Gas delivery and exhaust system for semiconductor processing chamber

Abstract

The invention provides a gas conveying and exhausting system of a semiconductor processing chamber, which is used for conveying process gas to the semiconductor processing chamber and exhausting residual gas after reaction, and comprises a gas mixer and a diffuser which are arranged at the top of the processing chamber and are communicated with each other, the mixer is arranged in the processing chamber and is in fluid communication with the processing chamber, a process gas pipeline is connected to an inlet of the mixer, and an outlet of the mixer is communicated to an inlet of the diffuser; the processing chamber is provided with an air inlet located in the top and an air outlet located in the bottom, the air inlet is formed in the side opposite to the air outlet, and an outlet of the diffuser is communicated to the air inlet of the processing chamber; wherein the flow direction of gas in the processing chamber is a first direction, the outlet of the diffuser is gradually expanded from the center to the two sides in a second direction, and the second direction is perpendicular to the first direction. According to the invention, the film deposition uniformity can be improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, in particular to a semiconductor device, and in particular to a gas delivery and exhaust system for a semiconductor processing chamber. Background Art

[0002] Thin film deposition processes including chemical vapor deposition and atomic layer deposition are commonly used technologies in semiconductor chip manufacturing to form functional film layers such as dielectric layers on the surface of substrates. It is a process of forming a solid substance deposited on a substrate to form a thin film through a gas-phase chemical reaction between gaseous initial compounds at medium and high temperatures. The most important indicator for measuring the quality of a thin film deposition process is the uniformity of thin film deposition. If the deposited film is uneven, it will not only cause defects such as stress and resistance unevenness in the film itself, but also affect the subsequent lithography accuracy and etching uniformity, seriously affecting device performance. With the increasing integration of devices and the decreasing feature size of devices, the uniformity of deposited films has an increasingly greater impact on device performance. Improving the uniformity of thin film deposition has become a goal that technicians in this field are constantly pursuing.

[0003] Some existing methods to improve the uniformity of thin film deposition include rotating the substrate during deposition, adding catalytic materials to the reaction precursor to increase the activity of the precursor, or using a gas supply device such as a shower head to improve the distribution of the reaction gas. However, these methods may introduce new impurities or the required equipment structure is too complicated, resulting in increased costs. Therefore, new means are still needed to further improve the uniformity of thin film deposition. Summary of the invention

[0004] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a gas delivery and exhaust system for a semiconductor processing chamber to further improve the distribution uniformity of process gases in the deposition chamber and further improve the uniformity of thin film deposition.

[0005] To achieve the above-mentioned purpose and other related purposes, the present invention provides a gas delivery and exhaust system for a semiconductor processing chamber, which is used for delivering process gas to the semiconductor processing chamber and discharging residual gas after the reaction, and comprises: a gas mixer and a diffuser arranged at the top of the processing chamber, the mixer and the diffuser are interconnected and fluidically connected to the processing chamber, a process gas pipeline is connected to the inlet of the mixer, and the outlet of the mixer is connected to the inlet of the diffuser; the processing chamber is provided with an air inlet located at the top and an exhaust port located at the bottom, the air inlet is arranged on the opposite side of the exhaust port, and the outlet of the diffuser is connected to the air inlet of the processing chamber; wherein the gas flow direction in the processing chamber is a first direction, and the outlet of the diffuser gradually expands from the center to both sides in a second direction, and the second direction is perpendicular to the first direction.

[0006] Optionally, the air inlet and the air outlet of the processing chamber have the same morphology.

[0007] Optionally, the bottom of the diffuser is configured as an integral structure with the top cover of the processing chamber, and the outlet of the diffuser and the air inlet of the processing chamber are the same opening.

[0008] Optionally, the top surface of the diffuser has an arc surface structure, and the distance between the top surface of the diffuser and the bottom surface of the diffuser gradually decreases in a direction away from the diffuser inlet.

[0009] Optionally, the bottom surface of the diffuser has several of the following structures: a wave-shaped protrusion structure, a plurality of columns distributed at intervals, and a plurality of spherical protrusions distributed at intervals.

[0010] Optionally, the outlet of the diffuser includes a first air outlet section, a second air outlet section and a third air outlet section connected in sequence, and the air outlet areas of the first air outlet section and the third air outlet section at both ends are equal and larger than the air outlet area of ​​the second air outlet section in the middle.

[0011] Optionally, the mixer and the diffuser are connected to each other through a plurality of holes which are arranged at intervals and have gradually changing pore sizes or inclined directions.

[0012] Optionally, the gas delivery and exhaust system of the semiconductor processing chamber also includes an exhaust chamber, which is connected to the exhaust port of the processing chamber, and the cross-sectional area of ​​the exhaust chamber gradually decreases in the direction away from the processing chamber, and the exhaust pipeline is connected to one end of the exhaust chamber away from the processing chamber.

