Baffle structure, spraying assembly and semiconductor equipment applying same
By designing an inclined baffle structure and vent holes, the problem of uneven film thickness caused by the spray plate was solved, uniform gas distribution and film uniformity were achieved, and product quality was improved.
Patent Information
- Application Number
- CN202423045295.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2034-12-10
AI Technical Summary
Traditional shower plates cause gas to slowly diffuse from the center to the edge, resulting in uneven target film thickness and affecting product yield.
A baffle structure is designed, in which the baffle body is tilted downward, and the vents are arranged tilted from the center to the edge, forming multiple circles of evenly distributed vents to adjust the gas flow field to achieve uniform distribution.
By adjusting the gas flow field, the gas is prevented from concentrating in the middle of the film, ensuring the uniformity of the target film thickness and improving product yield.
Smart Images
Figure CN223481270U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of semiconductor technology, and in particular to a baffle structure, a spray assembly, and a semiconductor device using the same. Background Technology
[0002] Spray plates in semiconductor equipment are commonly used in chemical vapor deposition (CVD) processes during semiconductor manufacturing, as well as other process steps requiring uniform gas distribution on the semiconductor surface. They guide reactant and degassing gases through a central conduit into the spray head and then discharge them from both the spray head and the outer side of the central conduit, achieving uniform gas distribution. Therefore, spray plates play a crucial role in semiconductor processing equipment by transporting and controlling gas flow, as well as ensuring uniform gas distribution, significantly impacting the efficiency and quality of semiconductor manufacturing processes.
[0003] In the chemical vapor deposition process, when the spray plate distributes gas onto the semiconductor surface, the gas diffuses slowly from the center to the edge, resulting in a stepped thickness of the target film with poor uniformity, which in turn affects the product yield and may even lead to product abnormalities. Utility Model Content
[0004] The present invention provides a baffle structure, a spray assembly, and a semiconductor device using the same, which solves the technical problem of uneven target film thickness caused by gas slowly diffusing from the center to the edge in traditional spray plates.
[0005] To address the aforementioned problems, according to one aspect of this application, an embodiment of the present invention provides a baffle structure located between an air inlet and a spray plate. The baffle structure includes a baffle body and a vent hole, the vent hole being formed on the baffle body; the baffle body is inclined downwards along a direction from the center to the edge.
[0006] In some embodiments, the vent is inclined, with its lower end inclined toward the center of the baffle body.
[0007] In some embodiments, the baffle body forms a first included angle α with the horizontal plane, and the first included angle α satisfies: 5°≤α≤15°.
[0008] In some embodiments, a second included angle β is formed between the axis of the vent and the vertical plane, and the second included angle β satisfies: 5°≤β≤15°.
[0009] In some embodiments, a plurality of vent holes are provided, and the plurality of vent holes are arranged in at least two rings, and the at least two rings of vent holes are evenly distributed radially on the baffle body.
[0010] In some embodiments, the vent holes are evenly distributed in the circumferential direction for each ring.
[0011] In some embodiments, in two adjacent rings of vents, the density of the vents closer to the baffle body is greater than the density of the vents farther from the baffle body.
[0012] According to another aspect of this application, an embodiment of the present invention provides a spray assembly, the spray assembly including the baffle structure described above.
[0013] In some embodiments, the spray assembly further includes a spray plate and an air inlet unit. The air inlet unit has an air inlet, and the baffle structure is fixed between the air inlet and the spray plate. There are gaps between the baffle body and the air inlet, and between the baffle body and the spray plate, to facilitate gas transfer.
[0014] According to another aspect of this application, an embodiment of the present invention provides a semiconductor device including the spray assembly described above.
[0015] Compared with the prior art, the baffle structure of this utility model has at least the following beneficial effects:
[0016] The baffle structure provided by this utility model is located between the air inlet and the spray plate. The baffle structure includes a baffle body and a vent hole, which is opened on the baffle body. The baffle body is inclined downward along the direction from the center to the edge.
[0017] When gas enters through the inlet, it passes over the upper surface of the baffle body. Because the edge of the baffle body is inclined downward, the flow field around the baffle body changes, allowing the gas to flow better towards the edge. Furthermore, the downward inclination of the edge creates a larger area between the baffle body and the intake unit above it, ensuring a more abundant gas supply. This prevents most of the gas from concentrating in the middle of the film, which would result in a stepped thickness and poor uniformity of the target film.
