Vapor deposition real-time deposition rate regulation and control method and system as well as preparation method and equipment of silicon carbide coating

Abstract

The invention relates to a vapor deposition real-time deposition rate regulation and control method and system and a preparation method and equipment of a silicon carbide coating. The regulation and control method comprises the following steps that (1) the current mass deposition rate in the vapor deposition treatment process is obtained; (2) comparing the current mass deposition rate with a target mass deposition rate to obtain a deposition rate comparison result; (3) if the deposition rate comparison result is that the difference value between the current mass deposition rate and the target mass deposition rate is not within the preset range, at least one parameter of the real-time deposition temperature, the real-time deposition pressure and the real-time mass flow rate of the gas source in the vapor deposition treatment process is corrected; (4) after the step (3), repeating the steps (1)-(3) for n times until the deposition rate comparison result is within a preset value; n is an integer. According to the method, the deposition thickness of the coating in unit time can be more accurately controlled, so that the uniformity of the thickness of the coating and the quality of the coating are improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor material technology, and in particular to a method and system for controlling a real-time deposition rate of vapor deposition, and a method and device for preparing a silicon carbide coating. Background Art

[0002] At present, the tray base material commonly used for chip epitaxial growth is a graphite substrate, and silicon carbide not only has excellent high-temperature stability, thermal conductivity, oxidation resistance, corrosion resistance and low dielectric constant, but also has a thermal expansion coefficient that is highly close to that of the graphite substrate. Therefore, silicon carbide has become an ideal choice for graphite tray surface protection materials, meeting the application requirements of chip epitaxial growth and is widely used in the field of semiconductor chip epitaxial growth. However, the silicon carbide coated graphite base needs to withstand a high and low temperature cycle in each furnace. During this process, the silicon carbide coating is prone to cracks, shedding and other damage, which will cause the wafer on the base to be contaminated and seriously affect the service life of the base. At present, silicon carbide coatings are usually deposited using a vapor deposition process. How to improve the quality of the coating obtained by the vapor deposition process has become a technical problem that needs to be solved urgently. Summary of the invention

[0003] Based on this, it is necessary to provide a method and system for real-time deposition rate control of vapor deposition, and a method and equipment for preparing silicon carbide coatings, so as to improve the quality of coatings obtained by vapor deposition process.

[0004] In one aspect of the present application, a method for controlling a vapor deposition rate in real time is provided, comprising the following steps:

[0005] (1) obtaining the current mass deposition rate during the vapor deposition process;

[0006] (2) comparing the current mass deposition rate with the target mass deposition rate to obtain a deposition rate comparison result;

[0007] (3) if the deposition rate comparison result is that the difference between the current mass deposition rate and the target mass deposition rate is not within a preset range, then correcting at least one parameter of the real-time deposition temperature, the real-time deposition pressure, and the real-time mass flow rate of the gas source during the vapor deposition process;

[0008] (4) After step (3), steps (1) to (3) are repeated n times until the deposition rate comparison result shows that the difference is within the preset value; n is an integer.

[0009] The above method controls the current mass deposition rate during the vapor deposition process, obtains the current mass deposition rate based on the mass change per unit time, and then dynamically adjusts at least one parameter of the real-time deposition temperature, real-time deposition pressure and real-time mass flow rate of the gas source during the vapor deposition process according to the comparison result between the current mass deposition rate and the target mass deposition rate, thereby controlling the deviation between the current mass deposition rate and the target mass deposition rate within a preset range, and more accurately controlling the deposition thickness of the coating per unit time, thereby improving the uniformity of the coating thickness, and further achieving the purpose of improving the coating quality.

[0010] Because there may be multiple crystal transformations during the growth process of the coating, and the process conditions such as temperature, pressure and atmosphere of different crystal transformations are slightly different, the above method makes subtle adjustments to the temperature, pressure and atmosphere of the coating during the growth process in real time, which not only improves the uniformity of the coating thickness, but also reduces metal contamination in the coating and improves the purity of the coating. The above method has achieved unexpected results in improving the quality of the coating.

[0011] The coating prepared by the above method has strong bonding force and is not easy to produce damages such as cracks and falling off during thermal cycles, thereby avoiding contamination of the wafer on the base and increasing the service life of the base.

