In-situ coherent X-ray characterization device for group III nitride growth

Abstract

The invention relates to the field of semiconductors, and provides an in-situ coherent X-ray characterization device, which comprises an X-ray device, a spraying device, a reaction device and a base, the spraying device is provided with at least three gas inlets and gas channels, and the gas inlets, the gas channels and the deposition chamber are communicated; the reaction device comprises a reaction shell and a deposition chamber, the reaction shell is made of a transparent material and can allow X-rays to pass through, and a sample bracket is arranged in the deposition chamber; a thermal radiation channel communicated to the sample bracket is formed in the base, and an optical fiber coupler is arranged at the bottom of the base and is connected to a thermal radiation source through an optical fiber; the X-ray radiation source and the X-ray detector are respectively arranged on two opposite sides of the reaction device, and the X-ray device and / or the sample bracket can rotate relative to the central axis of the deposition chamber. According to the invention, the core contradiction between the traditional MOCVD system and coherent X-ray in-situ characterization is overcome, and the high-resolution, dynamic and non-destructive observation of the whole growth process of the III-group nitride under the real epitaxial condition is realized for the first time.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to an in-situ coherent X-ray characterization apparatus for the growth of group III nitrides. Background Technology

[0002] Group III nitride semiconductors are key materials for manufacturing high-brightness LEDs, lasers, high-frequency high-power electronic devices, and deep-ultraviolet optoelectronic devices. Their performance is highly dependent on the crystal quality, interface steepness, and strain control level of the epitaxial thin film, which are determined by the atomic-scale dynamics of the metal-organic vapor phase epitaxy (MOCVD) process. To gain a deeper understanding of transient processes such as surface step flow, two-dimensional nucleation, island aggregation, dislocation motion, and strain relaxation, there is an urgent need to develop techniques for in-situ, real-time, and non-destructive observation under real growth conditions. Synchrotron radiation X-ray technology, due to its nanometer-scale spatial resolution, sub-second temporal resolution, and high sensitivity to crystal defects and surface fluctuations, is considered an ideal tool for studying epitaxial growth mechanisms. However, successfully applying this technology to the MOCVD environment faces several severe challenges.

[0003] First, there is a fundamental conflict between the traditional MOCVD reaction chamber and the requirements for X-ray penetration. Existing commercial MOCVD equipment generally uses sealed chambers made of stainless steel or thick-walled quartz to withstand high temperatures, high pressures, and corrosive atmospheres. However, metallic materials have extremely strong absorption of high-energy X-rays, while ordinary quartz is prone to corrosion or crystallization in long-term high-temperature NH3 environments, leading to a rapid decrease in transmittance. In addition, most chamber window angles are fixed, making it impossible to adjust the incident and scattering geometry, which severely limits the ability to detect different regions of reciprocal lattice space and makes it difficult to meet the requirements of coherent diffraction imaging (CDI) or XPCS for large solid angle scattering signals.

[0004] Secondly, the positional stability of samples at high temperatures is insufficient for coherent measurements. Coherent X-ray technology is extremely sensitive to the positional stability of the sample relative to the incident beam, typically requiring drift control at the sub-micron or even nanometer level. However, traditional MOCVD systems often employ surround resistance heating or hot-wall designs, causing the entire cavity structure to expand thermally, resulting in sample displacements of several to tens of micrometers during heating. This thermal drift not only decorrelates speckle patterns but also renders long-term observation data unreliable, fundamentally hindering XPCS's quantitative analysis of surface dynamics.

[0005] Third, multi-component precursor delivery methods are prone to pre-reaction and window contamination. Group III organometallic sources readily undergo thermal decomposition or pre-reaction with ammonia in the gas phase, generating nanoparticles. If a single-channel mixing spray head is used, the gas may react before entering the deposition zone, not only reducing film purity but also depositing on the X-ray window, causing a continuous decrease in transmittance. Simultaneously, traditional exhaust structures often require additional ductwork, which can easily obstruct the X-ray path, further reducing the signal-to-noise ratio.

[0006] Finally, there is a lack of flexible X-ray geometry adjustment mechanisms. The few existing in-situ CVD devices that attempt to integrate X-rays mostly employ fixed incident / detection angles, allowing them to acquire only limited information in reciprocal space. Crystal growth involves multi-scale structural evolution at the surface, interface, and bulk levels, requiring coordinated characterization through various geometric configurations such as grazing incidence, transmission, and high-angle reflection. Fixed geometric designs cannot meet this requirement, making it difficult to effectively capture key physical processes.

[0007] In summary, current technologies do not provide an integrated device that can meet the stringent process conditions of Group III nitride MOCVD while also being compatible with high-sensitivity coherent X-ray in-situ characterization. This technological gap severely restricts a deeper understanding of the microscopic mechanisms of semiconductor epitaxial growth and hinders the rational design and process optimization of high-performance devices. Summary of the Invention

[0008] This invention provides an in-situ coherent X-ray characterization device for the metal-organic vapor phase epitaxial growth of group III nitrides, which addresses the shortcomings of existing technologies and achieves the following technical effects: through the synergistic effect of structures such as transparent cavity, rotatable X-ray geometry, bottom fiber heating, three-channel gas isolation, and integrated exhaust, the core contradiction between traditional MOCVD systems and in-situ coherent X-ray characterization is successfully overcome, and for the first time, high-resolution, dynamic, and non-destructive observation of the entire growth process of group III nitrides under real epitaxial conditions is realized.

[0009] The present invention provides an in-situ coherent X-ray characterization device for the organic vapor phase epitaxial growth of group III nitride metals, comprising an X-ray device, and a spray device, a reaction device and a base that are sequentially and sealed from top to bottom; The outer wall of the spray device is connected to at least three gas inlets, and the interior of the spray device forms at least three mutually isolated gas channels. Each gas channel is connected to one of the gas inlets and all of them are connected to the deposition chamber of the reaction device. The reaction apparatus includes a reaction shell and a deposition chamber inside it. The reaction shell is made of a transparent material that allows X-rays to pass through. The deposition chamber is equipped with a sample holder for placing samples. The reaction shell is also equipped with exhaust channels that connect the deposition chamber to the outside. The base has a thermal radiation channel that connects to the sample holder. The bottom of the thermal radiation channel is provided with an optical fiber coupler and is connected to the thermal radiation source through an optical fiber. The X-ray device, including the X-ray radiation source and the X-ray detector, is respectively disposed on opposite sides of the reaction device, and the X-ray device and at least one of the sample holders are rotatably disposed relative to the central axis of the deposition chamber.

[0010] According to some embodiments of the present invention, the reaction shell includes a first reaction shell and a second reaction shell, both made of transparent material. The first reaction shell is sleeved on the outside of the second reaction shell, and a heat-insulating gap is formed between the two. The second reaction shell defines the deposition chamber and is equipped with the sample holder inside.

[0011] According to some embodiments of the present invention, the base includes a fixed base and a rotating base. The rotating base is installed inside the fixed base and is rotatably disposed around the central axis of the fixed base. The rotating base is fixedly connected to the sample holder through a mounting tube. The heat radiation channel is formed inside the mounting tube. The fiber optic coupler is installed inside the rotating base. The central axes of the fixed base, the rotating base, the mounting tube, and the deposition chamber all coincide with each other.

