Chemical vapor deposition apparatus

Abstract

The present invention provides a chemical vapor deposition apparatus, comprising: a reaction chamber; a gas inlet device arranged at the top of the interior of the reaction chamber and used for conveying a gas into the reaction chamber; and a tray arranged in the reaction chamber, located below the gas inlet device, and used for carrying a wafer to be processed. The gas inlet device comprises a plurality of stacked gas inlet channels horizontally arranged in the radial direction thereof, a gas inlet of each of the gas inlet channels is in communication with a gas source, and a first distance between a gas outlet of each of the gas inlet channels and the central axis of the gas inlet device is R1. A second distance between the edge of the wafer close to the gas outlet of the gas inlet channel and the central axis of the gas inlet device is R2, and the ratio of the first distance R1 to the second distance R2 ranges from 0.2 to 0.82. The present invention exhibits improved process source efficiency while ensuring wafer growth uniformity.

Description

A chemical vapor deposition device Technical Field

[0001] This invention relates to the field of semiconductor equipment technology, and in particular to a chemical vapor deposition apparatus. Background Technology

[0002] MOCVD (Metal-organic Chemical Vapor Deposition) is a core process for preparing semiconductor compound materials. It typically uses organic compounds of Group III and II elements, as well as hydrides of Group V and VI elements, as reactant gases for growing epitaxial thin films. MOCVD is usually carried out in a temperature-controlled reaction chamber. By introducing the aforementioned reactant gases into the chamber and allowing them to react chemically on the wafer, single-crystal thin films of Group III-V and II-VI compound semiconductors and their multi-component solid solutions are formed. MOCVD plays a crucial role in the production of various thin film materials (such as gallium nitride), including semiconductor devices, optoelectronic devices, gas sensors, superconducting thin films, ferroelectric / ferromagnetic thin films, and high-dielectric materials.

[0003] However, existing metal-organic chemical vapor deposition (MOCVD) equipment with horizontal gas inlet has the following shortcomings: On the one hand, when the wafer growth uniformity meets the product yield requirements, the equipment's process efficiency is low, meaning the equipment's utilization rate of reactant gases is low, resulting in waste of reactant gases and increased production costs. On the other hand, when the equipment's process efficiency is improved, the wafer growth uniformity is poor, leading to a large difference in film thickness between the wafer edge and the wafer center, affecting the wafer's product yield. Therefore, there is an urgent need for a MOCVD system that can meet the requirements of wafer growth uniformity while also having high process efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a chemical vapor deposition apparatus that, while ensuring uniform wafer growth, improves process efficiency, thereby reducing production costs and increasing wafer yield.

[0005] To achieve the above objectives, the present invention provides a chemical vapor deposition apparatus, comprising: a reaction chamber; an inlet device disposed at the top of the interior of the reaction chamber for supplying gas into the reaction chamber; and a tray disposed within the reaction chamber and below the inlet device for supporting a wafer to be processed; the inlet device includes a plurality of stacked inlet channels arranged horizontally along its radial direction, each inlet channel having an inlet connected to a gas source, and a first distance R1 between the outlet of each inlet channel and the central axis of the inlet device; a second distance R2 between the edge of the wafer near the outlet of the inlet channel and the central axis of the inlet device, and the ratio of the first distance R1 to the second distance R2 being in the range of 0.2 to 0.82.

[0006] Optionally, the ratio of the first distance R1 to the second distance R2 is in the range of 0.38 to 0.76.

[0007] Optionally, the ratio of the first distance R1 to the second distance R2 is in the range of 0.6 to 0.76.

[0008] Optionally, the Reynolds number of the reactant gas is between 15 and 50 on the gas flow cross section of the concentric circle at the center of the wafer.

[0009] Optionally, the height of the process chamber of the chemical vapor deposition equipment is 25~35mm.

[0010] Optionally, the gas source includes a Group III precursor gas source and a Group V precursor gas source.

[0011] Optionally, the molar ratio of the group V precursor gas source to the group III precursor gas source introduced into the reaction chamber per unit time is in the range of 450 to 650.

[0012] Optionally, the gas source may further include a doped gas source.

[0013] Optionally, the intake passages closest to and furthest from the tray are used to provide at least a Group V precursor gas source, and at least one intake passage in between is used to provide at least a Group III precursor gas source.

