Gas shower head and chemical vapor deposition equipment

Abstract

The present invention provides a shower head, comprising a diffusion plate and a cooling plate, and an air baffle arranged at the interface between the two, wherein the air baffle is located between two adjacent gas diffusion channels on the diffusion plate. When the cooling plate is deformed due to heat during a deposition reaction, the air baffle can prevent the gas between different gas delivery channels from flowing laterally at the gap between the diffusion plate and the cooling plate and causing early mixing of different gases, thereby ensuring the stability of the reaction gas process parameters, avoiding the formation of polymer deposition at the gap, and thus avoiding the resulting particulate pollution.

Description

Technical Field

[0001] The invention relates to the technical field of chemical vapor deposition, and in particular to a gas shower head and chemical vapor deposition equipment. Background Art

[0002] Chemical vapor deposition (CVD) is a process technology that produces solid materials by chemically reacting reactants under gaseous conditions to generate solid substances that are deposited on the surface of a heated solid substrate. This is achieved through a chemical vapor deposition device. Specifically, the CVD device introduces the reaction gas into the reaction chamber through an air intake device, and controls the reaction conditions such as the pressure and temperature of the reaction chamber to make the reaction gas react, thereby completing the deposition process steps.

[0003] Metal organic chemical vapor deposition (MOCVD) devices are mainly used for the preparation of thin-layer single crystal functional structural materials of III-V compounds, II-VI compounds or alloys, such as gallium nitride, gallium arsenide, indium phosphide, zinc oxide, etc. As the application scope of the functional structural materials continues to expand, metal organic chemical vapor deposition devices have become an important chemical vapor deposition device. Metal organic chemical vapor deposition generally uses II or III metal organic sources and VI or V hydride sources as reaction gases, uses hydrogen or nitrogen as carrier gas, and performs vapor phase epitaxial growth on a substrate in a thermal decomposition reaction mode, thereby growing various II-VI compound semiconductors, III-V compound semiconductors, and thin-layer single crystal materials of their multi-component solid solutions.

[0004] However, in the existing metal organic chemical vapor deposition device, part of the structure of the shower head is deformed due to heat, which leads to unstable delivery accuracy of the reaction gas, thereby having a negative impact on the deposition result. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a shower head for carrying a substrate to be processed, comprising:

[0006] A diffusion plate, comprising a plurality of columns of first gas diffusion channels connected to a first reaction gas source and a plurality of columns of second gas diffusion channels connected to a second reaction gas source, wherein the plurality of columns of first gas diffusion channels and the plurality of columns of second gas diffusion channels are alternately arranged in columns;

[0007] A cooling plate located below the diffusion plate, comprising a first gas outlet channel and a second gas outlet channel matching the first gas diffusion channel and the second gas diffusion channel;

[0008] The first gas diffusion channel and the second gas diffusion channel and the first gas outlet channel and the second gas outlet channel form a plurality of gas delivery channels from the gas source to the reaction chamber;

[0009] The diffusion plate and the cooling plate are two separate components, which are assembled into one by a detachable mechanical method; a plurality of air baffles are arranged between adjacent gas delivery channels that convey different gases, and the air baffles are used to prevent different reaction gases between adjacent gas delivery channels from mixing between the diffusion plate and the cooling plate. The second gas outlet channel is optional, and the cooling plate is provided with a groove for accommodating the air baffle, and the vertical distance between the surface of the air baffle and the surface of the groove is less than the distance between the channel walls of the first gas outlet channel or the second gas outlet channel.

[0010] Optionally, a vertical distance between a surface of the air baffle strip and a surface of the recessed portion is smaller than a quarter of a distance between channel walls of the first air outlet channel or the second air outlet channel.

[0011] Optionally, the cross-section of the air baffle strip is square.

[0012] Optionally, the cross-section of the air baffle strip is triangular.

[0013] Optionally, the air baffle strip is integrally provided with the diffusion plate, and the lower portion of the air baffle strip is inserted into the cooling plate.