[0012] According to some embodiments of the present invention, a hollow heat transfer channel is formed inside the sample holder, the top end of the heat transfer channel is fixed with a sample and its bottom end is connected to the thermal radiation channel, and the inner diameter of the heat transfer channel decreases continuously from its bottom end to its top end.

[0013] According to some embodiments of the present invention, the second reaction shell defines a continuous exhaust channel between the sample holder and the mounting tube, respectively; The base has at least one vacuum port on its outer wall, and the two ends of the vacuum port are respectively connected to the exhaust channel and an external vacuum device.

[0014] According to some embodiments of the present invention, the spraying device includes a first housing, a second housing, and a third housing, all of which are hollow. The third housing is sleeved on the outside of the second housing and defines a third air intake channel between the two. The second housing is sleeved on the outside of the first housing and defines a second air intake channel between the two. The inside of the first housing defines a first air intake channel. Both the first housing and the second housing extend into the interior of the second reaction housing, such that the first air intake channel and the second air intake channel are respectively connected to the deposition chamber; a flow gap is defined between the second housing and the second reaction housing, and the third air intake channel is connected to the deposition chamber through the flow gap; The gas inlet includes a first gas inlet, a second gas inlet, and a third gas inlet, which are respectively connected to the first air intake channel, the second air intake channel, and the third air intake channel.

[0015] According to some embodiments of the present invention, the in-situ coherent X-ray characterization apparatus further includes: An optical imaging device is installed at the top of the spray device. The optical imaging device includes an optical housing, a dichroic mirror, a beam blocker, a short-pass filter, and an optical pyrometer. A conduction space is formed inside the optical housing. The beam blocker, the dichroic mirror, and the short-pass filter are installed in the conduction space and are connected to the first air intake channel through a radiation inlet. The dichroic mirror is located above the radiation inlet and is set at a preset angle relative to the radiation inlet. The beam blocker is set opposite to the dichroic mirror to block blackbody radiation transmitted by the dichroic mirror. The short-pass filter is set opposite to the dichroic mirror to filter blackbody radiation reflected by the dichroic mirror. The filter outlet of the short-pass filter is set towards the optical pyrometer.

[0016] According to some embodiments of the present invention, the optical pyrometer and the thermal radiation source are respectively connected to a controller, the controller being used to receive the detection results of the optical pyrometer and adjust the operating parameters of the thermal radiation source according to the detection results.

[0017] According to some embodiments of the present invention, the spraying device and the reaction device are sealed together by a first connecting flange, and the reaction device and the base are sealed together by a second connecting flange. At least one of the first connecting flange and the second connecting flange is provided with a cooling pipe for conveying coolant.

[0018] According to some embodiments of the present invention, an incident window is provided between the X-ray radiation source and the deposition chamber, and a scattering window is provided between the X-ray detector and the deposition chamber; The angle between the incident window and the X-ray radiation source is adjustable, and / or the angle between the scattering window and the X-ray detector is adjustable.

[0019] According to some embodiments of the present invention, the in-situ coherent X-ray characterization apparatus further includes: The positioning mechanism includes a base, a positioning base, a reaction positioning device, and a detector positioning device, wherein the positioning base is rotatably mounted on the base; The reaction positioning device is a six-legged platform, which includes a first platform, a second platform, and six retractable legs located between the first platform and the second platform. The base is mounted on the first platform, and the second platform is rotatably mounted on the positioning base. The X-ray detector is mounted on a detector positioning device, which is rotatably mounted on the positioning base.

[0020] According to some embodiments of the present invention, the detector positioning device includes a first bracket, a sliding engagement member, and a second bracket. The first bracket is provided with a first sliding member extending in a vertical direction, and the second bracket is provided with a second sliding member extending in a horizontal direction. The sliding engagement member is slidably engaged with the first sliding member and the second sliding member, respectively. The X-ray detector is mounted on the second bracket.

[0021] According to some embodiments of the present invention, the base is detachably mounted on the positioning mechanism via a dedicated connecting structure, so that the reaction device can be quickly and conveniently installed and disassembled relative to the X-ray device, and can share the same X-ray device with other types of reaction devices to improve efficiency.

[0022] In summary, the device of the present invention has at least the following advantages compared with related technologies: First, it significantly improves X-ray compatibility and observation flexibility.

[0023] By employing a reaction shell integrally constructed from X-ray transparent material, this device ensures that high-energy coherent X-ray beams can penetrate the cavity without obstruction, obtaining a sufficiently strong scattered signal to meet the high signal-to-noise ratio requirements of technologies such as CDI and XPCS. Simultaneously, at least one of the X-ray radiation source and detector (or the sample holder) can rotate around the central axis of the deposition chamber, enabling independent adjustment of the incident and scattering angles. This adjustable geometry overcomes the limitations of traditional fixed-window systems, allowing for flexible switching between multiple measurement modes such as grazing incidence, transmission, and reflection in a single growth experiment, comprehensively covering key regions of reciprocal space, thereby achieving multi-dimensional synchronous observation of surface dynamics, interface evolution, and bulk structure.

[0024] Secondly, it fundamentally ensures positional stability under high temperatures.

[0025] Abandoning traditional resistance heating or hot-wall designs, this device employs a bottom-mounted non-contact thermal radiation heating mechanism. Heat energy is introduced into the thermal radiation channel within the base via an optical fiber coupler, precisely irradiating the back of the sample from bottom to top. This method highly localizes the thermal effect area, keeping the cavity body cold-walled and significantly suppressing overall thermal expansion. Simultaneously, the absence of metal electrodes avoids physical obstruction of the X-ray path. As a result, the sample maintains sub-micron spatial stability even at growth temperatures as high as 1400℃, meeting the stringent requirements of coherent X-ray measurements for optical path stability and ensuring the reliability and temporal consistency of long-term observation data.

[0026] Third, it effectively suppressed gas-phase pre-reaction and protected the X-ray window.

[0027] The spray device features three isolated gas channels that independently deliver Group III precursors, Group V gases, and carrier / protective gases. Each component is physically isolated before entering the deposition chamber, mixing and reacting only near the sample surface, fundamentally preventing gas-phase nucleation and particle formation. Furthermore, this structure, combined with the outermost channel to introduce curtain gas, forms a dynamic gas curtain barrier on the inner surface of the transparent window, effectively preventing the deposition of corrosive byproducts, significantly extending the window's lifespan, and ensuring long-term high X-ray transmittance.

[0028] Fourth, the exhaust path was optimized, reducing interference with X-ray observation.

[0029] The exhaust channel cleverly utilizes the natural gap between the reaction shell and the sample holder to exhaust the waste gas, eliminating the need for an additional exhaust pipe. This reduces the dead volume within the cavity and completely avoids the path of the X-ray beam, preventing the obstruction of scattered signals by traditional exhaust structures and further improving the signal-to-noise ratio and data quality of in-situ observations. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in this invention 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 some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0031] Figure 1 This is a three-dimensional structural schematic diagram of the in-situ coherent X-ray characterization device provided by the present invention.

[0032] Figure 2 This is a side view of the in-situ coherent X-ray characterization device provided by the present invention.

[0033] Figure 3 It is along Figure 2 One of the cross-sectional views of line AA in the middle.

