Chemical vapor deposition apparatus

Abstract

The present invention provides a chemical vapor deposition apparatus. Gas heating and feeding devices are arranged at the top of a process chamber, the gas heating and feeding devices supply hot gas to the position above carrying areas of a carrying device, and the hot gas assists in heating laminar flow ejected from a process gas feeding device, so that the temperature difference between the upper surfaces and the lower surfaces of substrates in the carrying areas is reduced, and the formation of deposits on the ceiling of the process chamber is suppressed. In addition, the hot gas can also suppress diffusion of laminar-flow process gas away from the substrates, thereby concentrating the process gas near the surfaces of the substrates to enhance film formation on the surfaces of the substrates.

Description

Chemical vapor deposition equipment Technical Field

[0001] The present invention relates to the technical field of semiconductor processing equipment, and in particular to a chemical vapor deposition equipment. Background Art

[0002] The process chamber is a crucial part of semiconductor device manufacturing. In gas-phase reactors, the process chamber is where gases introduce reactants and establish a flow field. For example, epitaxial growth on a wafer involves using gases in the process chamber to introduce reactants and epitaxially grow a specific single-crystalline thin film on the wafer surface. For example, a silicon carbide epitaxial layer grown on a conductive silicon carbide substrate creates a homogeneous silicon carbide epitaxial wafer that can be further fabricated into power devices such as Schottky diodes, MOSFETs, and IGBTs. Device design places high demands on the quality and performance of the epitaxial layer, which is also affected by the substrate processing technology.

[0003] For process chambers used to grow materials via vapor-phase reactions, controlling the temperature field within the process chamber is a crucial factor influencing the reaction. To increase production capacity, multiple large substrates (e.g., 8-inch, 12-inch) are typically laid out flat in the reaction chamber for simultaneous deposition reactions. This requires a sufficiently large process chamber. The larger the chamber, the more difficult it is to achieve the temperature required for a hot-wall process chamber, which can affect the uniformity of the growing epitaxial layer and the quality of the single-crystal thin film. This results in reduced epitaxial growth yield and lower production efficiency.

[0004] Summary of the Invention

[0005] In view of the above-mentioned defects of the gas phase reaction device in the prior art, the present invention provides a chemical vapor deposition device to solve one or more of the above-mentioned problems.

[0006] In order to achieve the above object, one embodiment of the present invention provides a chemical vapor deposition apparatus, comprising:

[0007] process chamber;

[0008] A wafer carrier is disposed in the process chamber, wherein the top surface of the wafer carrier faces the top of the process chamber and is provided with a plurality of wafer carrier areas surrounding the middle portion of the wafer carrier, and a bottom heating device is provided at the bottom of the wafer carrier to heat each of the wafer carrier areas;

[0009] a process gas inlet device, penetrating the top surface of the process chamber and extending to above the middle portion of the wafer carrier device to provide process gas;

[0010] a flow guide portion, disposed at the bottom of the process gas inlet device to guide the process gas to form a laminar flow through each of the wafer carrier areas;

[0011] A heating gas inlet device is arranged around the process gas inlet device at the top of the process chamber and is configured to provide hot gas above each of the carrier areas to assist in heating and stabilizing the laminar flow. The hot gas is chemically inert to the process gas.

[0012] The chemical vapor deposition apparatus of the present invention has the beneficial effect of disposing a heated gas inlet device at the top of the process chamber of the chemical vapor deposition apparatus. The heated gas inlet device supplies hot gas above each wafer loading area of ​​the wafer loading apparatus. This hot gas assists in heating the laminar flow ejected from the process gas inlet device, thereby reducing the temperature difference between the upper and lower surfaces of the substrate in each wafer loading area and suppressing the formation of deposits on the ceiling of the process chamber. Furthermore, the heated gas can inhibit the laminar flow of process gas from diffusing away from the substrate, concentrating it near the substrate surface, thereby improving film formation on the substrate surface.

[0013] Optionally, the heating air inlet device includes an air outlet surface located in the process chamber and surrounding the process air inlet device, and a plurality of the carrier areas form a carrier area around the process air inlet device, the carrier area is located below the air outlet surface, and the vertical distance between the carrier area and the air outlet surface is H, the maximum radial length of the area enclosed by the outer edge of the carrier area is L, and the ratio of H to L is not less than 0.2:1.

[0014] Optionally, the ratio of H to L does not exceed 4:1.

[0015] Optionally, at least two mutually unconnected hollow areas are provided on the top surface of the process chamber around the process air inlet device, the number of the heating air inlet devices is at least 2, and the heating air inlet devices are detachably arranged in the hollow areas by static sealing, and the heating air inlet devices can be raised and lowered relative to the process chamber, and the heating air inlet devices are arranged in the hollow areas one by one.

[0016] Optionally, the heating air intake device includes a column, the outer wall of the column and the inner wall of the hollow area are adapted to each other through a threaded connection to achieve a detachable static seal, and a plurality of auxiliary air intake channels are provided in the direction from the top surface of the column to the bottom surface.

[0017] Optionally, the process chamber includes a cover body, the cover body is provided with a cover through-opening, the heating air inlet device includes a spray orifice plate, a lifting device and a hollow elastic device with openings at both ends, one end of the hollow elastic device is sealed and arranged on the top surface of the cover body across the cover through-opening and the other end is fixedly provided with the spray orifice plate, so that the spray orifice plate is communicated with the cover through-opening through the inside of the hollow elastic member, one end of the lifting device is arranged around the side wall of the spray orifice plate, and the other end is arranged around the hollow elastic member on the top surface of the cover.

[0018] Optionally, the hollow elastic member includes a bellows.

