Pollution detection method, device and system for epitaxial growth equipment

Abstract

The invention provides a pollution detection method, device and system for epitaxial growth equipment, and belongs to the technical field of semiconductor manufacturing. The pollution detection method for the epitaxial growth equipment comprises the following steps: in the process of carrying out an epitaxial growth process on a pollution-free substrate by utilizing the epitaxial growth equipment, detecting the pollution of the pollution-free substrate; obtaining the minority carrier lifetime of an intermediate wafer grown after each epitaxial gas is introduced; and determining the pollution state of the pipeline for transmitting each epitaxial gas according to the minority carrier lifetime of the intermediate wafer corresponding to each epitaxial gas. Through the scheme disclosed by the invention, the polluted pipeline in the epitaxial growth equipment can be accurately detected.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor manufacturing technology, and in particular to a contamination detection method, device and system for epitaxial growth equipment. Background Art

[0002] In the field of semiconductor manufacturing, epitaxial growth technology is a key process used to grow a single crystal layer on a substrate to obtain an epitaxial layer. At present, the epitaxial growth methods used in the semiconductor industry are all chemical vapor deposition methods, which introduce epitaxial gases containing elements that constitute the required materials into a reaction chamber. These epitaxial gases react chemically under specific conditions (such as high temperature, low pressure or plasma environment), so that the material is deposited on the surface of the substrate to form a solid film, forming an epitaxial layer.

[0003] During the epitaxial growth process, epitaxial gas is an important factor affecting the quality of the epitaxial layer. However, in the epitaxial growth equipment, the epitaxial gas needs to be transported to the reaction chamber through pipelines. Pollution sources in the pipelines, such as metal particles, organic residues or dust, may seriously affect the electrical properties and structural integrity of the wafer, thereby reducing the performance and reliability of the wafer.

[0004] Therefore, it is very important to detect the contamination status of the pipelines that transport epitaxial gases. Summary of the invention

[0005] The present disclosure provides a contamination detection method, device and system for epitaxial growth equipment, which can accurately locate contaminated pipelines in the epitaxial growth equipment.

[0006] The technical solution of the present disclosure is achieved as follows: In a first aspect, the present disclosure provides a contamination detection method for an epitaxial growth device, the contamination detection method for the epitaxial growth device comprising: obtaining the minority carrier lifetime of an intermediate wafer grown after each epitaxial gas is introduced during an epitaxial growth process on a non-contaminated substrate using the epitaxial growth device; determining the contamination state of a pipeline transmitting each epitaxial gas based on the minority carrier lifetime of the intermediate wafer corresponding to each epitaxial gas.

[0007] In a second aspect, the present disclosure provides a contamination detection device for an epitaxial growth device, which includes: an acquisition part and a determination part; the acquisition part is configured to acquire the minority carrier lifetime of an intermediate wafer grown after each epitaxial gas is introduced during an epitaxial growth process on a non-contaminated substrate using the epitaxial growth device; the determination part is configured to determine the contamination state of a pipeline transmitting each epitaxial gas based on the minority carrier lifetime of the intermediate wafer corresponding to each epitaxial gas.

[0008] In a third aspect, the present disclosure provides a contamination detection system for an epitaxial growth device, the contamination detection system for the epitaxial growth device comprising: a minority carrier lifetime detection module and a processing module; the minority carrier lifetime detection module is configured to obtain the minority carrier lifetime of an intermediate wafer grown after each epitaxial gas is introduced during an epitaxial growth process on a non-contaminated substrate using the epitaxial growth device; the processing module is configured to determine the contamination state of a pipeline transmitting each epitaxial gas based on the minority carrier lifetime of the intermediate wafer corresponding to each epitaxial gas.

[0009] In a fourth aspect, the present disclosure provides a computer-readable storage medium storing a program or instruction, which, when executed by a processor, implements the steps of the contamination detection method for epitaxial growth equipment as described in the first aspect.

[0010] In a fifth aspect, the present disclosure provides a computer program product, wherein the computer program product includes a computer program or instructions. When the computer program product runs on a processor, the processor executes the computer program or instructions to implement the steps of the contamination detection method for epitaxial growth equipment as described in the first aspect.

[0011] In a sixth aspect, the present disclosure provides a chip, comprising a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run a program or instruction to implement the contamination detection method for the epitaxial growth equipment as described in the first aspect.