[0034] Figure 4 This is a cross-sectional view of the spray device and reaction device inside the in-situ coherent X-ray characterization device provided by the present invention after installation.

[0035] Figure 5 It is along Figure 2 The second sectional view of line AA in the middle.

[0036] Figure 6 yes Figure 5 Enlarged diagram of point B in the middle.

[0037] Figure 7 yes Figure 5 Enlarged diagram of point C in the middle.

[0038] Figure 8 This is a schematic diagram of the positioning mechanism provided by the present invention.

[0039] Figure 9 This invention provides a distribution map of temperature and reactant concentration in a deposition chamber obtained through computational fluid dynamics simulation.

[0040] Figure 10 This is a schematic diagram and result diagram of sample temperature calibration using optical interferometry provided by the present invention.

[0041] Figure 11 This is one of the representative X-ray scattering experimental results provided by this invention.

[0042] Figure 12 This is the second representative X-ray scattering experimental result provided by this invention.

[0043] Figure 13 This is the third representative X-ray scattering experimental result provided by this invention.

[0044] Figure 14 This is the fourth representative X-ray scattering experimental result provided by this invention.

[0045] Figure 15 This is the fifth representative X-ray scattering experimental result provided by this invention.

[0046] Figure label: 1. Spraying device; 11. First housing; 12. Second housing; 13. Third housing; 14. First gas inlet; 15. Second gas inlet; 16. Third gas inlet; 17. First air intake channel; 18. Second air intake channel; 19. Third air intake channel; 2. Reaction apparatus; 21. Deposition chamber; 22. First reaction shell; 23. Second reaction shell; 24. Exhaust channel; 25. Sample holder; 26. Insulation gap; 27. Heat transfer channel; 28. Flow gap 3. Base; 31. Fixed base; 32. Rotating base; 33. Mounting tube; 34. Heat radiation channel; 35. Vacuum port; 41. X-ray radiation source; 42. X-ray detector; 43. Entrance window; 51. Fiber optic coupler; 52. Fiber optic cable; 53. Thermal radiation source; 6. Optical imaging device; 61. Optical housing; 62. Dichroic mirror; 63. Beam blocker; 64. Short-pass filter; 65. Optical pyrometer; 66. Radiation entrance; 67. Conduction space; 68. Thermocouple; 71. First connecting flange; 72. Second connecting flange; 73. Cooling pipe; 74. Mounting fork; 75. Diffractometer bracket; 76. Vacuum port; 77. Heat dissipation groove; 8. Positioning mechanism; 81. Base; 82. Positioning base; 83. Response positioning device; 831. First platform; 832. Support leg; 833. Second platform; 84. Detector positioning device; 841. First bracket; 842. Sliding mating part; 843. Second bracket. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0048] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. It should also be noted that in the description of the present invention, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0049] The following description, with reference to the accompanying drawings, introduces an in-situ coherent X-ray characterization device for group III nitride metal-organic vapor phase epitaxy (MOCVD) growth. It should be noted that the application scenarios and functions of this device are roughly as follows: This device is mainly used in synchrotron radiation source or high-brightness X-ray laboratory environments, aiming to solve the technical problem that existing MOCVD systems cannot achieve in-situ observation of atomic-scale dynamic processes under high temperature, high pressure, and corrosive atmosphere conditions.

[0050] Specifically, this device can simultaneously introduce coherent X-ray beams during the epitaxial growth of group III nitride (such as GaN, AlN, InGaN) thin films, enabling real-time, non-destructive characterization of key physicochemical processes on the sample surface, including crystal structure evolution, strain distribution, step dynamics, island formation, and interfacial reactions. Its core functions include: maintaining a stable MOCVD process environment; ensuring high X-ray transmittance in the incident and scattering paths; achieving sub-micron-level spatial stability of the sample at high temperatures; supporting multi-angle X-ray geometry adjustment; and integrating optical temperature measurement and closed-loop temperature control systems to ensure precise control of the growth temperature.

[0051] By integrating the epitaxial growth system with a high-precision X-ray detection platform, this device provides a powerful in-situ experimental tool for studying the growth mechanism of semiconductor materials, optimizing epitaxial process parameters, and improving device performance.

[0052] like Figures 1 to 15 As shown, the in-situ coherent X-ray characterization apparatus for group III nitride metal-organic vapor phase epitaxial growth according to the first aspect of the present invention includes an X-ray apparatus and a spray device 1, a reaction device 2 and a base 3 that are sequentially and sealed from top to bottom.

[0053] At least three gas inlets are connected to the outer wall of the spray device 1, and at least three mutually isolated gas channels are formed inside the spray device 1. The gas channels are connected to the gas inlets one by one and are all connected to the sedimentation chamber 21 of the reaction device 2.

[0054] The reaction device 2 includes a reaction shell and a deposition chamber 21 inside it. The reaction shell is made of a transparent material that allows X-rays to pass through. The deposition chamber 21 is equipped with a sample holder 25 for placing samples. The reaction shell is also equipped with an exhaust channel 24 that connects the deposition chamber 21 to the outside.

[0055] The base 3 has a thermal radiation channel 34 that connects to the sample holder 25. The bottom of the thermal radiation channel 34 is provided with an optical fiber coupler 51 and is connected to the thermal radiation source 53 through an optical fiber 52. The X-ray device includes an X-ray radiation source 41 and an X-ray detector 42, which are respectively located on opposite sides of the reaction device 2. The X-ray device and at least one of the opposite deposition chambers 21 in the sample holder 25 are rotatably arranged along their central axes.

[0056] According to an embodiment of the present invention, the in-situ coherent X-ray characterization apparatus adopts a vertically stacked modular design. The spray device 1 is located at the top, and its outer wall is provided with at least three gas inlets, forming three mutually isolated gas channels inside. Each channel is connected to its corresponding gas inlet and extends downwards into the deposition chamber 21 of the reaction device 2, achieving independent transport and spatial isolation of the multi-component precursors. It can be understood that the three mutually isolated gas channels can effectively prevent the pre-reaction of Group III organometallic precursors and Group V gases (such as NH3) before entering the deposition chamber 21, thereby ensuring the purity of the gas flow and the controllability of the reaction.

[0057] The reaction device 2 is located in the middle and includes a reaction shell made of X-ray transparent material and a deposition chamber 21 defined inside it. The X-ray transparent reaction shell allows high-energy X-ray beams to penetrate the cavity, thereby enabling the device to perform in-situ observations without compromising its airtightness.

[0058] A sample holder 25 is installed inside the deposition chamber 21 to support the semiconductor substrate. An exhaust channel 24 is also provided inside the reaction shell, with one end connected to the deposition chamber 21 and the other end leading to the outside, for discharging reaction byproducts and unreacted gases. The base 3 is located at the bottom, and a thermal radiation channel 34 is formed inside it, extending upwards to the bottom of the sample holder 25. An optical fiber coupler 51 is installed at the bottom of the thermal radiation channel 34, connecting to an external thermal radiation source 53 via an optical fiber 52, achieving non-contact bottom heating. It can be understood that the thermal radiation channel 34 and the optical fiber coupler 51 can precisely introduce heat energy into the bottom of the sample in the form of light radiation, thereby avoiding the obstruction and thermal interference of the X-ray path caused by traditional resistance heating.