[0013] Optionally, the gas delivery and exhaust system of the semiconductor processing chamber includes more than two mixers stacked up and down and more than two diffusers stacked up and down, the mixers and diffusers are connected one-to-one, the upper diffuser and the lower diffuser outlet are connected to each other, the process gas enters the corresponding diffuser through different mixers, and enters the processing chamber successively through the outlet of the bottom diffuser.

[0014] More optionally, the semiconductor processing chamber has two or more exhaust pipelines of the gas delivery and exhaust system, and residual gas of the process gas is exhausted through different exhaust pipelines.

[0015] As described above, the gas delivery and exhaust system of the semiconductor processing chamber of the present invention has the following beneficial effects: the improved structural design of the present invention can make the process gas entering the processing chamber through the outlet of the diffuser flow in the processing chamber along a direction roughly parallel to the surface of the substrate, and the gas outlet of the diffuser gradually expands from the center to both sides in the second direction, so that the reaction gas diffuses from the center to the outside in the second direction, and through the exhaust port of the processing chamber located on the other side of the gas inlet in the first direction, the reaction gas is evenly diffused to the substrate surface in the processing chamber along the first direction and the second direction, thereby achieving a uniform diffusion effect of the lateral airflow in the chamber, which helps to improve the uniformity of thin film deposition. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1a FIG. 1 is a front view of an exemplary gas delivery and exhaust system for a semiconductor processing chamber provided by the present invention.

[0017] Figure 1b Shown Figure 1a Schematic cross-section of .

[0018] Figure 2 FIG. 2 is another exemplary front view of a gas delivery and exhaust system for a semiconductor processing chamber provided by the present invention.

[0019] Figure 3 The figure shows the exploded structure of FIG1 .

[0020] Figure 4 and 5 Shown are schematic top views of a diffuser of a gas delivery and exhaust system for a semiconductor processing chamber provided by the present invention in different examples.

[0021] Figure 6 FIG. 1 is a schematic diagram showing an exemplary structure of an exhaust chamber of a gas delivery and exhaust system for a semiconductor processing chamber provided by the present invention.

[0022] Figure 7 FIG. 1 is an exemplary schematic diagram showing an inlet of a diffuser and a gas outlet of a processing chamber of a gas delivery and exhaust system of a semiconductor processing chamber provided by the present invention.

[0023] Figures 8 to 12 FIG. 1 is a schematic cross-sectional view of a gas delivery and exhaust system for a semiconductor processing chamber provided by the present invention in different examples, wherein: Fig. 9 For the corresponding Figure 4 An exemplary cross-sectional structural diagram of Fig.10 and Fig.11 for Figure 5 Schematic diagram of the cross-sectional structure in different examples. DETAILED DESCRIPTION

[0024] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. For example, when describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional view showing the device structure will not be partially enlarged according to the general proportion, and the schematic diagram is only an example, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0025] For ease of description, spatially relative terms such as "under", "below", "below", "below", "above", "on", etc. may be used herein to describe the relationship of one element or feature shown in the drawings to other elements or features. It will be understood that these spatially relative terms are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the drawings. In addition, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

[0026] In the context of the present application, a structure in which a first feature is described as being "above" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0027] It should be noted that the diagrams provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and the diagrams only show the components related to the present invention rather than the number, shape and size of the components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the layout of the components may also be more complicated. In order to make the diagrams as concise as possible, not all structures are marked in the drawings.

[0028] Most of the existing chemical vapor deposition equipment uses a spray device with multiple spray ports located at the top of the processing chamber to transport the reaction gas into the processing chamber, and the residual gas is discharged through the exhaust port located at the bottom of the processing chamber. A major problem with equipment of this structure is that the spray port is easily blocked, resulting in uneven gas distribution. Some laminar reaction chambers use long strip-shaped air inlets with regular morphology to transport the reaction gas into the chamber, and the residual gas is discharged through the circular hole-shaped air outlet at the bottom of the chamber. However, in equipment of this structure, since the gas path will eventually converge into an air inlet / outlet pipe, the axial distribution of the gas at the long strip-shaped air inlet / outlet is not uniform, resulting in large differences in the distribution of gas in the chamber. For example, the reaction gas is overly concentrated in the middle of the chamber, resulting in the final deposited film showing a defect of being thick in the middle and thin at the edges, which seriously affects the device yield. In this regard, the inventor of this case has proposed an improvement plan after long-term research.

