Epitaxial equipment cleaning method, epitaxial wafer, and computer-readable medium

Abstract

The present disclosure provides an epitaxial equipment cleaning method, an epitaxial wafer, and a computer-readable medium. The method includes: performing preliminary purging and preliminary heating of a reaction chamber of the epitaxial equipment; performing repeatable cleaning steps on the reaction chamber, the repeatable cleaning steps including: purging, heating, hydrogen baking, supplying etching gas, purging, and cooling the reaction chamber; cooling the reaction chamber to a process temperature during epitaxial growth; placing a blank test silicon wafer in the reaction chamber to grow a film to obtain a test epitaxial wafer; detecting surface particles of the test epitaxial wafer to determine whether the cleanliness index of the reaction chamber meets the preset cleanliness index; if the cleanliness index of the reaction chamber does not meet the preset cleanliness index, performing the repeatable cleaning steps again until the cleanliness index meets the preset cleanliness index. The epitaxial equipment cleaning method, epitaxial wafer, and computer-readable medium disclosed in the present disclosure can reduce epitaxial wafer particle contamination and improve product quality.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor processing technology, and in particular to an epitaxial equipment cleaning method, an epitaxial wafer, and a computer-readable medium. Background Art

[0002] Silicon epitaxial growth is a key process in semiconductor chip manufacturing. Under certain conditions, a polished wafer is used as a substrate to grow an epitaxial layer with controlled resistivity and thickness, free of crystal-origin particles (COP) defects, and oxygen deposits. Methods primarily include vacuum epitaxial deposition, vapor phase epitaxial deposition, and liquid phase epitaxial deposition. Vapor phase epitaxial deposition is the most widely used. Under high temperature, a silicon source gas reacts with hydrogen to form single crystal silicon, which is then deposited on the surface of the silicon wafer to form the epitaxial layer.

[0003] The epitaxial process requires a large amount of special gases such as HCl (hydrogen chloride), SiHCl3 (silicon chloride), B2H6 (diboride dihydride), and H2 (hydrogen). Among them, HCl, SiHCl3, and B2H6 are all highly toxic gases. These gases will affect the personal and environmental safety around the factory. Therefore, the gases in the epitaxial equipment need to be safely handled to avoid accidents.

[0004] The epitaxial gas scrubber is a device specifically designed to treat epitaxial waste gases. Connecting the epitaxial furnace's exhaust pipe to the scrubber's air inlet, the epitaxial waste gases enter the scrubber, react, and then are discharged as clean gas.

[0005] Typically, the exhaust gases from epitaxial processing equipment are processed by a scrubber and then exhausted into the atmosphere. However, when the scrubber of an epitaxial processing equipment fails, the impurities and byproducts generated by the reaction in the epitaxial furnace chamber cannot be promptly discharged from the chamber. Instead, they return to the reaction chamber through the exhaust pipe, degrading the chamber environment and causing particle deposition on the surface of the epitaxial wafer, seriously affecting product quality. Summary of the Invention

[0006] The embodiments of the present disclosure provide a method for cleaning epitaxial equipment, which can reduce particle contamination of epitaxial wafers and improve product quality.

[0007] The technical solutions provided by the embodiments of the present disclosure are as follows:

[0008] In a first aspect, an embodiment of the present disclosure provides a method for cleaning an epitaxial device, comprising the following steps:

[0009] The first step is to preliminarily purge the reaction chamber of the epitaxial equipment;

[0010] The second step is to preliminarily heat the reaction chamber of the epitaxial device;

[0011] The third step is to perform a repeatable cleaning step on the reaction chamber, wherein the repeatable cleaning step includes:

[0012] The first sub-step is to purge the reaction chamber;

[0013] The second sub-step is to increase the temperature of the reaction chamber;

[0014] The third sub-step is to perform hydrogen baking on the reaction chamber;

[0015] The fourth sub-step is to deliver an etching gas into the reaction chamber to etch contaminants on the surface of the reaction chamber and the surfaces of internal components;