[0059] The X-ray apparatus includes an X-ray radiation source 41 and an X-ray detector 42, which are respectively disposed on opposite sides of the reaction device 2. At least one of the X-ray apparatus and the sample holder 25 can rotate relative to the central axis of the deposition chamber 21 to adjust the X-ray incident and scattering geometry. In this way, the relative rotatable arrangement of the X-ray apparatus and the sample holder 25 can support dynamic adjustment of the incident angle and scattering angle, realize scanning of multiple regions of reciprocal space, and thus adapt to various X-ray characterization modes.

[0060] It should be noted that in the study of metal-organic vapor phase epitaxy (MOCVD) of group III nitride semiconductor materials, understanding the atomic-scale growth kinetics is crucial for optimizing epitaxial quality and improving device performance. However, traditional characterization methods have long been limited to offline analysis, failing to capture the dynamic evolution of these transient and non-equilibrium states. Although synchrotron X-ray technology possesses the potential for in-situ, non-destructive, and high spatiotemporal resolution, its successful integration into a real MOCVD environment still faces multiple technical barriers, such as limited X-ray penetration, high-temperature positional instability, and conflicts between airflow and optical paths.

[0061] Therefore, in order to solve the technical problems existing in the above-mentioned related technologies, this invention provides an in-situ coherent X-ray characterization device for the metal-organic vapor phase epitaxial growth of group III nitrides. Through the synergistic effect of structures such as transparent cavity, rotatable X-ray geometry, bottom fiber 52 heating, three-channel gas isolation, and integrated exhaust, it successfully overcomes the core contradiction between traditional MOCVD systems and in-situ coherent X-ray characterization. For the first time, it achieves high-resolution, dynamic, and non-destructive observation of the entire growth process of group III nitrides under real epitaxial conditions. Its specific working principle is described below: First, addressing the issues of insufficient X-ray penetration and geometric flexibility, this device employs a fully transparent reaction shell combined with an adjustable X-ray device. Traditional MOCVD chambers are mostly made of stainless steel or thick-walled quartz, which strongly absorb high-energy X-rays, resulting in severe attenuation of the scattered signal. More importantly, a fixed window angle only allows for a single incident / scattering configuration, failing to cover the critical regions in reciprocal space required to characterize different physical processes. In contrast, this invention constructs the entire reaction shell from a material with high X-ray transmittance, and arranges the X-ray radiation source 41 and detector on opposite sides of the reaction device 2, with at least one (or the sample holder 25) capable of rotating around the central axis of the deposition chamber 21. This design allows for independent adjustment of the incident and scattering angles, enabling flexible switching between various measurement modes such as grazing incidence, transmission, or high-angle reflection in a single growth experiment. Crucially, this rotatable mechanism is based on a highly stable sample position, ensuring strict spatiotemporal correspondence of data acquired at different angles, providing a reliable foundation for constructing a four-dimensional crystal growth evolution model.

[0062] Secondly, addressing the core bottleneck of sample position drift at high temperatures leading to coherent signal decorrelation, this device abandons traditional resistance heating or hot-wall designs, instead employing a bottom-mounted non-contact thermal radiation heating mechanism. In conventional MOCVD systems, heaters are typically arranged around the cavity or sample holder, causing the entire structure to expand thermally. During heating, the sample undergoes displacements of several micrometers to tens of micrometers, far exceeding the sub-micrometer stability threshold tolerated by coherent technologies such as XPCS. This invention features a thermal radiation channel 34 extending from the base 3 to the sample holder 25, with an integrated fiber coupler 51 at the bottom. A flexible optical fiber 52 precisely guides the energy from an external high-power laser to the back of the sample. Because the heat energy acts only on a localized area of ​​the sample, the cavity body remains in a cold-wall state, significantly suppressing overall thermal deformation. Simultaneously, the electrode-free and coil-free heating path completely avoids X-ray beams, preventing background noise caused by metal components. This structure not only achieves stable heating capacity up to 1400℃, but more importantly, it ensures that the positional drift of the sample is controlled within the submicron level during long-term high-temperature growth, thereby maintaining the high temporal correlation of the speckle pattern. This enables XPCS to effectively resolve the diffusion dynamics of surface atomic clusters or the wave behavior of step edges.

[0063] Third, addressing the issues of multi-component precursor pre-reaction and window contamination, this device employs a three-channel isolation structure within the spray device 1 to achieve precise gas delivery and window self-protection. Group III organometallic sources and ammonia readily undergo thermal decomposition or pre-reaction in the gas phase, generating nanoparticles that not only reduce film purity but also deposit on the X-ray window, causing a continuous decrease in transmittance. This invention constructs three physically isolated gas channels within the spray device 1, corresponding to the Group III source, Group V source, and auxiliary gas, respectively. Each gas is transported within an independent channel until it enters the deposition chamber 21, where it begins to mix and react, fundamentally suppressing gas-phase nucleation. Furthermore, the outermost channel can be vented with inert curtain gas, forming a dynamic gas curtain on the inner surface of the quartz window, effectively preventing the diffusion of reaction byproducts into the window and significantly extending its lifespan. Simultaneously, the exhaust channel 24 cleverly utilizes the annular gap between the reaction shell and the sample holder 25, efficiently removing waste gas without additional piping. This reduces the dead volume within the chamber and avoids the obstruction of the X-ray path by traditional exhaust pipes, further improving the observation signal-to-noise ratio.

[0064] In summary, this device is not simply a combination of MOCVD and X-ray equipment. Instead, it deeply integrates a transparent cavity with rotatable X-ray geometry, bottom fiber 52 thermal radiation heating, a three-channel gas isolation spray, and an integrated low-interference exhaust structure. This creates a novel experimental platform that meets the stringent requirements of in-situ coherent X-ray characterization in four dimensions: material compatibility, thermomechanical stability, gas flow purity, and optical path freedom. Notably, this device is the first to achieve real-time, high-resolution, multi-modal observation of atomic-scale dynamic processes under actual group III nitride MOCVD growth conditions. This provides an irreplaceable experimental tool for revealing the microscopic mechanisms of epitaxial growth and guiding the fabrication of high-performance optoelectronic and power devices.

[0065] Furthermore, based on the above-mentioned basic working principle, the specific working process of the in-situ coherent X-ray characterization device of the present invention is illustrated below: First, the semiconductor substrate to be epitaxially grown is placed on the sample holder 25 inside the deposition chamber 21 of the reaction apparatus 2. The spray device 1, the reaction apparatus 2, and the base 3 are then sequentially and sealed together via a flange structure to form a closed reaction chamber. Subsequently, the chamber is evacuated and purged with high-purity nitrogen or hydrogen multiple times to remove air and moisture, ensuring a clean reaction environment.

[0066] Next, process gases are introduced into three isolated gas channels through three gas inlets on the outer wall of the spray device 1. The first gas inlet 14 introduces a Group III metal-organic precursor, the second gas inlet 15 introduces a Group V gas, and the third gas inlet 16 introduces a carrier gas or protective gas (such as hydrogen or nitrogen). Because the three gas channels are isolated from each other inside the spray device 1, the component gases do not mix before entering the deposition chamber 21, effectively avoiding gas-phase pre-reaction and particle formation. Only after the gases flow to the area above the deposition chamber 21 do they fully mix under high temperature and undergo thermal decomposition and surface reaction, achieving the epitaxial growth of a Group III nitride film.