[0014] Optionally, the air baffle includes an upper portion and a lower portion, the upper portion is inserted into the diffusion plate, and the lower portion is inserted into the cooling plate.

[0015] Optionally, the air baffle is made of a high temperature resistant and corrosion resistant material.

[0016] Optionally, the air baffle is made of stainless steel or Teflon.

[0017] Optionally, the cooling plate is made of stainless steel.

[0018] Optionally, each column of the first gas diffusion channels and the second gas diffusion channels includes a plurality of discrete gas diffusion paths, the gas diffusion paths are arranged in a strip shape, and the gas barrier strip is in a long strip shape.

[0019] Optionally, each of the first gas diffusion channels and the second gas diffusion channels comprises a plurality of discrete gas diffusion paths, the gas diffusion paths are arranged in a ring, and the gas barrier strip is ring-shaped. Furthermore, the present invention also provides a chemical vapor deposition device, comprising a reaction chamber, wherein a support component and a workpiece to be processed located on the support component are arranged in the reaction chamber, the support component can rotate in a substantially horizontal direction, a gas shower head is arranged above the support component, and the gas shower head has the features described in any of the preceding claims.

[0020] The advantages of the present invention are that an air baffle is added at a designated position between the diffusion plate and the cooling plate of the gas shower head. Even if the cooling plate is deformed during deposition, the gap between the diffusion plate and the cooling plate is increased, and the lateral flow of gas between different gas delivery channels can be prevented, thereby ensuring the stability of the reaction gas process parameters, avoiding the formation of polymer deposition in the gap, and thus avoiding the resulting particulate pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1A It is a schematic diagram of the structure of a chemical vapor deposition device in the prior art;

[0023] Figure 1B for Figure 1A A partial enlarged view of the gas shower head in the middle reaction chamber;

[0024] Figure 2A A partial enlarged side view of a gas shower head according to an embodiment of the present invention;

[0025] Figure 2B for Figure 2A A magnified view of Example A;

[0026] Figure 3A-3B A partial enlarged side view of a gas shower head according to another embodiment of the present invention;

[0027] Figure 4 A schematic top view of a gas shower head according to an embodiment of the present invention;

[0028] Figure 5 FIG. 1 is a schematic top view of a gas shower head according to another embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Figure 1A The structure diagram of a chemical vapor deposition device in the prior art when performing a deposition process includes a reaction chamber 100, a gas shower head 100 is arranged at the upper part of the reaction chamber 100, a rotatable base 120 is arranged below the gas shower head 100, and a substrate W is placed above the base 120. Figure 1A A plurality of substrates W are schematically marked in the figure. A heating device not shown in the figure can heat the substrate W from below the susceptor 120 through the susceptor 120 to make the substrate reach the reaction temperature. The gas shower head 100 is used to transport a plurality of reaction gases to the top of the substrate for deposition reaction. Usually, the gas shower head 100 includes a diffusion plate 111 and a cooling plate 112. When the deposition reaction is carried out, the heat of the susceptor 120 will radiate upward to the cooling plate 112, causing the cooling plate 112 to expand. Because the edges of the cooling plate 112 and the diffusion plate 111 are fixed, the cooling plate 112 will slightly arch downward when expanding, resulting in a gap between the cooling plate 112 and the diffusion plate 111.