[0014] Optionally, the intake channel includes five layers, with the first, third, and fifth layers providing at least a Group V precursor gas source and the second and fourth layers providing at least a Group III precursor gas source in the direction away from the tray.

[0015] Optionally, the air intake device further includes a plurality of air supply pipes, the air inlet of each air supply pipe being connected to the gas source, and the air outlet of each air supply pipe being connected to the air inlet of at least one of the air intake channels.

[0016] Optionally, the air intake device is provided with a plurality of buffer chambers, and the plurality of buffer chambers are respectively connected to the air supply pipe and the air intake channel.

[0017] Optionally, a gas distribution chamber is connected between the buffer chamber and the air inlet channel, and the buffer chamber and the gas distribution chamber are connected through multiple air distribution holes.

[0018] Optionally, the air intake device is further provided with a cooling fluid channel, which is arranged around the air delivery pipe and the air intake channel is arranged circumferentially along the cooling fluid channel.

[0019] Optionally, the reaction chamber includes a chamber body and a chamber top cover located on top of the chamber body. The chamber top cover has a mounting hole at its center, and the bottom of the air intake device passes through the mounting hole and is fixedly mounted on the chamber top cover.

[0020] Compared with the prior art, the technical solution of the present invention has at least the following advantages: by setting the ratio of the first distance R1 to the second distance R2 from the central axis of the air intake device to 0.2~0.82, the growth non-uniformity of the self-rotating wafer W can be kept within 2.5% and the process efficiency of the chemical vapor deposition equipment is above 18%. This satisfies the requirements for the growth uniformity of the wafer W, improves the process efficiency of the equipment and the utilization efficiency of the reaction gas, thereby reducing production costs and promoting the green production and sustainable development of enterprises. Attached Figure Description

[0021] Figure 1 is a schematic diagram of a chemical vapor deposition apparatus according to an embodiment of the present invention;

[0022] Figure 2 is a schematic diagram showing the positional distribution of an air intake device, a tray, and a wafer according to an embodiment of the present invention.

[0023] Figure 3 is a schematic diagram of the air intake device in a chemical vapor deposition apparatus according to an embodiment of the present invention;

[0024] Figure 4 is a schematic diagram of the growth rate curve and growth non-uniformity curve of thin film deposition on the tray and wafer surface in a chemical vapor deposition apparatus provided in an embodiment of the present invention, when the first distance R1 and the second distance R2 have different ratios. Detailed Implementation

[0025] The technical solutions, structural features, achieved objectives, and effects of the present invention will be described in detail below with reference to the accompanying drawings in the embodiments of the present invention.

[0026] It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions. They are only used to facilitate and clarify the purpose of illustrating the embodiments of the present invention, and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationship, or adjustments to the size should still fall within the scope of the technical content disclosed in the present invention, provided that they do not affect the effects and objectives that the present invention can produce.

[0027] It should be noted that, in this invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only the expressly listed elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0028] Research has found that the low process efficiency and poor wafer growth uniformity of existing chemical vapor deposition equipment with horizontal air inlet devices are due to the following two aspects:

[0029] (1) Regarding process efficiency, during the reaction process, since the reaction gas output from the outlet of the horizontal gas inlet device is sprayed out in the horizontal direction, and the diffusion deposition direction of the reaction gas to the wafer surface is vertical, the flow rate of the reaction gas in the horizontal direction will affect the growth rate of the reaction gas on the wafer surface. The faster the flow rate of the reaction gas in the horizontal direction, the shorter the residence time of the reaction gas above the wafer, which will lead to a reduction in the utilization efficiency of the reaction gas (i.e., a reduction in process efficiency). At the same time, the duty cycle K of the reaction gas also has a significant impact on process efficiency. The duty cycle K refers to the ratio of the wafer area S1 to the potential deposition area S2 formed by the reaction gas input from the outlet of the horizontal gas inlet device into the reaction chamber, i.e., K=S1 / S2. When the wafer area S1 remains unchanged, the smaller the potential deposition area S2, the larger the duty cycle K, which allows the reaction gas to be more concentrated above the wafer, thereby improving process efficiency.

[0030] (2) Regarding the uniformity of wafer growth, as shown in Figure 4, during the reaction process, when the tray carrying the wafer is in a static state, the growth rate curve (GR, unit is micron / h) of the wafer surface from the outlet of the horizontal air inlet device to the outer edge of the tray shows an increasing trend followed by a decrease, with a growth rate peak. When the growth rate peak is within the diameter range of the wafer, the large difference in growth rate will cause uneven growth of the wafer.