[0067] Simultaneously, the external thermal radiation source 53 is activated, and its high-energy beam is conducted via optical fiber 52 to the optical fiber coupler 51 at the bottom of the base 3, and then shines upward onto the back of the sample through the thermal radiation channel 34 inside the base 3. This non-contact heating method rapidly heats the sample to the target growth temperature. Because the heat energy is concentrated on a localized area of ​​the sample, and no metal heating element is involved, the entire reaction shell remains at a relatively low temperature, significantly suppressing structural drift caused by thermal expansion and ensuring that the sample maintains submicron-level spatial stability during long-term operation at high temperatures.

[0068] Simultaneously with the epitaxial growth, the X-ray apparatus is activated. The X-ray source 41 emits a high-brightness, highly coherent beam of X-rays, which passes through the reaction chamber made of transparent material and strikes the sample surface at a set angle. The X-ray signal, scattered by the sample, passes through the opposite side of the reaction chamber and is received by the X-ray detector 42 located on the opposite side. Depending on experimental requirements, the incident and scattering angles can be dynamically adjusted by rotating at least one component of the X-ray source 41, the X-ray detector 42, or the sample holder 25 around the central axis of the deposition chamber 21.

[0069] Throughout the growth process, byproducts and excess precursors generated during the reaction are discharged through an exhaust channel 24 within the reaction chamber. This exhaust channel 24 connects the deposition chamber 21 to the outside environment, and its path design avoids obstruction of the X-ray beam by additional pipes, ensuring unobstructed observation optical path. The discharged gas is removed by an external vacuum pump system, thereby maintaining the internal pressure at a stable set value.

[0070] Therefore, through the aforementioned collaborative operation mechanism, this device achieves simultaneous growth and in-situ coherent X-ray characterization of group III nitride thin films under real MOCVD process conditions. Researchers can obtain multi-dimensional information such as crystal structure, surface morphology, interface evolution, and dynamic behavior in real time during a single experiment, providing direct and reliable experimental basis for a deeper understanding of epitaxial mechanisms and optimization of growth parameters.

[0071] In summary, the device of the present invention has at least the following advantages compared with related technologies: First, it significantly improves X-ray compatibility and observation flexibility.

[0072] By employing a reaction shell integrally constructed from X-ray transparent material, this device ensures that high-energy coherent X-ray beams can penetrate the cavity without obstruction, obtaining a sufficiently strong scattered signal to meet the high signal-to-noise ratio requirements of technologies such as CDI and XPCS. Simultaneously, at least one of the X-ray radiation source 41 and the detector (or the sample holder 25) can rotate around the central axis of the deposition chamber 21, enabling independent adjustment of the incident and scattering angles. This adjustable geometry overcomes the limitations of traditional fixed-window systems, allowing for flexible switching between multiple measurement modes such as grazing incidence, transmission, and reflection in a single growth experiment, comprehensively covering key regions of the reciprocal lattice space, thereby achieving multi-dimensional synchronous observation of surface dynamics, interface evolution, and bulk structure.

[0073] Secondly, it fundamentally ensures positional stability under high temperatures.

[0074] Abandoning traditional resistance heating or hot-wall designs, this device employs a bottom-mounted non-contact thermal radiation heating mechanism. Thermal energy is introduced into the thermal radiation channel 34 within the base 3 via fiber optic coupler 51, precisely irradiating the back of the sample from bottom to top. This method highly localizes the thermal effect area, keeping the cavity body in a cold-wall state and significantly suppressing overall thermal expansion. Simultaneously, the absence of metal electrodes avoids physical obstruction of the X-ray path. As a result, the sample maintains sub-micron spatial stability even at growth temperatures as high as 1400℃, meeting the stringent requirements of coherent X-ray measurements for optical path stability and ensuring the reliability and temporal consistency of long-term observation data.

[0075] Third, it effectively suppressed gas-phase pre-reaction and protected the X-ray window.

[0076] The spray device 1 has three isolated gas channels that independently deliver Group III precursors, Group V gases, and carrier / protective gases. These components are physically isolated before entering the deposition chamber 21, mixing and reacting only near the sample surface, fundamentally preventing gas-phase nucleation and particle formation. Furthermore, this structure can be combined with the outermost channel to introduce curtain gas, forming a dynamic gas curtain barrier on the inner surface of the transparent window. This effectively blocks the deposition of corrosive byproducts, significantly extending the window's lifespan and ensuring long-term high X-ray transmittance.

[0077] Fourth, the exhaust path was optimized, reducing interference with X-ray observation.

[0078] The exhaust channel 24 cleverly utilizes the natural gap between the reaction shell and the sample holder 25 to exhaust the waste gas, eliminating the need for an additional exhaust pipe. This reduces the dead volume inside the cavity and completely avoids the path of the X-ray beam, preventing the obstruction of the scattered signal by the traditional exhaust structure and further improving the signal-to-noise ratio and data quality of in-situ observation.

[0079] like Figure 3 and Figure 4 As shown, according to some embodiments of the present invention, the reaction shell includes a first reaction shell 22 and a second reaction shell 23, both made of transparent material. The first reaction shell 22 is sleeved on the outside of the second reaction shell 23 and a heat-insulating gap 26 is formed between them. The second reaction shell 23 defines a deposition chamber 21 and is equipped with a sample holder 25.

[0080] Specifically, the first reaction shell 22 serves as the outer layer enclosing the second reaction shell 23, and the thermal insulation gap 26 formed between them constitutes a low thermal conductivity region, effectively suppressing heat conduction from the high temperature inside the deposition chamber 21 to the external environment. Since both shells are made of X-ray transparent material, X-ray beams can sequentially penetrate the first reaction shell 22, the thermal insulation gap 26, and the second reaction shell 23, allowing for unobstructed observation of the sample inside the deposition chamber 21 without sacrificing X-ray transparency due to the added thermal insulation structure.

[0081] For example, during epitaxial growth, the deposition chamber 21 needs to be maintained at a high temperature above 1200°C, while the external flange, sealing ring, and X-ray window surrounding structure need to be kept at a lower temperature to ensure sealing reliability and material life. At this time, the insulation gap 26 can significantly reduce the heat flux density, making the temperature of the outer first reaction shell 22 much lower than that of the inner second reaction shell 23, thereby protecting the peripheral components from thermal damage.

[0082] In this way, the above structure improves the thermal stability and process safety of the cavity without increasing the complexity of the X-ray absorption path, helps to maintain the uniformity of the temperature field during long-term growth, and extends the overall service life of the device.

[0083] It should be noted that, in any embodiment, the second reaction shell 23 is a thermally insulated structure and is made of a transparent material that is transmissive to X-ray radiation, so that the substrate or device within the deposition chamber 21 can be probed with X-rays during MOCVD growth. The second reaction shell 23 forms a barrier between the deposition chamber 21 and the insulation gap 26, allowing the pressure and chemical composition of the deposition chamber 21 and the insulation gap 26 to differ, thereby enabling independent control in certain situations to achieve precise adjustment of process conditions.

