Atomic layer deposition device for uniform coating of inner surface of hemispherical curved surface

Abstract

The application discloses an atomic layer deposition device for uniformly coating the inner surface of a semispherical curved surface, and aims at solving the problems of poor uniformity and stability of the inner surface coating of a curved optical window in the prior art coating technology.The gas passage part in the atomic layer deposition device is vertically fixed on a cabin base, a surrounding rim is arranged on the upper surface of an air extraction plate in the circumferential direction, the surrounding rim, a convex rim and a cover plate surround a gas cavity, the air extraction plate is fixed on the upper surface of the gas passage part, a hollow spherical shell is fixed on the upper surface of the cover plate, a sample support is sleeved outside the gas passage part, a semispherical sample is placed on the annular platform of the sample support, a cabin is installed on the cabin base, the cabin is sleeved outside the sample support, a cabin cover is covered on the top of the cabin, and a semispherical heater is arranged on the lower surface of the cabin cover.The cabin structure of the atomic layer deposition device is designed, so that the uniform coating of the inner surface of the semispherical curved surface is realized, and a more uniform and stable flow field distribution is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to a device for thin film deposition on the inner surface of a hemispherical curved surface. BACKGROUND

[0002] The surfaces of optical lenses and windows need to be coated with various functional optical films to achieve functions such as light filtering, anti-reflection, and hardening protection. In order to meet the needs of certain special scenarios, some optical windows are curved, and their surface shapes usually have a certain radius of curvature, such as hemispherical samples with fixed curvature and variable diameter or deep-arched surfaces with continuously variable curvature and diameter. Achieving uniform coating on the inner or outer surface of such hemispherical or curved optical windows is extremely challenging. Existing traditional coating techniques have certain shortcomings in uniform coating on curved surfaces. Magnetron sputtering and evaporation coating techniques can achieve uniform coating on the outer surface of curved surfaces under certain conditions by designing special sample holder shapes, designing target and sample linkage mechanisms, and precisely controlling the coating process. However, the uniformity of the coating is poor, and the diffraction Newton's ring phenomenon often occurs due to uneven film thickness, which seriously damages the appearance and performance of the window. Moreover, in the case of decreasing the radius of the curved surface, increasing the aspect ratio, and coating the inner surface, the difficulty of uniform coating increases, the uniformity of the film layer deteriorates rapidly, and even coating cannot be performed. For pulsed laser deposition, molecular beam epitaxy, and chemical vapor deposition techniques, due to the limitations of the technology itself, they are not suitable for curved surface coating.

[0003] In addition to traditional coating techniques, atomic layer deposition (ALD) technology achieves layer-by-layer deposition of single-atom thickness through the cyclic and alternating reaction of precursors. Compared with other coating techniques, ALD technology can precisely control the properties of thin films at the atomic level, achieve a bottom-up layer-by-layer growth mechanism through surface chemical saturation adsorption reaction, has unique self-limiting growth characteristics, and has excellent high precision, high flatness, high adhesion, low-temperature deposition, and excellent three-dimensional conformality. Therefore, ALD technology has unique advantages in the field of uniform coating of ultra-thin films, complex films, 3D structures (such as micro-nano structures, flat surfaces, curved surfaces, and macroscopic complex shape surfaces), and is applied in the fields of semiconductors, integrated circuits, photovoltaics, and optical coating. ALD technology originated in Finland in the 1970s, and after long-term development, the technology has become mature and has formed an industry. Currently, the main ALD technology and equipment manufacturers are mainly concentrated in Europe, Japan, the United States, and other overseas countries, and the domestic ALD technology development is relatively slow and backward. So far, domestic ALD technology has mastered certain coating and equipment design-manufacturing-production-application technology in the fields of conventional films such as aluminum oxide and silicon oxide, and wafer-level thin film deposition, but there is still a certain gap with foreign countries in high-end technology and equipment.

[0004] The ALD technology has incomparable advantages over traditional coating methods in the field of curved surface coating, but the existing ALD equipment is still dominated by meeting the needs of thin film deposition on the surface of inch-level wafer samples. The equipment is more suitable for coating on the surface of planar samples, and mainly pursues to realize large-scale automatic wafer thin film deposition by optimizing the design of the chamber structure, or to greatly improve the deposition efficiency by using new space ALD technology. There is almost no equipment for coating on the surface of curved, large-length-ratio and large-size optical window samples such as hemispherical optical windows. Although there is a large-chamber-structure equipment in foreign ALD equipment, in theory, the uniform deposition of the film layer can be realized by using the vapor deposition characteristics of the ALD technology, but this method has disadvantages in uniform heating of large-size curved samples, and the highly sensitive characteristics of the ALD technology to the deposition temperature have high requirements for the uniformity and stability of the sample surface temperature field, so the applicability is limited. Domestic ALD technology is in the early stage of development due to technical barriers, and the proportion of research-type ALD equipment is high, almost all of which are flat small-chamber-structure, and cannot undertake the task of uniform coating on the surface of large-size curved optical windows. SUMMARY

[0005] The purpose of the present application is to solve the problem of poor uniformity and stability of the inner surface coating of the curved optical window in the existing coating technology, and to provide an atomic layer deposition device for uniform coating on the inner surface of a hemispherical curved surface, so as to realize uniform coating on the inner surface of a hemispherical sample.

