chamber PC2 to transmit the doping gas into the second growth chamber PC2, so as to form a second epitaxial layer above the first epitaxial layer, and the resistance value of the second epitaxial layer is different from that of the first epitaxial layer.

[0093] In some embodiments, the growth assembly further includes a buffer chamber LL located outside the plurality of growth chambers; before transmitting the substrate formed with the first epitaxial layer into the second growth chamber PC2 through the transmission structure WHC, the following steps are further included:

[0094] Transmit the substrate formed with the first epitaxial layer into the buffer chamber LL through the transmission structure WHC, and cool the substrate in the buffer chamber LL.

[0095] In some embodiments, the resistance value of the second epitaxial layer is greater than that of the first epitaxial layer; after forming the second epitaxial layer above the first epitaxial layer, the following steps are further included:

[0096] Select another one of the plurality of growth chambers as the third growth chamber PC3, and transmit the substrate formed with the first epitaxial layer and the second epitaxial layer into the third growth chamber PC3 through the transmission structure WHC;

[0097] Transmit the reaction gas into the third growth chamber PC3 through the reaction gas transmission pipeline, and control the doping structure communicated with the third growth chamber PC3 to transmit the doping gas into the third growth chamber PC3, so as to form a third epitaxial layer above the second epitaxial layer, and the resistance value of the third epitaxial layer is greater than that of the second epitaxial layer.

[0098] For example, select one of the multiple growth chambers as the first growth chamber PC1. After placing the substrate into the first growth chamber PC1 through the transfer structure WHC, connect the first growth chamber PC1 to the first doping structure 11. While transporting the reaction gas into the first growth chamber PC1 through the reaction gas transport pipeline, transport the doping gas with a relatively high concentration into the first growth chamber PC1 through the first transport pipeline 111 in the first doping structure 11, so as to generate the first epitaxial layer with a relatively high ion doping concentration and a relatively low resistivity on the substrate. Then, transfer the substrate with the first epitaxial layer grown thereon to the buffer chamber LL through the transfer structure WHC. After cooling in the buffer chamber LL, transfer it to the second growth chamber PC2 by the transfer structure WHC again. Next, connect the second growth chamber PC2 to the second doping structure 12. While transporting the reaction gas into the second growth chamber PC2 through the reaction gas transport pipeline, transport the doping gas with a medium concentration into the second growth chamber PC2 through the second transport pipeline 121 in the second doping structure 12, so as to generate the second epitaxial layer with a medium ion doping concentration and a medium resistivity on the first epitaxial layer, that is, the resistivity of the second epitaxial layer is higher than that of the first epitaxial layer. Then, transfer the substrate with the first epitaxial layer and the second epitaxial layer grown thereon to the buffer chamber LL through the transfer structure WHC. After cooling in the buffer chamber LL, transfer it to the third growth chamber PC3 by the transfer structure WHC again. Next, connect the third growth chamber PC3 to the third doping structure 13. While transporting the reaction gas into the third growth chamber PC3 through the reaction gas transport pipeline, transport the doping gas with a relatively low concentration into the third growth chamber PC3 through the third transport pipeline 131 in the third doping structure 13, so as to generate the third epitaxial layer with a relatively low ion doping concentration and a relatively high resistivity on the second epitaxial layer, that is, the resistivity of the third epitaxial layer is higher than that of the second epitaxial layer.

[0099] The epitaxial device and the method for forming an epitaxial layer provided by this specific embodiment can grow epitaxial layers with different doping concentrations within the same machine tool by setting multiple independent growth chambers, a transfer structure for transferring substrates between different growth chambers, and multiple doping structures respectively communicating with the multiple growth chambers. That is, it can grow multiple epitaxial layers with different resistivity values within the same machine tool without switching the machine tool, which not only simplifies the epitaxial process, improves the epitaxial growth efficiency, but also reduces the epitaxial cost and can generate epitaxial layers that meet specific doping concentration or resistivity requirements. At the same time, the epitaxial device provided by this specific embodiment grows multiple epitaxial layers with different resistivity values through multiple independent growth chambers, which can avoid the mutual influence between adjacent two growth processes when growing epitaxial layers with different resistivity values in the same growth chamber, and can maximize the avoidance or reduction of the influence of the self-doping effect of the growth chamber itself on the epitaxial layer growth process, thus contributing to improving the growth quality of the epitaxial layer.

[0100] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An epitaxial device, characterized in that, Comprising: A growth component, at least including a plurality of mutually independent growth chambers, and a plurality of the growth chambers are all used for accommodating a substrate; A transfer structure, located outside the plurality of growth chambers, for transferring the substrate between the plurality of growth chambers; A reaction gas transfer pipeline, communicating with the plurality of growth chambers, for respectively transferring reaction gases to the plurality of growth chambers, the reaction gases being used to form an epitaxial layer on the surface of the substrate; A doping component, including a plurality of doping structures located outside the growth component, the plurality of doping structures being in one-to-one communication with the plurality of growth chambers, and the plurality of doping structures being respectively used for transferring a plurality of doping gases with different concentrations.

2. The epitaxial device according to claim 1, wherein The growth component further includes: A buffer chamber, located outside the plurality of growth chambers, the buffer chamber being used for storing and cooling the substrate.