[0019] Optionally, the process chamber includes a cover body, the cover body is provided with a cover through-opening, the heating air inlet device includes a spray orifice plate, an air guide cover plate and a hollow adapter with openings at both ends, the top of the hollow adapter is arranged on the bottom surface of the cover body across the cover through-opening, the air guide cover plate is sealed on the top surface of the cover body across the cover through-opening, and the spray orifice plate is suspended in the hollow adapter in a height-adjustable manner.

[0020] Optionally, the chemical vapor deposition equipment further includes an external heating device, which is arranged around the inner wall of the process chamber to supply heat to the process chamber.

[0021] Optionally, the chemical vapor deposition equipment further includes an internal heating device, which is disposed within a side wall of the process air inlet device to supply heat to the process chamber, and the internal heating device and the external heating device are radially opposite to each other along the process chamber.

[0022] Optionally, the internal heating device and the external heating device are both located above the top surface of the carrier device.

[0023] Optionally, several of the carrier areas form a carrier area around the process air inlet device, and the minimum radial distance between the edge of the carrier area closest to the external heating device and the external heating device is 5% to 40% of the radial width of the carrier area.

[0024] Optionally, several of the carrier areas form a carrier area around the process air inlet device, and the minimum radial distance between the edge of the carrier area closest to the internal heating device and the internal heating device is 5% to 40% of the radial width of the carrier area.

[0025] Optionally, the external heating device includes at least two external heating elements arranged in sequence along the axial direction of the process chamber within the inner wall of the process chamber, and the internal heating device includes at least two internal heating elements arranged within the side wall of the process air inlet device, and at least two of the internal heating elements are arranged in a one-to-one correspondence with at least two of the external heating elements.

[0026] Optionally, the process chamber, the process air inlet device, the heating air inlet device and the wafer carrier device enclose a reaction space, and the distance between adjacent external heating elements and the distance between adjacent internal heating elements do not exceed 5% of the height of the reaction space.

[0027] Optionally, the process air inlet device includes an air inlet body and an air inlet channel axially extending through the air inlet body, the air inlet body passes through the top surface of the process chamber and extends to above the middle of the wafer carrier device, and the internal heating device is arranged in the air inlet body around the air inlet channel.

[0028] Optionally, a heat insulating device is provided between the internal heating device and the air intake passage, and the heat insulating device surrounds the air intake passage.

[0029] Optionally, the chemical vapor deposition equipment further includes a rotating device provided on the wafer carrier to drive the wafer carrier to rotate around the axis of the process chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG1 is a schematic structural diagram of a chemical vapor deposition device provided by the present invention.

[0031] FIG. 2 is a schematic top view of the carrying device in FIG. 1 .

[0032] FIG3 is a schematic structural diagram of the process air inlet device and the internal heating device of the present invention.

[0033] FIG4 is a schematic structural diagram showing an optional structure of a process air inlet device and an internal heating device.

[0034] FIG. 5 is a schematic top view of the heated air intake device of the present invention.

[0035] FIG6 is a schematic structural diagram showing another optional structure of the process air inlet device and the internal heating device of the present invention.

[0036] FIG. 7 is a schematic structural diagram showing another optional structure of the internal heating device of the present invention.

[0037] FIG8 is a schematic structural diagram of an internal heating element of a partition of the internal heating device.

[0038] FIG9 is a schematic structural diagram showing an external heating element of a partition of the external heating device.

[0039] FIG10 shows a simplified schematic diagram of a process chamber.

[0040] FIG11 is a schematic top view showing a structure composed of a carrying device, an internal heating device and an external heating device.

[0041] FIG12 is a schematic diagram showing the relationship between the temperature gradient curves of the interaction between adjacent inner heating elements and outer heating elements.

[0042] FIG13 is a top view of a cover on the top of a process chamber in an optional embodiment;

[0043] FIG14 is a schematic diagram showing a partial structure of a heating air intake device in an optional embodiment;

[0044] FIG15 is a schematic diagram showing a partial structure of a heating air intake device in another optional embodiment. DETAILED DESCRIPTION

[0045] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0046] Example

[0047] This embodiment provides a first chemical vapor deposition device. The chemical vapor deposition device has a process chamber, and a carrying portion, i.e., a wafer carrier, is provided inside the process chamber, and the top of the process chamber and the wafer carrier are arranged relative to each other. The carrying portion is used to carry the substrate to be processed, and can be a carrying device, or can be other structures well known to those skilled in the art. The gas phase reaction device can be, for example, a vapor deposition device, specifically, a chemical vapor deposition (CVD) device or a physical vapor deposition (PVD) device. The chemical vapor deposition device can be a plasma-enhanced chemical vapor deposition (PECVD) device, a metal organic chemical vapor deposition (MOCVD) device, etc. This embodiment is described using an MOCVD device as an example. It should be understood that the device is merely exemplary, and the present invention is not limited to this device.

[0048] The chemical vapor deposition apparatus shown in FIG1 includes a process chamber 11. The cross-section of process chamber 11 is generally circular or quasi-circular, or may be rectangular or have other structures known to those skilled in the art, which will not be described in detail herein. A wafer carrier 12 is disposed within process chamber 11, with the top surface of wafer carrier 12 facing the top of process chamber 11.