[0031] like Figure 1B As shown in FIG. 1 , it is a partial enlarged view of the gas shower head after thermal expansion. A plurality of gas diffusion channels 113 are provided in the diffusion plate 111, and a plurality of gas outlet channels 114 corresponding to the gas diffusion channels 113 are provided in the cooling plate 112. In order to make the substrate below react uniformly, a plurality of gas diffusion channels 113 that pass the same gas are arranged at intervals, so that the gas diffusion channels 113 that convey different gases are adjacent to each other, as shown in FIG. Figure 1B As shown by the middle arrow, when a gap is generated between the diffusion plate 111 and the cooling plate 112, the gas flowing downward through a certain gas diffusion channel 113 will diffuse to the surrounding at the gap. On the one hand, the diffused gas will react with other gases in the adjacent gas diffusion channel and be deposited into a polymer in the gap. The polymer will adhere to the side wall of the gas diffusion channel 113 or the gas outlet channel 114 to affect the gas flow rate. Even if it passes through the gas outlet channel 114 into the reaction chamber 100, it will fall on the substrate W and cause defects. On the other hand, after the reaction gas is dispersed at the gap, the gas flow flowing out of the gas outlet channel 114 will differ from the gas flow rate set by the process conditions, which will have a negative impact on the deposition rate and uniformity of the substrate, resulting in fluctuations in process parameters and deposition effects.

[0032] like Figure 2A The figure shows a partially enlarged side schematic diagram of a gas shower head of the present invention, which includes a diffusion plate 211. The reaction gas enters the diffusion plate 211 through a gas pipeline connected to the outside of the reaction chamber for preliminary diffusion, so that the gas can basically ensure uniform gas flow rate when flowing into the gas diffusion channel 213 on the diffusion plate 211. The two adjacent columns of gas diffusion channels 213 arranged on the diffusion plate 211 are used to transport different gases. The two columns here are not limited to linear columns. For the convenience of description, each ring arranged in other annular intervals is also included in the description of the column. A cooling plate 212 is arranged below the diffusion plate 211 to control the temperature of the gas shower head as a whole, so that it maintains a low temperature and prevents the reaction gas from starting to decompose before reaching the surface of the substrate. In some embodiments, the temperature is reduced by opening a fluid channel in the cooling plate and passing a coolant circulation. A plurality of gas outlet channels 214 corresponding to the gas diffusion channels 213 are arranged in the cooling plate 212. The diffusion plate 211 and the cooling plate 212 are two separate components, which are assembled into one by a detachable mechanical method to facilitate the replacement and repair of the individual parts. The first gas diffusion channel 213A and the first gas outlet channel 214A form a gas delivery channel of the same gas source, and the second gas diffusion channel 213B and the second gas outlet channel 214B form a gas delivery channel of another gas source. A plurality of air blocking strips 215 are arranged between adjacent gas delivery channels for delivering different gases. Figure 2A In the embodiment, the number of air baffles 215 between adjacent gas delivery channels that transport different gases is 1, and the air baffle 215 passes through the contact surface between the diffuser plate 211 and the cooling plate 212, that is, the air baffle 215 passes through the surface gap between the diffuser plate 211 and the cooling plate 212.

[0033] When the cooling plate 212 is heated and bends downward to expand the gap between it and the diffusion plate 211, the air barrier strip 215 can block the single reaction gas from diffusing horizontally to the adjacent gas diffusion channel 213. Even if the gap becomes larger, the diffused gas can be maintained between the adjacent air barrier strips 215 on both sides of the single gas diffusion channel 213 without contacting the gas diffusion channel 213 that transports another gas. In other embodiments, there can be multiple air barrier strips 215 between adjacent gas diffusion channels 213. The more the number, the greater the resistance, and it is easier to transport the gas downward along the existing vertical channel than the horizontal diffusion.