[0018] The spray assembly provided by this utility model is designed based on the above-mentioned baffle structure. Its beneficial effects are the same as those of the above-mentioned baffle structure, and will not be repeated here.
[0019] The semiconductor device provided by this utility model is designed based on the above-mentioned spray assembly. Its beneficial effects are the same as those of the above-mentioned spray assembly, and will not be repeated here.
[0020] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and to implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. Attached Figure Description
[0021] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0022] Figure 1 This is a schematic diagram of a baffle structure provided in an embodiment of the present utility model;
[0023] Figure 2 This is a cross-sectional view of a baffle structure provided in an embodiment of this utility model;
[0024] Figure 3 yes Figure 2 A partial enlarged view of point A in the middle;
[0025] Figure 4 This is a schematic diagram of the structure of an air intake unit in a spray assembly provided by an embodiment of this utility model;
[0026] Figure 5 This is a cross-sectional view of a spray assembly provided in an embodiment of the present utility model;
[0027] Figure 6 This is a cross-sectional view of a spray assembly provided in an embodiment of the present invention from another angle;
[0028] Figure 7 The pressure curve is obtained by comparing the spray assembly provided in this embodiment with a comparative example, at a position 1mm above the heating plate.
[0029] Figure 8 The pressure curve at a position 1 mm above the heating plate is normalized after comparing the spray assembly provided in this embodiment with a comparative example.
[0030] Figure 9 The velocity curve is obtained by comparing the spray assembly provided in this embodiment with a comparative example, at a position 1 mm above the heating plate.
[0031] Figure 10 The speed curve at a position 1mm above the heating plate is normalized after comparing the spray assembly provided in this embodiment with a comparative example.
[0032] Figure 11 This is a pressure cloud map at a position 1mm above the heating plate using the spray assembly provided in this embodiment;
[0033] Figure 12The pressure cloud diagram is taken at a position 1 mm above the heating plate after using the straight-hole conical plate in the comparative example.
[0034] Figure 13 The pressure cloud diagram is taken at a position 1mm above the heating plate after using the straight hole plate in the comparative example.
[0035] Figure 14 The pressure cloud diagram is taken 1 mm above the heating plate after using the oblique hole plate in the comparative example.
[0036] Figure label:
[0037] 1. Baffle structure; 11. Baffle body; 12. Vent hole; 2. Air intake unit; 21. Air inlet. Detailed Implementation
[0038] To further illustrate the technical means and effects adopted by this utility model to achieve its intended purpose, the specific implementation methods, structures, features, and effects according to this utility model application are described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "an embodiment" or "an embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.
[0039] In the description of this utility model, it should be clarified that the terms "first," "second," etc., in the specification, claims, and drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence; the terms "vertical," "lateral," "longitudinal," "front," "back," "left," "right," "up," "down," "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing this utility model, and do not mean that the device or element referred to must have a specific orientation or position, and therefore should not be construed as a limitation of this utility model.
[0040] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0041] Chemical vapor deposition (CVD) is a technique that transforms gaseous precursors into solid thin films at high temperatures. During CVD, spraying technology is typically used to uniformly distribute the reactant gases within the reaction chamber to ensure uniform film growth. The spraying assembly is a crucial component of CVD equipment; it is responsible for ejecting the reactant gases through vents and directing them toward the semiconductor substrate, where they are deposited to form a thin film on the substrate surface.
[0042] In traditional technologies, spraying components typically include a spray plate and a baffle, with gas passing sequentially through the baffle and spray plate onto the membrane. However, in typical structures, the air inlet is connected to the middle of the baffle, causing most of the gas to concentrate in the center of the membrane. This results in a stepped thickness distribution in the target membrane, leading to poor thickness uniformity and consequently affecting product performance.
[0043] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.
[0044] Example 1
[0045] This embodiment provides a baffle structure, such as Figure 1-Figure 3 As shown, the baffle structure is located between the air inlet and the spray plate. The baffle structure includes a baffle body 11 and an air vent 12. The air vent 12 is opened on the baffle body 11. The baffle body 11 is inclined downward along the direction from the center to the edge.
