TWI856263B - Chemical vapor deposition device and substrate temperature control method - Google Patents

Abstract

The present invention discloses a chemical vapor deposition device and a substrate temperature control method. The device includes a reaction chamber, in which a substrate tray supported by a rotating shaft is arranged. The substrate tray is located below an air inlet nozzle. A plurality of downwardly recessed substrate carrying areas are arranged on the substrate tray for placing substrates. A plurality of first independent air channels are arranged in the substrate tray, each of which is connected to a substrate carrying area, so that heat-conducting gas is introduced into the pit space between the bottom surface of the substrate and the upper surface of the substrate carrying area. A heater is arranged below the substrate tray, and the heater is arranged around the rotating shaft, so as to control the temperature of the upper substrate, and the temperature control of the substrate is realized by utilizing the gas in the pit space for heat conduction. The present invention realizes heating temperature consistency between wafers on a substrate tray.

Description

Chemical vapor deposition device and substrate temperature control method

The present invention relates to the field of semiconductor technology, and in particular to a chemical vapor deposition device and a substrate temperature control method.

Chemical vapor deposition (CVD) reactors, especially metal organic chemical vapor deposition (MOCVD) reactors, are the main equipment for producing optical devices such as light emitting diode (LED) epitaxial wafers. Typical chemical vapor deposition (CVD) and metal organic chemical vapor deposition (MOCVD) reactors need to rotate the carrier plate with the processed substrate during deposition, so as to provide a uniform deposition effect for the substrate. As shown in Figure 1, a typical vapor deposition reactor structure is a reaction chamber surrounded by the side walls of the reaction chamber, and the reaction chamber includes a rotating shaft, and a substrate tray 10 with a plurality of substrates 20 is mounted on the top of the rotating shaft. The top of the reaction chamber includes a gas inlet nozzle, which is used to uniformly inject the reaction gas from the reaction gas source into the reaction chamber to achieve processing of the substrate 10. The bottom of the reaction chamber also includes a vacuum device to control the internal air pressure of the reaction chamber and remove the waste gas generated during the reaction process.

In the MOCVD reaction process, not only the type of gas and the gas flow have a great influence on the deposition effect, but also the temperature distribution is an important factor affecting the formation of the crystal structure. Therefore, please continue to refer to Figure 1. A heater 30 is provided in the area below the edge of the substrate tray 20. The substrate (wafer) 20 is placed in the wafer supporting groove 13 on the substrate tray 10. The edge of the wafer supporting groove 13 is provided with a plurality of wafer supporting steps 12. Each of the wafers 20 is placed on the wafer supporting step 12. The height between the bottom surface 11 of the wafer supporting groove 13 and the top surface of the wafer supporting step 12 is h. In the chemical vapor deposition process, especially the metal vapor chemical deposition MOCVD process, the above-mentioned wafer 20 and the substrate tray 10 enter the chemical reaction chamber together for the process coating. For each of the wafers 20, its heating mode is: 1. receiving radiation heating of the bottom surface (bottom plane) 11 of the wafer holding groove 13; 2. thermal conduction heating of the gas between the bottom of the wafer 20 and the corresponding bottom surface 11.

The heater 30 is usually placed parallel to the substrate tray 10. When the heater 30 is powered on, the temperature rises and the heat is transferred to the substrate tray 10 by radiation heat transfer. The substrate tray 10 is usually made of materials with good thermal conductivity such as graphite or silicon carbide, which can evenly distribute the received heat energy so that the temperature of the bottom surface 11 is uniform. The bottom surface 11 then transfers the heat to the bottom of the wafer 20 by radiation and heat transfer of the gas in the wafer holding groove 13 below the wafer 20.

It can be seen that during the above-mentioned process of the wafer 20 being heated by radiation, the height h between the bottom surface 11 of the wafer carrying groove 13 and the top surface of the wafer supporting step 12 and the surface emissivity of the bottom surface 11 will affect the temperature uniformity of the wafer 20. However, these two factors cannot be guaranteed to be completely consistent during the processing of the substrate tray 10, which will cause deviations in the process results between wafers.

