Epitaxial device and epitaxial layer forming method

Abstract

The invention relates to an epitaxial device and a forming method of an epitaxial layer. The epitaxy apparatus includes: a processing chamber; an injection pipeline; the first doping structure comprises a first transmission pipeline which is connected with the first doping source and the injection pipeline; the second doping structure comprises a second transmission pipeline and a first mixer, the second transmission pipeline is connected with a first gas outlet of the first mixer and the injection pipeline, a first gas inlet of the first mixer is connected with a second doping source, and a second gas inlet of the first mixer is connected with a dilution source; the third doping structure comprises a third transmission pipeline, a second mixer and a third mixer, the third transmission pipeline is connected with a third gas outlet of the third mixer and the injection pipeline, a fifth gas inlet of the third mixer is connected with the second gas outlet, and a sixth gas inlet of the third mixer is connected with a dilution source; a third gas inlet of the second mixer is connected with a third doping source, and a fourth gas inlet is connected with a dilution source. According to the invention, the growth process of the epitaxial layer is simplified, and the growth cost of the epitaxial layer 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, substrates formed using epitaxial processes have the advantages of low cost and low defects, and are therefore increasingly being used in the manufacture of special devices. Forming epitaxial layers with different resistance values ​​through epitaxial processes, such as forming epitaxial layers extending from ultra-low resistance to ultra-high resistance, can meet the manufacturing needs of a variety of special devices and is a hot topic of current research. However, the current generation of epitaxial layers with different resistance values ​​requires multiple epitaxial processes and requires switching between 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 epitaxial layers with regions having different resistance values, improve the growth efficiency of epitaxial layers with regions having different resistance values ​​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 an epitaxial layer with regions with different resistance values, improve the growth efficiency of the epitaxial layer with regions with different resistance values ​​and reduce the production cost.

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

[0007] a processing chamber for accommodating a substrate;

[0008] an injection pipe connected to the processing chamber;

[0009] A first doping structure, located outside the processing chamber, comprises a first transmission pipeline, one end of the first transmission pipeline is connected to a first doping source, and the other end of the first transmission pipeline is connected to the injection pipeline, and the first doping source is used to store and supply a first doping gas;

[0010] a second doping structure, located outside the processing chamber, comprising a second transmission pipeline and a first mixer, wherein the first mixer comprises a first gas inlet, a second gas inlet and a first gas outlet, one end of the second transmission pipeline is connected to the first gas outlet of the first mixer, and the other end is connected to the injection pipeline, the first gas inlet of the first mixer is connected to a second doping source, the second gas inlet of 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;

[0011] The third doping structure is located outside the processing chamber, and includes a third transmission pipeline, a second mixer and a third mixer. The second mixer includes a third gas inlet, a fourth gas inlet and a second gas outlet. The third mixer includes a fifth gas inlet, a sixth gas inlet and a third gas outlet. One end of the third transmission pipeline is connected to the third gas outlet, and the other end is connected to the injection pipeline. The fifth gas inlet of the third mixer is connected to the second gas outlet. The sixth gas inlet of the third mixer is connected to a dilution source. The third gas inlet of the second mixer is connected to a third doping source. The fourth gas inlet of the second mixer is connected to the dilution source. The third doping source is used to store and supply a third doping gas.

[0012] In some embodiments, the types of the first doping gas, the second doping gas, and the third doping gas are the same, and the concentration of the first doping gas in the first doping source, the concentration of the second doping gas in the second doping source, and the concentration of the third doping gas in the third doping source are the same.

[0013] In some embodiments, at least two of the first doping gas, the second doping gas, and the third doping gas are of different types.

[0014] In some embodiments, it further includes a dilution main pipeline connected to the dilution source;

[0015] The second doping structure also 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 dilution main pipeline.

[0016] In some embodiments, the third doping structure further includes:

[0017] a third doping source input pipeline connected to the third gas inlet in the second mixer;

[0018] a second dilution branch pipe, one end of which is connected to the fourth air inlet in the second mixer, and the other end of which is connected to the dilution main pipe;

[0019] The third dilution branch pipe has one end connected to the sixth air inlet in the third mixer and the other end connected to the dilution main pipe.

[0020] In some embodiments, the first doping structure further includes a first switch valve located in the first transmission pipeline;

[0021] The second doping structure further includes a second switch valve located in the second doping source input pipeline and a third switch valve located in the first dilution branch pipeline;

[0022] The third doping structure also includes a fourth switch valve located in the third doping source input pipeline, a fifth switch valve located in the second dilution branch pipeline, a sixth switch valve located in the third dilution branch pipeline, and a seventh switch valve located in the third dilution branch pipeline, and the seventh switch valve is located between the sixth switch valve and the third mixer.