[0046] Specifically, the baffle structure includes a baffle body 11 and a vent 12. The vent 12 is formed on the baffle body 11, which is located between the air inlet and the spray plate. Gaps exist between the baffle body 11 and the air inlet 21, and between the baffle body 11 and the spray plate, to facilitate gas transfer. Gas enters from the air inlet, is transferred through the vent 12 on the baffle body 11 to the spray plate, enters the chamber through the spray plate, undergoes a deposition reaction on the hot plate surface supporting the wafer, and is then discharged from the exhaust port below the chamber.
[0047] In this embodiment, the baffle body 11 is inclined downward along the direction from the center to the edge. Specifically, the general outline of the baffle body 11 is a circular structure with a certain thickness. When the baffle body 11 is placed between the air inlet and the spray plate, the center of the circular structure is at the highest position. Along the direction from the center to the edge, the baffle body 11 gradually tilts downward to form a slope, similar to an open umbrella.
[0048] When the gas enters through the inlet, it passes over the upper surface of the baffle body 11. Since the edge of the baffle body 11 is inclined downward, the flow field around the baffle body 11 changes, allowing the gas to flow better towards the edge. Furthermore, the downward inclination of the edge creates a larger area between the baffle body 11 and the air intake unit above it, which allows for more abundant gas and avoids the problem of most of the gas concentrating in the middle of the film, resulting in a stepped thickness and poor thickness uniformity of the target film.
[0049] In a specific embodiment, the vent 12 is inclined, with its lower end tilted toward the center of the baffle body 11. The vent 12 penetrates the thickness of the baffle body 11, extending from the upper surface of the baffle body 11 to the lower surface of the baffle body 11.
[0050] The vent 12 is inclined, with its lower end tilted toward the center of the baffle body 11. That is to say, if a certain vent 12 starts from point A on the upper surface of the baffle body 11 and ends at point B on the lower surface of the baffle body 11, then point A on the upper surface and point B on the lower surface are not in a vertically corresponding relationship, but rather, in the radial direction, point B on the lower surface is closer to the center position.
[0051] When the vent 12 is tilted, it increases flow resistance and reduces the flow velocity at the edge. Furthermore, when the tilted vent 12 is combined with the tilted baffle body 11, the pressure difference at the position 1mm above the heating plate is minimized and optimized. The smaller the pressure difference, the more uniform the gas distribution.
[0052] In a specific embodiment, such as Figure 3 As shown, the baffle body 11 forms a first angle α with the horizontal plane, which satisfies the condition: 5° ≤ α ≤ 15°. That is, the angle between the baffle body 11 and the spray plate, or between the baffle body 11 and the plane of the cavity, is between 5° and 15°. This angle is the optimal range to ensure gas uniformity; too large or too small an angle will cause gas accumulation. For example, if the angle is less than 5°, the change compared to a horizontally positioned baffle body 11 is minimal, and it does not affect the flow field. However, when the angle is greater than 15°, gas may accumulate at the edge of the baffle body 11, potentially resulting in a thicker membrane at the edge.
[0053] In a specific embodiment, such as Figure 3As shown, the axis of the vent 12 forms a second included angle β with the vertical plane, which satisfies: 5°≤β≤15°. Combined with the above 5°≤α≤15°, the included angle between the axis of the vent 12 and the vertical plane is between 5° and 15°. The slope of the linear distribution of the flow velocity varies under different structures. In this case, a small slope ensures that the flow velocity and radius maintain a linear relationship, which can replenish the amount of reactant consumed from the center to the edge. The slope of the linear distribution affects the amount of replenishment, which has a significant impact on the uniformity of the deposition process. The limitation of this embodiment makes the pressure distribution with radius at a position of 1 mm on the wafer approximately parabolic, but the pressure difference between the center and the edge is very small, thus better ensuring the uniformity of the gas.
[0054] In a specific embodiment, such as Figure 1 As shown, multiple vent holes 12 are provided, forming at least two concentric rings, which are radially and evenly distributed on the baffle body 11. More specifically, in one embodiment, it is assumed that the multiple vent holes 12 form three concentric rings, from the inside out: a first ring, a second ring, and a third ring. These three rings of vent holes 12 are radially evenly distributed on the baffle body 11, meaning the radial distance between the first and second rings is equal to the radial distance between the second and third rings. Furthermore, to ensure that the gas can fill the entire baffle body 11, the multiple vent holes 12 need to substantially cover the entire baffle body 11. This embodiment limits the radial distribution of at least two rings of vent holes 12 on the baffle body 11 so that, under the action of the inclined baffle body 11 and the vent holes 12, the gas can diffuse evenly outwards, ensuring that each ring of vent holes has a relatively sufficient amount of gas.