[0049] As shown in Figure 2, the wafer carrier 12 has a number of wafer carrier areas 121, which are used to place substrates 2 to be processed, such as wafers. The wafer carrier areas 121 are arranged around the middle area of ​​the wafer carrier 12 so that each wafer carrier area 121 is exposed to the environment of the reaction space. The number and arrangement of the wafer carrier areas 121 on the wafer carrier 12 can be flexibly adjusted according to process requirements, so as to meet the need for each wafer carrier area 121 to be exposed to the environment of the reaction space. In some embodiments, the wafer carrier areas 121 on the wafer carrier 12 are distributed in a ring array around the middle area of ​​the wafer carrier 12. The wafer carrier 12 can be a disc, and the sizes of the wafer carrier areas 121 distributed thereon can be the same, completely different, or not completely the same. For example, each wafer carrier area 121 is used to carry an 8-inch wafer or a 12-inch wafer, or some wafer carrier areas 121 are used to carry an 8-inch wafer, and other wafer carrier areas 121 are used to carry a 12-inch wafer.

[0050] As also shown in Figures 1 and 3, the chemical vapor deposition equipment of this embodiment is provided with a process gas inlet device 13. The process gas inlet device 13 passes through the top surface of the process chamber 11 and extends to the upper middle portion of the wafer carrier 12. Each wafer carrier area 121 of the wafer carrier 12 is arranged around the process gas inlet device 13. The process gas inlet device 13 includes a gas inlet body 133 and a gas inlet channel 131 arranged axially along the gas inlet body 133 and communicating with the process chamber. The gas inlet body 133 passes through the top surface of the process chamber and extends to the upper middle portion of the wafer carrier. That is, the wafer carrier area 121 is not arranged directly below the process gas inlet device 13. During the gas phase reaction, the process gas inlet device 13 delivers process gases to the process chamber. The process gases are reaction source gases and carrier gases for reacting to generate target products. For example, for Group III-V MOCVD, the process gases are Group III metal organic source gas, Group V hydride source gas, and carrier gas. As shown in Figures 1 and 3, the process gas inlet device 13 can only be provided with an inlet channel 131, which transports a mixture of a reaction source gas and a carrier gas. Alternatively, as shown in Figure 4, the inlet channel 131 is provided in the middle of the gas inlet body 133, and a peripheral inlet channel 132 is further provided around the inlet channel 131, wherein the carrier gas is introduced through the peripheral inlet channel 132, and different reaction source gases (which can also be mixed with a certain amount of carrier gas) are mixed and then introduced through the central gas inlet channel 131, and the bottom outlet of the peripheral inlet channel 132 is arranged so that the carrier gas flow is above the process gas flow. In addition, if multiple reaction gases are included, then one reaction source gas is mixed with the carrier gas and introduced from the central gas inlet channel 131, and another reaction source gas is mixed with the carrier gas and then introduced from the peripheral inlet channel 132.

[0051] In some embodiments, the wafer carrier 12 is further provided with a rotating device to drive the wafer carrier 12 to rotate axially about the process chamber 11. The top of the rotating device can be rotatably connected to the middle portion of the bottom surface of the wafer carrier 12 and disposed opposite the process gas inlet device 13, or it can be rotatably connected to the side of the wafer carrier 12. The rotating device drives the wafer carrier 12 to rotate axially about the process chamber 11, thereby driving the substrates placed in each wafer carrier area 121 to rotate synchronously.

[0052] As also shown in Figures 1, 3, and 4, the chemical vapor deposition apparatus is further provided with a flow guide 20, which is disposed at the bottom of the process gas inlet device 13 and is used to guide the process gas flowing out of the process gas inlet device 13 to form a laminar flow 3 flowing through each of the wafer carrier areas 121. It is understood that the flow guide 20 can also be configured as a flow guide cylinder surrounding the bottom of the process gas inlet device 13, or can be an opening provided in the side wall of the process gas inlet device 13 to form a laminar flow 3 above each wafer carrier area 121. Specific implementation methods are conventional technical means of those skilled in the art.

[0053] As shown in Figure 1, the chemical vapor deposition equipment of this embodiment is also provided with a heating gas inlet device 15. The heating gas inlet device 15 is arranged at the top of the process chamber 11 around the process gas inlet device 13, and is configured to provide hot gas to the top of each carrier area 121 to assist in heating the laminar flow 3. The hot gas provided by the heating gas inlet device 15 is usually an auxiliary gas, and the auxiliary gas is chemically inert to the process gas provided by the process gas inlet device 13.

[0054] As shown in Figures 1 and 5, the heating air inlet device 15 includes a plurality of auxiliary air inlet channels 151 disposed on the top surface of the process chamber 11, surrounding the process air inlet device 13. The direction of the gas flow formed by the plurality of auxiliary air inlet channels 151 is substantially parallel to the axial line of the process chamber 11. In other words, the heating air inlet device 15 provides a vertical air flow 4, and the direction of the formed air flow is substantially perpendicular to the wafer carrier device 12.

[0055] In an alternative embodiment, the auxiliary gas inlet channels 151 may be slit-shaped channels extending in the same direction, for example, in a radial direction parallel to the cover. These slit-shaped channels may be divided into multiple groups, each group being used to transport the same or different gases. In an alternative embodiment to this embodiment, as shown in FIG5 , the auxiliary gas inlet channels 151 may be hole-shaped structures, such as circular holes, elliptical holes, diamond-shaped holes, or similar hole structures. These holes may be arranged as concentric rings, strip-like intervals, staggered groups of holes, or fan-shaped areas. In this embodiment, the circular holes are arranged as shown in FIG5 , with multiple groups of circular holes radially spaced apart in the cover 111 on the top surface of the process chamber 11. Preferably, the multiple groups of circular holes are spaced apart at the same spacing angle, more preferably, evenly spaced apart at the same spacing angle as the substrate placement angle in the process chamber's wafer carrier 12. Each group of circular holes includes multiple circular holes, which are spaced apart radially along the cover 111, preferably also evenly spaced apart. The number of circular holes in the multiple groups of circular holes may be the same or different. Preferably, the number of circular holes in the multiple groups of circular holes is the same.