[0023] In some embodiments, the first doping structure further includes a first flow controller located in the first transmission pipeline, and the first flow controller is located downstream of the first switch valve;

[0024] The second doping structure further includes a second flow controller located in the second doping source input pipeline, a third flow controller located in the first dilution branch pipeline, and a fourth flow controller located in the second transmission pipeline, wherein the second flow controller is located downstream of the second switch valve, and the third flow controller is located downstream of the third switch valve;

[0025] The third doping structure also includes a fifth flow controller located in the third doping source input pipeline, a sixth flow controller located in the second dilution branch pipeline, a seventh flow controller located between the second mixer and the third mixer, and an eighth flow controller located in the third dilution branch pipeline, and the fifth flow controller is located downstream of the fourth switch valve, the sixth flow controller is located downstream of the fifth switch valve, and the eighth flow controller is located downstream of the sixth switch valve.

[0026] In some embodiments, further comprising an exhaust main duct;

[0027] The first doping structure further includes a first one-way valve, an air inlet of the first one-way valve is connected to the first transmission pipeline, and an air outlet of the first one-way valve is connected to the exhaust main pipeline;

[0028] The second doping structure further includes a second exhaust branch pipe, a second one-way valve and a third one-way valve, one end of the second exhaust branch pipe is connected to the second transmission pipe, and the other end is connected to the air inlet of the second one-way valve, the air outlet of the second one-way valve is connected to the exhaust main pipe, the air inlet of the third one-way valve is connected to the second transmission pipe, and the air outlet of the third one-way valve is connected to the exhaust main pipe;

[0029] The third doping structure also includes a connecting pipe, a third exhaust branch pipe, a fourth exhaust branch pipe, a fourth one-way valve, a fifth one-way valve and a sixth one-way valve. One end of the connecting pipe is connected to the second air outlet of the second mixer, and the other end is connected to the fifth air inlet of the third mixer. The third exhaust branch pipe is located upstream of the seventh flow controller, one end of the third exhaust branch pipe is connected to the connecting pipe, and the other end is connected to the air inlet of the fourth one-way valve, and the air outlet of the fourth one-way valve is connected to the exhaust main pipe. The fourth exhaust branch pipe is located downstream of the seventh flow controller, one end of the fourth exhaust branch pipe is connected to the connecting pipe, and the other end is connected to the air inlet of the fifth one-way valve, and the air outlet of the fifth one-way valve is connected to the exhaust main pipe. The air inlet of the sixth one-way valve is connected to the third transmission pipe, and the air outlet of the sixth one-way valve is connected to the exhaust main pipe.

[0030] According to some other embodiments, the present invention further provides a method for forming an epitaxial layer, comprising the following steps:

[0031] Providing an epitaxial device as described above;

[0032] placing a substrate into the processing chamber;

[0033] Selecting any one of the first transmission pipeline, the second transmission pipeline and the third transmission pipeline to be connected to the injection pipeline to form a first epitaxial layer on the substrate;

[0034] Selecting another one of the first transmission pipeline, the second transmission pipeline and the third transmission pipeline to be connected to the injection pipeline, forming a second epitaxial layer above the first epitaxial layer, wherein the resistance value of the second epitaxial layer is different from the resistance value of the first epitaxial layer;

[0035] A third one of the first transmission pipeline, the second transmission pipeline and the third transmission pipeline is selected to be connected to the injection pipeline to form a third epitaxial layer above the second epitaxial layer, and the resistance value of the third epitaxial layer is different from the resistance value of the second epitaxial layer and the resistance value of the first epitaxial layer.

[0036] In some embodiments, before selecting another one of the first transmission pipeline, the second transmission pipeline, and the third transmission pipeline to be connected to the injection pipeline, the following steps are also included:

[0037] A gas purge process is performed on the processing chamber.

[0038] The epitaxial device and the method for forming an epitaxial layer provided by the present invention are provided with a first doping structure, a second doping structure and a third doping structure, and the second doping structure includes a first mixer, and the third doping structure includes a two-stage mixer (i.e., a second mixer and a third mixer), so that the concentration of the doping gas output by the second doping structure can be adjusted by the first mixer, and the concentration of the doping gas output by the third doping structure can be adjusted by the synergistic action of the second mixer and the third mixer, so that the concentration of the doping gas output by the second doping structure is lower than the concentration of the doping gas output by the first doping structure, and the concentration of the doping gas output by the third doping structure is lower than the concentration of the doping gas output by the second doping structure, so that epitaxial layers with different doping concentrations (i.e., different resistivities) can be generated by the epitaxial device, and there is no need to switch the machine when generating epitaxial layers in different resistance value regions, which not only simplifies the growth process of the epitaxial layer and reduces the growth cost of the epitaxial layer, but also helps to improve the growth efficiency of the epitaxial layer, and can generate an epitaxial layer that meets specific doping concentration or resistivity requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic structural diagram of an epitaxial device in a specific embodiment of the present invention;

[0040] Figure 2 is a schematic diagram of a first doping structure in a specific embodiment of the present invention;

[0041] Figure 3 is a schematic diagram of a second doping structure in a specific embodiment of the present invention;

[0042] Figure 4 is a schematic diagram of a third doping structure in a specific embodiment of the present invention;

[0043] Figure 5 It is a flow chart of a method for forming an epitaxial layer in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0044] The specific implementation manner of the epitaxial device and the method for forming an epitaxial layer provided by the present invention is described in detail below with reference to the accompanying drawings.