[0006] The atomic layer deposition device for uniform coating on the inner surface of a hemispherical curved surface comprises a cover, a hemispherical heater, a hollow hemispherical shell, a cover plate, an exhaust plate, a disc-shaped heater, a gas passage piece, a cylindrical heater, a sample support, a chamber body and a chamber body base. A first gas inlet and a first gas outlet are opened on the chamber body base. The gas passage piece is cylindrical, and an inlet passage and an outlet passage are opened along the axial direction of the gas passage piece. The gas passage piece is vertically fixed on the upper surface of the chamber body base. The inlet passage in the gas passage piece is communicated with the first gas inlet, and the outlet passage in the gas passage piece is communicated with the first gas outlet. The cylindrical heater is sleeved outside the gas passage piece.

[0007] The exhaust plate is disc-shaped, and a surrounding rim is arranged on the upper surface of the exhaust plate in the circumferential direction. A plurality of gas holes are opened in the radial direction of the surrounding rim, and the plurality of gas holes are uniformly distributed along the circumferential direction of the exhaust plate. A second gas inlet and a second gas outlet are opened on the exhaust plate. A convex rim is arranged on the circumference of the second gas inlet, and the upper surfaces of the surrounding rim and the convex rim are flush. The cover plate is fixedly arranged on the exhaust plate, and a third gas inlet is opened on the cover plate. The third gas inlet is communicated with the second gas inlet, and the surrounding rim, the convex rim and the cover plate form a gas cavity.

[0008] The suction plate is fixed on the upper surface of the gas passage piece, the second gas inlet communicates with the gas inlet passage in the gas passage piece, the second gas outlet communicates with the gas outlet passage in the gas passage piece, a disc-shaped heater is arranged on the lower surface of the suction plate, and a hollow hemispherical shell is fixedly arranged on the upper surface of the cover plate, and a central gas hole is formed in the center of the hollow hemispherical shell.

[0009] The sample support is mounted on the cabin base, the sample support is sleeved outside the gas passage piece, the top of the sample support is provided with an annular platform, the hemispherical sample is placed on the annular platform and covers the upper part of the hollow hemispherical shell, and a ventilation gap is formed between the hemispherical sample and the hollow hemispherical shell.

[0010] The cabin is mounted on the cabin base, the cabin is sleeved outside the sample support, and the cabin cover covers the top of the cabin.

[0011] The cabin structure of the atomic layer deposition device is designed to realize uniform film coating on the inner surface of the hemispherical curved surface, actively control the gas flow field, obtain more uniform and stable flow field distribution, and realize uniform and stable heating of the hemispherical curved surface sample by reasonably designing the heating mode.

[0012] The atomic layer deposition device for uniformly coating the inner surface of the hemispherical curved surface mainly comprises the following structural characteristics:

[0013] 1. Cabin configuration: through the special configuration design of the cabin, uniform film coating on the inner surface of the hemispherical curved surface can be realized.

[0014] 2. Series two-stage pressure stabilizing structure:

[0015] The gas inlet passage in the gas passage piece realizes the first pressure relief, the hollow hemispherical shell realizes the second pressure relief, the gas passage piece and the hollow hemispherical shell are connected in series to form a two-stage pressure stabilizing structure, the gas pressure is stabilized, which is beneficial to obtain a more stable gas flow field and plays an important role in uniform film coating.

[0016] 3. Active flow guiding structure:

[0017] The film coating gas is limited in the limited space between the inner surface of the hemispherical sample and the outer surface of the hollow hemispherical shell, and the inner surface of the hemispherical sample and the outer surface of the hollow hemispherical shell form a good gas flow guiding effect, which is beneficial to the discrete and uniform motion of the gas.

[0018] 4. Uniform suction structure:

[0019] The reaction tail gas is collected through the exhaust plate and then discharged from the cabin. The side wall of the exhaust plate is uniformly provided with a circle of exhaust holes with uniform aperture, which can realize synchronous exhaust in 360° direction, further improving the uniformity of the flow field. At the same time, the uniformly distributed exhaust plate is located below the lower edge of the hemispherical sample, away from the sample, to realize remote exhaust and reduce the disturbance of the flow field near the exhaust port to the uniform coating.