[0029] Specifically, the present invention provides a gas delivery and exhaust system for a semiconductor processing chamber, which is used to deliver process gas (also referred to as reaction gas) to the semiconductor processing chamber and exhaust the residual reaction gas and the inert gas used as the carrier gas after the reaction. Figures 1a to 6 As shown, it includes a mixer 12 and a diffuser 13 arranged on the top of a processing chamber 11 (the processing chamber can also be called a deposition chamber). The processing chamber 11 is a space for thin film deposition on a substrate, such as a wafer, and includes a closed space surrounded by a top cover plate 111, a side wall plate 112 and a bottom plate 113. The processing chamber 11 as a whole can be made of metal materials such as stainless steel, and the inner surface can be coated. A carrier for carrying a substrate can be provided inside the processing chamber 11. The carrier can be, for example, a disc based on vacuum adsorption or electrostatic adsorption, and a plurality of through holes can be provided on the disc for lifting pins to move up and down to transfer the substrate to the carrier, or to transfer the substrate from the surface of the carrier.

[0030] In order to facilitate temperature regulation of the wafer, a heating and / or cooling device may be provided inside the stage. The bottom of the stage is usually connected to a lifting shaft 116 to drive the substrate to rise and fall and / or rotate during the deposition process. The lifting shaft 116 extends from the inside of the processing chamber 11 to the outside, and the power supply line and / or gas supply line can be received in the lifting shaft 116. The lifting shaft 116 can also be further connected to the lifting cylinder to drive the substrate up and down when necessary, which helps to further improve the uniformity of thin film deposition. The processing chamber 11 is provided with an air inlet 114 located on the top cover plate 111 and an exhaust port 115 located on the bottom plate 113, and the air inlet 114 and the exhaust port 115 are preferably located on opposite sides. In other words, the air inlet 114 is arranged on the side opposite to the exhaust port 115. In other words, the air inlet 114 and the exhaust port 115 of the processing chamber 11 may not be on the same horizontal plane, but the orthographic projections of the two on the same horizontal plane preferably fall on the opposite ends of the center line of the processing chamber 11. The structural morphology of the gas inlet 114 and the gas outlet 115 can be the same or different, and in this embodiment, they are preferably the same, so that the gas inlet surface and the gas outlet surface of the processing chamber 11 form a symmetrical structure with the center line of the processing chamber 11. This structure helps to extend the flow path of the process gas and avoid local accumulation of the process gas, so that the gas diffusion is more uniform, which helps to improve the uniformity of thin film deposition.

[0031] The mixer 12 and the diffuser 13 are interconnected, and the fluid is connected to the processing chamber 11. The process gas pipeline 14 is connected to the inlet of the mixer 12, and the outlet of the mixer 12 is connected to the inlet of the diffuser 13; the outlet 131 of the diffuser 13 is connected to the gas inlet 114 of the processing chamber 11. In a more preferred example, the outlet 131 of the diffuser 13 corresponds to the gas inlet 114 of the processing chamber 11 and is interconnected, and the gas in the diffuser 13 enters the processing chamber 11 through the outlet 131 of the diffuser 13. In order to improve the uniformity of gas diffusion, the size and shape of the outlet 131 of the diffuser 13 and the gas inlet 114 of the processing chamber 11 are matched and preferably completely consistent. When the bottom of the diffuser and the processing chamber are an integrated structure, the outlet 113 of the diffuser and the gas inlet 114 of the processing chamber are the same opening, so that the resistance of the process gas on the transmission path can be reduced and the uniformity of gas diffusion can be improved. The gas flow direction in the processing chamber 11 is a first direction, and the outlet 113 of the diffuser 13 gradually expands from the center to both sides in a second direction, and the second direction is perpendicular to the first direction. After the process gas enters the processing chamber 11, under the action of the exhaust power provided by the exhaust port at the chamber outlet, the process gas flows in the processing chamber in a direction substantially parallel to the substrate surface.

[0032] By using the gas delivery and exhaust system provided by the present invention, different reaction gases are delivered to the mixer 12 for mixing, and the uniformly mixed gas enters the diffuser 13 through the inlet on one side of the diffuser 13, and after further diffusion in the diffuser 13, enters the gas inlet 114 of the processing chamber 11 at the bottom of the same side through the outlet 131 of the diffuser 13. Since the outlet of the diffuser 13 gradually expands from the center to both sides in the second direction, and the gas inlet and exhaust port of the processing chamber 11 are located on opposite sides in the first direction, the gas flow rate flowing out of the outlet of the diffuser 13 accordingly presents the characteristic of gradually expanding from the center to both sides in the second direction. That is, the process gas will diffuse from the center to both sides in the second direction during entering the processing chamber 11, and under the effect of the suction provided by the gas outlet on the other side of the processing chamber 11, the reaction gas will be forced to form a uniform laminar flow dispersed in the first direction and the second direction along the parallel substrate surface during the flow in the first direction, and avoid being concentrated in the middle of the processing chamber, so that the reaction gas is uniformly diffused in the entire cavity of the reaction chamber and diffused to the substrate surface. The uniformly diffused gas molecules are adsorbed on the substrate surface and / or react with the gas already adsorbed and deposited on the substrate surface to form a thin film, and the residual process gas and reaction by-products are discharged through the exhaust port of the processing chamber.