[0012] In some embodiments, step (1) comprises the following steps:

[0013] The current mass deposition rate is obtained based on the mass change in the previous period of time with the current moment as the end point of time; optionally, the duration of the previous period of time is 5s to 50s.

[0014] In some embodiments, step (2) comprises the following steps:

[0015] Comparing the current mass deposition rate with the target mass deposition rate to obtain a difference between the current mass deposition rate and the target mass deposition rate;

[0016] The difference is compared with the preset range to obtain the deposition rate comparison result; the deposition rate comparison result includes whether the difference is within the preset range.

[0017] In some embodiments, if the difference between the current mass deposition rate and the target mass deposition rate is a negative number, the method for correcting at least one parameter among the real-time deposition temperature, the real-time deposition pressure and the real-time mass flow rate of the gas source during the vapor deposition process is to increase the value of the at least one parameter.

[0018] In some embodiments, if the difference between the current mass deposition rate and the target mass deposition rate is a positive number, the method for correcting at least one parameter among the real-time deposition temperature, the real-time deposition pressure and the real-time mass flow rate of the gas source during the vapor deposition process is to reduce the value of the at least one parameter.

[0019] In some embodiments, modifying the magnitude of the value of the at least one parameter comprises the following steps:

[0020] Based on the absolute value of the difference between the current mass deposition rate and the target mass deposition rate, the correction range of the real-time deposition temperature is 3°C to 10°C for every 1 μm / h difference, the correction range of the real-time deposition pressure is 30Pa to 100Pa, and the correction range of the real-time mass flow rate of the gas source is 0.5% to 5%.

[0021] The second aspect of the present application provides a control system for real-time deposition rate of vapor deposition, comprising:

[0022] A rate acquisition module, used to acquire the current mass deposition rate during the vapor deposition process;

[0023] a comparison result determination module, configured to compare the current mass deposition rate with the target mass deposition rate to obtain a deposition rate comparison result when the deposition rate comparison result indicates that the difference between the current mass deposition rate and the target mass deposition rate is not within a preset range; and

[0024] A rate correction module is used to correct at least one parameter among the real-time deposition temperature, the real-time deposition pressure and the real-time mass flow rate of the gas source in the vapor deposition process according to the deposition rate comparison result, so as to correct the current mass deposition rate in the vapor deposition process until the deposition rate comparison result is: the difference between the current mass deposition rate and the target mass deposition rate is within the preset value.

[0025] The third aspect of the present application provides a method for preparing a silicon carbide coating, comprising the following steps:

[0026] The silicon carbide coating is prepared by vapor deposition, and the vapor deposition real-time deposition rate control method described in the first aspect is used during the vapor deposition process.

[0027] The fourth aspect of the present application provides a vapor deposition device, including the vapor deposition real-time deposition rate control system described in the second aspect.

[0028] According to a fifth aspect of the present application, a computer device is provided, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method according to the first aspect when executing the computer program. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the structure of a vapor deposition device in one embodiment.

[0030] Figure 2 Schematic diagram of sampling positions for coating thickness uniformity test in one embodiment.

[0031] Reference numerals:

[0032] 1. Mass flow meter; 2. Gas mixing box; 3. Air intake pipe; 4. Weight sensor; 5. Rotating device; 6. CVD deposition chamber; 7. Graphite substrate; 8. Temperature sensor; 10. Pressure sensor; 11. Exhaust pipe; 12. Control system; 13. Vacuum system. DETAILED DESCRIPTION

[0033] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0035] In the field of chip epitaxial growth, the graphite base is the carrier and heating element of the single crystal substrate. The quality of the graphite base greatly affects the uniformity and purity of the epitaxial thin film material. However, in the actual epitaxial process, byproducts such as acidic gases and organic compounds will be generated. These substances will corrode the graphite substrate and consume it quickly, affecting the surface temperature of the substrate during the epitaxial process, making the graphite base unable to be used for a long time. In addition, during the operation, the graphite base will drop graphite powder, which will contaminate the growing chip. This has become the primary reason for limiting the application scope of chip epitaxial growth equipment.