[0031] Based on the above analysis, the growth uniformity and process efficiency of the wafer are both related to the distance between the outlet of the horizontal gas inlet device and the edge of the wafer. Specifically, based on the reasons in aspect (1), the outlet of the horizontal gas inlet device can be moved towards the wafer, that is, the distance can be reduced. Since the diameter of the gas inlet device increases, the total flow area of ​​the outlet increases, thereby slowing down the flow rate of the reactive gas output from the outlet of the horizontal gas inlet device. At the same time, reducing the distance can also reduce the potential deposition area S2 of the reactive gas, increase the duty cycle K of the reactive gas, and thus improve the process efficiency.

[0032] Based on aspect (2), if the interval distance is larger, the peak value of the growth rate is less likely to fall within the diameter range of the wafer, thereby improving the growth uniformity of the wafer; conversely, if the interval distance is smaller, the peak value of the growth rate will fall within the diameter range of the wafer, thereby causing uneven growth of the wafer. Thus, the reasons in aspect (1) and aspect (2) are mutually restrictive. Therefore, the approach adopted by this invention is to adjust the distance from the outlet of the horizontal air intake device to the edge of the wafer to ensure that the growth uniformity of the wafer meets the product yield while improving the process efficiency.

[0033] Based on the above-described inventive concept, embodiments of the present invention provide a chemical vapor deposition (CVD) apparatus. Referring to Figures 1-3, the CVD apparatus includes a reaction chamber 100, which comprises a chamber body 101 and a chamber top cover 102 located on top of the chamber body 101. The chamber top cover 102 covers the chamber body 101 to form an airtight internal processing space. A mounting hole 121 is provided at the center of the chamber top cover 102 for mounting and fixing an air intake device 103. The air intake device 103 is typically made of corrosion-resistant stainless steel with good thermal conductivity. The bottom of the air intake device 103 passes through the mounting hole 121, and its top is fixedly mounted on the chamber top cover 102. The air intake device 103 supplies reaction gas radially into the reaction chamber 100. The bottom of the chamber body 101 is provided with a tray 104 (usually made of graphite). The tray 104 is located below the air intake device 103 and is used to support multiple wafers W to be processed. The multiple wafers W are rotationally symmetrical about the central axis of the air intake device 103. The distance between the upper surface of the tray 104 and the lower surface of the chamber top cover 102 (or the lower surface of the top plate if there is a top plate or other structure below the chamber top cover 102) is 25~35mm, that is, the height of the process chamber is 25~35mm.

[0034] The air intake device 103 includes a plurality of horizontally arranged, radially arranged air intake channels 131 stacked on top of each other. The air intake channels 131 in the same layer are spaced apart around the central axis AA of the air intake device 103. The air inlet 1311 of each air intake channel 131 is connected to a gas source 105, which provides reactive gases for thin film growth on the surface of the wafer W. In one embodiment, the air intake channel 131 closest to and farthest from the tray 104 is used to provide a Group V precursor gas source, such as nitrogen-containing gas; at least one air intake channel 131 in between is used to provide a Group III precursor gas source, such as gallium-containing gas. In this embodiment, the air intake channel 131 includes five layers. Along the direction away from the tray 104, the first, third, and fifth layers are used to provide at least Group V hydrides, such as NH3; the second and fourth layers are used to provide at least Group III organic compounds, such as trimethylgallium or triethylgallium. Furthermore, the first distance between the air outlet 1312 of each air intake channel 131 and the central axis AA of the air intake device 103 is R1, the second distance between the edge of the wafer W near the air outlet 1312 of the air intake channel 131 and the central axis AA of the air intake device 103 is R2, and the ratio of the first distance R1 to the second distance R2 is in the range of 0.2 to 0.82.

[0035] In some embodiments, a drive shaft 106 is fixedly connected to the bottom of the tray 104. The bottom of the drive shaft 106 vertically penetrates the bottom wall of the chamber body 101 and is located outside the chemical vapor deposition apparatus. The drive shaft 106 drives the tray 104 and simultaneously drives the wafer W to rotate at high speed, so that different types of reactive gases reaching the upper surface of the tray are fully mixed under the drive of the high-speed rotating tray. The drive shaft 106 can be driven by an external motor or cylinder (not shown). The bottom of the chamber body 101 is also provided with an exhaust device (not shown) for discharging the gases in the reaction chamber 100 (including both waste gases generated by the reaction and some reactive gases that did not have time to participate in the reaction).