For example: In the LED manufacturing process, it often happens that the wavelength uniformity of each wafer 20 meets the standard, but the average wavelength deviation between the wafers 20 on the substrate tray 10 is large. If the temperature of a wafer 20 in a wafer supporting groove 13 is found to be abnormal, it is necessary to mechanically repair the wafer supporting groove 13 offline, adjust the height h between the bottom surface 11 of the wafer supporting groove 13 and the top surface of the wafer supporting step 12, or adjust the roughness of the bottom surface 11 of the wafer supporting groove 13 to improve the surface emissivity, thereby improving the temperature consistency between the wafers 20. However, the above temperature adjustment method cannot achieve instant adjustment, and the adjustment method is time-consuming and labor-intensive, resulting in increased wafer preparation costs and reduced yields.

The purpose of the present invention is to provide a chemical vapor deposition device and a substrate temperature control method, so as to monitor and fine-tune the temperature of each wafer in real time during the deposition process, so as to achieve the purpose of heating temperature consistency between each wafer on the substrate tray.

In order to achieve the above purpose, the present invention is implemented by the following technical solutions: a chemical vapor deposition device, comprising a reaction chamber, a gas inlet nozzle is arranged at the top of the reaction chamber, a substrate tray supported by a rotating shaft is arranged in the reaction chamber, the substrate tray is located below the gas inlet nozzle, the substrate tray is used to carry a substrate, a plurality of substrate carrying areas recessed downwards are arranged on the substrate tray, and a plurality of first independent Air channels, each first independent air channel is connected to one of the substrate carrying areas, and a heat-conducting gas with independently adjustable components is introduced into the pit space between the bottom surface of the substrate and the upper surface of the substrate carrying area, and the heat-conducting gas contains one or more gas components; a heater is arranged under the substrate tray, and the heater is arranged around the rotating axis to control the temperature of the upper substrate, and the substrate uses the gas in the pit space for heat conduction to achieve temperature control of the substrate.

Preferably, the flow rate of the heat conductive gas is 1~500sccm.

Preferably, the heat-conducting gas includes one or more of hydrogen, nitrogen, helium, and argon.

Preferably, the heat-conducting gas composition in the pit space between any two substrate-carrying areas and the corresponding substrates is different.

Preferably, the rotating shaft includes a plurality of second independent air passages respectively connected to the plurality of first independent air passages, and each set of first and second independent air passages together constitute an independent air flow path for the gas to flow to the pit space.

Preferably, the rotating shaft includes an upper part and a lower part, the upper part is located in the reaction chamber, and the lower part is located in the atmosphere outside the reaction chamber. Each second independent air channel has an air inlet, and the air inlet is located at the lower part of the rotating shaft. A certain flow of gas is input into the air inlet by the air supply device outside the reaction chamber, and the air supply device outputs heat-conducting gas with multiple components that are independently adjustable to the air inlets of the plurality of second independent air channels.

Preferably, the side wall of the lower part of the rotating shaft is sealed with the reaction chamber by a plurality of magnetic fluid rings, and a plurality of airtight annular spaces are formed between different magnetic fluid rings, and each of the air inlets is located in a different annular space.

Preferably, the second independent air passage in the rotating shaft includes an axial hole extending upward from the lower part of the rotating shaft to the upper part of the rotating shaft; the air inlet is a side hole opened on the circumferential side surface of the rotating shaft; the bottom of the axial hole is connected to the corresponding side hole, and the axial hole is connected to the first independent air passage through a connecting hole on the top surface or the side wall of the top of the rotating shaft.

Preferably, the distances between the lateral surfaces of any two second independent airways and the top surface of the rotation axis are different.

Preferably, each axial hole and/or each side hole is independent of each other and not connected to each other.

Preferably, the flow rate of the multi-channel heat-conducting gas output by the gas supply device is adjusted so that the substrate is not lifted by the gas in the pit space.

Preferably, it further comprises: a plurality of gas flow controllers, respectively used to control the flow of various heat-conducting gases in a plurality of pit spaces; at least one detection sensor, used to monitor the temperature of each substrate; a control module, receiving the temperature of the substrate fed back by the detection sensor, and sending corresponding control commands to the plurality of gas flow controllers according to preset conditions, to control the flow of various heat-conducting gases in each pit space corresponding to each gas flow controller, so as to adjust the gas ratio of the pit space under each substrate.