[0036] Traditional technology usually uses a vapor deposition process to deposit a protective coating with high temperature stability, thermal conductivity and corrosion resistance on the surface of the graphite tray. The performance parameters of the coating, such as thermal stability and thermal uniformity, play a decisive role in the quality of epitaxial material growth. Therefore, it is the core key component of the equipment in the field of epitaxial growth, and the performance and service life of the coated graphite base are also closely related to the quality of the coating. The coating deposited by the current vapor deposition process is prone to damage such as cracks and shedding during thermal cycles. Those skilled in the art usually enhance the bonding between the substrate and the coating by pretreating the base or introducing a transition layer; some also optimize the deposition temperature and deposition pressure through a lot of trial and error to improve the coating quality. The vapor deposition process involves many parameters, and the parameters interact with each other. The impact on the coating performance is usually nonlinear. This method is not only time-consuming, but also difficult to achieve good results. The inventor of the present application has taken a different approach and started from regulating the real-time deposition rate of vapor deposition to solve this technical problem.

[0037] Based on this, in the first aspect of the present application, a method for controlling the real-time deposition rate of vapor deposition is provided in one embodiment, comprising the following steps:

[0038] (1) obtaining the current mass deposition rate during the vapor deposition process;

[0039] (2) comparing the current mass deposition rate with the target mass deposition rate to obtain a deposition rate comparison result;

[0040] (3) if the deposition rate comparison result is that the difference between the current mass deposition rate and the target mass deposition rate is not within a preset range, then correcting at least one parameter of the real-time deposition temperature, the real-time deposition pressure, and the real-time mass flow rate of the gas source during the vapor deposition process;

[0041] (4) After step (3), steps (1) to (3) are repeated n times until the deposition rate comparison result shows that the difference is within the preset value; n is an integer.

[0042] It can be understood that n includes zero, that is, a correction is performed once to adjust the deposition rate comparison result within the preset value.

[0043] It is understandable that the target mass deposition rate is an average deposition rate preset by those skilled in the art based on the target deposition thickness and deposition time. As an example, a target mass deposition rate of 30 μm / h to 60 μm / h may be used to deposit a 90 μm to 150 μm silicon carbide coating.

[0044] It can be understood that the current mass deposition rate is based on the mass change per unit time.

[0045] Understandably, the preset range means that the deviation between the current mass deposition rate and the target mass deposition rate needs to be controlled within a certain range according to the target coating quality. As an example, if the deviation needs to be controlled within 5 μm / h, the preset range is -5 μm / h to 5 μm / h.

[0046] The above method controls the current mass deposition rate during the vapor deposition process, obtains the current mass deposition rate based on the mass change per unit time, and then dynamically adjusts at least one parameter of the real-time deposition temperature, real-time deposition pressure and real-time mass flow rate of the gas source during the vapor deposition process according to the comparison result between the current mass deposition rate and the target mass deposition rate, thereby controlling the deviation between the current mass deposition rate and the target mass deposition rate within a preset range, and more accurately controlling the deposition thickness of the coating per unit time, thereby improving the uniformity of the coating thickness, and further achieving the purpose of improving the coating quality.

[0047] Because there may be multiple crystal transformations during the growth process of the coating, and the process conditions such as temperature, pressure and atmosphere of different crystal transformations are slightly different, the above method makes subtle adjustments to the temperature, pressure and atmosphere of the coating during the growth process in real time, which not only improves the uniformity of the coating thickness, but also reduces metal contamination in the coating and improves the purity of the coating. The above method has achieved unexpected results in improving the quality of the coating.

[0048] The coating prepared by the above method has strong bonding force and is not easy to produce damages such as cracks and falling off during thermal cycles, thereby avoiding contamination of the wafer on the base and increasing the service life of the base.

[0049] In some embodiments, the current mass deposition rate of the coating is the increase in coating thickness per unit time.

[0050] In some embodiments, step (1) comprises the following steps:

[0051] Based on the mass change in the previous period of time with the current moment as the end point of time, the current mass deposition rate is obtained.

[0052] By obtaining the current mass deposition rate based on the mass change in the previous period, the deposition thickness of the coating per unit time can be controlled more accurately.

[0053] Furthermore, the length of the first period of time is 5s to 50s, preferably 5s to 20s. This time period is not only conducive to reducing the difference between the current mass deposition rate and the target mass deposition rate, improving the uniformity of the coating thickness, but also facilitates operation and data processing.