[0036] In this embodiment, by setting the ratio of the first distance R1 to the second distance R2 to 0.2~0.82, simulation experiments verified that, as shown in Figure 4 and Table 1, the growth non-uniformity of the self-rotating wafer W can be maintained within 2.5%, and the process efficiency of the chemical vapor deposition equipment is above 18%. This satisfies the growth uniformity requirements of wafer W while improving the process efficiency and utilization efficiency of the reactive gas, thereby reducing production costs. The growth non-uniformity of wafer W is defined as the ratio of the difference between the maximum and minimum growth rates to the average value of twice the growth rate.

[0037]

[0038] Table 1. Growth unevenness and process efficiency at different ratios of first distance R1 and second distance R2

[0039] Specifically, with neither the tray 104 nor the wafer W rotating, the growth rate curves 11, 12, 13, 14, 15, and 16 shown in Figure 4 correspond to growth trends where the ratio of the first distance R1 to the second distance R2 is 0.2, 0.38, 0.6, 0.76, 0.82, and 0.9, respectively. The third distance R3 in Figures 2 and 4 is the distance from the edge of the wafer W away from the air outlet 1312 of the air inlet channel 131 to the central axis AA of the air inlet device 103. The difference between the third distance R3 and the second distance R2 is the diameter of the wafer W. During the processing of the wafer W, the tray 104 can rotate around its own axis, and the wafer W can also rotate around its own axis to ensure a more uniform thickness of the thin film on the surface of the wafer W. When the wafer W rotates, the rotation growth rate curves 21, 22, 23, 24, 25, and 26 of the wafer W can be obtained, as shown by the dashed line between R2 and R3 in Figure 4. These curves correspond to the growth trends of the rotating wafer with ratios of 0.2, 0.38, 0.6, 0.76, 0.82, and 0.9, respectively, representing the ratios of the first distance R1 to the second distance R2.

[0040] In this embodiment, when the ratio of the first distance R1 to the second distance R2 is 0.2, the wafer growth non-uniformity is 0.6% and the process efficiency is 18.3%. At this ratio, the wafer growth non-uniformity is low, which means that the wafer growth has good uniformity. This is because the growth rate peak P1 of the growth rate curve 11 is far from the edge of the wafer W, and the growth rate within the diameter range of the wafer W is relatively uniform (as shown by the rotation growth rate curve 21 in Figure 4). Therefore, at this ratio, the wafer growth is relatively uniform and has a high process efficiency.

[0041] Furthermore, as can be seen from Figure 4 and Table 1, the ratio of the first distance R1 to the second distance R2 is approximately between 0.2 and 0.9. The process source efficiency increases with the increase of the R1 / R2 ratio, and the growth non-uniformity of the self-rotating wafer W increases with the increase of the R1 / R2 ratio. Specifically, when the ratio of the first distance R1 to the second distance R2 is 0.82, the wafer growth non-uniformity is 2.4% and the process efficiency is 26.7%. At this ratio, the wafer growth non-uniformity increases slightly but is still within the product yield requirement. At this time, the process efficiency is significantly improved. This is because the first distance R1 from the outlet 1312 of the air intake channel 131 to the central axis AA of the air intake device 103 increases, that is, the length of the air intake channel 131 is increased. On the one hand, the increased diameter of the air intake device 103 leads to an increase in the total flow area of ​​the outlet, thereby reducing the flow rate of the reactive gas. On the other hand, it reduces the distance between the outlet 1312 and the edge of the wafer W, that is, it reduces the potential deposition area S2 of the reactive gas and increases the duty cycle K of the reactive gas. Thus, while meeting the wafer growth uniformity, the process efficiency is significantly improved.

[0042] Furthermore, when the ratio of the first distance R1 to the second distance R2 is 0.9, although the process efficiency is improved to 28.7%, the growth non-uniformity of wafer W also increases to 7%. This growth non-uniformity of wafer W cannot meet the product yield requirements. This is because the growth rate peak P6 of the growth rate curve 16 corresponding to this ratio is located within the diameter of wafer W (i.e., the distance between R2 and R3), resulting in a large growth difference within the diameter of wafer W (as shown by the self-rotation growth rate curve 26 in Figure 4), which in turn causes the growth non-uniformity of wafer W.