[0034] exist Figure 2AThe air barrier strip 215 shown in the figure is divided into an upper part and a lower part. A groove for accommodating the upper part of the air barrier strip 215 is provided in the diffuser plate 211, and a groove for accommodating the lower part of the air barrier strip 215 is provided in the cooling plate 212. In some embodiments, the distance between the air barrier strip 215 and the surface of the groove in the cooling plate 212, that is, the distance between the lower surface of the air barrier strip 215 and the wall of the groove of the cooling plate 212, or the distance between the air barrier strip 215 and the cooling plate 212, is less than the distance between the channel walls of the adjacent air outlet channel 214. According to ΔP, which is proportional to L / d 3 △P is the gas pressure drop, L is the length of the gas through, and d is the diameter of the gas through. Figure 2B As shown, in the partial enlarged view, the distance between the lower part of the air barrier strip 215 and the groove in the cooling plate 212 can be divided into the distance d2 between the air barrier strip 215 and the side wall of the groove in the cooling plate 212 and the distance d3 between the air barrier strip 215 and the bottom wall of the groove in the cooling plate 212, and the distance to the channel wall of the gas outlet channel 214 in the cooling plate 212 is d1, d1, d2 and d3 can all be regarded as d in the above formula, and the air pressure drop △P is more sensitive to the change of d. When the distance between the lower part of the air barrier strip 215 and the groove wall of the cooling plate 212 is less than the distance between the channel wall of the adjacent gas outlet channel 214, when the gas flows into the gap between the air barrier strip 215 and the cooling plate 212, it encounters greater pressure resistance than flowing into the vertical gas outlet channel 214, forcing the gas to flow into the reaction chamber along a preset path. In other embodiments, the distance between the lower part of the air baffle strip 215 and the groove wall of the cooling plate 212 is less than one-fourth of the distance between the channel wall of the adjacent air outlet channel 214, which can produce a better blocking effect, and during installation, the distance between the two is not completely close, that is, the values ​​of d2 and d3 are not zero, which can leave space for thermal expansion and completely compress when heated to prevent air cross-talk. Similarly, the distance between the upper part of the air baffle strip 215 and the groove wall of the diffuser plate 211 can also be set under the same conditions.

[0035] The cross-section of the air baffle 215 can be a square as shown in Figure 2. When the cooling plate 212 is deformed and bent downward, the distance between the square-section air baffle 215 and the side cooling plate 212 remains unchanged, and only the distance between the air baffle 215 and the bottom cooling plate 212 becomes larger. This will not affect the initial pressure of the air baffle 215 on the lateral diffusion of the gas. In some other embodiments, the cross-section of the air baffle can also be other shapes, such as a triangle with the bottom side facing downward. At the same time, the air baffle 215 can be integrally arranged with the diffuser plate, and the two hypotenuse sides of the triangle have lateral component surfaces relative to the vertical sides of the square. The shape of the groove in the cooling plate 212 is the same as that of the air baffle 215. In this way, when the cooling plate is deformed downward, the distance between the side of the air baffle 215 and the side wall of the groove in the cooling plate 212 can be reduced, or even completely close to achieve the purpose of preventing lateral gas leakage.

[0036] In such Figure 3A In another embodiment of the gas shower head of the present invention shown in FIG. 1 , the difference from the above embodiment is that the air retaining strip 315 is integrally arranged with the diffuser plate 311, and the lower part of the air retaining strip 315 penetrates through the interface between the diffuser plate and the cooling plate and penetrates into the cooling plate, so that the gap between the air retaining strip and the diffuser plate 311 can be completely blocked, and space can be left for the cooling plate to deform, thereby preventing extrusion damage caused by deformation. Figure 3B In the embodiment shown in , the air barrier strip 315 is integrally arranged with the cooling plate, and the upper part of the air barrier strip 315 is inserted into the groove of the diffusion plate 311. The air barrier strip 315 can be made of a material that is resistant to high temperature and corrosion, so that it can withstand the heat radiation from the base upward and the corrosion from the side of the gas while maintaining a stable chemical state without generating polluting particles. For example, stainless steel and Teflon can be selected. Similarly, for the purpose of high temperature resistance and corrosion resistance, the cooling plate can also be made of stainless steel.