[0054] It can be understood that if the mass change data is collected every 10 seconds, the current mass deposition rate is obtained based on the mass change in the previous 10 seconds.

[0055] The deposition rate from the coating mass change to the current mass of the coating can be calculated. The specific calculation process is as follows:

[0056] The current mass deposition rate of the coating is r, the density of the coating is ρ, the deposition area of ​​the coating is S, the unit time is t (the duration of the previous period is t), the mass change of the coating per unit time is m, r = m / (ρ*S*t).

[0057] In some embodiments, step (2) comprises the following steps:

[0058] Comparing the current mass deposition rate with the target mass deposition rate to obtain a difference between the current mass deposition rate and the target mass deposition rate;

[0059] The difference is compared with the preset range to obtain the deposition rate comparison result; the deposition rate comparison result includes whether the difference is within the preset range.

[0060] Further, the preset range is -10 μm / h to 10 μm / h. The difference between the current mass deposition rate and the target mass deposition rate within this range can obtain better coating thickness uniformity, purity and bonding strength.

[0061] The preset range is preferably -5 μm / h to 5 μm / h, which further improves the uniformity of coating thickness and bonding strength.

[0062] In some embodiments, if the difference between the current mass deposition rate and the target mass deposition rate is a negative number, the method for correcting at least one parameter among the real-time deposition temperature, the real-time deposition pressure and the real-time mass flow rate of the gas source during the vapor deposition process is to increase the value of the at least one parameter.

[0063] In some embodiments, if the difference between the current mass deposition rate and the target mass deposition rate is a positive number, the method for correcting at least one parameter among the real-time deposition temperature, the real-time deposition pressure and the real-time mass flow rate of the gas source during the vapor deposition process is to reduce the value of the at least one parameter.

[0064] In some embodiments, modifying the magnitude of the value of the at least one parameter comprises the following steps:

[0065] Based on the absolute value of the difference between the current mass deposition rate and the target mass deposition rate, the correction range of the real-time deposition temperature is 3°C to 10°C, the correction range of the real-time deposition pressure is 30Pa to 100Pa, and the correction range of the real-time mass flow rate of the gas source is 0.5% to 5% for every 1μm / h difference. Under this correction range, the uniformity of the coating thickness and the coating quality can be further improved.

[0066] In some embodiments, if the difference between the current mass deposition rate and the target mass deposition rate is a negative number, the real-time deposition temperature, the real-time deposition pressure and the real-time mass flow rate of the gas source during the vapor deposition process are increased.

[0067] In some embodiments, if the difference between the current mass deposition rate and the target mass deposition rate is a positive number, the real-time deposition temperature, the real-time deposition pressure and the real-time mass flow rate of the gas source during the vapor deposition process are reduced.

[0068] In some embodiments, if the current mass deposition rate is less than the target mass deposition rate, based on the absolute value of the difference between the current mass deposition rate and the target mass deposition rate, the real-time deposition temperature is increased by 3°C to 10°C, the real-time deposition pressure is increased by 30Pa to 100Pa, and the real-time mass flow rate of the gas source is increased by 0.5% to 5% for every 1 μm / h of the difference.

[0069] The composition of the gas source is different based on the deposition object. As an example, the gas source in the process of vapor deposition of silicon carbide coating includes inert gas, hydrogen and organic silicon source gas. Further, the gas source in the process of vapor deposition of silicon carbide coating includes argon, hydrogen and methyltrichlorosilane.

[0070] As an example, in the process of vapor deposition of silicon carbide coating, if the real-time deposition rate is regulated as follows: the current mass deposition rate is less than the target mass deposition rate by 1 μm / h, and the real-time deposition temperature is increased by 10°C, the real-time deposition pressure is increased by 100Pa, and the real-time mass flow rate of the gas source is increased by 5%. The specific regulation process is as follows:

[0071] The initial deposition temperature is 1100°C, the initial deposition pressure is 10000Pa, the inert gas flow rate is 100g / min, the hydrogen flow rate is 100g / min, and the flow rate of the organic silicon source gas is 10g / min. The adjustment is made at 10s intervals. If the current mass deposition rate is 1μm / h less than the target mass deposition rate, the deposition temperature is adjusted to 1110°C, the deposition pressure is adjusted to 10100Pa, the inert gas flow rate is adjusted to 105g / min, and the hydrogen flow rate is 105g / min. The flow rate of the organosilicon source gas is 10.5 g / min; if the current mass deposition rate is 2 μm / h less than the target mass deposition rate, the flow rates of the inert gas, hydrogen and organosilicon source gas are all increased by 10%, the deposition temperature is increased by 20°C, and the deposition pressure is increased by 200 Pa, that is: the deposition temperature is adjusted to 1120°C, the deposition pressure is adjusted to 10200 Pa, the inert gas flow rate is adjusted to 110 g / min, the hydrogen flow rate is 110 g / min, and the organosilicon source gas flow rate is 11 g / min.

[0072] In some embodiments, if the current mass deposition rate is greater than the target mass deposition rate, based on the absolute value of the difference between the current mass deposition rate and the target mass deposition rate, the real-time deposition temperature is reduced by 3°C to 10°C, the real-time deposition pressure is reduced by 30Pa to 100Pa, and the real-time mass flow rate of the gas source is reduced by 0.5% to 5% for every 1 μm / h of the difference.

[0073] As an example, in the process of vapor deposition of silicon carbide coating, if the real-time deposition rate is regulated as follows: the current mass deposition rate is greater than the target mass deposition rate by 1 μm / h, and at the same time the real-time deposition temperature is reduced by 10°C, the real-time deposition pressure is reduced by 100Pa, and the real-time mass flow rate of the gas source is reduced by 5%. The specific regulation process is as follows:

[0074] The initial deposition temperature is 1100°C, the initial deposition pressure is 10000Pa, the inert gas flow rate is 100g / min, the hydrogen flow rate is 100g / min, and the flow rate of the organic silicon source gas is 10g / min. The adjustment is made at 10s intervals. If the current mass deposition rate is 1μm / h greater than the target mass deposition rate, the deposition temperature is adjusted to 1090°C, the deposition pressure is adjusted to 9900Pa, the inert gas flow rate is adjusted to 95g / min, and the hydrogen flow rate is 95g / min. The flow rate of the organosilicon source gas is 9.5 g / min; if the current mass deposition rate is 2 μm / h less than the target mass deposition rate, the flow rates of the inert gas, hydrogen and organosilicon source gas are all reduced by 10%, the deposition temperature is reduced by 20°C, and the deposition pressure is reduced by 200 Pa, that is: the deposition temperature is adjusted to 1080°C, the deposition pressure is adjusted to 9800 Pa, the inert gas flow rate is adjusted to 90 g / min, the hydrogen flow rate is 90 g / min, and the organosilicon source gas flow rate is 9 g / min.

[0075] The second aspect of the present application provides a control system for real-time deposition rate of vapor deposition, comprising:

[0076] A rate acquisition module, used to acquire the current mass deposition rate during the vapor deposition process;

[0077] a comparison result determination module, configured to compare the current mass deposition rate with the target mass deposition rate to obtain a deposition rate comparison result when the deposition rate comparison result indicates that the difference between the current mass deposition rate and the target mass deposition rate is not within a preset range; and

[0078] A rate correction module is used to correct at least one parameter among the real-time deposition temperature, the real-time deposition pressure and the real-time mass flow rate of the gas source in the vapor deposition process according to the deposition rate comparison result, so as to correct the current mass deposition rate in the vapor deposition process until the deposition rate comparison result is: the difference between the current mass deposition rate and the target mass deposition rate is within the preset value.

[0079] The third aspect of the present application provides a method for preparing a silicon carbide coating, comprising the following steps:

[0080] The silicon carbide coating is prepared by vapor deposition, and the vapor deposition real-time deposition rate control method described in the first aspect is used during the vapor deposition process.

[0081] The fourth aspect of the present application provides a vapor deposition device, including the vapor deposition real-time deposition rate control system described in the second aspect.