[0012] The present disclosure provides a contamination detection method for epitaxial growth equipment. The contamination state of the pipeline used to transmit each epitaxial gas is determined according to the minority carrier lifetime of the intermediate wafer grown after each epitaxial gas is introduced. The specific contaminated pipeline in the epitaxial growth equipment can be accurately located, so that only the contaminated pipeline can be accurately cleaned instead of cleaning all the pipelines. In addition, the detection of the minority carrier lifetime is non-contact, and the minority carrier lifetime of the wafer can be detected without opening the reaction chamber, and the detection efficiency is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic diagram of epitaxial gases introduced during epitaxial growth is provided for the present disclosure; Figure 2 A schematic diagram of the structure of a reaction chamber in an epitaxial growth device provided by the present disclosure; Figure 3 A schematic diagram of a process for detecting contamination of an epitaxial growth device provided by the present disclosure; Figure 4 A schematic flow chart of another contamination detection method for epitaxial growth equipment provided by the present disclosure; Figure 5A schematic flow chart of another method for detecting contamination of an epitaxial growth device provided by the present disclosure; Figure 6 A schematic diagram of a process for determining the contamination state of a pipeline for transmitting epitaxial gas provided by the present disclosure; Figure 7 A schematic diagram of a process for determining the contamination state of an epitaxial layer provided by the present disclosure; Figure 8 A schematic diagram of a process for determining the contamination state of a spare part to be tested provided by the present disclosure; Fig. 9 A structural block diagram of a contamination detection device for epitaxial growth equipment provided in the present disclosure. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the present disclosure to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of the present application.

[0015] The terms "first", "second", etc. in the specification of this application are used to distinguish similar objects, rather than to describe a specific order or precedence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the present disclosure can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more.

[0016] Epitaxial growth is a process in materials science that involves depositing a single crystal thin film of the same or different material as the substrate on a substrate. During the process of epitaxial growth on a substrate, the epitaxial gases introduced include: silicon source gas, such as trichlorosilane (TCS / SiHCl3), etching gas, such as hydrogen chloride (HCl), doping gas, such as diborane (B2H6), carrier gas, such as hydrogen (H2).

[0017] The process of epitaxial growth is: Purging: Before epitaxial growth, the substrate needs to be thoroughly cleaned, and the particle contamination attached to the surface of the substrate during the transfer process is blown away by the carrier gas; Heating, gradually raising the temperature inside the epitaxial chamber to a temperature required for epitaxial growth; Baking: high temperature baking is performed in a carrier gas atmosphere to remove natural oxides and organic matter on the surface of the substrate; Etching: Treat the wafer surface with etching gas to ensure the flatness of the epitaxial layer; Deposition, introducing silicon source gas at high temperature to deposit the epitaxial layer; Cooling gradually reduces the temperature inside the epitaxial chamber.

[0018] like Figure 1 As shown in the figure, it is a schematic diagram of the epitaxial gases introduced during the epitaxial growth process. The process covered by the black arrow corresponding to each epitaxial gas in the figure indicates that the epitaxial gas needs to be introduced in the process. For example, the carrier gas needs to be introduced in the entire process of epitaxial growth, the silicon source gas and the doping gas are introduced in the deposition process, and the etching gas is introduced in the etching process.

[0019] As can be seen from the above, epitaxial gas is involved in each stage of epitaxial growth. If the pipeline for transmitting epitaxial gas is contaminated, the purity of the gas may decrease, thereby affecting the performance of the epitaxial layer finally grown.

[0020] In the related art, when it is detected that the epitaxial layer is contaminated, the epitaxial growth equipment is usually cleaned or replaced as a whole, but there is a lack of methods for more detailed positioning of the specific contaminated pipeline.

[0021] Therefore, the present disclosure aims to provide a method for detecting contamination of an epitaxial growth device that can accurately locate the contamination source of the epitaxial growth device. The method for detecting contamination of an epitaxial growth device provided by the present disclosure is described in detail below with reference to the accompanying drawings through specific embodiments and their application scenarios.

[0022] See also Figure 2 , which shows a schematic diagram of a reaction chamber 10 in an epitaxial growth device in the related art. The reaction chamber 10 includes: a pipeline 101 for transmitting carrier gas, a pipeline 102 for transmitting silicon source gas, a pipeline 103 for transmitting doping gas, a pipeline 104 for transmitting etching gas, an exhaust gas exhaust pipeline 105 for discharging the exhaust gas after the reaction, a susceptor 106 for carrying a substrate W, and a support frame 107 for supporting the susceptor 106 and driving the susceptor 106 to rotate around the central axis X at a certain speed during the epitaxial growth process. During the rotation of the susceptor 106, the substrate W can rotate around the central axis X with the susceptor 106, that is, the substrate W remains stationary relative to the susceptor 106. The figure exemplarily shows that the pipelines for transmitting epitaxial gas are pipelines 101 to pipeline 104, and in practice, more pipelines or fewer pipelines may also be included. Figure 1 The dashed arrows are used to represent the epitaxial gas entering the reaction chamber 10 and the tail gas discharged from the reaction chamber 10 .