[0016] The fifth sub-step is to purge the reaction chamber to discharge the etching products and residual etching gas;

[0017] The sixth sub-step is to cool the reaction chamber;

[0018] Step 4: Cooling the reaction chamber to reduce the chamber temperature to the process temperature during epitaxial growth;

[0019] Step 5: placing a blank test silicon wafer in the reaction chamber to grow a film to obtain a test epitaxial wafer;

[0020] Step 6: Detect surface particles of the test epitaxial wafer to determine whether the cleanliness index of the reaction chamber meets the preset cleanliness index; and if the cleanliness index of the reaction chamber does not meet the preset cleanliness index, perform the third step, the fourth step, the fifth step and the sixth step again until the cleanliness index meets the preset cleanliness index.

[0021] Illustratively, in the fourth sub-step, before supplying the etching gas into the reaction chamber, the height of the susceptor in the reaction chamber is lowered from a first height to a second height, so that the etching gas is supplied into the reaction chamber and can etch at least the upper dome, the lower dome, and the back surface of the susceptor of the reaction chamber;

[0022] In the fifth step, when the blank test silicon wafer is placed in the reaction chamber to grow a film, the susceptor carrying the blank test silicon wafer is raised from the second height to the first height.

[0023] Exemplarily, in the first step, the reaction chamber is purged with nitrogen for 2 to 4 hours at a nitrogen flow rate of 25 to 30 L / min.

[0024] Exemplarily, in the second step, the chamber temperature of the reaction chamber after the initial temperature increase is 1180° C., and the temperature increase rate is 3° C. / s.

[0025] Illustratively, in the second sub-step, after the reaction chamber is heated, the chamber temperature is 1160-1180° C., and the heating rate is 3° C. / s.

[0026] Illustratively, in the fourth sub-step, while the chamber temperature of the reaction chamber is maintained at 1160-1180° C., the reaction chamber is purged by introducing hydrogen into the reaction chamber, and the hydrogen flow rate is 6 slm.

[0027] Exemplarily, in the fourth step, the reaction chamber is controlled to execute an idle procedure with an idle time of 30 minutes, so as to cool the reaction chamber to a process temperature for epitaxial growth.

[0028] Exemplarily, in the fifth step, the number of blank test silicon wafers used for film growth is 15.

[0029] Exemplarily, when the exhaust gas treatment device of the epitaxial equipment is in a shutdown state, the first step, the second step, the third step, the fourth step, the fifth step, and the sixth step are performed to clean the epitaxial equipment.

[0030] In the second aspect, the embodiment of the present disclosure also provides an epitaxial wafer, which is formed by epitaxial growth on a silicon wafer using an epitaxial device, and the epitaxial device is cleaned using the method described above during the epitaxial growth process, and the surface particle detection result of the epitaxial wafer is that the LLS@200nm average is less than 0.4ea.

[0031] In a third aspect, an embodiment of the present disclosure further provides a computer-readable storage medium, wherein the computer-readable storage medium stores at least one instruction, and the at least one instruction is used to be executed by a processor to implement the epitaxial device cleaning method provided by the embodiment of the present disclosure.

[0032] The beneficial effects brought about by the embodiments of the present disclosure are as follows:

[0033] In the above scheme, when cleaning the reaction chamber of the epitaxial equipment, the reaction chamber is first preliminarily purged to remove particles on the chamber surface and pipelines, and then the reaction chamber is heated up and a repeatable cleaning step is performed. When performing the repeatable cleaning step, the reaction chamber is first purged and heated up again, and after the chamber is heated up, etching gas is delivered into the chamber to etch the chamber surface and the surface of the chamber internal components to remove contaminants on the chamber surface and the surface of the chamber internal components, and then the etching products and residual etching gas are discharged out of the reaction chamber by purge again; after performing the above repeatable cleaning step, the reaction chamber is cooled again, and the surface particle detection result obtained by the blank test silicon wafer after film growth is used to verify whether the current cleaning index of the reaction chamber meets the preset cleaning index, and when the cleaning index of the reaction chamber does not meet the preset cleaning index, the above repeatable cleaning step is performed again until the cleaning index meets the preset cleaning index. In this way, the reaction chamber of the epitaxial equipment can be effectively cleaned to discharge the impurity by-products generated by the epitaxial reaction out of the reaction chamber in time, thereby improving the environment of the reaction chamber, reducing the phenomenon of particle deposition on the surface of the epitaxial wafer, and improving product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram showing the structure of a reaction chamber of an epitaxial device;