[0045] This specific embodiment provides an epitaxial device, Figure 1 is a schematic diagram of the structure of an epitaxial device in a specific embodiment of the present invention, Figure 2is a schematic diagram of a first doping structure in a specific embodiment of the present invention, Figure 3 is a schematic diagram of a second doping structure in a specific embodiment of the present invention, Figure 4 is a schematic diagram of a third doping structure in a specific embodiment of the present invention. Figure 2 , Figure 3 and Figure 4 The solid arrows in the figure indicate the flow direction of the gas. Figure 1-Figure 4 As shown, the epitaxial device comprises:

[0046] a processing chamber for accommodating a substrate;

[0047] an injection pipe 10 connected to the processing chamber;

[0048] A first doping structure 11, located outside the processing chamber, includes a first transmission pipeline 111, one end of the first transmission pipeline 111 is connected to a first doping source, and the other end is connected to the injection pipeline 10, and the first doping source is used to store and supply a first doping gas;

[0049] The second doping structure 12 is located outside the processing chamber, and includes a second transmission pipeline 121 and a first mixer 30. The first mixer 30 includes a first gas inlet, a second gas inlet and a first gas outlet. One end of the second transmission pipeline 121 is connected to the first gas outlet of the first mixer 30, and the other end is connected to the injection pipeline 10. The first gas inlet of the first mixer 30 is connected to a second doping source, and the second gas inlet of the first mixer 30 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.

[0050] The third doping structure 13 is located outside the processing chamber, and includes a third transmission pipeline 131, a second mixer 41 and a third mixer 47. The second mixer 41 includes a third gas inlet, a fourth gas inlet and a second gas outlet. The third mixer 47 includes a fifth gas inlet, a sixth gas inlet and a third gas outlet. One end of the third transmission pipeline 131 is connected to the third gas outlet, and the other end is connected to the injection pipeline 10. The fifth gas inlet of the third mixer 47 is connected to the second gas outlet, and the sixth gas inlet of the third mixer 47 is connected to a dilution source. The third gas inlet of the second mixer 41 is connected to a third doping source, and the fourth gas inlet of the second mixer 41 is connected to the dilution source. The third doping source is used to store and supply a third doping gas.

[0051] Specifically, the first doping structure 11, the second doping structure 12 and the third doping structure 13 are all located outside the processing chamber and are all connected to the injection pipe 10. The first doping structure 11, the second doping structure 12 and the third doping structure 13 can respectively transmit doping gas to the injection pipe 10 to form an epitaxial layer on the surface of the substrate through an epitaxial process. No mixer is provided in the first doping structure 11, so the first doping gas in the first doping source is directly transmitted to the injection pipe 10 without dilution, and then transmitted to the processing chamber by the injection pipe 10, so that a first epitaxial layer with a high ion doping concentration and a low resistivity can be formed above the substrate. 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 to the injection pipe 10 through the second transmission pipe 121, and then transmitted to the processing chamber by the injection pipe 10, so that a second epitaxial layer can be formed above the substrate. Since the concentration of the second doping gas transmitted to the injection pipe 10 by the second doping structure 12 is lower than the concentration of the first doping gas transmitted to the injection pipe 10 by the first doping structure 11, the ion doping concentration of the second epitaxial layer is lower than the ion doping concentration of the first epitaxial layer, and the resistivity of the second epitaxial layer is higher than the resistivity of the first epitaxial layer. The third doping structure 13 is provided with two-stage mixers, the second mixer 41 and the third mixer 47. 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 to the processing chamber through the injection pipe 10, so that a third epitaxial layer can be formed above the substrate. Since the gas transmitted to the injection pipe 10 by the third doping structure 13 is secondary diluted, the concentration of the third doping gas transmitted to the injection pipe 10 by the third doping structure 13 is lower than the concentration of the second doping gas transmitted to the injection pipe 10 by the second doping structure 12, the ion doping concentration of the third epitaxial layer is lower than the ion doping concentration of the second epitaxial layer, and the resistivity of the third epitaxial layer is higher than the resistivity of the second epitaxial layer.