Preferably, it also includes: an air supply device, the air supply device includes a plurality of air sources, each of the gas flow controllers controls the flow of different air sources, mixes to form the plurality of heat-conducting gases, and delivers the heat-conducting gases to each of the independent airflow paths accordingly.

On the other hand, the present invention also provides a method for controlling the temperature of a substrate in a chemical vapor deposition device, comprising: providing a chemical vapor deposition device as described above; placing a substrate on a substrate tray in a reaction chamber of the chemical vapor deposition device, on which a plurality of substrate carrying areas are recessed downward, and the substrate tray is supported by a rotating shaft; introducing a heat-conducting gas with independently adjustable components into a pit space between the bottom surface of the substrate and the bottom surface of the substrate carrying area, wherein the heat-conducting gas contains one or more gas components; the substrate is not lifted by the gas in the pit space; a heater under the substrate tray controls the temperature of the gas in the pit space, and the temperature control of the substrate is achieved by heat conduction of the gas in the pit space.

Preferably, the air pressure in the pit space is adjusted by controlling the flow rate of the gas input at the air inlet to ensure that the substrate is not lifted by the gas in the pit space.

Compared with the prior art, the present invention has at least one of the following advantages: the present invention introduces a heat-conducting gas with independently adjustable components into the pit space between the bottom surface of the substrate and the upper surface of the substrate carrying area, and the heat-conducting gas contains one or more gas components; a heater is arranged under the substrate tray, and the heater is arranged around the rotating axis to control the temperature of the upper substrate. The substrate uses the gas in the pit space for heat conduction to achieve temperature control of the substrate, thereby achieving temperature consistency between each substrate or wafer on the substrate tray.

During the deposition process, the substrate tray rotates, and the in-situ detector (detection sensor) monitors the temperature of each substrate in real time and feeds back the temperature value to the control module. According to the pre-set algorithm, the control module sends a command to the gas flow controller to independently adjust the ratio of the heat-conducting gas under each substrate, thereby maintaining the temperature consistency between each substrate or wafer on the substrate tray. It can be seen that the above adjustment method is simple and convenient, reduces the substrate preparation cost, and improves the yield.

10,200: Substrate tray

11: Bottom surface

12,402: Wafer support platform

13: Wafer carrying groove

20: Wafer

30,500: Heater

100: reaction chamber

300: substrate

400: pit space

401: substrate carrying area

600: Rotation axis

2001: First independent airway

2010:Entrance

6001: Rotating shaft

6002: Shell

6003: Second independent airway

6004: Airway spacer ring

6005: Magnetic fluid sealing liquid

6006: Bearings

6011: First air inlet

6012: Second air inlet

6013: Third air inlet

6014: Fourth air inlet

6020: Axial hole

FIG. 1 is a schematic diagram of the cross-sectional structure of a wafer carrying groove in a substrate tray in the prior art; FIG. 2 is a schematic diagram of the structure of a chemical vapor deposition device provided in an embodiment of the present invention; FIG. 3 is a schematic diagram of the comparison of thermal conductivity between nitrogen, hydrogen and helium at different temperatures provided in an embodiment of the present invention; FIG. 4 is a schematic diagram of the cross-sectional structure of an independent airflow path in a chemical vapor deposition device provided in an embodiment of the present invention; Figure 5 is a schematic diagram of the structure of a substrate tray in a chemical vapor deposition device provided in an embodiment of the present invention; Figure 6 is a schematic diagram of the structure of a rotating shaft in a chemical vapor deposition device provided in an embodiment of the present invention; Figure 7 is a schematic diagram of the structure of an air channel in a rotating shaft in a chemical vapor deposition device provided in an embodiment of the present invention; Figure 8 is a schematic diagram of the airflow control process in a chemical vapor deposition device provided in an embodiment of the present invention.