[0043] Optionally, when the ratio of the first distance R1 to the second distance R2 is 0.38 to 0.76, as shown in Figure 4 and Table 1, when the ratio of the first distance R1 to the second distance R2 is 0.38, the wafer growth non-uniformity is 0.2%. At this ratio, the wafer growth non-uniformity is lower than that of a wafer with a ratio of 0.2, meaning that the wafer growth has better uniformity and the process efficiency is improved to 19.7%. When the ratio of the first distance R1 to the second distance R2 is 0.76, the wafer growth non-uniformity is 0.14%. At this ratio, the wafer growth non-uniformity is lower than that of a wafer with a ratio of 0.82, meaning that the wafer growth has better uniformity and the process efficiency can still be maintained at 25.3%, still having a high process efficiency.

[0044] Preferably, when the ratio of the first distance R1 to the second distance R2 is 0.6 to 0.76, as shown in Figure 4 and Table 1, the process efficiency of the chemical vapor deposition equipment provided in this embodiment of the invention can exceed 22%, and the growth non-uniformity of the wafer W is less than 1.5%, that is, the growth uniformity of the wafer W is not significantly damaged. This achieves a significant improvement in process efficiency and a reduction in production costs while ensuring that the growth uniformity of the wafer meets the product yield.

[0045] Optionally, in this embodiment, the Reynolds number of the reactant gas is between 15 and 50. The Reynolds number is defined by the characteristic dimensions, surface average velocity, and average gas properties (average density and average viscosity) of the gas flow cross-section on a concentric circle at the center of wafer W. When the Reynolds number of the reactant gas is too high, the horizontal flow velocity of the reactant gas is too fast, and the residence time of the reactant gas above the wafer is too short, leading to a significant reduction in the utilization efficiency of the reactant gas (i.e., a reduction in process efficiency). Conversely, when the Reynolds number is too low, the reactant gas will be excessively consumed before reaching the wafer (i.e., in the region between the outlet 1312 and the edge of wafer W near the outlet 1312), thereby reducing process efficiency.

[0046] Optionally, in this embodiment, the molar ratio of the Group V precursor gas source to the Group III precursor gas source introduced per unit time is in the range of 450 to 650, so that when the ratio of the first distance R1 and the second distance R2 is set to 0.2 to 0.82, an appropriate amount of Group V precursor gas source and Group III precursor gas source are fully decomposed when reaching the wafer W, thereby improving the utilization efficiency of the reactant gas. Referring simultaneously to Figures 1 and 3, the gas inlet device 103 also includes a plurality of gas delivery pipes 132. The inlet of each gas delivery pipe 132 is connected to the gas source 105, and the outlet of each gas delivery pipe 132 is connected to the inlet 1311 of at least one gas inlet channel 131. Specifically, in this embodiment, the gas delivery pipes 132 are vertically arranged along the axial direction of the gas inlet device 103, and the number of gas delivery pipes 132 is the same as the number of gas inlet channels 131, that is, the gas delivery pipes 132 and the gas inlet channels 131 are arranged in a one-to-one correspondence. In some embodiments, the number of gas supply pipes 132 may be less than the number of air intake channels 131. In this case, one gas supply pipe 132 may be connected to multiple air intake channels 131, but the present invention is not limited thereto.

[0047] Furthermore, in this embodiment, as shown in Figures 1 and 3, a buffer chamber 133 is connected between the interconnected gas supply pipe 132 and the air inlet channel 131. The air inlet of the gas supply channel 132 is connected to the corresponding gas source 105, the air outlet of the gas supply channel 132 is connected to the air inlet of the buffer chamber 133, and the air outlet of the buffer chamber 133 is connected to the air inlet 1311 of the air inlet channel 131. The buffer chamber 133 buffers the high-velocity gas in the gas supply pipe 132 and initially homogenizes the reaction gas within the buffer chamber, thereby slowing down the flow rate of the reaction gas injected through the corresponding air inlet channel 131. In this embodiment of the invention, the air inlet device 103 includes five buffer chambers 133 arranged sequentially along a direction away from the tray 104 (i.e., from the outside to the inside), namely the first to the fifth buffer chambers. In some other embodiments, multiple buffer chambers 133 may also be arranged sequentially from top to bottom.