[0035] Figure 2 A schematic diagram showing the structure of an epitaxial device;

[0036] Figure 3 A flow chart showing a method for cleaning an epitaxial device according to an embodiment of the present disclosure;

[0037] Figure 4 A flow chart showing repeatable cleaning steps in the epitaxial device cleaning method provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0038] To make the purpose, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0039] Unless otherwise defined, the technical or scientific terms used in this disclosure should have the usual meanings understood by people with ordinary skills in the field to which this disclosure belongs. The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "an" or "the" do not indicate a quantity limitation, but rather indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0040] like Figure 1 As shown, the epitaxial growth equipment may include a reaction chamber, internal components disposed inside the reaction chamber, and a heating assembly disposed outside the reaction chamber. The reaction chamber may include an upper quartz bell jar 110, a lower quartz bell jar 120, an air inlet 130, and an exhaust port 140. The internal components may include a susceptor 210, a susceptor support rod 220, and a wafer support rod 230, wherein the susceptor 210 is used to place the silicon wafer 10. The heating assembly includes an upper lamp group 310 disposed above the susceptor 210 and a lower lamp group 320 disposed below the susceptor 210.

[0041] During epitaxial growth, a silicon wafer is transported into the reaction chamber and placed on the susceptor 210. The upper lamp assembly 310 and the lower lamp assembly 320 heat the wafer. Raw material gas is then supplied to the main surface of the silicon wafer, causing vapor phase growth. After vapor phase growth, the resulting epitaxial wafer is removed from the reaction chamber. During the growth process, the susceptor support rods 220 secure the susceptor 210 and rotate it, ensuring uniform epitaxial growth across the substrate.

[0042] Figure 2 Figure 1 shows the schematic diagram of the epitaxial growth equipment. A transfer blade within front-end module B transfers the silicon wafer from load port A to load lock unit C, which is then evacuated and backfilled with nitrogen. A transfer robot within transfer unit D transfers the wafer from load lock unit C through transfer unit D into reaction chamber E for epitaxial growth. After growth is complete, the wafer returns along the same path.

[0043] The gas enters the reaction chamber through the gas mixing system or bubbler, and the following reactions occur:

[0044] SiHCl3+H2→Si↓+3HCl↑

[0045] During the semiconductor epitaxial growth process, many dangerous byproducts are generated during the epitaxial growth (EPI) process, and these byproducts spread throughout the process chamber and back-end pipelines.

[0046] The epitaxial process requires a large amount of special gases such as HCl (hydrogen chloride), SiHCl3 (silicon chloride), B2H6 (diboride dihydride), and H2 (hydrogen). Among them, HCl, SiHCl3, and B2H6 are all highly toxic gases. These gases will affect the personal and environmental safety around the factory. Therefore, the gases in the epitaxial equipment need to be safely handled to avoid accidents.

[0047] Typically, the exhaust gases from epitaxial processing equipment are processed by a scrubber and then exhausted into the atmosphere. However, when the scrubber of an epitaxial processing equipment fails, the impurities and byproducts generated by the reaction in the epitaxial furnace chamber cannot be promptly discharged from the chamber. Instead, they return to the reaction chamber through the exhaust pipe, degrading the chamber environment and causing particle deposition on the surface of the epitaxial wafer, seriously affecting product quality.

[0048] In order to improve particle contamination on the surface of an epitaxial wafer during epitaxial growth, embodiments of the present disclosure provide an epitaxial equipment cleaning method, an epitaxial wafer, and a computer-readable medium.