[0056] In order to obtain hot gas from the auxiliary gas ejected from the heating gas inlet device 15, the heating gas inlet device 15 optionally further includes a gas supply device connected to the plurality of auxiliary gas inlet channels 151 to provide the hot gas. Specifically, the heating gas inlet device 15 further includes a gas heating device. Before the auxiliary gas enters the process chamber 11 through the plurality of auxiliary gas inlet channels 151, the gas heating device heats the auxiliary gas to a certain temperature to obtain hot gas. The hot gas is then sprayed into the process chamber 11 through the plurality of auxiliary gas inlet channels 151. The process chamber 11 is adjusted to an appropriate height and the auxiliary gas flow rate is adjusted to an appropriate level so that the heated vertical airflow 4 can reach above the laminar flow 3 without disrupting the laminar flow 3 and can transfer heat to the laminar flow 3, thereby reducing the temperature difference between the top and bottom surfaces of the substrate 2.

[0057] In some application scenarios, for example, when the process chamber 11 is relatively high, or due to the gas transmission path, even heated auxiliary gas will lose heat during the transmission process, resulting in the auxiliary gas reaching the laminar flow 3 not having a heating effect. Therefore, as shown in FIG1 , an external heating device 16 is further provided on the inner wall of the process chamber 11 to transfer heat into the process chamber 11.

[0058] To further enhance the heating effect on the auxiliary gas, particularly when the process chamber 11 has a large radial dimension, as shown in FIG1 , the process chamber 11 may further be provided with an internal heating device 18. The internal heating device 18 is disposed within the sidewall of the process gas inlet device 13. Preferably, the internal heating device 18 is disposed further away from the process gas inlet passage 131. Furthermore, the internal heating device 18 and the external heating device 16 are disposed radially opposite each other along the process chamber 11 to enhance the heating effect within the process chamber 11.

[0059] Referring again to FIG. 1 , the chemical vapor deposition apparatus is further provided with a bottom heating device 14 , which is disposed below the wafer carrier 12 .

[0060] Since the bottom heating device 14 heats the wafer carrier 12 and then transfers heat to the substrate 2 to heat the substrate 2, the process gas is ejected from the process gas inlet device 13 and flows over the top surface of the wafer carrier 12 in the form of a laminar flow 3. In this process, the laminar flow 3 can be quickly heated by the heat transfer of the wafer carrier 12. Therefore, it is necessary to reduce or avoid the heat transfer from the internal heating device 18 to the gas inlet channel 131. As shown in Figures 3 and 4, the internal heating device 18 is arranged in the gas inlet body 133 around the gas inlet channel 131, and is arranged in a manner further away from the gas inlet channel 131, thereby better radiating heat into the process chamber 11, while radiating as little heat into the gas inlet channel 131 as possible, reducing the impact on the reaction source gas in the gas inlet channel 131. Furthermore, the material selection of the gas inlet body 133 can reduce or isolate the heat transfer from the internal heating device 18 to the gas inlet channel 131. Furthermore, as shown in FIG6 , in order to further provide thermal insulation protection for the air inlet channel 131, a thermal insulation device 19 is provided on the periphery of the air inlet channel 131 to reduce or isolate the heat transfer from the internal heating device 18 to the air inlet channel 131. The thermal insulation device 19 may include a cooling medium channel surrounding the air inlet channel 131, into which a circulating cooling medium, such as cooling water, may pass; the thermal insulation device 19 may be provided in contact with the outer wall of the air inlet channel 131, or may be located within the side wall of the air inlet body 133 between the internal heating device 18 and the air inlet channel 131. The thermal insulation device 19 may also be a thermal insulation coating or a heat reflective coating applied to the outer wall of the air inlet channel 131. A heat reflective device, such as a metal plate, may also be provided between the internal heating device 18 and the air inlet channel 131, or between the internal heating device 18 and the thermal insulation device 19.

[0061] In some application scenarios, when the height of the process chamber 11 is relatively high, in order to facilitate processing and save processing costs, the internal heating device 18 can be set to 2 partitions along the axial direction of the process air inlet device 13, or it can be 3 partitions or more partitions, and each partition is provided with an internal heating element. As shown in Figure 7, in this embodiment, it is set to 2 partitions, and the first internal heating element 181 and the second internal heating element 182 are respectively provided in the two partitions. The heating power control method for each partition of the internal heating device 18 can be: the second heating element 182 is consistent with the bottom heating device 14; the first internal heating element 181 is consistent with the second internal heating element 182; or the partitions other than the second internal heating element 182 increase along the axial direction of the process air inlet device 13 toward the substrate 2.

[0062] As shown in Figure 8, the first internal heating element 181 is arranged around the central air inlet channel 131, and the input wire 183 and output wire 184 for current flow in and out extend to the top of the process air inlet device 13. More specifically, each partition is a graphite heater.

[0063] As shown in Figures 1 and 9, the external heating device 16 is arranged at the inner wall of the process chamber 11 and is arranged along the circumference of the process chamber 11. In some embodiments, in order to facilitate processing and save processing costs, the external heating device 16 also includes a plurality of partitions, each of which includes an external heating element. The external heating element is arranged around the inner wall of the process chamber 11, and the input wire 163 and the output wire 164 for the flow of current in and out extend to the top of the process chamber 11 for extraction. More specifically, each partition is a graphite heater. Referring to Figure 1, the external heating device 16 includes a plurality of partitions arranged in sequence on the side wall of the process chamber 11 along the axial direction of the process chamber 11. And the plurality of external heating elements are arranged opposite to the plurality of partitions of the internal heating device 18 along the axial direction of the process chamber 11. Optionally, corresponding to the internal heating device 18 with two partitions, the external heating device 16 is also provided with two partitions, and the first external heating element 161 and the second external heating element 162 are respectively provided in the two partitions. The first external heating element 161 and the first internal heating element 181 are arranged opposite to each other along the radial direction of the process chamber 11, and the second external heating element 162 and the second internal heating element 182 are arranged opposite to each other along the radial direction of the process chamber 11.