[0055] In a specific embodiment, the vent holes 12 in each ring are evenly distributed circumferentially. For better explanation, the first, second, and third rings of vent holes described above are continued. The vent holes 12 in each ring are evenly distributed circumferentially, meaning that in the first ring, adjacent vent holes 12 are equidistant circumferentially; in the second ring, adjacent vent holes 12 are also equidistant circumferentially; and in the third ring, adjacent vent holes 12 are equidistant circumferentially. This embodiment limits the vent holes 12 in each ring to be evenly distributed circumferentially, ensuring that the gas in that ring is sprayed evenly along the circumference.
[0056] In a specific embodiment, among two adjacent circles of the vent holes 12, the density of the vent holes 12 in the circle closer to the baffle body 11 is greater than that of the vent holes 12 in the circle farther from the baffle body 11. In the first circle of vent holes, the circumferential distance between adjacent vent holes 12 is L1, in the second circle of vent holes, the circumferential distance between adjacent vent holes 12 is L2, and in the third circle of vent holes, the circumferential distance between adjacent vent holes 12 is L3, then L1 < L2 < L3. Due to the inclined setting of the baffle body 11, more gas may accumulate in the outer circle. In this embodiment, it is defined that the density of the vent holes 12 in the outer circle is smaller, which can avoid the increase in the thickness of the outer circle of the film caused by excessive gas in the outer circle.
[0057] The baffle structure provided in this embodiment can adjust the pressure distribution above the wafer by changing the structure and distribution of the baffle body 11 and the vent holes 12, so that the gas can be uniformly sprayed onto the wafer.
[0058] Embodiment 2
[0059] This embodiment provides a spraying component, and the spraying component includes the baffle structure 1 described in Embodiment 1.
[0060] In a specific embodiment, as Figure 4-Figure 6 shown, the spraying component further includes a spraying plate and an air inlet unit 2. The air inlet unit 2 has an air inlet 21. The baffle structure 1 is fixed between the air inlet 21 and the spraying plate, and there are gaps between the baffle body 11 and the air inlet 21 and between the baffle body 11 and the spraying plate to achieve gas transfer.
[0061] After applying the baffle structure 1 provided in Embodiment 1 to the spraying component, the gas enters the chamber from the air inlet through the baffle body 11, the vent holes 12 and the spraying plate, and is discharged from the air extraction port below the chamber after deposition reaction on the surface of the hot plate carrying the wafer. In this embodiment, the baffle body 11 is different from the traditional baffle, mainly reflected in that a first included angle α is formed between the baffle body 11 and the horizontal plane, and a second included angle β is formed between the axis of the vent hole 12 and the vertical plane. When these two change, the entire gas flow field will change accordingly.
[0062] In order to more intuitively reflect the effect of the baffle structure in this embodiment, the software simulation is used to analyze the changing trend of the corresponding flow field when the baffle structure changes. As Figures 7-14 shown, for the convenience of comparison, all simulation boundary conditions are kept consistent, that is, the fluid is nitrogen, the temperature is 293K, the volume flow rate at the air inlet is 1E - 5 kg / s, and the outlet pressure is 10 Pa. In addition, in order to illustrate the influence of this embodiment on the pressure in the reaction chamber, three comparative examples are selected for comparison. The three comparative examples are respectively:
[0063] The first type features a horizontally positioned baffle body 11 with an inclined vent 12, depicted in the figure as a slanted plate. Its pressure cloud diagram is shown below. Figure 14 As shown; the second type, the baffle body 11 is inclined, and the vent 12 on it is vertically set, which is shown as a straight-hole cone plate in the figure, and its pressure cloud diagram is as follows. Figure 12 As shown; the third type, the baffle body 11 is horizontally set, and the vent 12 opened on it is vertically set, which is shown as a straight hole plate in the figure, and its pressure cloud diagram is as follows. Figure 13 As shown in the figure. The pressure distribution cloud maps of the three comparative examples and this embodiment, taken from a position 1mm above the heating plate, are analyzed and compared. The solution in this embodiment is represented by an inclined cone plate, and its pressure cloud map is shown in the figure. Figure 11 As shown.