[0049] like Figure 3 and Figure 4 As shown, the epitaxial device cleaning method provided by the embodiment of the present disclosure includes the following steps:

[0050] The first step S01 is to preliminarily purge the reaction chamber of the epitaxial equipment;

[0051] The second step S02 is to preliminarily heat the reaction chamber of the epitaxial device;

[0052] In the third step S03, a repeatable cleaning step (clean recipe) is performed on the reaction chamber. The repeatable cleaning step includes:

[0053] First sub-step S031, purging the reaction chamber;

[0054] Second sub-step S032, heating the reaction chamber;

[0055] The third sub-step S033 is to perform hydrogen baking on the reaction chamber;

[0056] Fourth sub-step S034: delivering etching gas into the reaction chamber to etch contaminants on the surface of the reaction chamber and the surfaces of internal components;

[0057] Fifth sub-step S035: purging the reaction chamber to discharge etching products and residual etching gas;

[0058] The sixth sub-step S036 is to cool the reaction chamber;

[0059] The fourth step S04 is to cool the reaction chamber so that the chamber temperature of the reaction chamber is reduced to the process temperature during epitaxial growth;

[0060] Step S05: placing a blank test silicon wafer in the reaction chamber to grow a film to obtain a test epitaxial wafer;

[0061] The sixth step S06 is to detect the surface particles of the test epitaxial wafer to determine whether the cleanliness index of the reaction chamber meets the preset cleanliness index; and if the cleanliness index of the reaction chamber does not meet the preset cleanliness index, the third step S03, the fourth step S04, the fifth step S05 and the sixth step S06 are performed again until the cleanliness index meets the preset cleanliness index.

[0062] In the above scheme, when cleaning the reaction chamber of the epitaxial equipment, first, the reaction chamber is preliminarily purged to remove particles on the surface of the reaction chamber and on the pipelines;

[0063] Then, after the reaction chamber is heated, a repeatable cleaning step is performed. During the repeatable cleaning step, the reaction chamber is purged and heated again. After the chamber is heated, an etching gas is supplied into the chamber to etch the chamber surface and the surfaces of the chamber components, removing contaminants on the chamber surface and the surfaces of the chamber components. Then, the etching products and residual etching gas are discharged from the reaction chamber by another purge at a high flow rate.

[0064] After executing the above-mentioned repeatable cleaning steps, the reaction chamber is cooled again, and the surface particle detection results obtained after the blank test silicon wafer film growth are used to verify whether the current cleaning index of the reaction chamber meets the preset cleaning index. If the cleaning index of the reaction chamber does not meet the preset cleaning index, the above-mentioned repeatable cleaning steps are executed again until the cleaning index meets the preset cleaning index.

[0065] In this way, the reaction chamber of the epitaxial equipment can be effectively cleaned, so that the impurity by-products generated by the epitaxial reaction can be discharged out of the reaction chamber in time, thereby improving the environment of the reaction chamber, reducing the phenomenon of particle deposition on the surface of the epitaxial wafer, and improving product quality.

[0066] In some exemplary embodiments, the epitaxial equipment cleaning method provided in the embodiments of the present disclosure can be performed to clean the epitaxial equipment by performing the first step S01, the second step S02, the third step S03, the fourth step S04, the fifth step S05, and the sixth step S06 when the exhaust gas treatment device of the epitaxial equipment is in a shutdown state. In this way, the reaction chamber of the epitaxial equipment can be cleaned after the exhaust gas treatment device is shut down to promptly discharge impurities and byproducts generated by the reaction out of the chamber, thereby improving the chamber environment, reducing particle deposition on the surface of the epitaxial wafer, and improving product quality.

[0067] It should be noted that the epitaxial equipment cleaning method provided in the embodiments of the present disclosure is not limited to being applied after the exhaust gas treatment device is shut down, but can also be applied to other scenarios where the reaction chamber of the epitaxial equipment needs to be cleaned.