[0037] Figure 4 FIG. 4 is a partial top view of another embodiment of a gas shower head of the present invention, wherein a plurality of gas diffusion paths 416 are provided on the gas diffusion channels 413A and 413B indicated by dashed lines. The plurality of gas diffusion paths 416 on a single gas diffusion channel are used to introduce the same reaction gas. Figure 4 In the embodiment, the gas diffusion paths are arranged along a long strip, and accordingly, the air barrier strip 415 is a strip structure, which is arranged between two rows of gas diffusion paths 416 conveying different gases. The alternating arrangement of the plurality of rows of first gas diffusion channels and the plurality of rows of second gas diffusion channels described in the present invention is not limited to a straight line arrangement, and may also be an arrangement of other shapes. Figure 5 FIG. 1 is a partial top view of another embodiment of a gas shower head of the present invention. The difference from the above embodiment is that a plurality of gas diffusion paths 516 are provided on the gas diffusion channels 513A and 513B indicated by dotted lines. The plurality of gas diffusion paths 516 on a single gas diffusion channel are used to introduce the same reaction gas. Figure 5 In the embodiment, the gas diffusion paths are arranged along the edge of the circle. Accordingly, the air barrier strip 415 is an annular structure and is disposed between two rows of gas diffusion paths 516 conveying different gases.

[0038] Furthermore, the present invention also provides a chemical vapor deposition device, including a reaction chamber, wherein a support component and a workpiece to be processed located on the support component are arranged in the reaction chamber, and the support component can rotate in a substantially horizontal direction, including any one of the above-mentioned gas shower heads.

[0039] An air baffle is added at a designated position between the diffuser plate and the cooling plate of the gas shower head. Even if the cooling plate is deformed during deposition, the gap between the diffuser plate and the cooling plate is increased, which can prevent the lateral flow of gas between different gas delivery channels, thereby ensuring the stability of the reaction gas process parameters, avoiding the formation of polymer deposition in the gap, and thus avoiding the resulting particulate matter pollution.

[0040] The shower head disclosed in the present invention is not limited to the above-mentioned chemical vapor deposition device, but can also be applied to other thin film growth devices, which will not be described in detail here.

[0041] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A gas shower head for inputting a variety of reaction gases into a reaction chamber, characterized in that: include: A diffusion plate, comprising a plurality of columns of first gas diffusion channels connected to a first reaction gas source and a plurality of columns of second gas diffusion channels connected to a second reaction gas source, wherein the plurality of columns of first gas diffusion channels and the plurality of columns of second gas diffusion channels are alternately arranged in columns; A cooling plate located below the diffusion plate, comprising a first gas outlet channel and a second gas outlet channel matching the first gas diffusion channel and the second gas diffusion channel; The first gas diffusion channel and the second gas diffusion channel and the first gas outlet channel and the second gas outlet channel form a plurality of gas delivery channels from the gas source to the reaction chamber; The diffusion plate and the cooling plate are two separate components, which are assembled into one by a detachable mechanical method; a number of air baffles are arranged between adjacent gas delivery channels that transport different gases, and the air baffles pass through the contact surface of the diffusion plate and the cooling plate. The air baffles include an upper part and a lower part, the upper part is inserted into the diffusion plate, and the lower part is inserted into the cooling plate. The distance between the air baffle and the diffusion plate or the cooling plate is less than one-fourth of the distance between the channel walls of the first gas outlet channel or the second gas outlet channel and is not zero, and the air baffles are used to prevent different reaction gases between adjacent gas delivery channels from mixing between the diffusion plate and the cooling plate.

2. The gas shower head according to claim 1, characterized in that: The cooling plate is provided with a groove for accommodating the air baffle strip.

3. The gas shower head according to claim 2, characterized in that: A vertical distance between a surface of the air baffle strip and a surface of the groove is smaller than a quarter of a distance between channel walls of the first air outlet channel or the second air outlet channel.