The following is a further detailed description of a chemical vapor deposition device and a substrate temperature control method proposed by the present invention in combination with the attached drawings and specific implementation methods. According to the following description, the advantages and features of the present invention will be more clear. It should be noted that the attached drawings are in a very simplified form and are not in exact proportions, which are only used to conveniently and clearly assist in explaining the purpose of the implementation methods of the present invention. In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, please refer to the attached drawings. It should be noted that the structures, proportions, sizes, etc. depicted in the drawings attached to this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions for the implementation of the present invention, so they have no substantial technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention.

In conjunction with FIGS. 2 to 8 , the present embodiment provides a chemical vapor deposition apparatus, including a reaction chamber 100, wherein a gas inlet nozzle (understandably, a flat gas shower head) is disposed at the top of the reaction chamber 100, wherein a substrate tray 200 supported by a rotating shaft 600 is disposed in the reaction chamber 100, wherein the substrate tray 200 is located below the gas inlet nozzle, and wherein the substrate tray 200 is used to carry a substrate 300, wherein the substrate tray 200 is provided with a plurality of substrate carrying areas recessed downwards for placing the substrate 300, wherein the substrate tray 200 is provided with a plurality of The first independent air channel 2001, each of which is connected to a substrate carrying area, is used to pass heat-conducting gas with independently adjustable components into the pit space 400 between the bottom surface of the substrate 300 and the upper surface of the substrate carrying area, and the heat-conducting gas contains one or more gas components; a heater 500 is arranged below the substrate tray 200, and the heater 500 is arranged around the rotating shaft 600 to control the temperature of the upper substrate 300. The substrate 300 uses the gas in the pit space 400 for heat conduction to achieve temperature control of the substrate 300.

In this embodiment, please continue to refer to Figures 2 and 4. The rotating shaft 600 includes a plurality of second independent air channels 6003 that are respectively connected to the plurality of first independent air channels 2001. Each group of first independent air channels 2001 and second independent air channels 6003 together constitute an independent air flow path for the gas to flow to the pit space 400.

The rotating shaft 600 includes an upper part and a lower part, the upper part is located in the reaction chamber 100, and the lower part is located in the atmosphere outside the reaction chamber 100. Each second independent air channel 6003 has an air inlet (for example, the first air inlet 6011, the second air inlet 6012, the third air inlet 6013 and the fourth air inlet 6014 as shown in Figure 2). The air inlet is located at the lower part of the rotating shaft. A certain flow of gas is input into the air inlet by the air supply device outside the reaction chamber 100. The air supply device outputs heat-conducting gas with multiple components that are independently adjustable to the air inlets of the plurality of second independent air channels 6003.

The rotating shaft 600 includes a housing 6002 and a rotating shaft 6001, and the rotating shaft 6001 is sleeved inside the housing 6002. The rotating shaft 6001 is located in the reaction chamber 100 and contacts the substrate tray 200.

The side wall (housing 6002) at the lower part of the rotating shaft is sealed by a plurality of magnetic fluid rings (each magnetic fluid ring includes an airway baffle ring 6004 and a magnetic fluid sealing liquid 6005, the airway baffle ring 6004 is sleeved on the rotating shaft 6001, and the outer ring edge of the airway baffle ring 6004 is sealedly connected to the inner side wall of the housing 6002, and the inner ring edge is sealed by the magnetic fluid ring 6005. The fluid sealing liquid 6005 is sealed and connected to the surface of the rotating shaft 6001. The magnetic fluid sealing liquid 6005 realizes the rotational dynamic seal between the rotating shaft 6001 and the airway isolation ring 6004) and realizes the seal with the reaction chamber 100. A plurality of airtight annular spaces are formed between different magnetic fluid rings, and each of the air inlets is located in a different annular space. The rotating shaft 600 also includes a bearing 6006, which is arranged in the housing 6002, and the rotating shaft 6001 passes through the bearing 6006, and the bearing 6006 provides support for the rotating shaft 6001.