[0023] like Figure 3 As shown, it is a schematic flow chart of a contamination detection method for epitaxial growth equipment provided by the present disclosure, and the method may include the following steps S301 and S302.

[0024] In step S301, during an epitaxial growth process on a non-contaminated substrate using an epitaxial growth device, the minority carrier lifetime of an intermediate wafer grown after each epitaxial gas is introduced is obtained.

[0025] Under the premise of ensuring that the substrate is not contaminated, each time an epitaxial gas is introduced, after processing according to the epitaxial growth process, the minority carrier lifetime of the corresponding intermediate wafer is detected. After an epitaxial gas is introduced, the minority carrier lifetime of an intermediate wafer can be obtained.

[0026] The minority carrier lifetime refers to the average time interval from the generation to the disappearance of minority carriers (i.e., non-equilibrium carriers) in a semiconductor in thermal equilibrium at a certain temperature. Specifically, it is the time it takes for the minority carrier concentration to decrease to 1 / e (approximately equal to 0.368) of its original value. For n-type semiconductors, the minority carrier lifetime refers to the lifetime of non-equilibrium holes; for p-type semiconductors, it refers to the lifetime of non-equilibrium electrons.

[0027] In some embodiments, when the minority carrier lifetime of the substrate to be tested is greater than a reference threshold, the substrate to be tested is determined to be a non-contaminated substrate, so that it can be ruled out that the contamination is contamination of the substrate itself.

[0028] In step S302 , the contamination state of the pipeline transmitting each epitaxial gas is determined according to the minority carrier lifetime of the intermediate wafer corresponding to each epitaxial gas.

[0029] When the wafer is contaminated, the metal content in the wafer is abnormal, resulting in a corresponding decrease in the minority carrier lifetime. Therefore, based on the minority carrier lifetime of the intermediate wafer corresponding to each epitaxial gas, the contamination state of the pipeline transmitting each epitaxial gas can be determined as contaminated or non-contaminated. If the decrease in the minority carrier lifetime obtained after TCS is introduced is greater than the amplitude threshold, the contamination state of the pipeline used to transmit TCS is determined to be contaminated, otherwise, the contamination state is determined to be non-contaminated.

[0030] In addition, in some embodiments, after determining the contamination status of the pipeline corresponding to each epitaxial gas, the contaminated pipeline is cleaned. Specifically, if it is determined that the pipeline transmitting the target epitaxial gas is contaminated, the pipeline can be first flushed with nitrogen (N2). Nitrogen is an inert gas that can safely discharge the target epitaxial gas in the pipeline to prevent possible chemical reactions or explosion risks; after flushing the pipeline with nitrogen, a new target epitaxial gas is introduced, and the pipeline is flushed with the new target epitaxial gas for a period of time to ensure that all residual gases in the pipeline are removed; after the above steps are completed, the contamination status of the H2 pipeline is verified again according to the above steps S301 and S302, until the contamination status of the H2 pipeline is non-contaminated, and it is determined that the cleaning of the H2 pipeline is completed. Among them, the target epitaxial gas is any one of the above epitaxial gases.

[0031] The contamination detection of epitaxial growth equipment can be carried out at a certain frequency, such as once a week. Through regular inspection and maintenance, the service life of the pipeline can be extended and the replacement cost can be reduced.

[0032] In the present disclosure, the contamination state of the pipeline used to transmit each epitaxial gas is determined based on the minority carrier lifetime of the intermediate wafer grown after each epitaxial gas is introduced, so that the specific contaminated pipeline in the epitaxial growth equipment can be accurately determined, so that only the contaminated pipeline can be accurately cleaned instead of cleaning all the pipelines; in addition, the detection of the minority carrier lifetime is non-contact, and the minority carrier lifetime of the wafer can be detected without opening the reaction chamber, and the detection efficiency is high.

[0033] In some embodiments, in combination Figure 3 ,like Figure 4 As shown, in the above step S301, during the epitaxial growth process on the non-contaminated substrate using the epitaxial growth equipment, the minority carrier lifetime of the intermediate wafer grown after each epitaxial gas is introduced is obtained, which can be specifically achieved by the following step S301a.

[0034] In step S301a, during the epitaxial growth process on an uncontaminated substrate using an epitaxial growth device, in accordance with the order in which each epitaxial gas is introduced, and after determining that the pipeline for transmitting the Nth epitaxial gas is uncontaminated, the minority carrier lifetime of the intermediate wafer grown after the introduction of the N+1th epitaxial gas is obtained.

[0035] Wherein, N is a positive integer, and the last epitaxial gas introduced before the N+1th epitaxial gas is the Nth epitaxial gas.