[0020] 5. Inner and outer synchronous radiation type heating structure:

[0021] The sample is heated from the outside by the hemispherical heater, the hollow hemispherical shell, the cover plate and the exhaust plate are heated by the disc-shaped heater, the sample is heated from the inside by the high-temperature thermal radiation of the hollow hemispherical shell, the upper part of the sample support is heated by the annular heater to prevent heat loss, and the temperature gradient of the sample is reduced by the bidirectional heating to realize a more uniform and stable temperature field, so as to meet the higher requirements of ALD on the temperature field and improve the film quality.

[0022] The ALD equipment cabin structure is designed and optimized, the hemispherical curved surface inner surface is uniformly coated, TiO2, Al2O3, SiO2, In2O3, SnO x and other optoelectronic thin films can be deposited on glass, quartz, sapphire, silicon wafer and polymer substrates, and the uniformity is good. The present application solves the long-standing problem in the coating field and fills the domestic and international technical gap in the ALD field, and has a positive effect on promoting the localization of ALD equipment and the domestic ALD technology to catch up with the international advanced level.

[0023] The atomic layer deposition device disclosed by the present application has the following beneficial effects:

[0024] 1. For traditional evaporation and magnetron sputtering coating technology, the density distribution of the coating material particles in the cabin space presents a certain rule, and uniform distribution in space cannot be realized. Unlike this, all reaction particles in the ALD coating process exist in the form of gas in the cabin, and the spatial distribution is more uniform, and the free diffusion characteristics of gas in space can be fully utilized to realize uniform deposition of thin film. However, completely relying on the free diffusion characteristics of gas has the disadvantage of poor controllability, and it is more beneficial to realize the control of gas flow through certain technical means. The present application fully utilizes the uniform diffusion characteristics of ALD gas, and realizes the active guidance and control of gas motion path and gas flow field through special structure design, and through active manipulation of gas flow state, a more stable and uniform gas flow field can be realized, which is more suitable for hemispherical curved surface uniform coating.

[0025] 2. The traditional evaporation and magnetron sputtering coating technology is usually required to design a special sample holder, even a complex target-substrate linkage mechanism, and is limited by the radius of the curved surface, and can only be applied to the inner surface coating of simple shape samples such as hemispherical or spherical segment with large curved surface radius, and cannot be applied to the uniform coating of the inner surface of large aspect ratio samples such as deep arch. The equipment structure is complex, the cost is high, and the application range is greatly limited. In contrast, the ALD equipment provided by the application has simple structure and low manufacturing cost. For hemispherical samples with different curved surface radii, no structural design is required, only different sizes of hollow hemispherical shells, cover plates, exhaust plates, base heaters and sample holders need to be replaced, and uniform coating of the inner surface of hemispherical curved surface with any curved surface radius can be realized. Further, the hollow hemispherical shell is replaced by a spherical segment or a deep arch, and the ALD equipment of the application can be applied to the uniform deposition of the inner surface of the spherical segment or the deep arch.

[0026] 3. The application designs an internal and external synchrotron radiation heater structure, which innovatively clamps the hemispherical sample between two heat radiation sources, and uses a bidirectional radiation heat exchange method to synchronously heat the sample, thereby improving the large temperature gradient and poor temperature uniformity caused by single heat source radiation heating under vacuum conditions, greatly improving the uniformity of the temperature field, and reducing the temperature gradient of the sample, which plays a key role in improving the quality of the ALD film layer.

[0027] 4. The application is not limited to uniform coating of the inner surface of the hemispherical sample. If the above-mentioned hemispherical shell with any fixed curved surface radius in the application is modified into a deep arch part with any continuous variable curved surface radius, the equipment can also be used for uniform coating of the inner surface of the deep arch curved surface, has small technical migration resistance, wide application range and great application potential. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is an external structure diagram of an atomic layer deposition device for uniform coating of the inner surface of a hemispherical curved surface according to the application;

[0029] Figure 2 is an internal structure diagram of an atomic layer deposition device for uniform coating of the inner surface of a hemispherical curved surface according to the application;

[0030] Figure 3 is an internal structure diagram of an atomic layer deposition device for uniform coating of the inner surface of a hemispherical curved surface according to the application;

[0031] Figure 4 is a working principle diagram of gas flow in an atomic layer deposition device for uniform coating of the inner surface of a hemispherical curved surface;

[0032] Figure 5 is a structure diagram of a hatch cover;

[0033] Figure 6 is a structural diagram of a hemispherical heater;

[0034] Figure 7 is a structural diagram of a hollow hemispherical shell;

[0035] Figure 8 is a structural diagram of a cover plate;

[0036] Figure 9 is a structural diagram of an air extraction plate;

[0037] Figure 10 is a sectional diagram of an air extraction plate;

[0038] Figure 11 is a structural diagram of a disc-shaped heater;

[0039] Figure 12 is a structural diagram of a gas passage piece;

[0040] Figure 13 is a sectional diagram of a gas passage piece;

[0041] Figure 14 is a structural diagram of a cylindrical heater;

[0042] Figure 15 is a structural diagram of a sample holder;

[0043] Figure 16 is a structural diagram of a cabin;