[0082] In some embodiments, the vapor deposition apparatus structure is as follows Figure 1 As shown, it includes a mass flow meter 1, a gas mixing box 2, an air intake line 3, a weight sensor 4, a rotating device 5, a CVD deposition chamber 6, a graphite substrate 7, a temperature sensor 8, a pressure sensor 10, an exhaust line 11, a control system 12 and a vacuum system 13; the control system 12 includes a memory and a processor, the memory stores a computer program, and the processor implements the steps of the method described in the first aspect when executing the computer program; the gas mixing box 2 is connected to the CVD deposition chamber 6 through the air intake line 3, and the CVD deposition chamber 6 is connected to the vacuum system through the exhaust line 11. 13 is connected; the inert gas storage tank, the hydrogen storage tank and the organosilicon source gas storage tank are respectively connected to the gas mixing box 2, and the mass flowmeters 1 are respectively arranged on the respective connecting pipelines; the graphite substrate 7 is located on the rotating device 5 in the CVD deposition chamber 6, the weight sensor 4 is located between the graphite substrate 7 and the rotating device 5, and the CVD deposition chamber 6 is also provided with a temperature sensor 8; the pressure sensor 10 is located on the exhaust pipeline 11; the signal output ends of the weight sensor 4, the temperature sensor 8, the pressure sensor 10 and the three mass flowmeters 1 are respectively connected to the signal input end of the control system 12. The three mass flowmeters 1 are respectively used to control the mass flow of the inert gas, hydrogen and organosilicon source gas; the weight sensor 4 is used to monitor the mass change of the graphite substrate 7, and the current mass deposition rate in the vapor deposition process is obtained based on the mass change of the graphite substrate 7, and the rate acquisition module is used to obtain the mass change of the graphite substrate 7; the temperature sensor 8 is used to monitor the deposition temperature; the pressure sensor 10 is used to monitor the deposition pressure.

[0083] According to a fifth aspect of the present application, a computer device is provided, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method according to the first aspect when executing the computer program.

[0084] In some embodiments, the computer device may be a terminal. The computer device includes a processor, a memory, a network interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, a method for controlling the real-time deposition rate of vapor deposition is implemented. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a button, a trackball or a touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0085] According to a sixth aspect of the present application, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method described in the first aspect are implemented.

[0086] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided by the present invention can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0087] The following is a specific embodiment 1

[0088] Use Figure 1The vapor deposition device shown is used to prepare a silicon carbide coating. The vapor deposition device includes a mass flow meter 1, a gas mixing box 2, an air intake line 3, a weight sensor 4, a rotating device 5, a CVD deposition chamber 6, a graphite substrate 7, a temperature sensor 8, a pressure sensor 10, an exhaust line 11, a control system 12 and a vacuum system 13; the control system 12 includes a memory and a processor, the memory stores a computer program, and the processor implements the steps of the method described in the first aspect of the present application when executing the computer program; the gas mixing box 2 is connected to the CVD deposition chamber 6 through the air intake line 3, and the CVD deposition chamber 6 is connected to the CVD deposition chamber 6 through the air intake line 3. It is connected to the vacuum system 13 through the exhaust pipe 11; the inert gas storage tank, the hydrogen storage tank and the organosilicon source gas storage tank are respectively connected to the mixing box 2, and mass flow meters 1 are respectively arranged on their respective connecting pipes; the graphite substrate 7 is located on the rotating device 5 in the CVD deposition chamber 6, the weight sensor 4 is located between the graphite substrate 7 and the rotating device 5, and a temperature sensor 8 is also arranged in the CVD deposition chamber 6; the pressure sensor 10 is located on the exhaust pipe 11; the signal output ends of the weight sensor 4, the temperature sensor 8, the pressure sensor 10 and the three mass flow meters 1 are respectively connected to the signal input ends of the control system 12.