[0036] During epitaxial growth on a substrate, multiple epitaxial gases are usually introduced. In order to detect whether all pipelines transmitting epitaxial gases are contaminated during one epitaxial growth process, each epitaxial gas is introduced in the order of epitaxial growth process. After determining that the pipeline transmitting the previous epitaxial gas is not contaminated, the minority carrier lifetime of the intermediate wafer into which the next epitaxial gas is introduced is obtained.

[0037] The order of introducing gases can be the same as the order of introducing epitaxial gases during epitaxial growth, such as carrier gas, etching gas, silicon source gas, and doping gas. However, during epitaxial growth, the particles and flatness level of the substrate will be confirmed. If there are fewer particles or the flatness level is better, etching gas may not be introduced during epitaxial growth. In addition, the amount of etching gas introduced is smaller than that of carrier gas, silicon source gas, and doping gas, such as 6-8slm for TCS, 250sccm for B2H6, 60-70slm for H2, and 0.5slm for HCL.

[0038] For gases with less ventilation or that may participate in epitaxial growth, verification may not be performed or may be performed last. Therefore, in some embodiments, the order of the epitaxial gases introduced includes carrier gas, silicon source gas, doping gas, and etching gas.

[0039] In this way, if it is determined that the pipeline for transmitting the previous epitaxial gas is contaminated, the detection can be stopped, and after the contaminated pipeline is cleaned, it can be determined in the next round of detection whether the subsequent pipelines are contaminated. This method can improve the efficiency of pipeline detection. If the pipeline for transmitting the first epitaxial gas is contaminated, and the other pipelines are not contaminated, then after detecting that the pipeline for transmitting the first epitaxial gas is contaminated, there is no need to perform subsequent detection. After the pipeline for the first epitaxial gas is cleaned and the cleaning is verified to be complete, the subsequent pipelines can be detected.

[0040] If the pipeline is not contaminated, the minority carrier lifetime of the intermediate wafer during the epitaxial growth process changes little. Therefore, the minority carrier lifetime of the intermediate wafer can be compared with the standard value. If the difference with the standard value is greater than the difference threshold, the contamination state is determined to be contaminated; otherwise, the contamination state is determined to be uncontaminated.

[0041] However, if the same standard value is used for each intermediate wafer in the epitaxial growth process, there may be a problem of insufficient judgment accuracy. Therefore, in some embodiments, Figure 4 ,like Figure 5 As shown, the above-mentioned determination of the contamination state of the pipeline transmitting each epitaxial gas according to the minority carrier lifetime of the intermediate wafer corresponding to each epitaxial gas can be specifically implemented through the following steps S302a and S302b.

[0042] In step S302a, when the difference between the minority carrier lifetime of the intermediate wafer corresponding to the N+1th epitaxial gas and the minority carrier lifetime of the intermediate wafer corresponding to the Nth epitaxial gas is greater than or equal to the difference threshold, the contamination state of the pipeline transmitting the N+1th epitaxial gas is determined to be contaminated.

[0043] In step S302b, when the difference between the minority carrier lifetime of the reference wafer and the minority carrier lifetime of the intermediate wafer corresponding to the first epitaxial gas is greater than or equal to the difference threshold, the contamination state of the pipeline transmitting the first epitaxial gas is determined to be contaminated.

[0044] The reference wafer is a non-contaminated wafer having the same resistance as the intermediate wafer corresponding to the first epitaxial gas.

[0045] During the epitaxial growth process, for the intermediate wafer grown by introducing the first epitaxial gas, the reference object is a non-contaminated wafer with the same resistance value as the intermediate wafer generated after introducing the first epitaxial gas, and the minority carrier lifetimes of the two wafers with the same resistance value are basically the same. For the intermediate wafer grown by introducing the first epitaxial gas and then introducing other epitaxial gases, the reference object is the intermediate wafer before introducing the epitaxial gas.

[0046] Specifically, the epitaxial gases used in the epitaxial growth process are H2, TCS, B2H6 and HCL, and the difference threshold is 500usec. H2 is used as a carrier gas and is used throughout the epitaxy process, so it needs to be verified first. The method for verifying whether H2 is contaminated can be to only introduce H2 during the baking stage, obtain the number of minority carriers b of the intermediate wafer, and if the difference between the minority carrier lifetimes a and b of the reference wafer is greater than or equal to 500usec, the contamination state of the pipeline transmitting H2 is determined to be contaminated; otherwise, it is determined to be non-contaminated.