[0044] Figure 17 is a structural diagram of a cabin base;

[0045] Figure 18 is a sectional diagram of a cabin base;

[0046] Figure 19 is a structural diagram of a ring-shaped heater;

[0047] Figure 20 is a diagram showing the connection of an air extraction plate and a gas passage piece;

[0048] Figure 21 is a structural diagram of a deep-arched hemispherical shell in the tenth embodiment;

[0049] Figure 22 is a diagram showing the influence of heating methods on the temperature field of the inner surface of a hemispherical sample in the embodiment, wherein □, ○, △ and ☆ represent four heating schemes respectively;

[0050] Figure 23 is a diagram showing the coordinates of the temperature measurement points of the inner surface of a hemispherical sample in the embodiment. DETAILED DESCRIPTION

[0051] Specific embodiment one: the atomic layer deposition device for uniform coating of the inner surface of the hemispherical curved surface comprises a hatch 1, a hemispherical heater 2, a hollow hemispherical shell 3, a cover plate 4, an exhaust plate 5, a disc-shaped heater 6, a gas passage 7, a cylindrical heater 8, a sample holder 9, a cabin body 10 and a cabin base 11. The first gas inlet 11-1 and the first gas outlet 11-2 are opened on the cabin base 11. The gas passage 7 is cylindrical, and the gas inlet passage 7-1 and the gas outlet passage 7-2 are opened along the axial direction of the gas passage 7. The gas passage 7 is vertically fixed on the upper surface of the cabin base 11. The gas inlet passage 7-1 in the gas passage 7 is communicated with the first gas inlet 11-1, and the gas outlet passage 7-2 in the gas passage 7 is communicated with the first gas outlet 11-2. The cylindrical heater 8 is sleeved outside the gas passage 7.

[0052] The exhaust plate 5 is disc-shaped, and a surrounding rim 5-3 is arranged on the upper surface of the exhaust plate 5 in the circumferential direction. A plurality of gas holes 5-4 are opened in the radial direction of the surrounding rim 5-3, and the plurality of gas holes 5-4 are uniformly distributed along the circumferential direction of the exhaust plate 5. The second gas inlet 5-1 and the second gas outlet 5-2 are opened on the exhaust plate 5. The second gas inlet 5-1 is provided with a convex rim 5-5 in the circumferential direction, and the upper surfaces of the surrounding rim 5-3 and the convex rim 5-5 are flush. The cover plate 4 is fixedly arranged on the exhaust plate 5, and the third gas inlet 4-1 is opened on the cover plate 4. The third gas inlet 4-1 is communicated with the second gas inlet 5-1, and the surrounding rim 5-3, the convex rim 5-5 and the cover plate 4 form a gas cavity.

[0053] The exhaust plate 5 is fixed on the upper surface of the gas passage 7, the second gas inlet 5-1 is communicated with the gas inlet passage 7-1 in the gas passage 7, and the second gas outlet 5-2 is communicated with the gas outlet passage 7-2 in the gas passage 7. The disc-shaped heater 6 is arranged on the lower surface of the exhaust plate 5. The hollow hemispherical shell 3 is fixedly arranged on the upper surface of the cover plate 4, and the center gas hole 3-1 is opened at the center of the hollow hemispherical shell 3.

[0054] The sample holder 9 is installed on the cabin base 11, and the sample holder 9 is sleeved outside the gas passage 7. The top of the sample holder 9 is provided with an annular platform 9-1. The hemispherical sample 18 is placed on the annular platform 9-1 and covers the upper part of the hollow hemispherical shell 3. The hemispherical sample 18 and the hollow hemispherical shell 3 are left with a ventilation gap therebetween. The sample holder 9, the cover plate 4 and the exhaust plate 5 are also left with a ventilation gap therebetween.

[0055] The cabin body 10 is installed on the cabin base 11, and the cabin body 10 is sleeved outside the sample holder 9. The hatch 1 is arranged on the top of the cabin body 10. The lower surface of the hatch 1 is provided with the hemispherical heater 2, and the hemispherical heater 2 covers the upper part of the hemispherical sample 18.

[0056] The embodiment provides an ALD equipment suitable for uniform coating of the inner surface of a hemispherical curved surface.

[0057] Specific embodiment two: different from the specific embodiment one, the bottom base 11 is disc-shaped.

[0058] Specific embodiment three: different from the specific embodiment one or two, the gas passage piece 7 is fixedly connected with the bottom base 11 through the first bolts 12.

[0059] Specific embodiment four: different from any one of the specific embodiments one to three, the diameter of the gas inlet passage 7-1 is greater than the diameter of the gas outlet passage 7-2.

[0060] Specific embodiment five: different from any one of the specific embodiments one to four, the gas extraction plate 5 is fixed on the upper surface of the gas passage piece 7 through the fourth bolts 15.