Please continue to refer to Figure 7. The second independent air channel 6003 in the rotating shaft 600 includes an axial hole 6020 extending upward from the lower part of the rotating shaft 600 to the upper part of the rotating shaft 600; and is parallel to the axis of the rotating shaft 600; the air inlet is a side hole opened on the circumferential side surface of the rotating shaft 600; the bottom of the axial hole 6020 is connected to the corresponding side hole, and the axial hole 6020 is connected to the first independent air channel 2001 through the connecting hole on the top surface or the side wall of the top of the rotating shaft 600.

The distances between the side holes of any two second independent air channels 6003 and the top surface of the rotation axis 600 are different. Each axial hole 6020 and/or each side hole is independent of each other and not connected to each other. Each of the axial holes 6020 is connected to the inlet 2010 of the first independent air channel 2001.

As shown in FIG. 5 , the substrate tray 200 is provided with a plurality of substrate carrying areas 401 that are concave downwards, and a plurality of wafer supporting steps 402 are provided at the edge of the substrate carrying area 401, and each of the substrates 300 is mounted on the wafer supporting step 402. Therefore, the edges of the substrate 300 and the substrate carrying area 401 of the substrate tray 200 are not sealed circumferentially, so the temperature regulating airflow needs to flow continuously. After the heat conducting gas completes heat conduction at the bottom of the pit space 400, it flows out from the gap at the edge of the substrate. Since the regulating airflow usually has a small flow rate, it has little effect on the chemical reaction process on the top surface of the substrate tray.

Please continue to refer to FIG. 8, which further includes: a plurality of gas flow controllers, respectively used to control the flow of various heat-conducting gases in a plurality of pit spaces 400; at least one detection sensor (in-situ monitoring sensor), used to in-situ monitor the temperature of each substrate; a control module, receiving the temperature of the substrate (wafer) fed back by the detection sensor, and sending corresponding control commands to the plurality of gas flow controllers according to preset conditions, to control the flow of various heat-conducting gases in each pit space corresponding to each gas flow controller, so as to adjust the gas ratio of the pit space under each substrate.

The heat-conducting gas includes one or more of hydrogen, nitrogen, helium, and argon.

Specifically, regarding gas heat transfer, taking into account the existence of temperature gradients, as well as the interaction between molecules and the molecular kinetic energy of polyatomic gases, the following classic formula can be used to calculate the molecular thermal conductivity K:

Where K represents the thermal conductivity of gas; η represents the viscosity coefficient of gas; γ represents the adiabatic coefficient; c _v represents the constant volume heat capacity.

The pressure of the usual chemical vapor deposition process is higher than 1Torr. Under this condition, the product of the gas density and the mean free path is a constant, so the gas thermal conductivity K is a function of temperature and has nothing to do with pressure. Please continue to refer to Figure 3, which is a comparison of the thermal conductivity of nitrogen, hydrogen and helium at different temperatures. It can be seen that within the process temperature range of MOCVD (500~1100℃), the thermal conductivity of hydrogen is about 7 times that of nitrogen, and the thermal conductivity of helium is about 5.5 times that of nitrogen.

The heat-conducting gas composition of the pit space 400 between any two substrate carriers and the corresponding substrates 300 is different. It can be understood that the different composition here may be that the types of heat-conducting gases are not completely the same, and the ratios between the various heat-conducting gases are different.

The air pressure of the pit space 400 is adjusted by controlling the flow rate of the gas input at the air inlet, that is, adjusting the flow rate of the multi-path heat-conducting gas output by the gas supply device, so that the substrate is not lifted by the gas in the pit space; in this embodiment, the flow rate of the heat-conducting gas in the pit space 400 is 1-500 sccm (Standard cubic centimeters per minutes). It can be understood that due to the different substrate sizes, pressures, airflows, and temperatures of the specific chemical reaction processes, the flow rate of the heat-conducting gas on the back of the substrate is also different. For example, when the substrate area is large (for example, 4 or 6 inches), the corresponding flow rate of the heat-conducting gas can be increased, and when the substrate area is small (for example, 2 inches), the flow rate of the heat-conducting gas needs to be reduced, so the range of the flow rate of the above-mentioned heat-conducting gas is not limited thereto. The basic requirement for regulating the flow rate of the heat-conducting gas is that the air pressure is sufficient to conduct heat but does not cause the substrate to lift up and float.