[0047] The doping of B2H6 needs to be deposited on the wafer. If there is no TCS, it will not be deposited on the wafer, but only attached to its surface. Therefore, TCS must be verified before verifying B2H6. Verify TCS after confirming that the pipeline for transmitting H2 is not contaminated. The method for verifying whether TCS is contaminated can be to introduce TCS during the deposition stage. At this time, the epitaxial gas in the reaction chamber is a mixture of H2 and TCS. The number of minority carriers c of the intermediate wafer is obtained. If the difference between b and c is greater than or equal to 500usec, the contamination state of the pipeline for transmitting TCS is determined to be contaminated; otherwise, it is determined to be non-contaminated.

[0048] A method for verifying whether B2H6 is contaminated is to introduce B2H6 during the deposition stage, where the epitaxial gas in the reaction chamber is a mixture of H2, TCS and B2H6, and obtain the number d of minority carriers of the intermediate wafer. If the difference between c and d is greater than or equal to 500usec, the contamination state of the pipeline transmitting B2H6 is determined to be contaminated; otherwise, it is determined to be non-contaminated.

[0049] A method for verifying whether HCL is contaminated is to introduce HCL during the etching stage (such as introducing it at 5000sccm for 20s), where the epitaxial gas in the reaction chamber is a mixture of H2, TCS, B2H6 and HCL, and obtain e of the intermediate wafer. If the difference between d and e is greater than or equal to 500usec, the contamination state of the pipeline transmitting B2H6 is determined to be contaminated; otherwise, it is determined to be non-contaminated.

[0050] In the present disclosure, for each epitaxial gas introduced, the reference object is the wafer before the epitaxial gas is introduced, rather than a single unchanging standard. In this way, the accuracy of determining whether the pipeline is contaminated can be improved.

[0051] In some embodiments, in combination Figure 3 ,like Figure 6 As shown, the contamination detection method of the epitaxial growth equipment also includes the following steps S303 and S304. The above step S301 obtains the minority carrier lifetime of the intermediate wafer grown after each epitaxial gas is introduced during the epitaxial growth process on a non-contaminated substrate using the epitaxial growth equipment, which can be specifically achieved by the following step S301b.

[0052] In step S303, when the contamination state of the epitaxial layer grown on the non-contaminated substrate by the epitaxial growth equipment is contaminated, a minority carrier lifetime distribution diagram of the epitaxial layer is obtained.

[0053] The minority carrier lifetime distribution diagram is a graph used to describe the changes in the lifetime of minority carriers (such as electrons or holes) in semiconductor materials at different locations or under different conditions. It reflects the carrier behavior inside the material by measuring and recording the average survival time of minority carriers from generation to recombination under specific conditions.

[0054] In step S304, when the minority carrier lifetime distribution map includes the gas flow type distribution, it is determined that the contamination state of the pipeline for transmitting the epitaxial gas is contaminated.

[0055] Specifically, when the support frame 107 does not rotate, the minority carrier lifetime distribution diagram of the grown epitaxial layer is obtained to ensure that the uneven minority carrier lifetime distribution is not caused by the rotation of the support frame 107. Under this condition, if the minority carrier lifetime distribution diagram includes a gas flow type distribution (uneven minority carrier lifetime distribution), it can be explained that it is caused by uneven epitaxial gas flow, and the uneven epitaxial gas flow can be inferred that the epitaxial gas is contaminated.

[0056] In step S301b, when it is determined that the contamination state of the pipeline for transmitting epitaxial gas in the epitaxial growth equipment is contaminated, the minority carrier lifetime of the intermediate wafer grown after each epitaxial gas is introduced is obtained during the process of performing an epitaxial growth process on a non-contaminated substrate using the epitaxial growth equipment.

[0057] In addition to regular inspection and maintenance of epitaxial growth equipment, when it is determined that the pipeline transmitting epitaxial gas is contaminated, it should be dealt with in a timely manner to avoid the production of more unqualified epitaxial layers.

[0058] In the present disclosure, whether there is pipeline contamination is determined through the minority carrier lifetime distribution diagram of the epitaxial layer. If so, it is determined which specific pipeline is contaminated, thereby improving the detection efficiency.

[0059] In some embodiments, in combination Figure 6 ,like Figure 7 As shown, the contamination detection method for the epitaxial growth equipment also includes the following steps S305 and S306.

[0060] In step S305, a first minority carrier lifetime of the non-contaminated substrate and a second minority carrier lifetime of the epitaxial layer are obtained.

[0061] In step S306, when the second minority carrier lifetime is less than the preset threshold and the second minority carrier lifetime is less than the first minority carrier lifetime, it is determined that the contamination state of the epitaxial layer is contaminated.

[0062] The preset threshold value can be determined based on the statistical minority carrier lifetimes of multiple non-contaminated substrates. In this way, when it is determined that the epitaxial layer is contaminated, the epitaxial growth equipment is determined to be detected, which can further improve the detection efficiency.