[0033] The improved structural design of the present invention can avoid the problem of excessive concentration of gas in the center of the processing chamber in the prior art. The gas outlet of the diffuser gradually expands from the center to both sides in the second direction, so that the reaction gas diffuses from the center to the outside, and under the action of the exhaust port on the other side of the gas inlet of the processing chamber, the reaction gas is evenly diffused to the surface of the substrate in the processing chamber along the first direction and the second direction, thereby achieving the effect of axial uniform ventilation, which is helpful to improve the uniformity of thin film deposition.

[0034] The exhaust port 115 of the processing chamber 11 can be directly connected to the vacuum pump through the exhaust pipe 16. However, in the preferred example provided by the present invention, the gas delivery and exhaust system of the semiconductor processing chamber further includes an exhaust chamber 15, and the exhaust chamber 15 is connected to the exhaust port 115 of the processing chamber 11. An exemplary structure of the exhaust chamber 15 can be referred to Figure 6As shown, its cross-sectional area gradually decreases in the direction away from the processing chamber 11, and the exhaust pipe 16 is connected to the end of the exhaust chamber 15 away from the processing chamber 11. In other words, the cross-sectional area of ​​the exhaust chamber 15 is similar to a triangle, or a trapezoid that is wide at the top and narrow at the bottom, so that the exhaust channel gradually decreases from top to bottom, which helps to increase the exhaust pressure and prevent the residual gas from settling on the exhaust channel and causing the exhaust channel to be blocked. The exhaust surface inside the exhaust chamber 15 can form a funnel-like structure, that is, a sloped air-guiding surface is formed inside the exhaust chamber, which helps to further prevent the residual gas and reaction by-products from remaining in the exhaust chamber 15.

[0035] The exhaust line 16 of the gas delivery and exhaust system of the semiconductor processing chamber can be a single line, and the corresponding exhaust pump is a single line. The advantage of this arrangement is that the equipment structure is relatively simple, but the disadvantage is that different types of gases in the residual gas may react with each other and deposit on the exhaust line 16 and the vacuum pump, causing exhaust blockage and resulting in a decrease in the service life of the equipment. Therefore, in a preferred example provided by the present invention, there are more than two exhaust lines 16, and the residual gases of the process gases that react with each other are discharged through different exhaust lines 16, and different exhaust lines 16 are connected to different vacuum pumps. To facilitate exhaust, baffles can be provided at the entrances of different exhaust lines 16, and the opening and closing of each baffle corresponds to the pulse supply time point of each process gas to ensure that each exhaust line 16 and vacuum pump is only responsible for the discharge of a specific single gas, and the residual gases of the process gases that react with each other are discharged through different channels.

[0036] In one example, the diffuser 13 may be a structure having an independent closed diffusion chamber. That is, the diffuser 13 may have a closed cavity surrounded by a top plate, a side plate and a bottom plate and may be detachably arranged on the upper part of the processing chamber 11. In other words, the bottom plate of the diffuser 13 and the top plate of the processing chamber 11 are independent structures. The inlet of the diffuser 13 is located on its top plate and the outlet 131 is located on its bottom plate, and although the outlet 131 of the diffuser 13 and the air inlet on the processing chamber 11 are located on different plates, the two completely correspond to each other from top to bottom. The advantage of this split design is that different diffusers can be replaced as needed, and other structures can be set between the diffuser and the processing chamber as needed.

[0037] In some other examples, the bottom of the diffuser 13 is configured to be an integrated structure with the top cover of the processing chamber 11, so that the outlet 131 of the diffuser 13 and the air inlet of the processing chamber 11 are the same opening. In other words, the diffuser 13 has no bottom plate, or its bottom plate is the top cover of the processing chamber 11. Therefore, the outlet at the bottom of the diffuser 13 is also the air inlet located at the top of the processing chamber 11. The structure in which the diffuser bottom plate and the top cover of the processing chamber are combined into one further shortens the air inlet channel (i.e., one less layer of plate is provided in the air inlet path), which can avoid the generation of an air gap at the connection between the two, and is conducive to further uniform diffusion of the gas.