[0052] In this specific embodiment, the first doping structure 11, the second doping structure 12 and the third doping structure 13 are set independently of each other, and the second doping structure 12 includes the first mixer 30, and the third doping structure 13 includes a two-stage mixer (i.e., the second mixer 41 and the third mixer 47), so that the concentrations of the doping gas transmitted to the injection pipe 10 by the first doping structure 11, the second doping structure 12 and the third doping structure 13 are different from each other, so that epitaxial layers with different doping concentrations (i.e., different resistivities) can be generated by the epitaxial device, such as low-resistance to ultra-high-resistance epitaxial layers, and there is no need to switch the machine when generating epitaxial layers in different resistance value regions, which not only simplifies the growth process of the epitaxial layer and reduces the growth cost of the epitaxial layer, but also helps to improve the growth efficiency of the epitaxial layer, and can generate an epitaxial layer that meets the specific doping concentration or resistivity requirements. By setting the second mixer 41 and the third mixer 47 in the third doping structure 13, a doping gas with a lower concentration and stable concentration can be obtained by two dilutions, and it is also convenient to flexibly adjust the concentration of the diluted doping gas, thereby improving the flexibility of the epitaxial process. In addition, the first doping structure 11, the second doping structure 12 and the third doping structure 13 are independent of each other, so that an epitaxial layer with a specific structure or composition can be formed on the substrate by freely adjusting the order in which the first doping structure 11, the second doping structure 12 and the third doping structure 13 are connected to the injection pipe 10, thereby further improving the application field of the epitaxial device and further improving the flexibility of the epitaxial process.

[0053] In some embodiments, the types of the first doping gas, the second doping gas, and the third doping gas are the same, and the concentration of the first doping gas in the first doping source, the concentration of the second doping gas in the second doping source, and the concentration of the third doping gas in the third doping source are the same.

[0054] Specifically, by setting the types and 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 to be the same, on the one hand, it is convenient to flexibly adjust and combine the concentrations of the doping gases transmitted to the injection pipe 10 by the first doping structure 11, the second doping structure 12, and the third doping structure 13, thereby simplifying the process of forming an epitaxial layer with different resistance areas; on the other hand, it also avoids the contamination problem of doping ions in different areas of the epitaxial layer due to different types of doping gases.

[0055] In some embodiments, at least two of the first doping gas, the second doping gas, and the third doping gas are of different types to meet the deposition requirements of an epitaxial layer with a specific structure.

[0056] In some embodiments, the epitaxial device further includes a dilution main pipeline 14 connected to the dilution source;

[0057] The second doping structure 12 also 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 123 is connected to the second air inlet in the first mixer 30, and the other end is connected to the dilution main pipeline 14.

[0058] For example, if Figure 1 and Figure 3 As shown, the second doping gas in the second doping source enters the first mixer 30 through the second doping source input pipe 122, and the dilution gas in the dilution source enters the first mixer 30 through the dilution main pipe 14 and the first dilution branch pipe 123. After being uniformly mixed in the first mixer 30, the second doping gas and the dilution gas are transmitted to the injection pipe 10 through the second transmission pipe 121, and enter the processing chamber through the injection pipe 10. In one example, the dilution gas is hydrogen.

[0059] In some embodiments, the third doping structure 13 further includes:

[0060] A third doping source input pipeline 132 connected to the third air inlet in the second mixer 41;

[0061] A second dilution branch pipe 133, one end of which is connected to the fourth air inlet in the second mixer 41, and the other end of which is connected to the dilution main pipe 14;

[0062] The third dilution branch pipe 134 has one end connected to the sixth air inlet in the third mixer 47 and the other end connected to the dilution main pipe 14 .

[0063] For example, if Figure 1 and Figure 4As shown, the third doping gas in the third doping source enters the second mixer 41 through the third doping source input pipe 132, and the dilution gas in the dilution source enters the second mixer 41 through the dilution main pipe 14 and the second dilution branch pipe 133. The third doping gas and the dilution gas are mixed evenly in the second mixer 41 and then 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 pipe 134 to dilute the third doping gas again in the third mixer 47. Afterwards, the third mixer 47 transmits the evenly mixed gas to the injection pipe 10, and the gas enters the processing chamber through the injection pipe 10.

[0064] In some embodiments, the first doping structure 11 further includes a first switch valve 112 located in the first transmission pipeline 111;

[0065] The second doping structure 12 further includes a second switch valve 124 located in the second doping source input pipeline 122 and a third switch valve 125 located in the first dilution branch pipeline 123;

[0066] The third doping structure 13 also includes a fourth switch valve 135 located in the third doping source input pipeline 132, a fifth switch valve 136 located in the second dilution branch pipeline 133, a sixth switch valve 137 located in the third dilution branch pipeline 134, and a seventh switch valve 46 located in the third dilution branch pipeline 134, and the seventh switch valve 46 is located between the sixth switch valve 137 and the third mixer 47.