4. A gas shower head for inputting a variety of reaction gases into a reaction chamber, characterized in that: include: A diffusion plate, comprising a plurality of columns of first gas diffusion channels connected to a first reaction gas source and a plurality of columns of second gas diffusion channels connected to a second reaction gas source, wherein the plurality of columns of first gas diffusion channels and the plurality of columns of second gas diffusion channels are alternately arranged in columns; A cooling plate located below the diffusion plate, comprising a first gas outlet channel and a second gas outlet channel matching the first gas diffusion channel and the second gas diffusion channel; The first gas diffusion channel and the second gas diffusion channel and the first gas outlet channel and the second gas outlet channel form a plurality of gas delivery channels from the gas source to the reaction chamber; The diffuser plate and the cooling plate are two separate components, which are assembled into one by a detachable mechanical method; a plurality of air baffles are arranged between adjacent gas delivery channels that transport different gases, and the air baffles pass through the contact surface between the diffuser plate and the cooling plate. The air baffles are integrally arranged with the diffuser plate, and the lower part of the air baffles is inserted into the cooling plate. The distance of the gap between the air baffles and the cooling plate is less than one-fourth of the distance between the channel walls of the first gas outlet channel or the second gas outlet channel and is not zero, and the air baffles are used to prevent different reaction gases between adjacent gas delivery channels from mixing between the diffuser plate and the cooling plate.

5. A gas shower head for inputting a variety of reaction gases into a reaction chamber, characterized in that: include: A diffusion plate, comprising a plurality of columns of first gas diffusion channels connected to a first reaction gas source and a plurality of columns of second gas diffusion channels connected to a second reaction gas source, wherein the plurality of columns of first gas diffusion channels and the plurality of columns of second gas diffusion channels are alternately arranged in columns; A cooling plate located below the diffusion plate, comprising a first gas outlet channel and a second gas outlet channel matching the first gas diffusion channel and the second gas diffusion channel; The first gas diffusion channel and the second gas diffusion channel and the first gas outlet channel and the second gas outlet channel form a plurality of gas delivery channels from the gas source to the reaction chamber; The diffusion plate and the cooling plate are two separate components, which are assembled into one by a detachable mechanical method; a number of air baffles are arranged between adjacent gas delivery channels that transport different gases, and the air baffles pass through the contact surface between the diffusion plate and the cooling plate. The air baffles are integrally arranged with the cooling plate, and the upper part of the air baffles is inserted into the diffusion plate. The distance of the gap between the air baffles and the diffusion plate is less than one-fourth of the distance between the channel walls of the first gas outlet channel or the second gas outlet channel and is not zero, and the air baffles are used to prevent different reaction gases between adjacent gas delivery channels from mixing between the diffusion plate and the cooling plate.

6. The gas shower head according to any one of claims 1 to 5, characterized in that: The cross section of the air baffle strip is square.

7. The gas shower head according to any one of claims 1 to 5, characterized in that: The cross section of the air baffle strip is a triangle.

8. The gas shower head according to any one of claims 1 to 5, characterized in that: The air baffle is made of high temperature resistant and corrosion resistant material.

9. The gas shower head according to claim 8, characterized in that: The air baffle is made of stainless steel or Teflon.

10. The gas shower head according to any one of claims 1 to 5, characterized in that: The cooling plate is made of stainless steel.

11. The gas shower head according to any one of claims 1 to 5, characterized in that: Each column of the first gas diffusion channels and the second gas diffusion channels includes a plurality of discrete gas diffusion paths, the gas diffusion paths are arranged in a strip shape, and the gas barrier strip is in a long strip shape.

12. The gas shower head according to any one of claims 1 to 5, characterized in that: Each row of the first gas diffusion channels and the second gas diffusion channels includes a plurality of separate gas diffusion paths, the gas diffusion paths are arranged in a ring shape, and the gas barrier strip is in a ring shape.

13. Chemical vapor deposition equipment, characterized in that The invention comprises a reaction chamber, wherein a support component and a workpiece to be processed located on the support component are arranged in the reaction chamber, the support component can rotate in a substantially horizontal direction, a gas shower head is arranged above the support component, and the gas shower head has the features described in any one of claims 1 to 12.

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