[0038] In the present invention, the surface areas of the two ends of the outlet surface where the outlet 131 of the diffuser 13 is located are larger than the surface area of ​​the middle part, which is different from the single rectangular surface structure with equal areas at all places in the prior art. The outlet 131 of the diffuser 13 can be equal to the outlet surface, that is, the entire outlet surface is open. For example, in one example, Figure 7 As shown, the outlet 131 of the diffuser 13 includes a first outlet section 131a, a second outlet section 131b and a third outlet section 131c located in the same straight line and connected in sequence, each outlet section is rectangular, and in particular, the outlet surface of each section is a rectangular surface, and the outlet areas of the first outlet section 131a and the third outlet section 131c located at the two ends are equal and larger than the outlet area of ​​the second outlet section 131b located in the middle. It should be noted that Figure 7 The outlet 131 on the left side can also be understood as the air inlet 114 of the processing chamber 11. As mentioned above, in the preferred example, the outlet 131 of the diffuser 13 and the air inlet 114 of the processing chamber 11 are overlapped or even combined into one. It is only for the purpose of better introducing the diffuser that it is marked as the outlet 131 of the diffuser 13. The design of the exhaust port 115 of the processing chamber 11 is preferably the same as that of the processing chamber 11, that is, it also includes a first outlet section, a second outlet section and a third outlet section located in the same straight line and connected in sequence. The outlet surface of each outlet section is a rectangular surface. The outlet areas of the first outlet section and the third outlet section located at both ends are equal and larger than the outlet area of ​​the second outlet section located in the middle. Therefore, the exhaust power at both ends of the exhaust port is greater than the exhaust power in the middle position, which can further force the process gas to diffuse, avoid the process gas from gathering in the middle of the processing chamber during the flow process, and help to improve the diffusion uniformity of the process gas in the processing chamber, thereby improving the uniformity of thin film deposition.

[0039] In another example, the outlet of the diffuser 13 may also be non-linear, for example Figure 3As shown, the outlet of the diffuser (air inlet 114) smoothly transitions from the middle to both sides, and the air outlet area gradually increases from the middle to both sides, or the two ends of its outlet are trumpet-shaped with a relatively small opening size in the middle, or the outlet of the diffuser can be divided into more sections from the middle to both sides with gradually decreasing air outlet surfaces, etc. The present invention does not impose strict restrictions on this.

[0040] In other examples, the outlet 131 and the gas outlet surface of the diffuser 13 may also be unequal, for example, the outlet 131 is just a plurality of openings arranged on a larger gas outlet surface. In a further example, when the outlet 131 and the gas outlet surface are unequal, a gas outlet cavity may be arranged at the gas outlet end, and the process gas outputted through the outlet 131 enters the processing chamber 11 through the gas outlet cavity.

[0041] The mixer 12 may be a structure whose outer surface is generally rectangular, and one end of the mixer 12 is connected to the air inlet line 14. The volume of the mixing chamber inside the mixer 12 is usually relatively small, for example, smaller than the volume of the diffusion chamber inside the diffuser 13. The smaller mixing space allows the reaction gas and the carrier gas to be fully mixed, and form a gas flow with a relatively high air pressure to be transported to the diffuser 13. The air inlet line 14 is usually multiple, for example, usually includes more than two process gas pipelines and at least one carrier gas pipeline (the carrier gas pipeline is preferably one-to-one corresponding to the process gas pipeline). The carrier gas is, for example, an inert gas such as nitrogen and argon. From a cost perspective, nitrogen is preferred. The process gas can be alternately transported to the mixer 12 in a pulsed form, and after being fully mixed with the inert gas, it enters the diffuser 13 through the inlet of the diffuser 13, and after being further dispersed evenly in the diffuser 13, it is transported to the substrate surface in the processing chamber 11 through the outlet of the diffuser 13, and a thin film is uniformly deposited on the substrate surface.

[0042] The diffuser 13 and the mixer 12 can be connected, for example, by a pipeline. However, in a preferred example provided by the present invention, the mixer 12 and the diffuser 13 are connected by a plurality of holes arranged at intervals and having gradually changing apertures or inclined directions. For example, from the mixer 12 to the diffuser 13, the aperture gradually decreases so that the gas pressure gradually increases, or the hole forms a certain angle with the horizontal plane so that the process gas enters the diffuser 13 along the oblique upper direction, thereby further improving the uniformity of gas diffusion.

[0043] Many process gases in vapor deposition are formed by evaporation of solid or liquid reaction source substances. Different reaction sources enter the processing chamber 11 through the same channel, and there will be overlap of different reaction sources (such as insufficient purging in the ALD equipment, which will cause the previous reaction gas to remain inside the diffuser). Since the process gas itself has a certain temperature, the overlapping process gases will also react with each other to form deposits, and the quality of these deposits is poor (such as TiN and NH3 are very easy to form a porous Adduct mixture at 90°C). These loose deposits may fall off and form particle pollution after a certain external force or a certain amount of deposition, which will eventually shorten the service life of the entire processing chamber. Or in some processes, such as the ALD (atomic layer deposition) process, the loose porous structure usually locks the reaction source gas and cannot be purged clean. These captured reactants will continue to release the reaction source and form a CVD reaction in the chamber, thereby causing serious adverse effects on the quality of wafer film formation inside the processing chamber.