[0068] In some exemplary embodiments, in the first step S01, the reaction chamber is purged with nitrogen for 2 to 4 hours at a nitrogen flow rate of 25-30 L / min. For example, a preliminary nitrogen purge is performed for 3 hours at a nitrogen flow rate of 25-30 L / min. In this manner, a high-flow nitrogen purge can be used to remove surface particulate impurities from the reaction chamber and internal components.

[0069] In some exemplary embodiments, in the second step S02 , the temperature of the reaction chamber after the initial temperature increase is 1180° C., and the temperature increase rate is 3° C. / s.

[0070] In some exemplary embodiments, in the first sub-step, the reaction chamber may be purged with hydrogen (H 2 ) at a temperature of 1180° C., and specifically, the flow rate of hydrogen may be 6 slm.

[0071] In some exemplary embodiments, in the second sub-step S032, after the reaction chamber is heated, the chamber temperature may be 1160-1180°C, for example, 1180°C, and the heating rate may be 3°C / s.

[0072] In some exemplary embodiments, in the third sub-step S033, baking can be performed using hydrogen at a chamber temperature of 1160-1180°C. Specifically, the flow rate of hydrogen can be 6slm. At the same time, some etching gas, such as HCL, can also be introduced in this step, and the flow rate of HCL can be 3slm.

[0073] In some exemplary embodiments, in the fourth sub-step S034, the reaction chamber is etched by introducing HCL into the reaction chamber while the chamber temperature of the reaction chamber is maintained at 1160-1180° C. The etching gas may be, for example, HCL, and the flow rate of HCL may be 6 slm. In addition, in this step, hydrogen may also be introduced at the same time, and the flow rate of hydrogen may be 3 slm.

[0074] In some exemplary embodiments, in the fourth sub-step S034, before the etching gas is delivered into the reaction chamber, the height of the susceptor 210 in the reaction chamber is lowered from a first height to a second height, so that the etching gas is delivered into the reaction chamber and can at least etch the upper dome, the lower dome and the back side of the susceptor 210 of the reaction chamber.

[0075] Using the above solution, the etching gas is delivered to the reaction chamber to etch the quartz bell jar to be cleaned. Specifically, the etching gas can be HCl (hydrogen chloride), and the flow rate of HCl can be 3slm.

[0076] In this embodiment, by lowering the height of the susceptor 210, the flow path of the etching gas is changed, so that the etching gas is controlled to not only etch the deposits on the upper dome surface of the reaction chamber to be cleaned, but also etch the deposits on the lower dome and the back of the susceptor 210.

[0077] The first height and the second height may be silicon wafer exchange positions, which refer to the position exchange of silicon wafers during the semiconductor manufacturing process. In a semiconductor factory, silicon wafers need to be exchanged at different positions when passing through different processes. This position exchange can be performed by an automated system or a robot to ensure accurate transfer and processing of silicon wafers between different processes. In this embodiment, when epitaxial growth is performed on silicon wafers, the silicon wafers are transported into the reaction chamber and placed on the base 210, and then the base 210 is raised, and the base 210 carries the silicon wafers for epitaxial growth.

[0078] The second height may be the height of the base 210 when the silicon wafer is transported to the reaction chamber via a transport device such as a transport blade and loaded onto the base 210; the first height may be the position of the base 210 when the silicon wafer undergoes epitaxial growth in the reaction chamber.

[0079] In some exemplary embodiments, in the fifth step S05, while the blank test silicon wafer is placed in the reaction chamber for film growth, the susceptor 210 carrying the blank test silicon wafer is raised from the second height to the first height, i.e., the height of the susceptor 210 is raised and restored to the height used for epitaxial growth. In this way, the height adjustment of the susceptor 210 can be accomplished using the existing lifting mechanism of the susceptor 210.

[0080] It is understandable that the height adjustment method of the base 210 is not limited to this, as long as the height of the base 210 can be adjusted to change the flow path of the etching gas to etch the deposits on the lower dome and the back of the base 210.