[0048] Further, as shown in Figures 1 and 3, a gas distribution chamber 134 is connected between the buffer chamber 133 and the air inlet channel 131, and the buffer chamber 133 and the gas distribution chamber 134 are connected through multiple gas equalization holes 135. In this embodiment, the air inlet device 103 includes five gas distribution chambers 134 arranged sequentially along a direction away from the tray 104 (i.e., from the outside to the inside), namely the first to the fifth gas distribution chambers. Each gas distribution chamber 134 is located directly below its corresponding buffer chamber 133 and forms a connected air path through its corresponding gas equalization holes 135. This homogenizes the reaction gas flowing from the buffer chamber 133 into the corresponding gas distribution chamber 134, thereby ensuring uniform gas distribution in the reaction chamber 100 via the air inlet channel 131, improving the growth uniformity and process efficiency of the wafer W.

[0049] Specifically, in this embodiment, the air intake channels 131 are evenly or non-uniformly distributed around the outer periphery of the corresponding gas distribution chamber 134 along the circumferential direction of the gas distribution chamber 134, as shown in Figures 1 to 3. The air inlet 1311 of the air intake channel 131 is connected to the corresponding gas distribution chamber 134, and the air outlet 1312 of the air intake channel 131 is connected to the interior of the reaction chamber 100 in the horizontal direction. The gas delivery channel 132 sequentially provides reaction gas to the reaction chamber 100 through the corresponding gas delivery channel inlet connected to the gas source, the buffer chamber 133, the gas equalization hole 135, the gas distribution chamber 134, and the multiple air intake channels 131.

[0050] As shown in Figure 2, the air intake channel 131 has a horizontal, straight structure, extending along the radial direction of the air intake device 103. The first distance between the air outlet 1312 of the air intake channel 131 and the central axis AA of the air intake device 103 is R1. The second distance between the edge of the wafer W near the air outlet 1312 of the air intake channel 131 and the central axis AA of the air intake device 103 is R2. The ratio of the first distance R1 to the second distance R2 ranges from 0.2 to 0.82. This allows the reactive gas to pass horizontally across the wafer surface as much as possible and distribute evenly on the surface of the wafer W, ensuring the uniformity of wafer W growth and improving process efficiency. Furthermore, in this embodiment, the vertical spacing between the air outlet 1312 of each air intake channel 131 and the tray 104 is different, allowing for the layered injection of multiple reactive gases into the reaction chamber 100 in the vertical direction.

[0051] Meanwhile, to further prevent the reacting gases from reacting within the intake device 103 and blocking the intake passage 131, as shown in Figures 1 and 3, a cooling fluid passage 136 is also provided inside the intake device 103. The cooling fluid passage 136 is arranged around the gas delivery pipe 132, and the intake passage 131 is arranged circumferentially along the cooling fluid passage 136. The cooling fluid passage 136 is connected to an external cooler 107 (or a cooling fluid source) via a cooling fluid input pipe 171. The cooler 107 provides cooling fluid, which is transported to the cooling fluid passage 136 through the cooling fluid input pipe 171 to control the temperature of the gas delivery passage 132. The cooling fluid in the cooling fluid passage 136 is then returned to the external cooler 107 via a cooling fluid output pipe (not shown in the figures). In this embodiment, the cooling fluid can be water or other coolant.

[0052] In this embodiment, as shown in FIG1, the gas source 105 for providing the reaction gas includes a gallium source 151, a nitrogen source 152, and a dopant gas source 153. The gallium source 151 and the nitrogen source 152 are connected to the interior of the reaction chamber 100 through different inlet channels 131, and the dopant gas source 153 is connected to the interior of the reaction chamber 100 through at least one inlet channel 131 to introduce gallium-containing gas, nitrogen-containing gas, and dopant gas into the reaction chamber 100. Specifically, in this embodiment, the gallium-containing gas and the nitrogen-containing gas are process gases, that is, the gallium-containing gas and the nitrogen-containing gas introduced into the reaction chamber 100 can undergo a chemical deposition reaction under preset conditions to grow a thin film on the surface of the wafer W. The dopant gas, as an external dopant, can be introduced into the reaction chamber 100 together with the process gas to make the formed thin film contain dopants, thereby obtaining the desired semiconductor thin film. Optionally, the gallium-containing gas is trimethylgallium or triethylgallium, the nitrogen-containing gas is ammonia, and the doping gas is propane or ethylene to achieve external carbon doping.