[0044] To solve such problems, in one example of the present invention, the gas delivery and exhaust system of the semiconductor processing chamber may be provided with a heater (not shown) for heating the mixer 12 and / or the diffuser 13, and the heating temperature may be set to be higher than the conventional heating temperature of each reaction source material to prevent the process gas from recondensing and reacting with each other. The processing chamber 11 is at the reaction temperature.

[0045] In some examples, each inner surface of the diffuser 13 may be a smooth and flat surface. In other examples, the top surface and / or the bottom surface of the diffuser 13 may be a non-flat surface.

[0046] For example, in one example, Figure 8 As shown, the top surface of the diffuser 13 has an arc surface structure, and the top surface of the diffuser 13, especially the distance between the arc surface and the bottom surface of the diffuser 13, that is, the height of the diffuser 13 gradually decreases along the direction away from the air inlet. The top surface of the diffuser 13 can be all arc-shaped or include a horizontal top surface and an arc top surface connected to the rear end of the horizontal top surface (i.e., one end away from the inlet of the diffuser). In other words, the upper end surface of the diffuser 13 away from the mixer 12 is an arc surface. Compared with the existing pure right-angle surface, the setting of the arc surface not only relatively lengthens the diffusion path of the reaction gas, but also makes the gas transition smoothly in the diffuser, prevents gas aggregation, and helps to further improve the uniformity of gas diffusion.

[0047] In another example, Fig. 9 As shown, the lower surface of the diffuser 13 has a wavy structure, or the lower surface of the diffuser 13 is provided with Fig.10 Multiple columnar structures distributed at intervals as shown or as Fig.11 The multiple spherical protrusions shown, or a combination of multiple columnar structure protrusions and multiple spherical protrusions. When the bottom surface of the diffuser 13 is provided with columnar structures and / or spherical protrusions at intervals, the size of the columnar structure and the spherical protrusions can be flexibly set on the premise of ensuring that the gas has a completely connected flow path inside the diffuser 13. For example, the height of the columnar structure can be consistent with the height of the diffuser 13, or the upper and lower ends of the columnar structure are respectively connected to the upper and lower ends of the diffuser 13, so that the gas in the diffuser 13 meanders along the gap between the columnar structures, which helps to further extend the diffusion path of the process gas, and the particle molecules in the process gas collide with these protrusion structures during the diffusion process, which helps to reduce the agglomeration of molecules, promote uniform mixing of gases, and improve diffusion uniformity. The columnar structure is preferably a cylindrical column. The height of the spherical protrusion is preferably less than the height of the diffuser 13, for example, within half of the height of the diffuser 13, etc., to reserve space for gas diffusion.

[0048] In another example, the diffuser 13 may also be combined with Figure 8 The top arc structure shown and Figures 9 to 11 These structures are helpful to extend the diffusion path of the reaction gas in a limited space, reduce condensation between reaction source particles, and improve diffusion uniformity.

[0049] The chamber inside the existing mixer and diffuser is usually a single chamber, and different reaction sources are mixed and diffused through this single chamber. This structure is prone to the aforementioned different reaction sources overlapping and reacting with each other, forming loose sediments, and the sediments are easy to fall off and cause particle contamination, affecting the quality of thin film deposition, etc. In the preferred example provided by the present invention, Fig.12As shown, the gas delivery and exhaust system of the semiconductor processing chamber includes two mixers 12 stacked up and down and two diffusers 13 stacked up and down, and the gas outlets of all diffusers 13 are preferably arranged in correspondence with each other. The mixers 12 and the diffusers 13 are connected one by one, and the upper diffuser 13 is connected to the lower diffuser 13. The reaction gas enters the corresponding diffuser 13 through different mixers 12, and enters the processing chamber 11 successively through the outlet of the bottom diffuser 13. Different process gases are fully mixed with carrier gases in different mixers 12 and then transported to the corresponding diffuser 13, and then transported to the processing chamber 11. Since the diffusers 13 arranged up and down are connected only through corresponding connecting channels, the probability of different reaction gases contacting each other in the diffuser 13 is greatly reduced, which can effectively reduce or even avoid mutual deposition to form deposits before entering the processing chamber 11, which helps to improve the cleanliness of the equipment and ensure the process gas process quantity, and improve the quality and efficiency of thin film deposition. In some examples, reference Fig.12 As shown, a plurality of partitions 133 may be provided in the diffuser 13, and one end of the partition 133 adjacent to the inlet of the diffuser 13 is fixed to the mounting surface 134 of the diffuser 13, and a plurality of openings may be provided on the mounting surface 134, so that the diffusion chambers at both ends of the partition mounting surface 134 of the diffuser 13 are fluidically connected to each other, and the other end of the partition 133 is a free end, thereby dividing the diffuser 13 into two or more diffusion chambers that are interconnected at the outlet end to improve the effect of gas diffusion. In other embodiments, a plurality of mixers and diffusers may be stacked and arranged according to actual needs, and the present invention does not limit the number of mixers and diffusers, and any configuration of a plurality of mixers and diffusers that meets the process setting falls within the protection scope of the present invention.