[0063] In addition to the epitaxial gas, the spare parts in the reaction chamber that come into contact with the substrate, such as the susceptor, preheating ring, support pins, etc., may also cause contamination of the epitaxial layer. Figure 7 ,like Figure 8 As shown, the contamination detection method for the epitaxial growth equipment also includes the following steps S307 and S308.

[0064] In step S307 , when the contamination state of the epitaxial layer grown on the non-contaminated substrate by the epitaxial growth equipment is contaminated, a microscopic grain map of the epitaxial layer is obtained.

[0065] A microscopic particle map refers to an image of particle distribution and structure at a microscopic scale in the epitaxial layer of a semiconductor material. This image can show microscopic characteristics such as the size, shape, arrangement, and possible defects of particles in the epitaxial layer.

[0066] In step S308, the contamination state of the spare part to be tested of the epitaxial growth equipment is determined according to the microscopic particle map.

[0067] In some embodiments, when the particle density of the target area in the microscopic particle map is greater than a density threshold, the contamination state of the spare part to be tested that contacts the area corresponding to the target area in the epitaxial layer is determined to be contaminated.

[0068] The contact position between the spare part to be tested and the epitaxial layer in the reaction chamber is fixed. In the microscopic particle map, if the particle density in the target area is greater than the density threshold, it indicates that the contamination state of the spare part to be tested that contacts the area in the epitaxial layer corresponding to the target area is contaminated.

[0069] In some embodiments, if the microscopic particle image of a single epitaxial layer has too few particles to be observed, the microscopic particle images of multiple epitaxial layers grown using the epitaxial growth device may be superimposed, and the contamination status of the spare parts to be tested of the epitaxial growth device may be determined based on the superimposed microscopic particle images.

[0070] In this way, a comprehensive inspection was conducted on the possible contamination caused by the epitaxial growth equipment during the epitaxial growth process.

[0071] Based on the same concept as the above-mentioned contamination detection method for epitaxial growth equipment, the present disclosure also provides a contamination detection device for epitaxial growth equipment, Fig. 9 FIG. 9 is a structural block diagram of a contamination detection device 90 for an epitaxial growth device shown in the present disclosure. Fig. 9 As shown, the contamination detection device 90 of the epitaxial growth equipment includes: an acquisition part 901 and a determination part 902; the acquisition part 901 is configured to acquire the minority carrier lifetime of the intermediate wafer grown after each epitaxial gas is introduced during the epitaxial growth process on the non-contaminated substrate using the epitaxial growth equipment; the determination part 902 is configured to determine the contamination state of the pipeline transmitting each epitaxial gas according to the minority carrier lifetime of the intermediate wafer corresponding to each epitaxial gas.

[0072] In some embodiments, the acquisition part 901 is specifically configured to obtain the minority carrier lifetime of the intermediate wafer grown after the introduction of the N+1th epitaxial gas in the order in which each epitaxial gas is introduced, upon determining that the pipeline transmitting the Nth epitaxial gas is uncontaminated, where N is a positive integer.

[0073] In some embodiments, the determination part 902 is specifically configured to determine that the contamination state of the pipeline transmitting the N+1th epitaxial gas is contaminated when the difference between the minority carrier lifetime of the intermediate wafer corresponding to the Nth epitaxial gas and the minority carrier lifetime of the intermediate wafer corresponding to the N+1th epitaxial gas is greater than or equal to the difference threshold; and to determine that the contamination state of the pipeline transmitting the first epitaxial gas is contaminated when the difference between the minority carrier lifetime of the reference wafer and the minority carrier lifetime of the intermediate wafer corresponding to the first epitaxial gas is greater than or equal to the difference threshold, and the reference wafer is a non-contaminated wafer with the same resistance as the intermediate wafer corresponding to the first epitaxial gas.

[0074] In some embodiments, the order of the epitaxial gases introduced includes: carrier gas, silicon source gas, doping gas, and etching gas.

[0075] In some embodiments, the acquisition part 901 is further configured to, when the contamination state of the epitaxial layer grown on a non-contaminated substrate by an epitaxial growth device is contaminated, acquire a minority carrier lifetime distribution diagram of the epitaxial layer; the determination part 902 is further configured to, when the minority carrier lifetime distribution diagram includes a gas flow type distribution, determine that the contamination state of the pipeline for transmitting the epitaxial gas is contaminated; the acquisition part 901 is specifically configured to, when it is determined that the contamination state of the pipeline for transmitting the epitaxial gas in the epitaxial growth device is contaminated, acquire the minority carrier lifetime of the intermediate wafer grown after each epitaxial gas is introduced during an epitaxial growth process on a non-contaminated substrate using the epitaxial growth device.