3. The epitaxial device according to claim 1, characterized in that, One of the plurality of growth chambers is a first growth chamber, another one of the growth chambers is a second growth chamber, and still another one of the growth chambers is a third growth chamber; One of the plurality of doping structures is a first doping structure communicating with the first growth chamber, another one of the doping structures is a second doping structure communicating with the second growth chamber, and still another one of the doping structures is a third doping structure communicating with the third growth chamber, and the concentration of the doping gas transferred by the first doping structure is greater than the concentration of the doping gas transferred by the second doping structure, and the concentration of the doping gas transferred by the second doping structure is greater than the concentration of the doping gas transferred by the third doping structure.

4. The epitaxial device according to claim 3, characterized in that, The first doping structure includes a first transfer pipeline, one end of the first transfer pipeline is connected to a first doping source, and the other end is in communication with the first growth chamber, the first doping source being used for storing and supplying a first doping gas; The second doping structure includes a second transfer pipeline and a first mixer, the first mixer includes a first air inlet, a second air inlet, and a first air outlet, one end of the second transfer pipeline is connected to the first air outlet in the first mixer, and the other end is in communication with the second growth chamber, the first air inlet in the first mixer is connected to a second doping source, the second air inlet in the first mixer is connected to a dilution source, the second doping source being used for storing and supplying a second doping gas, and the dilution source being used for storing and supplying a dilution gas; The third doping structure includes a third transfer pipeline, a second mixer, and a third mixer, the second mixer includes a third air inlet, a fourth air inlet, and a second air outlet, the third mixer includes a fifth air inlet, a sixth air inlet, and a third air outlet, one end of the third transfer pipeline is connected to the third air outlet, and the other end is in communication with the third growth chamber, the fifth air inlet in the third mixer is connected to the second air outlet, the sixth air inlet in the third mixer is connected to the dilution source, the third air inlet in the second mixer is connected to a third doping source, the fourth air inlet in the second mixer is connected to the dilution source, the third doping source being used for storing and supplying a third doping gas.

5. The epitaxial device according to claim 4, characterized in that, The types of the first doping gas, the second doping gas, and the third doping gas are the same, and the concentrations of the first doping gas in the first doping source, the second doping gas in the second doping source, and the third doping gas in the third doping source are the same.

6. The epitaxial device according to claim 5, wherein The doping assembly further includes a dilution main pipeline connected to the dilution source; The second doping structure further includes a second doping source input pipeline and a first dilution branch pipeline. The second doping source input pipeline is connected to the first air inlet in the first mixer, and one end of the first dilution branch pipeline is connected to the second air inlet in the first mixer and the other end is connected to the dilution main pipeline.

7. The epitaxial device according to claim 6, wherein, The third doping structure further includes: a third doping source input pipeline connected to the third air inlet in the second mixer; a second dilution branch pipeline, one end of which is connected to the fourth air inlet in the second mixer and the other end is connected to the dilution main pipeline; a third dilution branch pipeline, one end of which is connected to the sixth air inlet in the third mixer and the other end is connected to the dilution main pipeline.

8. A method for forming an epitaxial layer, characterized in that, Including the following steps: Providing the epitaxial device as described in claim 1; Selecting one of the multiple growth chambers as a first growth chamber, and placing a substrate into the first growth chamber through the transfer structure; Transmitting the reaction gas into the first growth chamber through the reaction gas transmission pipeline, and controlling the doping structure communicated with the first growth chamber to transmit the doping gas to the first growth chamber, and forming a first epitaxial layer on the substrate; Selecting another one of the multiple growth chambers as a second growth chamber, and transmitting the substrate formed with the first epitaxial layer into the second growth chamber through the transfer structure; Transmitting the reaction gas into the second growth chamber through the reaction gas transmission pipeline, and controlling the doping structure communicated with the second growth chamber to transmit the doping gas to the second growth chamber, and forming a second epitaxial layer above the first epitaxial layer, and the resistance value of the second epitaxial layer is different from that of the first epitaxial layer.

9. The method for forming the epitaxial layer according to claim 8, wherein The growth assembly further includes a buffer chamber located outside the multiple growth chambers; before transmitting the substrate formed with the first epitaxial layer into the second growth chamber through the transfer structure, the following steps are further included: Transmitting the substrate formed with the first epitaxial layer into the buffer chamber through the transfer structure, and cooling the substrate in the buffer chamber.

10. The method for forming an epitaxial layer according to claim 9, wherein The resistance value of the second epitaxial layer is greater than that of the first epitaxial layer; after forming the second epitaxial layer above the first epitaxial layer, the following steps are further included: Selecting yet another one of the multiple growth chambers as a third growth chamber, and transmitting the substrate formed with the first epitaxial layer and the second epitaxial layer into the third growth chamber through the transfer structure; The reaction gas is transported to the third growth chamber through the reaction gas transport pipeline, and the doping structure communicated with the third growth chamber is controlled to transport the doping gas to the third growth chamber, so as to form a third epitaxial layer above the second epitaxial layer, and the resistance value of the third epitaxial layer is greater than that of the second epitaxial layer.

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