[0050] In addition, in order to further reduce or even avoid the contact between different process gases before entering the processing chamber, when one of the process gases enters the processing chamber 11 through one of the diffusers 13, the other diffusers 13 can supply inert gas horizontally in the direction of the corresponding gas outlet, thereby forming an air curtain-like effect in the circumferential direction of the flow path of the reaction gas, so that the process gas can only enter the processing chamber 11 from top to bottom, and cannot diffuse into other diffusers 13 in the horizontal direction.

[0051] In a preferred example provided by the present invention, the structure and arrangement of each of the mixers 12 and diffusers 13 adopts any one of the aforementioned solutions. For example, the outlet of each of the diffusers 13 includes a first air outlet section, a second air outlet section and a third air outlet section located in the same straight line and connected in sequence, the air outlet surface of each air outlet section is a rectangular surface, and the air outlet areas of the first air outlet section and the third air outlet section located at both ends are equal and larger than the air outlet area of ​​the second air outlet section located in the middle; or the air outlet surface of the diffuser 13 is an arc-shaped surface convex in the direction away from the center of the diffuser 13; or the top surface and / or the bottom surface of the diffuser 13 is a non-flat surface and is provided with one or more of the following structures: the upper surface has an arc structure and the height of the top surface of the diffuser from the bottom surface of the diffuser gradually decreases in the direction toward the outlet of the diffuser 13, the lower surface of the diffuser has a wavy structure, a plurality of columnar structures distributed at intervals are provided on the lower surface of the diffuser, and a plurality of spherical protrusions distributed at intervals are provided on the lower surface of the diffuser; or the mixer 12 and the diffuser 13 are connected through a plurality of holes arranged at intervals and with gradually changing apertures or inclined directions, or two or more of the above schemes are combined at the same time. For example, each diffuser 13 has a first outlet section, a second outlet section, and a third outlet section that are located in the same straight line and connected in sequence, and a spherical protrusion is provided on the upper surface or the lower surface of the diffuser, which is not listed one by one. Please refer to the above content for the detailed settings and advantages of each structure, which is not repeated one by one.

[0052] The gas delivery and exhaust system for the semiconductor processing chamber provided by the present invention can be used for atmospheric pressure chemical vapor deposition equipment, plasma enhanced chemical vapor deposition equipment, molecular beam epitaxy equipment, atomic layer deposition equipment, etc. In particular, in the atomic layer deposition equipment, since the gaseous precursor is alternately and repeatedly supplied to the surface of the wafer to form a material film on the wafer, it is very important to ensure that the previous gaseous precursor does not remain in the transmission channel. Therefore, it is particularly suitable to adopt the gas delivery and exhaust system provided by the present invention. Of course, the present invention is not limited to thin film deposition on wafers. In other processes such as liquid crystal panel production that require relatively high uniformity of thin film deposition, the gas delivery and exhaust system for the semiconductor processing chamber provided by the present invention is suitable. Depending on the specific applicable process, the equipment will also have other structures such as radio frequency devices. Since the other parts are not the invention points of this case, they will not be expanded one by one.