[0084] It should be explained that transparent materials refer to materials that have high transmittance to high-energy X-rays while being able to withstand the high temperatures, corrosive atmospheres, and certain pressures of the MOCVD process. For example, transparent materials can be fused silica, which has good chemical stability, high transmittance to X-rays >10 keV, and can operate for extended periods in environments below 1200℃, making it a preferred choice that balances transmittance, mechanical strength, and cost.

[0085] However, it should be noted that the above-mentioned embodiment of transparent material is only one of the many embodiments of the present invention and does not constitute a specific limitation on the type of transparent material. The transparent material can be selected according to the specific experimental requirements, as long as it meets the comprehensive performance requirements of the window material for in-situ coherent X-ray characterization.

[0086] like Figure 3 and Figure 4 As shown, the bottom of the insulation gap 26 is further provided with a narrow opening, which forms a channel and is in fluid communication with the vacuum suction device to achieve vacuuming of the insulation gap 26. The deposition chamber 21 is also in fluid communication with the vacuum suction device to create a vacuum environment in the deposition chamber 21 and allow the precursor gas to be discharged through the vacuum suction device.

[0087] Since both the insulation gap 26 and the deposition chamber 21 are evacuated by a vacuum suction device, a unidirectional airflow is formed within the system, exiting from the insulation gap 26 and the deposition chamber 21. This unidirectional flow prevents the precursor gas from flowing back into the insulation gap 26, thereby avoiding chemical reaction between the precursor and the first reaction shell 22. The vacuum suction device serves as the system's gas or fluid outlet, used to remove gases, such as excess precursor or air, to maintain the required vacuum conditions.

[0088] like Figure 3 and Figure 7 As shown, according to some embodiments of the present invention, the base 3 includes a fixed base 31 and a rotating base 32. The rotating base 32 is installed inside the fixed base 31 and is rotatably arranged around the central axis of the fixed base 31. The rotating base 32 is fixedly connected to the sample holder 25 through the mounting tube 33. A thermal radiation channel 34 is formed inside the mounting tube 33. The fiber optic coupler 51 is installed inside the rotating base 32.

[0089] The central axes of the fixed seat 31, the rotating seat 32, the mounting pipe 33, and the sedimentation chamber 21 all coincide with each other.

[0090] In this embodiment, the above structure enables independent rotation of the sample during the high-temperature epitaxial process, while avoiding disturbance to the reaction chamber, gas pipeline, X-ray path, and other peripheral equipment. The rotating base 32 is supported inside the fixed base 31, achieving airtightness and low-friction rotation through a high-vacuum rotary sealing mechanism, allowing the sample holder 25 and the substrate it supports to rotate smoothly around the central axis of the deposition chamber 21. Because the mounting tube 33 is rigidly connected to the sample holder 25, and the internal thermal radiation channel 34 extends axially, laser energy from the bottom thermal radiation source 53 can be continuously introduced to the back of the sample through the optical fiber 52 and the fiber coupler 51 integrated within the rotating base 32, maintaining stable and uniform non-contact heating even during rotation. Simultaneously, the strictly coaxial design of all components ensures that the center of the sample surface remains at the focal point of the X-ray beam at any rotation angle.

[0091] It is understood that, based on this embodiment, on the one hand, rotation can change the orientation of the crystal relative to the incident X-rays, which facilitates the systematic scanning of diffraction signals of different crystal planes in reciprocal space; on the other hand, the high consistency of the central axis effectively suppresses the drift of the scattering signal caused by eccentricity or shaking, and ensures the time correlation of speckle patterns in dynamic measurements such as X-ray photon correlation spectrum (XPCS).

[0092] Thus, without sacrificing thermal stability and X-ray compatibility, the above structure endows the device with the ability to actively control sample orientation, significantly improving the in-situ resolution capability for complex physical processes such as anisotropic growth behavior, surface reconstruction, and domain structure evolution.

[0093] Furthermore, the thermal radiation source 53 may include a laser radiation source configured to provide infrared radiation to the sample disposed along the central axis within the deposition chamber 21 to achieve the required heating conditions. The thermal radiation source 53 is capable of providing power up to about 1 kW, or higher power depending on process requirements. For example, the thermal radiation source 53 may include one or more lasers, which may be infrared lasers or other types of lasers, with an output power of about 500 W, 750 W, 1 kW or greater, or about 1.5 kW or greater.

[0094] like Figure 3 and Figure 7 As shown, according to some embodiments of the present invention, a hollow heat transfer channel 27 is formed inside the sample holder 25. The top end of the heat transfer channel 27 is fixed with a sample and its bottom end is connected to the heat radiation channel 34. The inner diameter of the heat transfer channel 27 decreases continuously from its bottom end to its top end.

[0095] The structural design in this embodiment achieves directional guidance and spatial focusing of heat energy flow by constructing a hollow heat transfer channel 27 with an inner diameter that gradually narrows from bottom to top inside the sample holder 25. Specifically, infrared or near-infrared radiation energy from the thermal radiation channel 34 of the base 3 enters from the bottom of the heat transfer channel 27 and gradually converges as the channel cross-sectional area continuously decreases during upward propagation, causing the heat flux density to continuously increase along the axial direction, eventually reaching its maximum value at the top of the channel (i.e., the sample mounting position). This geometric configuration can efficiently concentrate the heat energy input from the bottom to the sample area, rather than distributing it uniformly throughout the entire holder structure.

[0096] Because the sample is directly fixed at the top opening of the heat transfer channel 27, its back side can fully receive the thermal radiation focused by the channel, thus achieving the surface temperature required for high-temperature epitaxy with relatively low input power. Simultaneously, the lower part of the support, due to its wider channel and lower heat flux density, has a significantly lower temperature than the sample area, effectively reducing heat conduction to the base 3 and surrounding structures. This helps maintain the overall thermal stability of the cavity and reduces thermal interference to precision components such as the rotary seal and fiber coupler 51. Furthermore, this tapered structure also helps improve the temperature uniformity of the sample surface. In traditional cylindrical supports, thermal radiation is easily reflected multiple times on the sidewalls, forming localized hot spots; while the tapered channel, by limiting lateral heat diffusion, promotes the concentrated axial transmission of heat energy, reducing edge heat dissipation effects and significantly narrowing the temperature difference between the sample center and edge.

[0097] In summary, the tapered inner diameter design of the heat transfer channel 27 can achieve efficient focusing of thermal energy, precise temperature control of the sample area, and high uniformity of the surface temperature field while ensuring non-contact heating compatibility with X-ray observation, thereby providing a stable thermodynamic environment for high-quality group III nitride epitaxial growth.

[0098] Furthermore, the sample holder 25 can be made of graphite, silicon carbide-coated graphite, or tungsten to meet the requirements for high temperature and chemical stability. The sample holder 25 can be modularly designed to be detachable and replaceable, thereby facilitating the installation of different types of samples or adjusting the thermal radiation beam profile for MOCVD growth according to process requirements.

[0099] For example, the sample holder 25 may include a heat transfer channel 27 with a larger radius to allow a wider thermal radiation beam to propagate along the central axis through the heat transfer channel 27; or, the sample holder 25 may include a larger top surface to mount a larger sample for MOCVD growth. During MOCVD growth, the sample substrate 81 is mounted on the top surface of the sample holder 25, and the deposition process is achieved by providing premixed precursor gas and transferring thermal energy to the sample substrate 81 through the thermal radiation source 53.