[0067] Specifically, by setting the first switch 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 setting the second switch 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 setting the third switch 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 setting the fourth switch 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 setting the fifth switch 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 setting the sixth switch valve 137 in the third dilution branch pipeline 133, it is possible to control whether the dilution source is connected to the third dilution branch pipeline 133. By disposing the seventh switch valve 46 on the third dilution branch pipe 133 , the problem of leakage of the dilution gas in the third dilution branch pipe 133 can be further avoided.

[0068] In one example, the first doping structure 11 further includes a first injection valve 117, the inlet of the first injection valve 117 is connected to the first transmission pipeline 111, and the outlet is connected to the injection pipeline 10; the second doping structure 12 further includes a second injection valve 36, the inlet of the second injection valve 36 is connected to the second transmission pipeline 121, and the outlet is connected to the injection pipeline 10; the third doping structure 13 further includes a third injection valve 57, the inlet of the third injection valve 57 is connected to the third transmission pipeline 131, and the outlet is connected to the injection pipeline 10. Through the mutual cooperation of the first switch valve 112 and the first injection valve 117, the communication between the first doping source and the injection pipeline 10 can be better controlled, and the first doping gas can be prevented from leaking to the injection pipeline 10 when the first doping structure 11 is isolated from the injection pipeline 10. The cooperation between the second switch valve 124, the third switch valve 125 and the second injection valve 36 can better control the connection between the second doping structure 12 and 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 disconnected from the injection pipeline 10. The cooperation between the fourth switch valve 135, the fifth switch valve 136, the sixth switch valve 137, the seventh switch valve 46 and the third injection valve 57 can better control the connection between the third doping structure 13 and 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 disconnected from the injection pipeline 10.

[0069] In some embodiments, the first doping structure 11 further includes a first flow controller 113 located in the first transmission pipeline 111 , and the first flow controller 113 is located downstream of the first switch valve 112 ;

[0070] 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 transmission pipeline 121, and the second flow controller 126 is located downstream of the second switch valve 124, and the third flow controller 127 is located downstream of the third switch valve 125;

[0071] The third doping structure 13 also 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, and the fifth flow controller 138 is located downstream of the fourth switch valve 135, the sixth flow controller 139 is located downstream of the fifth switch valve 136, and the eighth flow controller 40 is located downstream of the sixth switch valve 137.

[0072] In this specific implementation manner, the first flow controller 113 is located downstream of the first switch valve 112, which means that the first flow controller 113 is located downstream of the first switch valve 112 along the transmission direction of the first doping gas in the first transmission pipeline 111 (for example Figure 2 The first flow controller 113 is located downstream of the first switch valve 112 in the direction indicated by the solid arrow in the middle. The second flow controller 126 is located downstream of the second switch valve 124, which means that the second flow controller 126 is located downstream of the second switch valve 124 along the flow direction of the second doping gas in the second doping source input pipeline 122. The third flow controller 127 is located downstream of the third switch valve 125, which means that the third flow controller 127 is located downstream of the third switch valve 125 along the flow direction of the dilution gas in the first dilution branch pipeline 123. The fifth flow controller 138 is located downstream of the fourth switch valve 135, which means that the fifth flow controller 138 is located downstream of the fourth switch valve 135 along the flow direction of the third doping gas in the third doping source input pipeline 132. The sixth flow controller 139 is located downstream of the fifth switch valve 136, which means that the sixth flow controller 139 is located downstream of the fifth switch valve 136 along the flow direction of the dilution gas in the second dilution branch pipeline 133. The eighth flow controller 40 being located downstream of the sixth switch valve 137 means that the eighth flow controller 40 is located downstream of the sixth switch valve 137 along the flow direction of the dilution gas in the third dilution branch pipe 134 .

[0073] In one example, the third doping structure 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 setting a plurality of flow controllers (e.g., 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 flow of gas in each pipeline (e.g., 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 accurately control the concentration of the diluted gas and avoid excessive gas flow affecting the normal operation of the epitaxial device.