In this embodiment, it also includes: an air supply device, the air supply device includes a plurality of air sources, each of the gas flow controllers controls the flow of different air sources, mixes to form the plurality of heat-conducting gases, and delivers the heat-conducting gases to each of the independent airflow paths accordingly.

On the other hand, the present embodiment also provides a method for controlling the temperature of a substrate of a chemical vapor deposition device, comprising: providing a chemical vapor deposition device as described above; placing a substrate on a substrate tray in a reaction chamber of the chemical vapor deposition device, on which a plurality of substrate carrying areas are recessed downward, the substrate tray being supported by a rotating shaft; introducing a heat-conducting gas with independently adjustable components into a pit space between the bottom surface of the substrate and the bottom surface of the substrate carrying area, the heat-conducting gas comprising one or more gas components; the substrate is not lifted by the gas in the pit space; a heater under the substrate tray controls the temperature of the gas in the pit space, and the temperature control of the substrate is achieved by heat conduction of the gas in the pit space.

The air pressure in the pit space is adjusted by controlling the flow rate of the gas input at the air inlet to ensure that the substrate is not lifted by the gas in the pit space.

In summary, in this embodiment, a heat-conducting gas with independently adjustable components is introduced into the pit space between the bottom surface of the substrate and the upper surface of the substrate carrying area, and the heat-conducting gas includes one or more gas components; a heater is arranged below the substrate tray, and the heater is arranged around the rotating axis to control the temperature of the upper substrate. The substrate uses the gas in the pit space for heat conduction to achieve temperature control of the substrate, thereby achieving temperature consistency between each substrate or wafer on the substrate tray.

During the deposition process, the substrate tray rotates, and the in-situ detector (detection sensor) monitors the temperature of each substrate in real time and feeds back the temperature value to the control module. According to the pre-set algorithm, the control module sends a command to the gas flow controller to independently adjust the ratio of the heat-conducting gas under each substrate, thereby maintaining the temperature consistency between each substrate or wafer on the substrate tray. It can be seen that the above adjustment method is simple and convenient, reduces the substrate preparation cost, and improves the yield.

It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variation thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, the elements defined by the phrase "including a..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

In the description of the present invention, it should be understood that the terms "center", "height", "thickness", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the attached drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

In the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", "connection", and "fixation" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two components or the interaction relationship between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

In the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or the first and second features not being in direct contact but being in contact through another feature between them. Moreover, the first feature being "above", "above" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

Although the content of the present invention has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the present invention. After reading the above content, various modifications and substitutions of the present invention will be obvious to those skilled in the art. Therefore, the scope of protection of the present invention should be limited by the scope of the attached patent application.

100: reaction chamber

200: Substrate tray

300: substrate

400: pit space

500: Heater

600: Rotation axis

2001: First independent airway

6001: Rotating shaft

6002: Shell

6003: Second independent airway

6004: Airway spacer ring

6005: Magnetic fluid sealing liquid

6006: Bearings

6011: First air inlet

6012: Second air inlet

6013: Third air inlet

6014: Fourth air inlet

Claims (12)