[0100] It should be noted that although the sample is described as a substrate in this document, it may also include epitaxial graphene, nanofabricated surfaces, surface channels, tapered channels or ridge structures, or other types of surface structures. Furthermore, the sample may include a sputtered back coating, such as a tungsten coating formed on the surface near the central hole, to improve thermal radiation absorption performance and enhance thermal coupling efficiency.

[0101] It should also be noted that the samples can be used to deposit p-type or n-type semiconductor materials, insulating materials, materials with quantum defects, various material polymorphs, heterojunction interfaces, semiconductor device structures, CMOS device structures, and the surfaces and structures of quantum devices.

[0102] like Figure 3 and Figure 7 As shown, in some specific embodiments of the present invention, the heat transfer channel 27 of the sample holder 25 extends along the central axis through the entire length of the sample holder 25 and forms openings at both ends thereon. The lower opening allows thermal radiation (e.g., laser radiation) to enter the heat transfer channel 27, while the upper opening located on the top surface allows thermal radiation to heat the sample mounted on the top surface.

[0103] The top surface includes a retractable mounting flange for supporting the sample. In the retracted state, the mounting flange is the only physical contact point between the sample and the sample holder 25, significantly reducing the contact area, decreasing thermal coupling between the sample and the sample holder 25, and further isolating heat from the sample to prevent heat transfer to the sample holder 25 and adjacent components. The mounting flange not only positions the sample along the central axis but also acts as a frame, maintaining the sample's stable position in the lateral direction.

[0104] It should be noted that the high thermal insulation design creates a high temperature gradient in the sample during etching or deposition. However, an excessively high temperature gradient may lead to a deterioration in sample performance, or even sample cracking due to internal thermal stress. To prevent or mitigate such problems, a collimator can be used to couple the laser fiber 52 to the sample chamber to enlarge the thermal radiation spot size, or a series of lenses, or a combination of the above methods, can be used. Furthermore, this invention can further ensure the sample maintains thermal stability throughout the entire process by real-time monitoring of the sample's thermal distribution map, thereby avoiding failures caused by high thermal gradients.

[0105] like Figure 3 and Figure 7 As shown, according to some embodiments of the present invention, the second reaction shell 23 defines a continuous exhaust channel 24 between the sample holder 25 and the mounting tube 33. At least one vacuum port 35 is provided on the outer wall of the base 3, and the two ends of the vacuum port 35 are connected to the exhaust channel 24 and an external vacuum device, respectively.

[0106] It is understandable that the above structure cleverly utilizes the natural gaps inside the reaction device 2 to construct an exhaust path, eliminating the need for an additional independent exhaust pipe. Specifically, the second reaction shell 23 serves as the inner wall of the deposition chamber 21, and an annular gap is formed between its inner side and the outer peripheral surface of the sample holder 25, as well as between its inner side and the outer wall of the mounting tube 33 supporting the holder. This gap is axially connected, forming a continuous exhaust channel 24 extending from the top of the deposition chamber 21 to the base 3 region. Byproduct gases and unreacted precursors generated during the reaction can be smoothly discharged from top to bottom along this channel, avoiding accumulation in dead corners of the cavity.

[0107] The exhaust channel 24 ultimately converges into the interior of the base 3 and connects to an external vacuum pump system via a vacuum port 35 located on the outer wall of the base 3. The vacuum port 35 is positioned far from the X-ray incident and scattering path, ensuring effective pumping capacity while avoiding physical obstruction of the X-ray beam by the exhaust port. Simultaneously, since the exhaust path is entirely formed by the fitting gaps between structural components, there are no protruding pipes or bends inside the overall cavity, significantly reducing dead volume, suppressing parasitic reactions, and contributing to maintaining a stable airflow field distribution.

[0108] In summary, this design ensures efficient exhaust while balancing the cleanliness requirements of the MOCVD process with the optical transparency requirements of X-ray in-situ characterization, effectively solving the problems of traditional exhaust structures that easily contaminate windows, interfere with optical paths, or increase system complexity.

[0109] like Figure 1 and Figure 3As shown, the base 3 further includes two vacuum ports 76 connected to the thermal radiation channel 34. The vacuum ports 76 and the base 3 form a multi-stage seal to maintain a vacuum state during the rotation of the rotating seat 32, ensuring the integrity of the deposition environment and the precision of the process.

[0110] like Figure 3 and Figure 4 As shown, according to some embodiments of the present invention, the spray device 1 includes a first housing 11, a second housing 12 and a third housing 13, all of which are hollow. The third housing 13 is sleeved on the outside of the second housing 12 and defines a third air intake channel 19 between the two. The second housing 12 is sleeved on the outside of the first housing 11 and defines a second air intake channel 18 between the two. The first housing 11 defines a first air intake channel 17 inside.

[0111] The first shell 11 and the second shell 12 both extend into the interior of the second reaction shell 23, so that the first air intake channel 17 and the second air intake channel 18 are respectively connected to the deposition chamber 21; a flow gap 28 is defined between the second shell 12 and the second reaction shell 23, and the third air intake channel 19 is connected to the deposition chamber 21 through the flow gap 28.

[0112] The gas inlets include a first gas inlet 14, a second gas inlet 15, and a third gas inlet 16, which are respectively connected to the first intake channel 17, the second intake channel 18, and the third intake channel 19.

[0113] In this embodiment, the device utilizes a three-layer coaxial nested shell design to construct three completely isolated gas delivery paths within a limited space, enabling the precise and independent introduction of different reaction components. Specifically, the first gas inlet channel 17, located in the innermost layer, directly delivers Group III metal-organic precursors (such as trimethylgallium) to the central region of the deposition chamber 21, ensuring its release directly above the sample; the second gas inlet channel 18 surrounds the first shell 11 and is used to deliver Group V gases (such as ammonia), which are initially mixed with the Group III source at its outlet to form a controllable reaction zone; the third gas inlet channel 19, located in the outermost layer, typically introduces a carrier gas or protective gas (such as hydrogen or nitrogen), which slowly diffuses into the deposition chamber 21 through the annular flow gap between the second shell 12 and the second reaction shell 23.

[0114] It is understandable that the design of the flow gap 28 has a dual function. On the one hand, it serves as a buffer diffusion zone for the third gas, preventing high-speed airflow from directly impacting the sample surface, thereby improving the uniformity of the film. On the other hand, the formed air curtain can effectively block the migration of reaction byproducts to the upper part of the spray device 1 and the X-ray window, reducing window contamination and maintaining long-term high transmittance.

[0115] In summary, because the three channels are physically completely isolated and only gradually converge near the sample surface, the premature reaction between the group III source and NH3 in the gas phase is significantly suppressed, reducing the risk of particle formation and improving the purity and interface steepness of the epitaxial film. Furthermore, each gas inlet corresponds to a specific channel, facilitating independent adjustment of flow rate, pressure, and temperature, providing highly flexible process control for optimizing growth kinetics.

[0116] like Figure 1 and Figure 3 As shown, according to some embodiments of the present invention, the in-situ coherent X-ray characterization device further includes an optical imaging device 6.