[0074] In some embodiments, the epitaxial device further includes an exhaust main pipe 15;

[0075] The first doping structure 11 further includes the first one-way valve 115, the air inlet of the first one-way valve 115 is connected to the first transmission pipeline 111, and the air outlet of the first one-way valve 115 is connected to the exhaust main pipeline 15;

[0076] The second doping structure 12 further includes a second exhaust branch pipe 129, a second one-way valve 35 and a third one-way valve 34, one end of the second exhaust branch pipe 129 is connected to the second transmission pipe 121, and the other end is connected to the air inlet of the second one-way valve 35, the air outlet of the second one-way valve 35 is connected to the exhaust main pipe 15, the air inlet of the third one-way valve 34 is connected to the second transmission pipe 121, and the air outlet of the third one-way valve 34 is connected to the exhaust main pipe 15;

[0077] The third doping structure 13 also 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 of the second mixer 41, and the other end is connected to the fifth air inlet of 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 fourth one-way valve 53. The air inlet of the fourth one-way valve 43 is connected to the exhaust main pipeline 15, the fourth exhaust branch pipeline 48 is located downstream of the seventh flow controller 43, one end of the fourth exhaust branch pipeline 48 is connected to the connecting pipeline 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 exhaust main pipeline 15, the air inlet of the sixth one-way valve 56 is connected to the third transmission pipeline 131, and the air outlet of the sixth one-way valve 56 is connected to the exhaust main pipeline 15.

[0078] Specifically, by setting the exhaust main pipeline 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 epitaxy 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 to avoid affecting the next epitaxy process. In one example, the first doping structure 11 also includes a first exhaust branch pipeline 114, one end of which is connected to the first transmission pipeline 111 and the other end is connected to the air inlet of the first one-way valve 115. The second doping structure 12 can also include a fifth exhaust branch pipeline 33, one end of which is connected to the second transmission pipeline 121 and the other end is connected to the air inlet of the third one-way valve 34. The third doping structure 13 can also include a sixth exhaust branch pipeline 55, one end of which is connected to the third transmission pipeline 131 and the other end is connected to the air inlet of the sixth one-way valve 56. By providing a one-way valve and an exhaust branch pipe in the first doping structure 11, the second doping structure 12 and the third doping structure 13, exhaust operation can be performed on each pipe separately, and the control in the external environment from entering the exhaust main pipe 15 into the first doping structure 11, the second doping structure 12 and the third doping structure 13 can be avoided.

[0079] 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 pipeline 129, wherein the first pressure gauge is used to detect the pressure in the second exhaust branch pipeline 129, and the first pressure regulating valve 32 is used to automatically adjust the pressure in the second exhaust branch pipeline 129 according to the pressure value detected by the first pressure gauge. Since the exhaust branch pipeline 129 is connected to the second transmission pipeline 121, the first pressure gauge 31 and the first pressure regulating valve 32 substantially detect and adjust the pressure in the second transmission pipeline 12.

[0080] 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 is connected to the connecting pipe 42, the second pressure gauge 45 and the second pressure regulating valve 50 are substantially used to detect and adjust the pressure in the connecting pipe 42. Since the fourth exhaust branch pipe 48 is connected to the third mixer 47, the third pressure gauge 51 and the third pressure regulating valve 52 are substantially used to detect and adjust the pressure in the third mixer 47.

[0081] This specific embodiment also provides a method for forming an epitaxial layer. Figure 5 : is a flow chart of the method for forming an epitaxial layer in a specific embodiment of the present invention. The method for forming an epitaxial layer provided in this specific embodiment can be applied to the growth process of epitaxial layers such as silicon epitaxial layers, silicon carbide epitaxial layers, and gallium nitride epitaxial layers. Figure 5 As shown, the method for forming the epitaxial layer comprises the following steps:

[0082] Step S61, providing the epitaxial device as described above, see Figure 1-Figure 4 ;

[0083] Step S62, placing the substrate into the processing chamber;

[0084] Step S63, selecting any one of the first transmission pipeline 111, the second transmission pipeline 121 and the third transmission pipeline 131 to be connected to the injection pipeline 10 to form a first epitaxial layer on the substrate;

[0085] Step S64, selecting another one of the first transmission pipeline 111, the second transmission pipeline 121 and the third transmission pipeline 131 to be connected to the injection pipeline 10, forming a second epitaxial layer above the first epitaxial layer, wherein the resistance value of the second epitaxial layer is different from the resistance value of the first epitaxial layer;

[0086] Step S65, select a third one of the first transmission pipeline 111, the second transmission pipeline 121 and the third transmission pipeline 131 to be connected to the injection pipeline 10, and form a third epitaxial layer above the second epitaxial layer, and the resistance value of the third epitaxial layer is different from the resistance value of the second epitaxial layer and different from the resistance value of the first epitaxial layer.