[0061] Specific embodiment six: different from any one of the specific embodiments one to five, the hollow hemispherical shell 3, the cover plate 4, the gas extraction plate 5 and the disc-shaped heater 6 are connected through the fifth bolts 16.

[0062] Specific embodiment seven: different from any one of the specific embodiments one to six, the width of the air gap between the hemispherical sample 18 and the hollow hemispherical shell 3 is 1-2 mm.

[0063] Specific embodiment eight: different from any one of the specific embodiments one to seven, the lower surface of the cover 1 is threadedly connected with the hemispherical heater 2.

[0064] Specific embodiment nine: different from any one of the specific embodiments one to eight, the hollow hemispherical shell 3 is replaced by a deep-arched hemispherical shell 3-1.

[0065] The deep-arched hemispherical shell 3-1 is adopted in the embodiment to be suitable for the deep-arched sample 18-1.

[0066] Specific embodiment ten: different from any one of the specific embodiments one to nine, the annular heater 17 is arranged on the lower surface of the annular platform 9-1.

[0067] Embodiment: The atomic layer deposition device for uniform coating of the inner surface of the hemispherical curved surface includes a hatch 1, a hemispherical heater 2, a hollow hemispherical shell 3, a cover plate 4, an exhaust plate 5, a disc-shaped heater 6, a gas passage 7, a cylindrical heater 8, a sample holder 9, a chamber body 10 and a chamber base 11. The chamber base 11 is provided with a first gas inlet 11-1 and a first gas outlet 11-2. The gas passage 7 is cylindrical and is provided with an inlet passage 7-1 and an outlet passage 7-2 along the axial direction of the gas passage 7. The diameter of the inlet passage 7-1 is twice the diameter of the outlet passage 7-2. The bottom of the gas passage 7 is vertically fixed to the upper surface of the chamber base 11 by a plurality of first bolts 12. The inlet passage 7-1 in the gas passage 7 is communicated with the first gas inlet 11-1, and the outlet passage 7-2 in the gas passage 7 is communicated with the first gas outlet 11-2. The cylindrical heater 8 is sleeved outside the gas passage 7.

[0068] The exhaust plate 5 is disc-shaped and is provided with a surrounding rim 5-3 on the outer circumferential direction of the upper surface of the exhaust plate 5. A plurality of gas holes 5-4 are radially arranged along the surrounding rim 5-3. The plurality of gas holes 5-4 are uniformly distributed along the circumferential direction of the exhaust plate 5. The exhaust plate 5 is provided with a second gas inlet 5-1 and a second gas outlet 5-2. The circumferential direction of the second gas inlet 5-1 is provided with a convex rim 5-5. The upper surfaces of the surrounding rim 5-3 and the convex rim 5-5 are flush. The cover plate 4 is fixedly arranged on the exhaust plate 5 and is provided with a third gas inlet 4-1. The third gas inlet 4-1 is communicated with the second gas inlet 5-1. The surrounding rim 5-3, the convex rim 5-5 and the cover plate 4 form a gas cavity.

[0069] The exhaust plate 5 is fixed to the upper surface of the gas passage 7 by a plurality of fourth bolts 15. The second gas inlet 5-1 is communicated with the inlet passage 7-1 in the gas passage 7, and the second gas outlet 5-2 is communicated with the outlet passage 7-2 in the gas passage 7. The disc-shaped heater 6 is arranged on the lower surface of the exhaust plate 5. The hollow hemispherical shell 3 is fixedly arranged on the upper surface of the cover plate 4. The hollow hemispherical shell 3 is provided with a central gas hole 3-1 at the center. The hollow hemispherical shell 3, the cover plate 4, the exhaust plate 5 and the disc-shaped heater 6 are connected by a plurality of fifth bolts 16. The plurality of fifth bolts 16 are arranged along the circumferential direction.

[0070] The bottom of the sample holder 9 is mounted on the chamber base 11 by a plurality of second bolts 13. The sample holder 9 is cylindrical and is sleeved outside the gas passage 7. The top of the sample holder 9 is provided with an annular platform 9-1. The annular platform 9-1 is provided with an annular heater 17 on the lower surface. The hemispherical sample 18 is placed on the annular platform 9-1 and covers the hollow hemispherical shell 3. The hemispherical sample 18 and the hollow hemispherical shell 3 are separated by a ventilation gap. The sample holder 9, the cover plate 4 and the exhaust plate 5 are also separated by a ventilation gap.

[0071] The bottom of the cabin body 10 is installed on the cabin base 11 through a plurality of third bolts 14, the cabin body 10 is sleeved outside the sample support 9, and the cabin cover 1 is covered on the top of the cabin body 10, and the lower surface of the cabin cover 1 is provided with a hemispherical heater 2, and the hemispherical heater 2 is covered on the upper part of the hemispherical sample 18.