[0089] The preparation method of silicon carbide coating is as follows:

[0090] After pretreatment, the disk-type graphite base was placed in the CVD deposition furnace of the above-mentioned vapor deposition equipment, and the temperature was raised to 1100°C at a rate of 2.5°C / min, and kept warm for 1 hour; then, 100g / min of argon, 100g / min of hydrogen and 10g / min of methyltrichlorosilane (MTS) were introduced at an initial flow ratio of 10:10:1 for deposition, and the pressure of the CVD deposition chamber 6 was controlled to be 10000±100Pa, and the deposition time was 3 hours;

[0091] At the beginning of deposition, the online weighing system is started, and the mass change data of the graphite base is obtained through the weight sensor 4. The control system 12 records the mass increase of the graphite base in real time (once every 10 seconds), and the current mass deposition rate is obtained by calculation. According to the difference between the current mass deposition rate and the target mass deposition rate of 50 μm / h, the deposition temperature, deposition pressure and the mass flow rates of the inert gas, hydrogen and organic silicon source gas are dynamically adjusted, so that the difference between the current mass deposition rate and the target mass deposition rate is within the preset range of -5 μm / h to 5 μm / h; the specific adjustment process is as follows:

[0092] If the current mass deposition rate is less than the target mass deposition rate of 50 μm / h, based on the absolute value of the difference between the current mass deposition rate and the target mass deposition rate, for every 1 μm / h difference, the real-time deposition temperature is increased by 3°C to 10°C, the real-time deposition pressure is increased by 30Pa to 100Pa, and the real-time mass flow rates of argon, hydrogen, and methyltrichlorosilane are all increased by 0.5% to 5%;

[0093] If the current mass deposition rate is greater than the target mass deposition rate of 50 μm / h, based on the absolute value of the difference between the current mass deposition rate and the target mass deposition rate, for every 1 μm / h difference, the real-time deposition temperature is reduced by 3°C to 10°C, the real-time deposition pressure is reduced by 30Pa to 100Pa, and the real-time mass flow rate of the gas source is reduced by 0.5% to 5%;

[0094] If the current mass deposition rate is equal to the target mass deposition rate of 50 μm / h, no adjustment is made to the deposition temperature, deposition pressure and atmosphere;

[0095] According to the above steps, the deposition temperature, deposition pressure, and the flow rates of argon, hydrogen, and methyltrichlorosilane were dynamically adjusted until the deposition time reached 180 min;

[0096] After the deposition is completed, methyltrichlorosilane and hydrogen are cut off, and argon is retained. The temperature in the CVD deposition chamber 6 is reduced to 700°C at a rate of 1°C / min and kept warm for 3 hours; then the temperature is reduced to room temperature at a rate of 0.5°C / min, and the argon gas is repeatedly replaced three times before the furnace cover is opened; the pressure of the CVD deposition chamber 6 is always controlled within the range of 10000±100Pa.

[0097] Comparative Example 1

[0098] The vapor deposition equipment used in Comparative Example 1 is a conventional vapor deposition equipment, which is different from the vapor deposition equipment of Example 1 in that the weight sensor 4 is not provided.

[0099] After pretreatment, the disk-type graphite base is placed in a CVD deposition furnace, and the temperature is raised to 1100°C at a rate of 2.5°C / min and kept at this temperature for 1 hour; then, argon, hydrogen and methyltrichlorosilane (MTS) are introduced at a flow ratio of 10:10:1 for deposition, and the deposition time is 3 hours. The pressure of the CVD deposition chamber is controlled to be 10000±100Pa, and the temperature in the CVD deposition chamber is reduced to 700°C at a rate of 1°C / min and kept at this temperature for 3 hours; after the deposition, methyltrichlorosilane and hydrogen are cut off, argon is retained, and then the temperature is reduced to room temperature at a rate of 0.5°C / min, and the furnace cover is replaced with argon three times before opening; the pressure of the CVD deposition chamber is always controlled within the range of 10000±100Pa.

[0100] The silicon carbide coatings prepared in Example 1 and Comparative Example 1 were tested for thickness uniformity and metal impurity content. The test results are shown in Table 1 below.

[0101] When testing the thickness uniformity of silicon carbide coating, the sampling position of the coating thickness uniformity test is as follows: Figure 2 Shown (front and back of base).

[0102] Table 1

[0103]

[0104] It can be seen from Table 1 above that the extreme difference value of the front silicon carbide coating of Comparative Example 1 is as high as 46.6, and that of Example 1 is 11.8. The extreme difference value of the back silicon carbide coating of Comparative Example 1 is as high as 32.1, and that of Example 1 is 14.2. The thickness uniformity of the silicon carbide film of Example 1 is better than that of Comparative Example 1.