[0081] In some exemplary embodiments, in the fifth sub-step S035 , the reaction chamber may be purged with hydrogen at a chamber temperature of 1150° C., with a hydrogen flow rate of 8 slm. In this manner, the etched products can be purged and discharged from the reaction chamber by a large flow of H 2 . The H 2 is then introduced to discharge impurities and residual HCl gas after etching through exhaust port 140 .

[0082] In some exemplary embodiments, in the sixth sub-step S036, when cooling the reaction chamber, the cooling rate may be 9°C / s, the cooling time may be 30s-35s, and the chamber temperature after cooling may be 850°C.

[0083] In some exemplary embodiments, in the fourth step S04, the reaction chamber is controlled to execute an idle program. The idle program in the reaction chamber means that the epitaxial equipment is in an idle state, that is, the equipment is not performing any task or work; wherein the idle time is 30 minutes, so that the reaction chamber can be cooled to the process temperature during epitaxial growth.

[0084] In some exemplary embodiments, in the fifth step S05 , the number of the blank test silicon wafers used for film growth is 15 pcs. However, the number of blank test silicon wafers is not limited thereto.

[0085] In addition, in the above-mentioned fifth step S05, specifically, if the particle inspection result of the blank test silicon wafer has an LLS@200nm average value less than 0.4ea, it means that the chamber cleaning index meets the standard and the equipment can resume normal production; if the LLS@200nm average value is greater than or equal to 0.4ea, the reaction chamber is cleaned again by performing a repeatable cleaning step (clean recipe).

[0086] LLS@200nm means: LLS stands for "Light Line Scatter," or light scattering. In the particle results of the silicon wafer test, the average LLS@200nm is less than 0.4ea, which means that the average light scattering value within the 200nm size range is less than 0.4 units. In other words, an average light scattering value less than 0.4 units is the preset cleanliness index (quality control standard) used to evaluate the particle level on the silicon wafer surface. It is understood that the preset cleanliness index is not limited to this.

[0087] The epitaxial equipment cleaning method provided by the disclosed embodiments improves the cleaning process and ultimately improves product quality. The average light scattering within the 200nm size range is reduced from 0.48 particles before the improvement to 0.16 particles.

[0088] Based on the above, in the second aspect of the present disclosure, an epitaxial wafer is further provided. The epitaxial wafer is formed by epitaxial growth on a silicon wafer using an epitaxial device, and the epitaxial device is cleaned during the epitaxial growth process using the method provided in an embodiment of the present disclosure. The surface particle detection result of the epitaxial wafer is that the LLS@200nm average is less than 0.4ea.

[0089] In addition, in a third aspect, an embodiment of the present disclosure further provides a computer-readable storage medium, wherein the computer-readable storage medium stores at least one instruction, and the at least one instruction is used to be executed by a processor to implement the epitaxial device cleaning method provided by an embodiment of the present disclosure.

[0090] An embodiment of the present application further 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 epitaxial device cleaning method described in each of the above embodiments.

[0091] An embodiment of the present application also provides a computer program product, which includes computer instructions, which are stored in a computer-readable storage medium; a processor of a computing device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computing device executes to implement the above-mentioned epitaxial device cleaning method in each of the above-mentioned embodiments.

[0092] Those skilled in the art will appreciate that in one or more of the above examples, the functions described in the embodiments of the present application 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. The storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0093] There are a few points to note:

[0094] (1) The drawings of the embodiments of the present disclosure only relate to the structures related to the embodiments of the present disclosure. Other structures may refer to conventional designs.

[0095] (2) For the sake of clarity, the thickness of layers or regions in the drawings used to describe the embodiments of the present disclosure are exaggerated or reduced, i.e., these drawings are not drawn to scale. It is understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "under" another element, the element may be "directly" "on" or "under" the other element or intervening elements may be present.

[0096] (3) In the absence of conflict, the embodiments of the present disclosure and the features therein may be combined with each other to form new embodiments.