[0087] Among them, the transmission pipeline connected to the injection pipeline 10 in step S64 (i.e., the other one of the first transmission pipeline 111, the second transmission pipeline 121 and the third transmission pipeline 131) is different from the transmission pipeline connected to the injection pipeline 10 in step S63 (i.e., any one of the first transmission pipeline 111, the second transmission pipeline 121 and the third transmission pipeline 131), and the transmission pipeline connected to the injection pipeline 10 in step S65 (i.e., the third one of the first transmission pipeline 111, the second transmission pipeline 121 and the third transmission pipeline 131) is different from the transmission pipeline connected to the injection pipeline 10 in step S63 (i.e., any one of the first transmission pipeline 111, the second transmission pipeline 121 and the third transmission pipeline 131) and the transmission pipeline connected to the injection pipeline 10 in step S64 (i.e., the other one of the first transmission pipeline 111, the second transmission pipeline 121 and the third transmission pipeline 131). In one example, after placing the substrate in the processing chamber, the first transmission pipe 111 and the injection pipe 10 are connected to transmit the first doping gas to the processing chamber to form a first epitaxial layer on the substrate; then, the second transmission pipe 121 and the injection pipe 10 are connected to transmit the first mixed gas including the second doping gas and the dilution gas to the processing chamber to form a second epitaxial layer above the first epitaxial layer, and the resistance of the first epitaxial layer is lower than the resistance of the second epitaxial layer; then, the third transmission pipe 131 and the injection pipe 10 are connected to transmit the third mixed gas including the third doping gas and the dilution gas to the processing chamber to form a third epitaxial layer above the second epitaxial layer, and the resistance of the second epitaxial layer is lower than the resistance of the third epitaxial layer.

[0088] In other examples, the order in which the first transmission pipeline 111 , the second transmission pipeline 121 , and the third transmission pipeline 131 are connected to the injection pipeline 10 may be adjusted as needed to meet the growth requirements of a specific epitaxial layer.

[0089] In order to prevent residual gas from the previous epitaxial process from affecting the next epitaxial process, in some embodiments, before selecting another one of the first transmission pipeline, the second transmission pipeline, and the third transmission pipeline to be connected to the injection pipeline 10, the following steps are also included:

[0090] A gas purge process is performed on the processing chamber.

[0091] The epitaxial device and the method for forming an epitaxial layer provided in this specific embodiment are provided with a first doping structure, a second doping structure and a third doping structure, and the second doping structure includes a first mixer, and the third doping structure includes a two-stage mixer (i.e., a second mixer and a third mixer), so that the concentration of the doping gas output by the second doping structure can be adjusted by the first mixer, and the concentration of the doping gas output by the third doping structure can be adjusted by the synergistic action of the second mixer and the third mixer, so that the concentration of the doping gas output by the second doping structure is lower than the concentration of the doping gas output by the first doping structure, and the concentration of the doping gas output by the third doping structure is lower than the concentration of the doping gas output by the second doping structure, so that epitaxial layers with different doping concentrations (i.e., different resistivities) can be generated by the epitaxial device, and there is no need to switch the machine when generating epitaxial layers in different resistance value regions, which not only simplifies the growth process of the epitaxial layer and reduces the growth cost of the epitaxial layer, but also helps to improve the growth efficiency of the epitaxial layer, and can generate an epitaxial layer that meets specific doping concentration or resistivity requirements.

[0092] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An epitaxial device, characterized in that: include: a processing chamber for accommodating a substrate; an injection pipe connected to the processing chamber; A first doping structure, located outside the processing chamber, comprises a first transmission pipeline, one end of the first transmission pipeline is connected to a first doping source, and the other end of the first transmission pipeline is connected to the injection pipeline, and the first doping source is used to store and supply a first doping gas; The second doping structure is located outside the processing chamber, and includes a second transmission pipeline and a first mixer. The first mixer includes a first gas inlet, a second gas inlet and a first gas outlet. One end of the second transmission pipeline is connected to the first gas outlet of the first mixer, and the other end is connected to the injection pipeline. The first gas inlet of the first mixer is connected to a second doping source, and the second gas inlet of the first mixer is connected to a dilution source. The second doping source is used to store and supply a second doping gas, wherein the dilution source is used to store and supply the dilution gas; The third doping structure is located outside the processing chamber, and includes a third transmission pipeline, a second mixer and a third mixer. The second mixer includes a third gas inlet, a fourth gas inlet and a second gas outlet. The third mixer includes a fifth gas inlet, a sixth gas inlet and a third gas outlet. One end of the third transmission pipeline is connected to the third gas outlet, and the other end is connected to the injection pipeline. The fifth gas inlet of the third mixer is connected to the second gas outlet. The sixth gas inlet of the third mixer is connected to a dilution source. The third gas inlet of the second mixer is connected to a third doping source. The fourth gas inlet of the second mixer is connected to the dilution source. The third doping source is used to store and supply a third doping gas.

2. The epitaxial device according to claim 1, characterized in that: The first doping gas, the second doping gas and the third doping gas are of the same type, and the concentration of the first doping gas in the first doping source, the concentration of the second doping gas in the second doping source and the concentration of the third doping gas in the third doping source are all the same.

3. The epitaxial device according to claim 1, characterized in that: At least two of the first doping gas, the second doping gas, and the third doping gas are of different types.

