Gradient aperture spray plate and gas diffusion device
By designing a gradient aperture spray plate and a gas diffusion device, the problems of uneven gas distribution and insufficient thermal management in ALD equipment are solved, achieving high precision, high efficiency, uniform deposition, and process stability, which is suitable for atomic layer deposition of large-size wafers.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGSU BOTAO INTELLIGENT THERMAL ENG CO LTD
- Filing Date
- 2025-05-12
- Publication Date
- 2026-05-01
AI Technical Summary
Traditional ALD equipment suffers from uneven gas distribution, inaccurate thermal management, and poor sealing performance, leading to uneven film thickness and multi-source cross-contamination, especially with poor performance consistency in large-size wafer deposition.
By employing gradient aperture spray plates and gas diffusion devices, and through variable diameter micropore array design and composite gas path topology, combined with heater devices and sealing components, uniform gas laminar distribution and thermal management are achieved, turbulence is suppressed and the effects of thermal expansion are compensated.
It significantly improves deposition uniformity and process stability, with film thickness uniformity within ±1.5% and multi-source cross-contamination rate reduced to below 0.1%, making it suitable for high-precision atomic layer deposition on large-size wafers.
Smart Images
Figure CN224186263U_ABST
Abstract
Description
Gradient aperture spray plate and gas diffusion device Technical Field
[0001] This invention belongs to the field of semiconductor thin film deposition technology, specifically relating to a gradient aperture spray plate and a gas diffusion device. Background Technology
[0002] Atomic layer deposition (ALD) is a technique for growing thin films layer by layer on a substrate surface by alternately introducing gaseous precursors. Its core advantages lie in atomic-level film thickness control and excellent step coverage, making it widely used in semiconductor devices, photovoltaic cells, and functional coatings. Traditional ALD equipment often employs a multi-chamber design to achieve alternating deposition of different precursors, but this suffers from problems such as equipment complexity, low process changeover efficiency, and multi-source cross-contamination. While single-chamber ALD simplifies equipment structure, it faces challenges such as uneven gas distribution, insufficient thermal management precision, and poor sealing performance. Existing technologies attempt to improve uniformity by optimizing the spray head structure or improving the heating module, but still suffer from defects such as insufficient turbulence suppression by the spray plate, substrate deformation due to thermal expansion, and lag in gas path switching response, resulting in uneven film thickness and multi-source cross-contamination problems due to uneven gas distribution. Especially in large-size wafer deposition, the film thickness deviation between the edge and center regions is significant, affecting the consistency of device performance. Therefore, there is an urgent need for an ALD device that integrates gas path optimization, dynamic thermal compensation, and efficient sealing to meet the demands of high-precision and high-efficiency industrial production.
[0003] Therefore, in order to address the above-mentioned technical problems, it is necessary to provide a gradient aperture spray plate and a gas diffusion device.
[0004] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention
[0005] The purpose of this invention is to provide a gradient aperture spray plate and a gas diffusion device.
[0006] To achieve the above objectives, the technical solution provided by a specific embodiment of this utility model is as follows:
[0007] A gradient aperture spray plate includes a plate body and a variable diameter micropore array formed on and extending through the plate body. The micropores of the variable diameter micropore array have a tapered section, a throat and a dilated section in sequence along a first through direction, and the throat has a constant inner diameter.
[0008] In one or more embodiments of this utility model, the tapering section along the first through direction tapers at a cone angle of 8°-15°.
[0009] In one or more embodiments of this utility model, the aperture of the tapered section ranges from dmm to 0.8mm.
[0010] In one or more embodiments of this utility model, the gradually expanding section along the first through direction gradually expands with a cone angle of 60°-75°.
[0011] In one or more embodiments of this utility model, the aperture of the gradually expanding section ranges from dmm to 2.2mm.
[0012] In one or more embodiments of this utility model, the inner diameter d of the throat is 0.2-0.5 mm.
[0013] In one or more embodiments of the present invention, a gas diffusion device includes a cavity structure and a gradient aperture spray plate that cooperates therewith. The cavity structure includes a cavity body that provides a first cavity and a plurality of air inlet channels that communicate with the cavity body. The plurality of air inlet channels are centrally symmetrically arranged in the cavity body, and the gradient aperture spray plate is disposed on the side of the first cavity away from the air inlet channels.