[0097] The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. The protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A method for cleaning epitaxial equipment, characterized in that: The steps include: The first step is to preliminarily purge the reaction chamber of the epitaxial equipment; The second step is to preliminarily heat the reaction chamber of the epitaxial device; The third step is to perform a repeatable cleaning step on the reaction chamber, wherein the repeatable cleaning step includes: The first sub-step is to purge the reaction chamber; The second sub-step is to increase the temperature of the reaction chamber; The third sub-step is to perform hydrogen baking on the reaction chamber; The fourth sub-step is to deliver an etching gas into the reaction chamber to etch contaminants on the surface of the reaction chamber and the surfaces of internal components; The fifth sub-step is to purge the reaction chamber to discharge the etching products and residual etching gas; The sixth sub-step is to cool the reaction chamber; Step 4: Cooling the reaction chamber to reduce the chamber temperature to the process temperature during epitaxial growth; Step 5: placing a blank test silicon wafer in the reaction chamber to grow a film to obtain a test epitaxial wafer; Step 6: Detect surface particles of the test epitaxial wafer to determine whether the cleanliness index of the reaction chamber meets the preset cleanliness index; and if the cleanliness index of the reaction chamber does not meet the preset cleanliness index, perform the third step, the fourth step, the fifth step and the sixth step again until the cleanliness index meets the preset cleanliness index.

2. The epitaxial equipment cleaning method according to claim 1, characterized in that: In the fourth sub-step, before supplying the etching gas into the reaction chamber, the height of the susceptor in the reaction chamber is lowered from a first height to a second height, so that the etching gas is supplied into the reaction chamber and can at least etch the upper dome, the lower dome and the back surface of the susceptor of the reaction chamber; In the fifth step, when the blank test silicon wafer is placed in the reaction chamber to grow a film, the susceptor carrying the blank test silicon wafer is raised from the second height to the first height.

3. The epitaxial equipment cleaning method according to claim 1, characterized in that: In the first step, the reaction chamber is purged with nitrogen gas for 2 to 4 hours at a nitrogen flow rate of 25 to 30 L / min.

4. The epitaxial equipment cleaning method according to claim 1, characterized in that: In the second step, the temperature of the reaction chamber after the initial heating is 1180° C., and the heating rate is 3° C. / s.

5. The epitaxial equipment cleaning method according to claim 1, wherein: In the second sub-step, after the reaction chamber is heated, the chamber temperature is 1160-1180° C., and the heating rate is 3° C. / s.

6. The epitaxial equipment cleaning method according to claim 1, characterized in that: In the third sub-step, the reaction chamber is baked by introducing hydrogen into the reaction chamber while maintaining the chamber temperature at 1160-1180° C., with a hydrogen flow rate of 6 slm.

7. The epitaxial equipment cleaning method according to claim 1, characterized in that: In the fourth step, the reaction chamber is controlled to execute an idle procedure with an idle time of 30 minutes, so as to cool the reaction chamber to a process temperature for epitaxial growth.

8. The epitaxial equipment cleaning method according to claim 1, characterized in that: In the fifth step, the number of blank test silicon wafers used for film growth is 15.

9. The epitaxial equipment cleaning method according to claim 1, characterized in that: When the tail gas treatment device of the epitaxial equipment is in a shutdown state, the first step, the second step, the third step, the fourth step, the fifth step, and the sixth step are performed to clean the epitaxial equipment.

10. An epitaxial wafer, characterized in that: The epitaxial wafer is formed by epitaxial growth on a silicon wafer using an epitaxial device, and during the epitaxial growth process, the epitaxial device is cleaned using the method described in any one of claims 1 to 9. The surface particle detection result of the epitaxial wafer is that the LLS@200nm average is less than 0.4ea.

11. A computer-readable medium, characterized in that The computer-readable medium stores at least one instruction, and the at least one instruction is configured to be executed by a processor to implement the epitaxial equipment cleaning method according to any one of claims 1 to 9.

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