[0072] The top of the hemispherical heater 2 in the embodiment is embedded in the inside of the cabin cover 1 and is detachably connected through threads, and the connection is vacuum sealed by a sealing ring. The disc-shaped heater 6, the air exhaust plate 5, the cover plate 4 and the hollow hemispherical shell 3 are sequentially stacked in the order from bottom to top, the second air inlet 5-1 of the air exhaust plate 5 and the third air inlet 4-1 of the cover plate 4 are aligned, a through hole with uniform position and consistent aperture is formed in the same radial dimension of the disc-shaped heater 6, the air exhaust plate 5 and the cover plate 4, a threaded hole is formed in the same dimension position of the hollow hemispherical shell 3, the disc-shaped heater 6, the air exhaust plate 5, the cover plate 4 and the hollow hemispherical shell 3 are fastened and connected by the fifth bolt 16, and the parts are vacuum sealed by a sealing ring at the connection, and no sealing ring is placed between the disc-shaped heater 6 and the air exhaust plate 5.

[0073] The air inlet and the air outlet of the air exhaust plate 5 and the gas passage 7 are aligned, and the fourth bolt 15 is used for fastening and connecting, and the connection is sealed by a sealing ring. The gas passage 7, the sample support 9 and the cabin body 10 are coaxially arranged.

[0074] The working mode of the ALD is a cyclic alternating reaction. Taking the scene of two precursors participating in the reaction as an example, one complete cycle includes four steps of precursor-in, cleaning, precursor-in and cleaning. Precursor-in and cleaning are a complete half-cycle reaction. The precursor enters the cabin in a gaseous form, is adsorbed and reacts on the substrate surface, and generates by-products at the same time. The cleaning step is to remove the excess precursors and reaction by-products, and to prepare for the next half-cycle reaction. Two complete half-cycles constitute a complete cycle to realize one-time deposition. The working principles and modes of the two half-cycles are similar, so the working principle of the present application is described by taking one half-cycle as an example.

[0075] The working principle diagram of the ALD device of the present application is shown in Figure 4 The position of the hemispherical sample 18 in the figure shows the placement position and mode of the sample in the film coating state. The working mode and working principle are as follows:

[0076] I. Sample placement:

[0077] The hemispherical sample 18 is placed on the sample support 9 in the placement mode shown in the figure, and the cabin is pumped to the required vacuum condition by a vacuum pump.

[0078] II. Heating:

[0079] The semi-spherical sample is heated from above by the semi-spherical heater 2, and the upper part of the sample holder 9 is heated by the ring-shaped heater 17;

[0080] The hollow semi-spherical shell 3, the cover plate 4 and the gas extraction plate 5 are heated by the disc-shaped heater 6, and the sample is heated from the inside by the heat radiation of the hollow semi-spherical shell 3, so that a more uniform and stable temperature field is achieved by internal and external heating to meet the high requirements of ALD on the temperature field.

[0081] The gas passage 7 is heated by the cylindrical heater 8 to prevent the condensation of the precursor.

[0082] III. Deposition:

[0083] When the atomic layer deposition is started, the precursor is a metal organic complex, for example, when the film to be deposited is an indium oxide film, the precursor is indium cyclopentadiene or trimethyl indium; when the film to be deposited is an aluminum oxide film, the precursor is trimethyl aluminum. The precursor enters the ALD device chamber from the first gas inlet 11-1 of the chamber base 11, moves in the chamber according to the direction indicated by the arrow, and is finally discharged from the chamber through the first gas outlet 11-2 of the chamber base 11. Figure 4

[0084] After the gas passes through the chamber base 11, it first enters the gas inlet passage 7-1 of the gas passage 7. Since the passage diameter increases, the pressure of the gas is released for the first time;

[0085] The gas continues to move, passes through the connection between the hollow semi-spherical shell 3, the cover plate 4, the uniform gas extraction plate 5 and the gas passage 7, and enters the hollow semi-spherical shell 3. The hollow design of the semi-spherical shell allows the gas pressure to be released for the second time, so that the hollow semi-spherical shell and the gas passage can realize the functions of gas pressure release and pressure stabilization, and play a certain role in stabilizing the gas flow field;

[0086] The gas continues to move from the outlet at the top of the hollow semi-spherical shell 3 to the space where the inner surface of the semi-spherical sample 18 is located, and flows in the narrow space formed by the inner surface of the semi-spherical sample 18 and the outer surface of the hollow semi-spherical shell 3. At this time, the inner surface of the semi-spherical sample 18 and the outer surface of the hollow semi-spherical shell 3 jointly play the roles of gas flow field restriction and flow guiding, and actively guide the gas to move along the inner surface of the semi-spherical sample 18, which is conducive to the completion of chemical adsorption and reaction;

[0087] ​Finally, the tail gas after adsorption and reaction in the last step is collected by the suction plate 5 and discharged outside the cabin through the exhaust passage of the gas passage piece 7. The suction plate 5 is disc-shaped, and the side surface is uniformly distributed with a circle of gas through holes with consistent hole diameters, which can realize uniform suction in the 360° direction, and cooperates with the flow guiding effect of the inner surface of the gas passage piece 7 and the outer surface of the hollow hemispherical shell 3 to realize more uniform flow field distribution. The height of the suction plate 5 is lower than the lower edge of the hemispherical sample 18, and the suction plate sinks through the suction port to improve the flow field distribution of the sample edge, which is more beneficial to the uniform deposition of the film at the edge part.