[0014] In one or more embodiments of the present invention, a deposition chamber structure is further included, which includes a deposition chamber body formed on a deposition chamber having a deposition cavity, the deposition cavity being disposed on the side corresponding to the expanding section of the plate body.
[0015] In one or more embodiments of the present invention, a silicon wafer tray with a support position is further provided in the deposition chamber, and a heater device is provided on the side of the silicon wafer tray away from the support position.
[0016] In one or more embodiments of this utility model, the air intake passage has a variable diameter.
[0017] In one or more embodiments of this utility model, the inner diameter of the air intake channel increases from the air intake end to the air outlet end in a ratio of 1:1.05 to 1:1.15.
[0018] In one or more embodiments of the present invention, the heater upper plate includes an upper heating body and a temperature gradient controller disposed thereon, and a heating flow channel is provided on the upper heating body corresponding to the air inlet channel.
[0019] Compared with existing technologies, the gradient aperture spray plate and gas diffusion device of this invention, through a composite gas path topology design and combined with laminar flow control of airflow via variable diameter micropores, solves the problems of uneven gas distribution and multi-source cross-contamination in traditional ALD equipment, significantly improving deposition uniformity and process stability. The split cover plate and hinged sealing device achieve efficient thermal management and airtightness control, making it suitable for high-precision atomic layer deposition processes on large-size wafers. Furthermore, the double-conical design of the micropores on the gradient aperture spray plate, with the upper tapering section suppressing turbulence generation and the lower expanding section increasing the gas coverage, combined with the three-way symmetrical air intake channel and hemispherical diffusion cavity, achieves laminar and uniform distribution of the reaction gas. The staged preheating function of the heater device can use the three-way heating channel to raise the airflow temperature in a stepwise manner, reducing the impact of temperature changes on the deposition process. The synergistic effect of the thermal expansion buffer layer and distributed thermocouples effectively compensates for structural deformation under high-temperature conditions, ensuring the uniformity of the silicon wafer tray surface temperature. The dynamic sealing compensation mechanism, achieved through the linkage adjustment of the vacuum adsorption tank and the micro-pressure sensor, adapts to the interface pressure changes caused by thermal expansion, significantly improving the airtightness of the equipment and the stability of the process. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 is a schematic diagram of the structure of a gradient aperture spray plate in one embodiment of the present invention;
[0022] Figure 2 is a schematic diagram of the micropore structure of the variable diameter micropore array in one embodiment of the present invention;
[0023] Figure 3 is a schematic diagram of the gas diffusion device in one embodiment of the present invention;
[0024] Figure 4 is a sectional view along line A-A of Figure 3;
[0025] Figure 5 is a schematic diagram of the gas diffusion device in one embodiment of the present invention;
[0026] Figure 6 is a diagram showing the pressure distribution on the tray surface in one embodiment of this utility model;
[0027] Figure 7 is a velocity distribution diagram on the tray surface in one embodiment of this utility model. Detailed Implementation
[0028] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.
[0029] As shown in Figures 1-2, the gradient aperture spray plate of this utility model includes a plate body 1 and a variable diameter micropore array formed on and through the plate body. The micropores 11 on the variable diameter micropore array can be arranged in an ordered manner or in a random manner. Figure 1 shows the feasibility of an ordered micropore arrangement.
[0030] To ensure sufficient uniformity of gas distribution, the micropores 11 of the variable-diameter micropore array sequentially have a tapered section 111, a throat 112, and a expanding section 113 along the first through-path (which may or may not be aligned with the thickness direction), as shown in Figure 2. The throat 112 can have a constant inner diameter. Furthermore, when the first through-path coincides with the thickness direction, each micropore can exhibit axial gradient aperture characteristics at different parts along the thickness direction, such as forming a composite flow channel structure with small-angle diffusion at the upper end (tapered section 111) and large-angle diffusion at the lower end (expanding section 113). Preferably, each micropore has a plate-hole composite axial gradient aperture characteristic (i.e., the axial direction of the plate body coincides with the axial direction of the hole) along the thickness direction, forming a composite flow channel structure with small-angle diffusion at the upper end and large-angle diffusion at the lower end.
[0031] As shown in Figures 3-5, the gas diffusion device of this utility model includes a cavity structure and a gradient aperture spray plate that cooperates with it. The gradient aperture spray plate is arranged such that the outlet direction of the gradually expanding section 113 is oriented toward the wafer. The cavity structure includes a cavity body that provides a first cavity and multiple air inlet channels that are connected to the cavity body. The multiple air inlet channels are centrally symmetrically arranged in the cavity body. The gradient aperture spray plate is disposed on the side of the first cavity away from the air inlet channels.