[0105] Example 1 obtains the current mass deposition rate based on the mass change per unit time by regulating the current mass deposition rate during the vapor deposition process, and then dynamically adjusts the real-time deposition temperature, real-time deposition pressure, and real-time mass flow rate of the gas source during the vapor deposition process according to the comparison result between the current mass deposition rate and the target mass deposition rate, so as to control the deviation between the current mass deposition rate and the target mass deposition rate within a preset range, and more accurately control the deposition thickness of the coating per unit time, thereby improving the thickness uniformity of the silicon carbide coating.

[0106] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0107] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for controlling the real-time deposition rate of vapor deposition, characterized in that: The steps include: (1) obtaining the current mass deposition rate during the vapor deposition process; (2) comparing the current mass deposition rate with the target mass deposition rate to obtain a deposition rate comparison result; (3) if the deposition rate comparison result is that the difference between the current mass deposition rate and the target mass deposition rate is not within a preset range, then correcting at least one parameter of the real-time deposition temperature, the real-time deposition pressure, and the real-time mass flow rate of the gas source during the vapor deposition process; (4) After step (3), steps (1) to (3) are repeated n times until the deposition rate comparison result shows that the difference is within the preset value; n is an integer.

2. The method for controlling the real-time deposition rate of vapor deposition according to claim 1, characterized in that: Step (1) comprises the following steps: The current mass deposition rate is obtained based on the mass change in the previous period of time with the current moment as the end point of time; optionally, the duration of the previous period of time is 5s to 50s.

3. The method for controlling the real-time deposition rate of vapor deposition according to claim 1 or 2, characterized in that: Step (2) comprises the following steps: Comparing the current mass deposition rate with the target mass deposition rate to obtain a difference between the current mass deposition rate and the target mass deposition rate; Comparing the difference with the preset range to obtain the deposition rate comparison result; The deposition rate comparison result includes whether the difference is within the preset range.

4. The method for controlling the vapor deposition rate in real time according to claim 1, characterized in that: If the difference between the current mass deposition rate and the target mass deposition rate is a negative number, then at least one parameter among the real-time deposition temperature, the real-time deposition pressure and the real-time mass flow rate of the gas source during the vapor deposition process is corrected by increasing the value of the at least one parameter.

5. The method for controlling the real-time deposition rate of vapor deposition according to claim 1, characterized in that: If the difference between the current mass deposition rate and the target mass deposition rate is a positive number, the method of correcting at least one parameter among the real-time deposition temperature, the real-time deposition pressure and the real-time mass flow rate of the gas source during the vapor deposition process is to reduce the value of the at least one parameter.

6. The method for controlling the real-time deposition rate of vapor deposition according to claim 4 or 5, characterized in that: Modifying the magnitude of the value of the at least one parameter comprises the following steps: Based on the absolute value of the difference between the current mass deposition rate and the target mass deposition rate, the correction range of the real-time deposition temperature is 3°C to 10°C for every 1 μm / h difference, the correction range of the real-time deposition pressure is 30Pa to 100Pa, and the correction range of the real-time mass flow rate of the gas source is 0.5% to 5%.

7. A control system for real-time deposition rate of vapor deposition, characterized in that: include: A rate acquisition module, used to acquire the current mass deposition rate during the vapor deposition process; a comparison result determination module, configured to compare the current mass deposition rate with the target mass deposition rate to obtain a deposition rate comparison result when the deposition rate comparison result is that the difference between the current mass deposition rate and the target mass deposition rate is not within a preset range; and, A rate correction module is used to correct at least one parameter among the real-time deposition temperature, the real-time deposition pressure and the real-time mass flow rate of the gas source in the vapor deposition process according to the deposition rate comparison result, so as to correct the current mass deposition rate in the vapor deposition process until the deposition rate comparison result is: the difference between the current mass deposition rate and the target mass deposition rate is within the preset value.

8. A method for preparing a silicon carbide coating, characterized in that: The steps include: A silicon carbide coating is prepared by vapor deposition, and the vapor deposition real-time deposition rate control method according to any one of claims 1 to 6 is used during the vapor deposition process.

9. A vapor deposition device, characterized in that: A control system for real-time deposition rate of vapor deposition comprising the system described in claim 7.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

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