[0088] The characteristics of the atomic layer deposition device for uniformly coating the inner surface of the hemispherical curved surface in this embodiment are summarized as follows:

[0089] 1. Cabin configuration: through the special configuration design of the cabin, the inner surface of the hemispherical sample can be uniformly coated;

[0090] 2. Series two-stage pressure stabilizing structure:

[0091] As described in the above working principle, the larger gas inlet passage 7-1 in the gas passage piece 7 realizes the first pressure relief, and the hollow hemispherical shell inside the hollow hemispherical shell 3 can realize the second pressure relief. The series connection of the gas inlet passage and the hollow hemispherical shell can form a two-stage pressure stabilizing structure, stabilize the gas pressure, and be beneficial to obtain a more stable gas flow field, which plays an important role in uniform coating.

[0092] 3. Active flow guiding structure:

[0093] As described in the above working principle, the gas is limited in the limited space between the inner surface of the hemispherical sample 18 and the outer surface of the hollow hemispherical shell 3, and the inner surface of the hemispherical sample 18 and the outer surface of the hollow hemispherical shell 3 form a good gas flow guiding effect, which is beneficial to the discrete and uniform motion of the gas.

[0094] 4. Uniformly distributed suction structure:

[0095] As described in the above working principle, the reaction tail gas is collected by the suction plate 5 and then discharged from the cabin. The side wall of the suction plate is uniformly distributed with a circle of suction holes with consistent hole diameters, which can realize synchronous suction in the 360° direction, further improving the uniformity of the flow field. At the same time, the uniformly distributed suction plate 5 is located below the lower edge of the hemispherical sample, away from the sample, realizes remote suction, and reduces the disturbance of the flow field near the suction port to the uniform coating.

[0096] 5. Internal and external synchronous radiation heating structure:

[0097] As described above, the sample is heated from the outside by the hemispherical heater 2, the hollow hemispherical shell, the cover plate and the exhaust plate are heated by the disc-shaped heater 6, the sample is heated from the inside by the high-temperature thermal radiation of the hollow hemispherical shell, the upper part of the sample holder 9 is heated by the annular heater 17 to prevent heat loss, and the temperature gradient of the sample is reduced by bidirectional heating to achieve a more uniform and stable temperature field to meet the high requirements of ALD on the temperature field and improve the film quality.

[0098] Figure 22 The temperature distribution of the inner surface of the hemispherical sample under different heating modes is shown. Since the inner surface of the sample is the film growth surface, the temperature distribution of the inner surface is monitored and used as a standard to measure the heating effect. The label numbers in the figure represent the heater numbers, and different combinations of numbers represent different heater setting schemes. The main function of the cylindrical heater 8 is to heat the gas inlet pipeline to prevent gas condensation, but its effect on the sample temperature field is not considered. The effects of the hemispherical heater 2, the disc-shaped heater 6 and the annular heater 17 on the inner surface temperature field of the hemispherical sample are considered. There are four schemes:

[0099] ① Hemispherical heater 2

[0100] ② Hemispherical heater 2 + disc-shaped heater 6

[0101] ③ Hemispherical heater 2 + annular heater 17

[0102] ④ Hemispherical heater 2 + disc-shaped heater 6 + annular heater 17

[0103] As shown in Figure 22 , the corresponding inner surface temperature field distribution of the hemispherical sample heated to about 140℃ by different heating schemes, the definition method of the horizontal coordinate radius and the corresponding sample inner surface position point are shown in Figure 23 . As can be seen from the figure, the heating effect of scheme ① and scheme ② is poor, the temperature at different positions on the entire inner surface of the hemispherical sample is constantly changing, with large fluctuations, and the temperature uniformity is poor; scheme ③ can maintain good temperature uniformity within a radius of 0-40mm; scheme ④ has the same effect as scheme ③, with very excellent temperature uniformity, but scheme ④ considers the effect of the disc-shaped heater 6, which can heat the gas inlet system, which has a very important positive effect on preventing precursor condensation and improving the efficiency of the precursor. Through the above analysis, the heating mode consistent with scheme ④ is finally adopted in this embodiment, achieving excellent temperature uniformity effect.