[0053] Furthermore, in this embodiment, as shown in FIG1, there is a gap 141 between the bottom surface of the air intake device 103 and the top surface of the tray 104. The air intake device 103 is also provided with a purge gas input pipe 137, which is arranged through the upper and lower surfaces of the air intake device 103. Its input end is connected to a purge gas source 108, and its output end is connected to the gap 141 for inputting purge gas into the reaction chamber.

[0054] In summary, the chemical vapor deposition equipment provided by the present invention sets the ratio of the first distance R1 to the second distance R2 from the central axis AA of the gas inlet device 103 to 0.2~0.82, so that the growth non-uniformity of the self-rotating wafer W can be kept within 2.5% and the process efficiency of the chemical vapor deposition equipment is above 18%. This satisfies the growth uniformity requirements of the wafer W, improves the process efficiency and utilization efficiency of the reaction gas, and thus reduces the production cost.

[0055] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A chemical vapor deposition apparatus, characterized in that, include: reaction chamber; An air intake device, which is located at the top inside the reaction chamber, is used to supply gas into the reaction chamber; The tray, which is set inside the reaction chamber and below the air intake device, is used to hold the wafers to be processed; The air intake device includes a plurality of stacked air intake channels arranged horizontally along its radial direction. The air inlet of each air intake channel is connected to a gas source, and the first distance between the air outlet of each air intake channel and the central axis of the air intake device is R1. The second distance between the edge of the wafer near the air outlet of the air inlet channel and the central axis of the air inlet device is R2, and the ratio of the first distance R1 to the second distance R2 is in the range of 0.2 to 0.

82.

2. The chemical vapor deposition apparatus as described in claim 1, characterized in that, The ratio of the first distance R1 to the second distance R2 ranges from 0.38 to 0.

76.

3. The chemical vapor deposition apparatus as described in claim 1, characterized in that, The ratio of the first distance R1 to the second distance R2 ranges from 0.6 to 0.

76.

4. The chemical vapor deposition apparatus according to any one of claims 1-3, characterized in that, On the gas flow cross section of the concentric circle at the center of the wafer, the Reynolds number of the reacting gas is between 15 and 50.

5. The chemical vapor deposition apparatus according to any one of claims 1-3, characterized in that, The height of the process chamber of the chemical vapor deposition equipment is 25~35mm.

6. The chemical vapor deposition apparatus according to any one of claims 1-3, characterized in that, The gas sources include Group III precursor gas sources and Group V precursor gas sources.

7. The chemical vapor deposition apparatus as described in claim 6, wherein the molar ratio of the group V precursor gas source to the group III precursor gas source introduced into the reaction chamber per unit time is in the range of 450 to 650.

8. The chemical vapor deposition apparatus as described in claim 6, characterized in that, The gas source also includes a doped gas source.

9. The chemical vapor deposition apparatus as described in claim 6, characterized in that, The intake passages closest to and furthest from the tray are used to provide at least a Group V precursor gas source, and at least one intake passage in between is used to provide at least a Group III precursor gas source.

10. The chemical vapor deposition apparatus as described in claim 9, characterized in that, The air intake channel comprises five layers. Along the direction away from the tray, the first, third, and fifth layers are used to provide at least a Group V precursor gas source, and the second and fourth layers are used to provide at least a Group III precursor gas source.

11. The chemical vapor deposition apparatus as described in claim 1, characterized in that, The air intake device further includes a plurality of air supply pipes, the air inlet of each air supply pipe being connected to the gas source, and the air outlet of each air supply pipe being connected to the air inlet of at least one of the air intake channels.

12. The chemical vapor deposition apparatus as described in claim 11, characterized in that, The air intake device is provided with several buffer chambers, and the multiple buffer chambers are respectively connected to the air supply pipe and the air intake channel.

13. The chemical vapor deposition apparatus as described in claim 12, characterized in that, A gas distribution chamber is connected between the buffer chamber and the air inlet channel, and the buffer chamber and the gas distribution chamber are connected through multiple air distribution holes.

14. The chemical vapor deposition apparatus as described in claim 13, characterized in that, The air intake device is also provided with a cooling fluid channel, which is arranged around the air delivery pipe and the air intake channel is arranged circumferentially along the cooling fluid channel.

15. The chemical vapor deposition apparatus as described in claim 1, characterized in that, The reaction chamber includes a chamber body and a chamber top cover located on top of the chamber body. The chamber top cover has a mounting hole in the center, and the bottom of the air intake device passes through the mounting hole and is fixedly installed on the chamber top cover.

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