[0032] As a preferred embodiment, the device also includes a sedimentation chamber structure comprising a sedimentation chamber body formed with a sedimentation cavity, the sedimentation cavity being disposed on the side corresponding to the expanding section of the plate body. The sedimentation cavity and the first cavity can be integrally defined by the same external structure to ensure the device is airtight and convenient.
[0033] As a preferred embodiment, the deposition chamber is also provided with a silicon wafer tray 4 having a support position, and a heater device 3 on the side of the silicon wafer tray 4 away from the support position is used to preheat the wafer.
[0034] As a preferred option, the intake passage is of variable diameter. The inner diameter of the intake passage increases from the intake end to the outlet end in a ratio of 1:1.05 to 1:1.15.
[0035] The atomic layer deposition apparatus based on gradient aperture spray structure of this utility model includes a cavity assembly, a split cover plate device and a gas path structure; a silicon wafer tray 4 is provided inside the cavity assembly, and a heater device 3 is provided below the silicon wafer tray 4. The heater device 3 includes an upper heater plate, a lower heater plate and a heating cover plate. Heating wires and thermocouples can be arranged between the upper heater plate and the lower heater plate to control the heating uniformity. Preferably, an integrated spiral heating wire and distributed thermocouples are used.
[0036] As a preferred embodiment, the split-type cover plate device includes an upper cover plate, a lower cover plate 2, and a hinge assembly. The upper cover plate 2 and the lower cover plate together define a closed vapor deposition space. The lower cover plate 2 and the upper cover plate are movably connected by the hinge assembly to form an integral definition of the cavity structure. A gradient aperture spray plate is installed on the lower cover plate 2 near the bottom opening.
[0037] As a preferred embodiment, the air passage structure connected to the lower cover plate 2 may include three sets of air intake channels symmetrically distributed at 180°, the air intake channels being connected to the first cavity to provide buffered and uniformly distributed gas to the gradient aperture spray plate.
[0038] As a preferred option, the hinge assembly can be an existing component, such as a hinge mounting base, hinge, hinge baffle, nitrogen spring support, pull rod, contact switch, and detection block, etc., wherein the nitrogen spring support triggers sealing pressure compensation in the closed state.
[0039] As a preferred embodiment, a thermal expansion buffer layer is provided between the lower plate of the heater and the heating cover plate. The buffer layer is a ring structure made of graphene composite ceramic, which has high thermal conductivity and low coefficient of thermal expansion.
[0040] As a preferred embodiment, a sealing assembly is further provided between the upper cover plate and the lower cover plate 2, which may include an annular sealing ring and a vacuum adsorption groove disposed adjacent to the sealing ring. The vacuum adsorption groove is located inside the sealing ring and is connected to the micro-pressure sensor array.
[0041] The atomic layer deposition apparatus of this embodiment includes a cavity and gas path structure defined by a split cover plate device. The cavity can be considered as consisting of a deposition chamber and a first cavity. A circular silicon wafer tray is located within the deposition chamber. Below the tray, a heater upper plate, a heater lower plate, and a heating cover plate are connected in sequence. The heater upper plate and heater lower plate are fixed together by bolts and embedded with a spiral molybdenum heating wire and a distributed thermocouple. The heater upper and lower plates are made of silicon carbide ceramic with a surface polished to a roughness Ra≤0.1μm. The heating cover plate is made of stainless steel. A thermal expansion buffer layer made of graphene composite ceramic is sandwiched between them, for example, with a thickness of 2mm.
[0042] The upper cover of the split-type cover plate device has a trapezoidal annular air passage inside, with the inner wall of the air passage coated with an anti-oxidation aluminum coating, and integrates a heating flow channel and a temperature gradient controller. The lower cover plate is movably connected to the upper cover plate via a pneumatic hinge assembly. The opening and closing angle of the hinge assembly can be 0-135° to meet the requirements of material replacement and sealing. When closed, a contact switch triggers sealing pressure compensation. The bottom surface of the lower cover plate can be fixed with a gradient aperture spray plate by high-temperature vacuum brazing, and the gradient aperture spray plate forms an array of variable diameter micropores.