A chemical vapor deposition device comprises a reaction chamber, a gas inlet nozzle is arranged at the top of the reaction chamber, a substrate tray supported by a rotating shaft is arranged in the reaction chamber, the substrate tray is located below the gas inlet nozzle, the substrate tray is used to carry a substrate, wherein the substrate tray is provided with a plurality of substrate holding areas which are recessed downwards for placing the substrate, a plurality of first independent gas channels are arranged in the substrate tray, each of the first independent gas channels is connected to one of the substrate holding areas, and a heat-conducting gas with independently adjustable components is introduced into a recessed space between the bottom surface of the substrate and the upper surface of the substrate holding area, and the heat-conducting gas contains a plurality of gas components; at least two of the substrate holding areas are respectively connected to the substrate holding areas. The composition of the heat-conducting gas in the pit space between the substrates is different; the flow rate of the heat-conducting gas is 1-500 sccm; the distance between the bottom surface of the substrate and the upper surface of the substrate carrying area is unchanged; the side wall of the lower part of the rotating shaft is sealed with the reaction chamber by a plurality of magnetic fluid rings, and a plurality of airtight annular spaces are formed between the different magnetic fluid rings, and each of the annular spaces is provided with an air inlet; the first independent air channel is connected with the corresponding annular space respectively; a heater is provided under the substrate tray, and the heater is provided around the rotating shaft to control the temperature of the upper substrate, and the substrate uses the heat-conducting gas in the pit space for heat conduction to achieve temperature control of the substrate. A chemical vapor deposition device as described in claim 1, wherein the heat-conducting gas comprises one or more of hydrogen, nitrogen, helium, and argon. The chemical vapor deposition device as described in claim 1, wherein the rotating shaft includes a plurality of second independent air channels that are respectively connected to a plurality of first independent air channels, and each set of the first and second independent air channels together constitute an independent air flow path for the heat-conducting gas to flow to the pit space. The chemical vapor deposition device as described in claim 3, wherein the rotating shaft includes an upper portion and a lower portion, the upper portion is located in the reaction chamber, and the lower portion is located in the atmosphere outside the reaction chamber, each of the second independent air channels has an air inlet, the air inlet is located at the lower portion of the rotating shaft, a certain flow of gas is input into the air inlet from an air supply device outside the reaction chamber, and the air supply device outputs the heat-conducting gas with multiple independently adjustable components to the air inlets of the plurality of second independent air channels. The chemical vapor deposition device as described in claim 4, wherein the second independent air channel in the rotating shaft includes an axial hole extending upward from the lower part of the rotating shaft to the upper part of the rotating shaft; the air inlet is a side hole opened on the circumferential side surface of the rotating shaft; the bottom of the axial hole is connected to the corresponding side hole, and the axial hole is connected to the first independent air channel through a connecting hole on the top surface or the side wall of the top of the rotating shaft. A chemical vapor deposition device as described in claim 5, wherein the distances between the side surface holes of any two of the second independent air channels and the top surface of the rotating shaft are different. A chemical vapor deposition device as described in claim 6, wherein each of the axial holes and/or each of the side holes are independent of each other and are not connected to each other. A chemical vapor deposition device as described in any one of claims 4 to 7, wherein the flow rate of the multiple heat-conducting gases output by the gas supply device is adjusted so that the substrate is not lifted by the gas in the pit space. A chemical vapor deposition device as described in any one of claim items 1 to 8, wherein further comprising: a plurality of gas flow controllers, respectively used to control the flow of various heat-conducting gases in a plurality of the pit spaces; at least one detection sensor, used to monitor the temperature of each substrate; a control module, receiving the temperature of the substrate fed back by the detection sensor, and sending corresponding control commands to the plurality of gas flow controllers according to preset conditions, to control the flow of various heat-conducting gases in each pit space corresponding to each gas flow controller, so as to adjust the gas ratio of the pit space under each substrate. The chemical vapor deposition device as described in claim 9, further comprising: a gas supply device, the gas supply device comprising a plurality of gas sources, each gas flow controller controlling the flow of different gas sources, mixing to form a plurality of heat-conducting gases, and delivering the heat-conducting gases to each of the independent gas flow paths accordingly. A method for controlling the temperature of a substrate of a chemical vapor deposition device, comprising: providing a chemical vapor deposition device as described in any one of claims 1 to 10; placing the substrate on the substrate tray in the reaction chamber of the chemical vapor deposition device, on the plurality of substrate carrying areas that are recessed downward, and the substrate tray is supported by the rotating shaft; introducing the heat-conducting gas with independently adjustable components into the pit space between the bottom surface of the substrate and the bottom surface of the substrate carrying area, the heat-conducting gas comprising one or more gas components; the substrate is not lifted by the gas in the pit space; the heater under the substrate tray controls the temperature of the gas in the pit space, and the temperature control of the substrate is achieved by heat conduction of the gas in the pit space. A substrate temperature control method for a chemical vapor deposition device as described in claim 11, wherein the air pressure in the pit space is adjusted by controlling the flow rate of the gas input at the gas inlet to ensure that the substrate is not lifted by the gas in the pit space.

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