Claims

1. An atomic layer deposition apparatus for uniformly coating the inner surface of a hemispherical curved surface, characterized by The atomic layer deposition device comprises a cover (1), a hemispherical heater (2), a hollow hemispherical shell (3), a cover plate (4), an air exhaust plate (5), a disc heater (6), a gas passage piece (7), a cylindrical heater (8), a sample support (9), a cabin body (10) and a cabin base (11), the cabin base (11) is provided with a first air inlet (11-1) and a first air outlet (11-2), the gas passage piece (7) is cylindrical, the gas passage piece (7) is provided with an air inlet passage (7-1) and an air outlet passage (7-2) along the axial direction of the gas passage piece (7), the gas passage piece (7) is vertically fixed on the upper surface of the cabin base (11), the air inlet passage (7-1) in the gas passage piece (7) is communicated with the first air inlet (11-1), the air outlet passage (7-2) in the gas passage piece (7) is communicated with the first air outlet (11-2), and the cylindrical heater (8) is sleeved outside the gas passage piece (7); The air exhaust plate (5) is disc-shaped, and a surrounding rim (5-3) is arranged on the upper surface of the air exhaust plate (5) in the circumferential direction, a plurality of air holes (5-4) are arranged in the radial direction of the surrounding rim (5-3), the plurality of air holes (5-4) are uniformly distributed along the circumferential direction of the air exhaust plate (5), the air exhaust plate (5) is provided with a second air inlet (5-1) and a second air outlet (5-2), the circumferential direction of the second air inlet (5-1) is provided with a convex rim (5-5), and the upper surfaces of the surrounding rim (5-3) and the convex rim (5-5) are flush; the cover plate (4) is fixedly arranged on the air exhaust plate (5), and the cover plate (4) is provided with a third air inlet (4-1), the third air inlet (4-1) is communicated with the second air inlet (5-1), and the surrounding rim (5-3), the convex rim (5-5) and the cover plate (4) form an air cavity; The air exhaust plate (5) is fixed on the upper surface of the gas passage piece (7), the second air inlet (5-1) is communicated with the air inlet passage (7-1) in the gas passage piece (7), the second air outlet (5-2) is communicated with the air outlet passage (7-2) in the gas passage piece (7), the disc heater (6) is arranged on the lower surface of the air exhaust plate (5), and the hollow hemispherical shell (3) is fixedly arranged on the upper surface of the cover plate (4), and the hollow hemispherical shell (3) is provided with a central air hole (3-1) at the center; The sample support (9) is installed on the cabin base (11), the sample support (9) is sleeved outside the gas passage piece (7), the top of the sample support (9) is provided with an annular platform (9-1), the hemispherical sample (18) is placed on the annular platform (9-1) and covers the upper portion of the hollow hemispherical shell (3), and a ventilation gap is formed between the hemispherical sample (18) and the hollow hemispherical shell (3); ventilation gaps are also formed between the sample support (9) and the cover plate (4) and the air exhaust plate (5); The cabin body (10) is installed on the cabin base (11) and sleeved outside the sample support (9), the cover (1) is arranged on the top of the cabin body (10), and the lower surface of the cover (1) is provided with the hemispherical heater (2), and the hemispherical heater (2) covers the upper portion of the hemispherical sample (18).

2. The atomic layer deposition apparatus for uniformly coating the inner surface of a hemispherical curved surface according to claim 1, wherein The cabin base (11) is disc-shaped.

3. The atomic layer deposition apparatus for uniformly coating the inner surface of a hemispherical curved surface according to claim 1, wherein The gas passage member (7) is fixedly connected with the cabin base (11) through a plurality of first bolts (12).

4. The atomic layer deposition apparatus for uniformly coating the inner surface of a hemispherical surface according to claim 1, wherein The diameter of the air inlet passage (7-1) is greater than that of the air outlet passage (7-2).

5. The atomic layer deposition apparatus for uniformly coating the inner surface of a hemispherical curved surface according to claim 1, wherein The air extraction plate (5) is fixed on the upper surface of the gas passage member (7) through a plurality of fourth bolts (15).

6. The atomic layer deposition apparatus for uniform coating of inner surface of a hemispherical curved surface according to claim 1, wherein The hollow hemispherical shell (3), the cover plate (4), the air extraction plate (5) and the disc-shaped heater (6) are connected through a plurality of fifth bolts (16).

7. The atomic layer deposition apparatus for uniform coating of inner surface of a hemispherical curved surface according to claim 1, wherein The width of the air gap between the hemispherical sample (18) and the hollow hemispherical shell (3) is 1-2 mm.

8. The atomic layer deposition apparatus for uniform coating of inner surface of a hemispherical curved surface according to claim 1, wherein The lower surface of the cabin cover (1) is threadedly connected with the hemispherical heater (2).

9. The atomic layer deposition apparatus for uniformly coating the inner surface of a hemispherical surface according to claim 1, wherein The hollow hemispherical shell (3) is replaced by a deep-arched hemispherical shell (3-1).

10. The atomic layer deposition apparatus for uniformly coating the inner surface of a hemispherical curved surface according to claim 1, wherein A ring-shaped heater (17) is arranged on the lower surface of the annular platform (9-1).

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