4. The epitaxial device according to claim 1, characterized in that: Also included is a dilution main pipeline connected to the dilution source; The second doping structure also 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 dilution main pipeline.

5. The epitaxial device according to claim 4, characterized in that: 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 pipe, one end of which is connected to the fourth air inlet in the second mixer and the other end of which is connected to the dilution main pipe; The third dilution branch pipe has one end connected to the sixth air inlet in the third mixer and the other end connected to the dilution main pipe.

6. The epitaxial device according to claim 5, characterized in that: The first doping structure further includes a first switch valve located in the first transmission pipeline; The second doping structure further includes a second switch valve located in the second doping source input pipeline and a third switch valve located in the first dilution branch pipeline; The third doping structure also includes a fourth switch valve located in the third doping source input pipeline, a fifth switch valve located in the second dilution branch pipeline, a sixth switch valve located in the third dilution branch pipeline, and a seventh switch valve located in the third dilution branch pipeline, and the seventh switch valve is located between the sixth switch valve and the third mixer.

7. The epitaxial device according to claim 6, characterized in that: The first doping structure further includes a first flow controller located in the first transmission pipeline, and the first flow controller is located downstream of the first switch valve; The second doping structure further includes a second flow controller located in the second doping source input pipeline, a third flow controller located in the first dilution branch pipeline, and a fourth flow controller located in the second transmission pipeline, wherein the second flow controller is located downstream of the second switch valve, and the third flow controller is located downstream of the third switch valve; The third doping structure also includes a fifth flow controller located in the third doping source input pipeline, a sixth flow controller located in the second dilution branch pipeline, a seventh flow controller located between the second mixer and the third mixer, and an eighth flow controller located in the third dilution branch pipeline, and the fifth flow controller is located downstream of the fourth switch valve, the sixth flow controller is located downstream of the fifth switch valve, and the eighth flow controller is located downstream of the sixth switch valve.

8. The epitaxial device according to claim 7, characterized in that: Also includes an exhaust main duct; The first doping structure further includes a first one-way valve, an air inlet of the first one-way valve is connected to the first transmission pipeline, and an air outlet of the first one-way valve is connected to the exhaust main pipeline; The second doping structure further includes a second exhaust branch pipe, a second one-way valve and a third one-way valve, one end of the second exhaust branch pipe is connected to the second transmission pipe, and the other end is connected to the air inlet of the second one-way valve, the air outlet of the second one-way valve is connected to the exhaust main pipe, the air inlet of the third one-way valve is connected to the second transmission pipe, and the air outlet of the third one-way valve is connected to the exhaust main pipe; The third doping structure also includes a connecting pipe, a third exhaust branch pipe, a fourth exhaust branch pipe, a fourth one-way valve, a fifth one-way valve and a sixth one-way valve. One end of the connecting pipe is connected to the second air outlet of the second mixer, and the other end is connected to the fifth air inlet of the third mixer. The third exhaust branch pipe is located upstream of the seventh flow controller, one end of the third exhaust branch pipe is connected to the connecting pipe, and the other end is connected to the air inlet of the fourth one-way valve, and the air outlet of the fourth one-way valve is connected to the exhaust main pipe. The fourth exhaust branch pipe is located downstream of the seventh flow controller, one end of the fourth exhaust branch pipe is connected to the connecting pipe, and the other end is connected to the air inlet of the fifth one-way valve, and the air outlet of the fifth one-way valve is connected to the exhaust main pipe. The air inlet of the sixth one-way valve is connected to the third transmission pipe, and the air outlet of the sixth one-way valve is connected to the exhaust main pipe.

9. A method for forming an epitaxial layer, characterized in that: The steps include: Providing the epitaxial device as claimed in claim 1; placing a substrate into the processing chamber; Selecting any one of the first transmission pipeline, the second transmission pipeline and the third transmission pipeline to be connected to the injection pipeline to form a first epitaxial layer on the substrate; Selecting another one of the first transmission pipeline, the second transmission pipeline and the third transmission pipeline to be connected to the injection pipeline, forming a second epitaxial layer above the first epitaxial layer, wherein the resistance value of the second epitaxial layer is different from the resistance value of the first epitaxial layer; A third one of the first transmission pipeline, the second transmission pipeline and the third transmission pipeline is selected to be connected to the injection pipeline to form a third epitaxial layer above the second epitaxial layer, and the resistance value of the third epitaxial layer is different from the resistance value of the second epitaxial layer and the resistance value of the first epitaxial layer.

10. The method for forming an epitaxial layer according to claim 9, characterized in that: Before selecting another one of the first transmission pipeline, the second transmission pipeline and the third transmission pipeline to be connected to the injection pipeline, the method further includes the following steps: A gas purge process is performed on the processing chamber.

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