[0076] In some embodiments, the acquisition part 901 is further configured to acquire a first minority carrier lifetime of an uncontaminated substrate and a second minority carrier lifetime of an epitaxial layer; the determination part 902 is further configured to determine that the contamination state of the epitaxial layer is contaminated when the second minority carrier lifetime is less than a preset threshold and the second minority carrier lifetime is less than the first minority carrier lifetime.

[0077] In some embodiments, the acquisition part 901 is further configured to acquire a microscopic particle map of the epitaxial layer when the contamination state of the epitaxial layer grown on a non-contaminated substrate by an epitaxial growth device is contaminated; the determination part 902 is further configured to determine the contamination state of the spare parts to be tested of the epitaxial growth device based on the microscopic particle map.

[0078] In some embodiments, the determination part 902 is specifically configured to determine the contamination state of the spare part to be tested that contacts the area corresponding to the target area in the epitaxial layer as contaminated when the particle density of the target area in the microscopic particle map is greater than a density threshold.

[0079] In some embodiments, the determining part 902 is further configured to determine the substrate to be tested as a non-contaminated substrate when the minority carrier lifetime of the substrate to be tested is greater than a reference threshold.

[0080] In the embodiments of the present application, each part can implement the contamination detection method for epitaxial growth equipment provided in the above method embodiments, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0081] The present disclosure provides a contamination detection system for epitaxial growth equipment. The contamination detection system for epitaxial growth equipment can accurately locate the contamination source of the epitaxial growth equipment according to the epitaxially generated wafer without opening the reaction chamber 10, and the contamination detection system for the epitaxial growth equipment includes: a minority carrier lifetime detection module and a processing module.

[0082] Among them, the minority carrier lifetime detection module is configured to obtain the minority carrier lifetime of the intermediate wafer grown after each epitaxial gas is introduced during the epitaxial growth process on the non-contaminated substrate using the epitaxial growth equipment; the processing module is configured to determine the contamination state of the pipeline transmitting each epitaxial gas according to the minority carrier lifetime of the intermediate wafer corresponding to each epitaxial gas.

[0083] The minority carrier lifetime detection module uses the microwave photoconductivity decay method (μPCD) to measure the minority carrier lifetime of the intermediate wafer. Specifically, a laser generates a light pulse to excite the carriers in the intermediate wafer, changing the conductivity of the semiconductor. A microwave generator generates a microwave signal, which interacts with the conductivity change of the intermediate wafer. The microwave detector detects the conductivity change caused by carrier excitation, thereby detecting the change of the microwave reflection signal, and the minority carrier lifetime is obtained based on the change of the microwave reflection signal.

[0084] The present disclosure also provides a computer-readable storage medium storing at least one instruction, wherein the at least one instruction is used to be executed by a processor to implement the contamination detection method for epitaxial growth equipment as described in the above embodiments.

[0085] The present disclosure also provides a computer program product, which includes computer instructions, which are stored in a computer-readable storage medium; a processor of an electronic device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the electronic device executes to implement the contamination detection method for epitaxial growth equipment described in the above-mentioned embodiments.

[0086] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned contamination detection method embodiment of the epitaxial growth equipment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0087] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0088] In the several embodiments provided in the present disclosure, it should be understood that the disclosed systems, devices, servers and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0089] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0090] In addition, each functional unit in each embodiment of the present disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0091] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program code.

[0092] Those skilled in the art should be aware that in one or more of the above examples, the functions described in the present disclosure can be implemented using hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any media that facilitates the transmission of computer programs from one place to another. Storage media can be any available media that can be accessed by a general or special-purpose computer.

[0093] It should be noted that the technical solutions described in the present disclosure can be combined arbitrarily without conflict.

[0094] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A contamination detection method for epitaxial growth equipment, characterized in that: The contamination detection method of the epitaxial growth equipment comprises: In the process of performing an epitaxial growth process on a non-contaminated substrate using the epitaxial growth device, obtaining the minority carrier lifetime of an intermediate wafer grown after each epitaxial gas is introduced; The contamination state of the pipeline transmitting each epitaxial gas is determined according to the minority carrier lifetime of the intermediate wafer corresponding to each epitaxial gas.

2. The contamination detection method for epitaxial growth equipment according to claim 1, characterized in that: The method of obtaining the minority carrier lifetime of the intermediate wafer grown after each epitaxial gas is introduced includes: According to the order of introducing each epitaxial gas, and under the condition that the pipeline transmitting the Nth epitaxial gas is determined to be free of pollution, the minority carrier lifetime of the intermediate wafer grown after the N+1th epitaxial gas is introduced is obtained, where N is a positive integer.