[0053] In summary, the gas delivery and exhaust system of the semiconductor processing chamber provided by the present invention includes a gas mixer and a diffuser arranged at the top of the processing chamber, the mixer and the diffuser are interconnected, and fluidically connected to the processing chamber, the process gas pipeline is connected to the inlet of the mixer, and the outlet of the mixer is connected to the inlet of the diffuser; the processing chamber is provided with an air inlet located at the top and an exhaust port located at the bottom, and the air inlet is arranged on the opposite side of the exhaust port, and the outlet of the diffuser is connected to the air inlet of the processing chamber; wherein, the gas flow direction in the processing chamber is a first direction, and the outlet of the diffuser gradually expands from the center to both sides in a second direction, and the second direction is perpendicular to the first direction. Through such an overall design, the flow path of the process gas can be extended as much as possible, so that the process gas entering the processing chamber through the outlet of the diffuser flows in the processing chamber in a direction roughly parallel to the surface of the substrate; the gas outlet of the diffuser gradually expands from the center to both sides in the second direction, so that the reaction gas diffuses from the center to the outside in the second direction, and under the action of the exhaust port of the processing chamber located on the other side of the gas inlet, the reaction gas is evenly diffused to the substrate surface in the processing chamber along the first direction, thereby achieving the effect of uniform ventilation in the chamber, which helps to improve the uniformity of thin film deposition. In a further solution, the present invention further forces the process gas to diffuse by setting the exhaust port of the processing chamber to have the exhaust areas of the first and third exhaust sections at both ends of the processing chamber equal and larger than the exhaust area of ​​the second exhaust section in the middle, thereby preventing the process gas from gathering in the middle of the processing chamber during the flow, and / or setting a circular arc surface structure on the top surface of the diffuser, and / or setting a columnar protrusion structure on the lower surface of the diffuser to further extend the diffusion path of the process gas and reduce the agglomeration of molecules, thereby effectively avoiding the problems of excessive concentration of gas in the center of the processing chamber in the prior art, and helping to improve the uniformity of gas diffusion, thereby improving the uniformity of thin film deposition. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has a high industrial utilization value.

[0054] 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 familiar with 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 a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A gas delivery and exhaust system for a semiconductor processing chamber, used to deliver process gas to the semiconductor processing chamber and exhaust residual gas after reaction, It is characterized in that include: A gas mixer and a diffuser are arranged at the top of the processing chamber, the mixer and the diffuser are connected to each other and are fluidically connected to the processing chamber, a process gas pipeline is connected to the inlet of the mixer, and the outlet of the mixer is connected to the inlet of the diffuser; the processing chamber is provided with an air inlet located at the top and an exhaust port located at the bottom, the air inlet is arranged at the opposite side of the exhaust port in a first direction, and the outlet of the diffuser is connected to the air inlet of the processing chamber; The gas flow direction in the processing chamber is a first direction, and the outlet of the diffuser gradually expands from the center to both sides in a second direction, and the second direction is perpendicular to the first direction.

2. The gas delivery and exhaust system for a semiconductor processing chamber according to claim 1, It is characterized in that The air inlet and the air outlet of the processing chamber have the same morphology.

3. The gas delivery and exhaust system for a semiconductor processing chamber according to claim 1, It is characterized in that The bottom of the diffuser is configured as an integral structure with the top cover plate of the processing chamber, and the outlet of the diffuser and the air inlet of the processing chamber are the same opening.

4. The gas delivery and exhaust system for a semiconductor processing chamber according to claim 1, It is characterized in that The top surface of the diffuser has an arc surface structure, and the distance between the top surface of the diffuser and the bottom surface of the diffuser gradually decreases in a direction away from the diffuser inlet.

5. The gas delivery and exhaust system for a semiconductor processing chamber according to claim 1, It is characterized in that The bottom surface of the diffuser has several of the following structures: a wave-shaped protrusion structure, a plurality of columns distributed at intervals, and a plurality of spherical protrusions distributed at intervals.

6. The gas delivery and exhaust system for a semiconductor processing chamber according to claim 1, It is characterized in that The outlet of the diffuser includes a first air outlet section, a second air outlet section and a third air outlet section which are connected in sequence. The air outlet areas of the first air outlet section and the third air outlet section at both ends are equal and larger than the air outlet area of ​​the second air outlet section in the middle.

7. The gas delivery and exhaust system for a semiconductor processing chamber according to claim 1, It is characterized in that The mixer and the diffuser are connected to each other through a plurality of holes which are arranged at intervals and have gradually changing pore diameters or inclined directions.

8. The gas delivery and exhaust system for a semiconductor processing chamber according to claim 1, It is characterized in that The gas delivery and exhaust system of the semiconductor processing chamber also includes an exhaust chamber, which is connected to the exhaust port of the processing chamber, and the cross-sectional area of ​​the exhaust chamber gradually decreases in the direction away from the processing chamber, and the exhaust pipeline is connected to one end of the exhaust chamber away from the processing chamber.

9. A gas delivery and exhaust system for a semiconductor processing chamber according to any one of claims 1 to 8, It is characterized in that The gas delivery and exhaust system of the semiconductor processing chamber includes more than two mixers stacked up and down and more than two diffusers stacked up and down. The mixers and diffusers are connected one by one, and the outlets of the upper diffuser and the lower diffuser are connected to each other. The process gas enters the corresponding diffuser through different mixers and enters the processing chamber successively through the outlet of the bottom diffuser.

10. The gas delivery and exhaust system for a semiconductor processing chamber according to claim 9, It is characterized in that The semiconductor processing chamber has more than two exhaust pipelines for the gas delivery and exhaust system, and the residual gas of the process gas is discharged through different exhaust pipelines.

Images