[0064] In some embodiments, the input wires 163 and the output wires 164 of each external heating element can be introduced into and led out from the side walls of the process chamber 11, or can be introduced into or led out from the edge of the cover 111 according to wiring requirements. The specific wiring method must not affect the heating effect of each side wall heating element and the airtightness of the process chamber 11.

[0065] Referring to Figure 12, it can be seen that no matter it is an external heating device 16 or an internal heating device 18, the heating effect of a single heating device on the auxiliary space 21 (i.e., the space in the process chamber 11 between the external heating device 16 and the internal heating device 18) is reflected in its temperature field, which shows a downward trend from the heating device toward the middle of the auxiliary space 21. Therefore, the distance between adjacent heating devices should not be too large, otherwise the auxiliary space temperature field corresponding to the spacing between adjacent heating devices along the same axial direction will show significant unevenness. More importantly, if such uneven adjacent temperature fields exist in the auxiliary space, it will affect the further heating effect of the hot gas.

[0066] Taking the space between the adjacent second outer heating element 162 and the second inner heating element 182 as an example, if the distance between the adjacent second outer heating element 162 and the second inner heating element 182 is too large, the temperature field of the auxiliary space 21 corresponding to the distance between the adjacent second outer heating element 162 and the second inner heating element 182 will have a significant downward trend compared to the temperature field of the space between the radially corresponding first outer heating element 161 and the first inner heating element 181. Therefore, it is necessary to control the distance between adjacent heating elements within a reasonable range.

[0067] In some embodiments, the distances between adjacent sections of the inner heating device and the distances between adjacent sections of the outer heating device are both greater than zero and do not exceed 5% of the height of the reaction space. In this case, the reaction space is the space enclosed by the process chamber 11, the process air inlet device 13, the heating air inlet device 15, and the wafer carrier 12. The height of the reaction space is the vertical distance from the outlet surface of the heating air inlet device 15 to the support surface of the support device 12. It is worth noting that in this reaction space, only the space through which the laminar flow 3 flows after being ejected from the bottom of the process air inlet device 13 constitutes the space where the vapor deposition reaction occurs.

[0068] In some embodiments, referring to Figure 1, there is a distance between adjacent internal heating elements of the internal heating device 18 and between adjacent external heating elements of the external heating device 16, that is, adjacent internal heating elements of the internal heating device 18 are spaced apart, and adjacent external heating elements of the external heating device 16 are also spaced apart.

[0069] In order to allow the heat radiated by the external heating device 16 to radiate as much as possible into the process chamber 11, thereby reducing or preventing heat loss due to radiation to the outside of the process chamber 11, the process chamber 11 of this embodiment may be provided with a thermal insulation component, and the thermal insulation component is positioned between the outer wall of the process chamber 11 and the external heating device 16. The thermal insulation component serves to reduce or prevent heat loss due to radiation of the heat radiated by the external heating device 16 to the outside of the process chamber 11, thereby facilitating the heating of the reaction space within the process chamber 11. Referring to FIG1 , a sidewall thermal insulation device 17 is provided within the sidewall of the process chamber 11, and the external heating device 16 is provided on the inner sidewall surface of the process chamber 11, with the sidewall thermal insulation device 17 positioned between the external heating device 16 and the outer sidewall of the process chamber 11.

[0070] In some embodiments, the side wall insulation device 17 is made of a thermal insulation material. In some specific embodiments, the side wall insulation device 17 can be a layer of graphite felt, or multiple layers of graphite felt stacked sequentially around the circumference of the process chamber 11 .

[0071] In some embodiments, the sidewall insulation device 17 may also be a chamber structure opened in the sidewall of the process chamber 11 along the circumference of the process chamber 11 , and the chamber structure is formed as an internal vacuum chamber structure.

[0072] 12 , when the radial range of the process chamber 11 is large, the external heating device 16 heats the auxiliary space to form a first temperature gradient curve, and the internal heating device 18 heats the auxiliary space to form a second temperature gradient curve. Both temperature gradient curves tend to descend toward the middle of the reaction space ( FIG. 12 is a schematic diagram of the general trend of the temperature gradient curves). In the verification of some embodiments, it was found that when the bottom heating device 14 is not started and the size of the wafer carrier area 251 is 12 inches in diameter, the heating powers of the external heating device 16 and the internal heating device 18 are adjusted to a target temperature of 1650 degrees Celsius. The actual measured temperature in the middle of the auxiliary space (near the intersection of the two temperature gradient curves shown in the figure) is only 900 to 1000 degrees Celsius and cannot continue to rise. Therefore, the bottom heating device 14 not only heats the wafers carried by the carrier area 121, but also can compensate heat to the middle of the auxiliary space, so that the temperature gradient change in the auxiliary space tends to approach the ideal temperature gradient curve shown in Figure 12, which is beneficial to the uniformity of the temperature field in the auxiliary space and is conducive to control. Otherwise, the auxiliary hot gas will be overheated or underheated. It can be seen that it is very important to reasonably adjust the minimum radial distance between the carrier area 121 and the internal heating device 18 and the external heating device 16.