[0043] As a preferred option, the variable-diameter micropores of the gradient aperture spray plate can adopt a multi-segment composite cone angle design. For example, the cone angle of the upper tapering section can be adjusted to 8°-15°, and the cone angle of the lower expanding section can be adjusted to 60°-75° to adapt to different gas viscosity requirements. As another preferred option, the upper part of a single variable-diameter micropore has a tapering section with a cone angle of 11°, the middle part has a throat with a diameter of 0.5mm, and the lower part has a expanding section with a cone angle of 70°. Of course, the diameter of the throat can also be any other value within the range of 0.2-0.5mm, such as 0.2, 0.3, or 0.4mm.
[0044] As a preferred embodiment, the first cavity of the lower cover plate is supplied with air during operation by an air passage structure. This air passage structure may include three sets of symmetrically distributed air inlets at 180° intervals, with the ends of the channels connected to a hemispherical diffuser cavity, i.e., the first cavity. The inner wall of the diffuser cavity may also have a honeycomb-shaped flow guiding structure. After entering the diffuser cavity through the air inlets, the gas subsequently enters the variable-diameter micropores of the gradient aperture spray plate. The tapered section suppresses airflow turbulence, while the expanding section increases the gas coverage area, forming a uniform laminar flow covering the surface of the silicon wafer tray.
[0045] As a preferred embodiment, the gas can be heated to the set temperature in stages through the heating channels of the upper cover. Furthermore, the number of stages of the heating channels can be expanded to three or four stages of temperature control according to actual process requirements.
[0046] During operation, the silicon wafer tray rotates at 30-120 rpm, alternately exposing the substrate to different precursor atmospheres. Thermocouples monitor the tray temperature in real time, and a PID controller adjusts the heating power, keeping the temperature difference within ±1℃. The sealing assembly includes an annular sealing ring and a vacuum adsorption tank. The adsorption pressure is dynamically adjusted based on feedback from a micro-pressure sensor to ensure the chamber's airtightness. Residual waste gas is discharged through an annular exhaust channel on the chamber's sidewall, with a flow rate controlled by a vacuum pump at 0.5-1.5 m / s. Simulation data for the prototype is shown in Figures 6-7.
[0047] The ALD device of this invention, verified through simulation, shows a significant improvement in gas pressure distribution uniformity, a reduction in velocity field standard deviation to below 20% of that of traditional structures, and no flow path intersections or backflows, proving the effectiveness of its laminar flow design. When using the ALD device of this invention for alumina thin film deposition, the film thickness uniformity reaches within ±1.5%, and the multi-source cross-contamination rate is reduced to below 0.1%.
[0048] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0049] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A gradient aperture spray plate, characterized in that, It includes a plate body and a variable diameter micropore array formed on and extending through the plate body. The micropores of the variable diameter micropore array have a tapered section, a throat and a tapered section in sequence along a first through direction. The throat has a constant inner diameter.
2. The gradient aperture spray plate according to claim 1, characterized in that, The tapering section along the first through direction tapers at a cone angle of 8°-15°.
3. The gradient aperture spray plate according to claim 2, characterized in that, The aperture of the tapered section ranges from dmm to 0.8mm.
4. The gradient aperture spray plate according to claim 1, characterized in that, The gradually expanding section along the first through direction gradually expands with a cone angle of 60°-75°.
5. The gradient aperture spray plate according to claim 4, characterized in that, The aperture range of the gradually expanding section is from dmm to 2.2mm.
6. The gradient aperture spray plate according to claim 1, characterized in that, The inner diameter d of the throat is 0.2-0.5 mm.
7. A gas diffusion device, characterized in that, The device includes a cavity structure and a gradient aperture spray plate according to any one of claims 1-6, wherein the cavity structure includes a cavity body providing a first cavity and a plurality of air inlet channels communicating with the cavity body, the plurality of air inlet channels being centrally symmetrically arranged in the cavity body, and the gradient aperture spray plate being disposed on the side of the first cavity away from the air inlet channels.
8. The gas diffusion device according to claim 7, characterized in that, It also includes a sedimentation chamber structure, which includes a sedimentation chamber body formed on a sedimentation chamber having a sedimentation cavity, the sedimentation cavity being disposed on the side corresponding to the expanding section of the plate body.
9. The gas diffusion device according to claim 8, characterized in that, The deposition chamber is also provided with a silicon wafer tray with a support position, and a heater device is provided on the side of the silicon wafer tray away from the support position.
10. The gas diffusion device according to claim 7, characterized in that, The air intake passage has a variable diameter.