[0064] In addition, to more intuitively illustrate the differences between the comparative examples and this embodiment, software simulations were performed on the pressure and velocity at a position 1mm above the wafer after using the baffle structures of the three comparative examples and this embodiment. Figures 7-10 As shown.
[0065] From the pressure distribution cloud map and position velocity curve, it can be seen that when the baffle body 11 is horizontally set and the vent 12 on it is vertically set, it is the third type of straight-hole plate in the comparative example. At this time, the airflow enters from the center, diffuses to the surroundings, and is discharged from the exhaust port at the bottom of the chamber. Figure 13 As shown, the pressure is high at the center and relatively low around the edges. Simulation analysis clearly demonstrates how the pressure changes when the baffle structure is altered, such as by tilting the baffle. Figure 11 and Figure 12 As shown, under the same process conditions, by changing the flow resistance of the baffle structure, different baffle structures are obtained. The flow velocity distribution curves at a 1mm cross-section on the upper surface of the heating plate are as follows. Figure 9 and Figure 10 As shown in the figure, the flow velocity distribution is small in the middle and large around the edges. The flow velocity at the edge of the heating plate decreases due to the inclined arrangement of the vent 12. This is because, when the flow rate remains constant, the inclined vent 12 increases flow resistance, thus reducing the flow velocity at the edges. The slope of the linear flow velocity distribution varies under different structures. When both the baffle body 11 and the vent 12 are inclined, the slope is small, and the flow velocity maintains a linear relationship with the radius, which can replenish the amount of reactant consumed from the center to the edge. The slope of the linear distribution affects the amount of replenishment, which has a significant impact on the uniformity of the deposition process. Therefore, the choice of baffle structure is crucial for generating a uniform film. The pressure curve distribution at 1 mm on the wafer is shown in the figure. The pressure distribution with radius approximates a parabola, but the pressure difference between the center and the edge is very small. Using the baffle structure 1 provided in this embodiment, the pressure difference is approximately 0.03 Pa.
[0066] Therefore, it can be seen that the pressure difference at the position 1mm above the heating plate is the smallest and optimal when using the baffle structure provided in this embodiment. Thus, the spray assembly provided in this embodiment can adjust the pressure distribution above the wafer to meet the process requirements.
[0067] Example 3
[0068] This embodiment provides a semiconductor device, which includes the spray assembly described in Embodiment 2.
[0069] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.
Claims
1. A baffle structure, characterized in that, The baffle structure is located between the air inlet and the spray plate. The baffle structure includes a baffle body and a vent hole, which is opened on the baffle body. The baffle body is inclined downward along the direction from the center to the edge.
2. The baffle structure according to claim 1, characterized in that, The vent is inclined, with its lower end tilted toward the center of the baffle body.
3. The baffle structure according to claim 2, characterized in that, The baffle body forms a first included angle α with the horizontal plane, and the first included angle α satisfies: 5°≤α≤15°.
4. The baffle structure according to claim 2 or 3, characterized in that, The vent axis forms a second included angle β with the vertical plane, and the second included angle β satisfies: 5°≤β≤15°.
5. The baffle structure according to claim 1, characterized in that, Multiple vents are provided, and the multiple vents form at least two rings. The at least two rings of vents are evenly distributed radially on the baffle body.
6. The baffle structure according to claim 5, characterized in that, The ventilation holes in each ring are evenly distributed in the circumferential direction.
7. The baffle structure according to claim 5, characterized in that, In two adjacent rings of vents, the density of the vents closer to the baffle body is greater than the density of the vents further away from the baffle body.
8. A spray assembly, characterized in that, The spray assembly includes the baffle structure as described in any one of claims 1-7.
9. The spray assembly according to claim 8, characterized in that, The spray assembly further includes a spray plate and an air inlet unit. The air inlet unit has an air inlet. The baffle structure is fixed between the air inlet and the spray plate. There are gaps between the baffle body and the air inlet, and between the baffle body and the spray plate, to facilitate gas transfer.
10. A semiconductor device, characterized in that, The semiconductor device includes the spray assembly as described in claim 8 or 9.