[0073] If the above-mentioned minimum radial distance is too small, the compensation effect of the bottom heating device 14 on the temperature field near the external heating device 16 and the temperature field near the internal heating device 18 will be too prominent, causing the temperature field of the auxiliary space 21 to show a significant trend of being high on both sides and low in the middle, thereby causing the auxiliary hot gas temperature to be too high and the top surface temperature of the substrate 2 to be higher than the bottom surface temperature. If the above-mentioned minimum radial distance is too large, the space in which the bottom heating device 14 can modulate the temperature field in the middle of the auxiliary space is limited, making the temperature field distribution in the auxiliary space more uneven, and easily causing the temperature of the hot gas to not reach the required temperature when it reaches the top of the laminar flow 3. Therefore, the minimum radial distance between the edge of each carrier area 121 and the internal heating device 18, as well as the minimum radial distance between the edge of each carrier area 121 and the external heating device, is 5% to 40% of the radial size of the carrier area 121. The specific percentage selected can be flexibly adjusted according to the radial size of the carrier area 121, the process temperature requirements, the film forming process requirements, etc. In some embodiments, the minimum radial distance between the edge of each carrier area 121 and the internal heating device 18, and the minimum radial distance between the edge of each carrier area 121 and the side wall heating device is 9% to 35% of the radial size of the carrier area.

[0074] In an embodiment of the present invention, a plurality of carrier areas 121 form a carrier region, and the minimum radial distance between the edge of the carrier area 121 closest to the external heating device 16 and the external heating device 16 is 5% to 40% of the radial width of the carrier area.

[0075] In some specific embodiments, referring to FIG. 11 , taking a wafer carrier area 121 as an example, wafer carrier area 121 is a circular area. The minimum radial distance between the edge of wafer carrier area 121 and the inner heating device 18 is L1, the minimum radial distance between the edge of wafer carrier area 121 and the sidewall of the outer heating device 16 is L2, and the radial dimension of wafer carrier area 121, i.e., its diameter, is L3. In some embodiments, when wafer carrier area 121 is a non-circular area (e.g., an ellipse), L3 is the average equivalent diameter.

[0076] In conventional horizontal flow deposition equipment, since the deposition reaction occurs by laminar flow 3 flowing through the surface of the substrate 2 carried by each carrier area 121, the process gas inlet is usually arranged on the side wall of the process chamber 11 to provide laminar flow. Due to the diffusion nature of the airflow, it is obviously not conducive to the deposition of substrates 2 far away from the process gas inlet for batch production, and the uniformity of the quality of the deposited film cannot be guaranteed. In this embodiment, the process gas inlet device 13 is arranged in a manner extending from the top surface of the process chamber 11 downward to above the top surface of the carrier device 12, and the various carrier areas 121 of the carrier device 12 are distributed around the process gas inlet device 13. In conjunction with the arrangement of the guide portion 20 at the bottom of the process gas inlet device 13 and the reasonable distance between the bottom of the process gas inlet device 13 and the carrier device 12, uniform laminar flow is achieved at the top of the carrier device 12, especially at the top of the carrier area 121, to ensure the uniformity of the quality of the deposited films in the same batch.

[0077] As shown in Figure 10, the bottom surface of the heating air inlet device 15 is the hot gas outlet surface, the vertical distance between the top surface of the carrier area 121 and the hot gas outlet surface above it is H, and the distance between the carrier area 121 and another carrier area 121 corresponding to the other end is L. The ratio of H to L is not less than 0.2:1, and the ratio of H to L does not exceed 4:1.

[0078] In some embodiments, the ratio of H to L is not less than 0.3:1.

[0079] In some embodiments, L is 150 mm to 1500 mm.

[0080] In some specific embodiments, H is 500 mm, L is 1500 mm, and each wafer loading area 121 is suitable for placing a 12-inch wafer.

[0081] In some embodiments, H is 500 mm, L is 150 mm, and each wafer carrier area 121 is suitable for placing a 4-inch wafer.

[0082] Furthermore, since the hot gas provided by the heated air inlet device 15 is intended to heat the laminar flow 3 without affecting film formation on the surface of the substrate 2, the interaction between the hot gas and the laminar flow 3 must not cause turbulence on the surface of the substrate 2 that would be detrimental to film deposition. Therefore, it is crucial to properly set the vertical distance H between the outlet surface of the heated air inlet device 15 and the corresponding wafer carrier area 121 below it. If H / L is too small, the hot gas flow rate will have poor adjustability. A slightly higher hot gas flow rate will seriously disrupt the laminar flow 3, while a slightly lower hot gas flow rate will quickly diffuse after being ejected and will not have a positive effect on the laminar flow 3. If H / L is too large, it is easy for the hot gas to not effectively have a positive effect on the laminar flow 3 even if the flow rate is increased to the limit, and the hot gas 3 will diffuse prematurely and fail to heat the laminar flow 3.

[0083] 1 again, the process chamber 11 further includes an exhaust channel 22, which is opened at the bottom surface of the process chamber 11. Alternatively, the exhaust channel 22 may also be opened at the side wall of the process chamber 11 and located below the wafer carrier 12.

[0084] Because the laminar flow 3 formed by the hot gas provided by the heating inlet device 15 and the process gas provided by the process inlet device 13 cannot cause turbulence on the surface of the substrate 2 that is detrimental to film deposition, the heating inlet device 15 needs to have a certain degree of height adjustability to adapt to the adjustability of the hot gas flow rate. If the height of the heating inlet device 15 is too low, the adjustability of the hot gas flow rate is poor, and a slightly higher gas flow rate will seriously disrupt the laminar flow 3. If the gas flow rate is slightly lower, the auxiliary gas will quickly diffuse after being ejected and will not have a positive effect on the laminar flow 3. If the height of the heating inlet device 15 is too high, it is easy to find that even if the flow rate is increased to the limit, the hot gas will not be able to have an effective positive effect on the laminar flow 3. The hot gas will diffuse too early and will not be able to effectively act on the laminar flow 3 to promote film formation.