3. The contamination detection method for epitaxial growth equipment according to claim 2, characterized in that: The method of determining the contamination state of a pipeline for transmitting each epitaxial gas according to the minority carrier lifetime of the intermediate wafer corresponding to each epitaxial gas comprises: When the difference between the minority carrier lifetime of the intermediate wafer corresponding to the Nth epitaxial gas and the minority carrier lifetime of the intermediate wafer corresponding to the N+1th epitaxial gas is greater than or equal to the difference threshold, determining that the contamination state of the pipeline transmitting the N+1th epitaxial gas is contaminated; When the difference between the minority carrier lifetime of the reference wafer and the minority carrier lifetime of the intermediate wafer corresponding to the first epitaxial gas is greater than or equal to the difference threshold, the contamination state of the pipeline transmitting the first epitaxial gas is determined to be contaminated, and the reference wafer is an uncontaminated wafer with the same resistance as the intermediate wafer corresponding to the first epitaxial gas.

4. The contamination detection method for epitaxial growth equipment according to claim 3, characterized in that: The order of the epitaxial gases introduced includes: carrier gas, silicon source gas, doping gas, and etching gas.

5. The contamination detection method for epitaxial growth equipment according to any one of claims 1 to 4, characterized in that: The contamination detection method of the epitaxial growth equipment also includes: When the contamination state of the epitaxial layer grown on the non-contaminated substrate by the epitaxial growth device is contaminated, obtaining a minority carrier lifetime distribution diagram of the epitaxial layer; In a case where the minority carrier lifetime distribution diagram includes a gas flow type distribution, determining that the contamination state of a pipeline for transmitting epitaxial gas is contaminated; The method of obtaining the minority carrier lifetime of the intermediate wafer grown after each epitaxial gas is introduced during the epitaxial growth process on the non-contaminated substrate using the epitaxial growth device comprises: When it is determined that the contamination state of the pipeline transmitting epitaxial gas in the epitaxial growth equipment is contaminated, during the process of performing an epitaxial growth process on a non-contaminated substrate using the epitaxial growth equipment, the minority carrier lifetime of the intermediate wafer grown after each epitaxial gas is introduced is obtained.

6. The contamination detection method for epitaxial growth equipment according to claim 5, characterized in that: The contamination detection method of the epitaxial growth equipment also includes: Obtaining a first minority carrier lifetime of the non-contaminated substrate and a second minority carrier lifetime of the epitaxial layer; When the second minority carrier lifetime is less than a preset threshold and the second minority carrier lifetime is less than the first minority carrier lifetime, it is determined that the contamination state of the epitaxial layer is contaminated.

7. The contamination detection method for epitaxial growth equipment according to claim 1, characterized in that: The contamination detection method of the epitaxial growth equipment also includes: When the contamination state of the epitaxial layer grown on the non-contaminated substrate by the epitaxial growth device is contaminated, obtaining a microscopic grain map of the epitaxial layer; The contamination state of the spare part to be tested of the epitaxial growth equipment is determined according to the microscopic particle map.

8. The contamination detection method for epitaxial growth equipment according to claim 7, characterized in that: Determining the contamination state of the spare parts of the epitaxial growth equipment according to the microscopic particle map includes: When the particle density of the target area in the microscopic particle map is greater than a density threshold, the contamination state of the spare part to be tested that contacts the area corresponding to the target area in the epitaxial layer is determined to be contaminated.

9. The contamination detection method for epitaxial growth equipment according to claim 1, characterized in that: The contamination detection method of the epitaxial growth equipment also includes: When the minority carrier lifetime of the substrate to be tested is greater than a reference threshold, the substrate to be tested is determined to be the non-contaminated substrate.

10. A contamination detection device for epitaxial growth equipment, characterized in that: The contamination detection device of the epitaxial growth equipment comprises: an acquisition part and a determination part; The acquisition part is configured to acquire the minority carrier lifetime of the intermediate wafer grown after each epitaxial gas is introduced during the epitaxial growth process on the non-contaminated substrate using the epitaxial growth device; The determining part is configured to determine the contamination state of the pipeline transmitting each epitaxial gas according to the minority carrier lifetime of the intermediate wafer corresponding to each epitaxial gas.

11. A contamination detection system for epitaxial growth equipment, characterized in that: The contamination detection system of the epitaxial growth equipment comprises: a minority carrier lifetime detection module and a processing module; The minority carrier lifetime detection module is configured to obtain the minority carrier lifetime of the intermediate wafer grown after each epitaxial gas is introduced during the epitaxial growth process on the non-contaminated substrate using the epitaxial growth device; The processing module is configured to determine the contamination state of the pipeline transmitting each epitaxial gas according to the minority carrier lifetime of the intermediate wafer corresponding to each epitaxial gas.

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