[0085] In response to the above issues:

[0086] In some embodiments, at least two mutually unconnected hollow areas are provided around the process air inlet device 13 on the top surface of the process chamber 11. The number of heating air inlet devices 15 is at least two and they are detachably provided in the hollow areas by static sealing. The heating air inlet devices 15 are raised and lowered relative to the process chamber 11. The heating air inlet devices 15 are provided in a one-to-one correspondence with the hollow areas, and the hollow areas are opposite to the wafer carrier area 121 along the axial direction of the process chamber 11. Specifically, referring to FIG13 , FIG13 is a top view of the cover 111 on the top of the process chamber 11, wherein a central hollow area 42 is provided in the middle area, the process air inlet device 13 is provided in the central hollow area 42, and a plurality of hollow areas 41 are provided around the central hollow area 42. The heating air inlet devices 15 are provided in the hollow areas 41 in the above-mentioned manner, and a heating air inlet device 15 is provided in each hollow area 41.

[0087] In some embodiments, the heating air intake device 15 includes a column, and the outer wall of the column is adapted to the inner wall of the hollow area 41 through a threaded connection to achieve a detachable static seal, and a plurality of auxiliary air intake channels are provided along the direction from the top surface of the column to the bottom surface.

[0088] In some embodiments, each hollow area 41 corresponds to each wafer carrier area 121 along the axial direction of the process chamber 11 .

[0089] In some embodiments, a cover through-hole 113 is provided on the cover 111 at the top of the process chamber 11. Referring to Figure 14, the cover 111 is provided with a cover through-hole 113 for setting up a heating air intake device 15. The heating air intake device 15 includes a spray hole plate 151, a lifting device 152, and a hollow elastic device 153 with openings at both ends. The spray hole plate 151 is provided with a plurality of spray holes 1511, which form an auxiliary air intake channel for the heating air intake device 15. The setting of the auxiliary air intake channel can refer to the relevant description of the first embodiment. One end of the hollow elastic device 153 is sealed and set on the top surface of the cover 111 across the cover through-hole 113 of the cover 111, and the other end is fixedly provided with the above-mentioned spray hole plate 151, so that the plurality of spray holes 1511 of the spray hole plate 151 are connected to the cover through-hole 113 through the hollow interior of the hollow elastic member 153. The top end of the lifting device 152 is disposed around the side wall of the spray plate 151 , and the bottom end is disposed around the hollow elastic member 153 on the top surface of the cover 111 .

[0090] In an optional embodiment, the hollow elastic member 153 includes a bellows or has a hollow structure that is expandable and contractible in a similar pleated form.

[0091] In an optional embodiment, the lifting device 152 includes a collar 1522 disposed at the top. The collar 1522 is fixedly disposed on the side of the spray orifice plate 151 and maintains the spray orifice plate 151 horizontally. The lifting device 152 includes a lifting adjustment joint 1521 disposed between the two ends of the lifting device 152, with one end fixedly connected to the collar 1522 and the other end fixed to the top surface of the cover body 111. Specifically, the lifting adjustment joint 1521 can be two upper and lower threaded components. The height of the collar 1522 can be adjusted by adjusting the depth of the threads, thereby causing the hollow elastic member 153, such as a bellows, to be stretched or compressed to adjust the height of the spray orifice plate 151.

[0092] In another optional embodiment, as shown in FIG15 , the heating air intake device 15 includes a spray orifice plate 151, an air guide cover plate 154, and a hollow adapter 155 with openings at both ends. The air guide cover plate 154 is provided with an air guide port 1541, which is connected to an external air supply component to introduce auxiliary gas. The top of the hollow adapter 155 is provided on the bottom surface of the cover body 11 across the cover body through-hole 113, and the air guide cover plate 154 is sealed on the top surface of the cover body 11 across the cover body through-hole 113. The spray orifice plate 151 is suspended in the hollow adapter 155, and the height of the spray orifice plate 151 in the hollow adapter 155 is adjustable. In an application scenario where the height of the spray orifice plate 151 needs to be adjusted, it is only necessary to change the height position of the spray orifice plate 151 in the hollow adapter 155. Optionally, the hollow adapter 155 can be configured to have an internal thread, while the side wall of the spray orifice plate 151 can be configured to have an external thread. The spray orifice plate 151 and the hollow adapter 155 are combined with each other through the cooperation of the internal and external threads, and the height of the spray orifice plate 151 in the hollow adapter 155 can be adjusted by adjusting the depth of the thread.

[0093] As described above, the heated air inlet device 15 has a certain degree of height adjustability, thereby making the hot gas flow rate adjustable to a certain extent. This ensures that the hot gas flow rate does not disrupt the laminar flow 3 and prevents the hot gas from quickly diffusing after being ejected. This effectively has a positive effect on the laminar flow 3, thereby promoting uniform film formation and improving film quality.

[0094] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A chemical vapor deposition device, characterized in that, Comprising: A process chamber; A wafer carrier device, disposed within the process chamber, the top surface of the wafer carrier device facing the top of the process chamber and provided with a plurality of wafer loading areas surrounding the middle of the wafer carrier device, and a bottom heating device is provided at the bottom of the wafer carrier device to heat the wafer loading areas; A process gas inlet device, penetrating the top surface of the process chamber and extending above the middle of the wafer carrier device to supply process gas; A flow guiding portion, disposed at the bottom of the process gas inlet device to guide the process gas to form a laminar flow flowing through each of the wafer loading areas; A heating gas inlet device, disposed around the process gas inlet device at the top of the process chamber, and configured to supply hot gas above each of the wafer loading areas to assist in heating and stabilizing the laminar flow, the hot gas being chemically inert with respect to the process gas.

2. The chemical vapor deposition apparatus according to claim 1, wherein The heating gas inlet device includes an air outlet surface located within the process chamber and surrounding the process gas inlet device, the plurality of wafer loading areas form a wafer loading region around the process gas inlet device, the wafer loading region is located below the air outlet surface, and the vertical distance between the wafer loading region and the air outlet surface is H, and the maximum radial length of the region surrounded by the outer edge of the wafer loading region is L, and the ratio of H to L is not less than 0.2:

1.

3. The chemical vapor deposition apparatus according to claim 2, wherein The ratio of H to L does not exceed 4:

1.

4. The chemical vapor deposition apparatus according to claim 1, wherein At least two non-communicating hollow areas are opened on the top surface of the process chamber around the process gas inlet device, the number of the heating gas inlet devices is at least 2 and is detachably disposed in the hollow areas by a static sealing method, and the heating gas inlet devices are vertically adjustable relative to the process chamber, and the heating gas inlet devices are disposed in the hollow areas one by one.

5. The chemical vapor deposition apparatus according to claim 4, characterized in that: The heating gas inlet device includes a column body, and the outer side wall of the column body is adapted to the inner side wall of the hollow area by a threaded connection to achieve a detachable setting with static sealing, and a plurality of auxiliary air inlet channels are provided in the direction from the top surface to the bottom surface of the column body.

6. The chemical vapor deposition apparatus according to claim 1, wherein The process chamber includes a cover body, the cover body is provided with a cover body through hole, the heating gas inlet device includes a spray hole plate, a lifting device and a hollow elastic device with openings at both ends, one end of the hollow elastic device straddles the cover body through hole and is hermetically disposed on the top surface of the cover body and the other end is fixedly provided with the spray hole plate, so that the spray hole plate communicates with the cover body through hole through the inside of the hollow elastic member, and one end of the lifting device surrounds the side wall of the spray hole plate and the other end surrounds the hollow elastic member and is disposed on the top surface of the cover body.

7. The chemical vapor deposition apparatus according to claim 6, wherein, The hollow elastic member includes a corrugated pipe.

8. The chemical vapor deposition apparatus according to claim 1, wherein: The process chamber includes a cover body, the cover body is provided with a cover body through hole, the heating gas inlet device includes a spray hole plate, a gas guiding cover plate and a hollow adapter with openings at both ends, the top of the hollow adapter straddles the cover body through hole and is disposed on the bottom surface of the cover body, the gas guiding cover plate straddles the cover body through hole and is hermetically disposed on the top surface of the cover body, and the spray hole plate is suspended in the hollow adapter in a height-adjustable manner.

9. The chemical vapor deposition apparatus according to claim 1, wherein: An external heating device is further included, and the external heating device surrounds the inner side wall of the process chamber to supply heat to the inside of the process chamber.

10. The chemical vapor deposition apparatus according to claim 9, wherein It further includes an internal heating device which is disposed around the side wall of the process gas inlet device to supply heat to the process cavity, and the internal heating device and the external heating device are radially opposite to each other along the process cavity.

11. The chemical vapor deposition apparatus according to claim 10, wherein: Both the internal heating device and the external heating device are located above the top surface of the wafer carrier device.

12. The chemical vapor deposition apparatus according to claim 9, wherein, A plurality of the wafer carrier areas form a wafer carrier region around the process gas inlet device, and the minimum radial distance between the edge of the wafer carrier area closest to the external heating device and the external heating device is 5% - 40% of the radial width of the wafer carrier region.

13. The chemical vapor deposition apparatus according to claim 10, wherein A plurality of the wafer carrier areas form a wafer carrier region around the process gas inlet device, and the minimum radial distance between the edge of the wafer carrier area closest to the internal heating device and the internal heating device is 5% - 40% of the radial width of the wafer carrier region.

14. The chemical vapor deposition apparatus according to claim 10, wherein The external heating device includes at least two external heating elements sequentially disposed around the inner side wall of the process cavity along the axial direction of the process cavity, and the internal heating device includes at least two internal heating elements disposed in the side wall of the process gas inlet device, and the at least two internal heating elements and the at least two external heating elements are arranged in one-to-one correspondence.

15. The chemical vapor deposition apparatus according to claim 14, characterized in that, The process cavity, the process gas inlet device, the heating gas inlet device and the wafer carrier device enclose a reaction space, and the distance between adjacent external heating elements and the distance between adjacent internal heating elements do not exceed 5% of the height of the reaction space.

16. The chemical vapor deposition apparatus according to claim 10, wherein The process gas inlet device includes an inlet body and an inlet channel axially penetrating the inlet body along the inlet body, the inlet body penetrates the top surface of the process cavity and extends above the middle of the wafer carrier device, and the internal heating device is disposed around the inlet channel in the inlet body.

17. The chemical vapor deposition apparatus according to claim 16, wherein: An insulation device is further disposed between the internal heating device and the inlet channel, and the insulation device surrounds the inlet channel.

18. The chemical vapor deposition apparatus according to claim 1, wherein, It further includes a rotation device disposed on the wafer carrier device to drive the wafer carrier device to rotate around the axis of the process cavity.

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