[0117] An optical imaging device 6 is installed at the top of the spray device 1. The optical imaging device 6 includes an optical housing 61, a dichroic mirror 62, a beam blocker 63, a short-pass filter 64, and an optical pyrometer 65. A conduction space 67 is formed inside the optical housing 61. The beam blocker 63, the dichroic mirror 62, and the short-pass filter 64 are installed in the conduction space 67 and are connected to the first air intake channel 17 through the radiation inlet 66.

[0118] The dichroic mirror 62 is located above the radiation entrance 66 and is set at a preset angle relative to the radiation entrance 66. The beam blocker 63 is set opposite to the dichroic mirror 62 to block the blackbody radiation transmitted by the dichroic mirror 62. The short-pass filter 64 is set opposite to the dichroic mirror 62 to filter the blackbody radiation reflected by the dichroic mirror 62. The filter outlet of the short-pass filter 64 is set towards the optical pyrometer 65.

[0119] It should be noted that the optical imaging device 6 is installed on the top of the spray device 1 and is integrated into the upper part of the reaction chamber to achieve non-contact, high-precision real-time monitoring of the sample surface temperature.

[0120] Specifically, the optical imaging device 6 includes an optical housing 61, a dichroic mirror 62, a beam blocker 63, a short-pass filter 64, and an optical pyrometer 65. A conduction space 67 is formed inside the optical housing 61 to house and fix the various optical components, and is connected to an external signal processing system through an interface on the top or side wall. The conduction space 67 communicates with the first air intake channel 17 inside the spray device 1 through a radiation inlet 66, thereby establishing an optical path with the deposition chamber 21, allowing the blackbody radiation emitted by the sample at high temperature to enter the optical imaging device 6 upwards along the first air intake channel 17.

[0121] Within the conduction space 67, a dichroic mirror 62 is positioned directly above the radiation entrance 66 at a preset angle (e.g., 45°) relative to the incident optical axis. This mirror selectively splits the broadband blackbody radiation from the sample according to wavelength: specific wavelengths are reflected, while others are transmitted. A beam blocker 63 is positioned opposite the dichroic mirror 62 on the transmission path to absorb or block stray radiation, preventing it from interfering with subsequent detection. A short-pass filter 64 is positioned on the reflected path, opposite the dichroic mirror 62, allowing only radiation shorter than a set cutoff wavelength to pass through, effectively filtering out long-wave infrared background noise and improving the signal-to-noise ratio. The filtered radiation beam is guided from the filter outlet of the short-pass filter 64 to an optical pyrometer 65, which calculates and outputs the true temperature of the sample surface in real time based on the Planck relationship between radiation intensity and temperature.

[0122] It is understandable that the structural design of the optical imaging device 6 has multiple technical advantages: First, by utilizing the existing first air intake channel 17 as the radiation transmission path, no additional opening is required, thus avoiding damage to the cavity's sealing or the introduction of X-ray obstruction; second, by combining the dichroic mirror 62 with the filter element, the optical basis for dual-band or multi-band colorimetric temperature measurement is realized, significantly improving the accuracy and anti-interference capability of high-temperature measurement; finally, all optical components are encapsulated inside the optical housing 61, isolated from the reaction atmosphere, which protects the precision components from corrosive gas corrosion and ensures the stability of long-term operation.

[0123] In summary, this optical imaging device 6 provides high-response speed and high-precision surface temperature feedback without interfering with the MOCVD process and X-ray observation, providing key support for achieving closed-loop temperature control, optimizing epitaxial growth kinetics, and ensuring the thermodynamic consistency of in-situ X-ray data.

[0124] For example, the dichroic mirror 62 can transmit infrared radiation, and in this case, a long-pass mirror with a cutoff wavelength of approximately 650 nm, 650 to 700 nm, 750 nm, 700 to 900 nm, 950 nm, or 600 to 1000 nm can be used. The dichroic mirror 62 reflects blackbody radiation to a short-pass filter 64102, which has a cutoff wavelength of approximately 1000 nm, 900 nm, 800 nm, 700 nm, or 600 to 1000 nm. The short-pass filter 64 is further configured to filter out any residual radiation from the thermal radiation source 53 and allow blackbody radiation emitted by the sample during MOCVD growth to pass through, thereby achieving high-precision imaging.

[0125] like Figure 1 and Figure 3As shown, the optical imaging device 6 further includes a thermocouple 68 embedded in the optical housing 61. The thermocouple 68 is configured to measure the temperature of the beam blocker 63 and the heat it dissipates to ensure that the temperature of the beam blocker 63 remains below a preset safety threshold. When the temperature exceeds this threshold, it indicates an unplanned or abnormal increase in the laser power of the thermal radiation source 53 passing through the deposition area, which could potentially lead to sample breakage or damage. Therefore, exceeding the threshold temperature will trigger an automatic stop of the deposition process to prevent further damage and allow for sample replacement.

[0126] According to some embodiments of the present invention, the optical pyrometer 65 and the thermal radiation source 53 are respectively connected to a controller, which is used to receive the detection results of the optical pyrometer 65 and adjust the operating parameters of the thermal radiation source 53 according to the detection results.

[0127] Thus, the above structure constitutes a closed-loop temperature control system, enabling real-time monitoring and dynamic control of the sample surface temperature. During device operation, the optical pyrometer 65 continuously collects the blackbody radiation signal after it has been filtered by the optical imaging device 6, and converts it into a corresponding temperature value, which is then output to the controller. The controller compares the measured temperature with the preset target growth temperature, generates adjustment commands based on a preset control algorithm, and dynamically adjusts the operating parameters such as the output power, pulse frequency, or working time of the thermal radiation source 53, thereby changing the intensity of the heat energy transferred to the sample through the fiber optic coupler 51 and the thermal radiation channel 34.

[0128] Since the temperature feedback comes directly from the sample surface radiation, rather than the temperature of the cavity environment or the support, this closed-loop system can effectively compensate for actual surface temperature fluctuations caused by factors such as changes in gas flow rate, exothermic precursor reactions, or attenuation of window transmittance. Simultaneously, the controller's fast response speed allows it to maintain temperature stability within a small range during critical stages of epitaxial growth, thereby significantly improving film thickness uniformity and composition consistency.

[0129] Furthermore, this closed-loop control mechanism works in close coordination with the non-contact heating and optical temperature measurement scheme, avoiding problems such as X-ray obstruction, contamination risk, and response lag caused by the insertion of traditional thermocouples 68. While ensuring the conditions for in-situ coherent X-ray characterization, it achieves high-precision active management of the thermal field in the MOCVD process.

[0130] like Figure 1 and Figure 3 As shown, according to some embodiments of the present invention, the spray device 1 and the reaction device 2 are sealed together by a first connecting flange 71, and the reaction device 2 and the base 3 are sealed together by a second connecting flange 72. At least one of the first connecting flange 71 and the second connecting flange 72 is provided with a cooling pipe 73 for conveying coolant.

[0131] This embodiment effectively solves the thermal management problem of critical sealing interfaces during high-temperature MOCVD operation by integrating cooling pipes 73 inside the connecting flange. In actual epitaxial growth, the internal temperature of the deposition chamber 21 can reach 1000–1400°C, and the heat will be conducted axially to the connection area between the spray device 1 and the reaction device 2, and between the reaction device 2 and the base 3. If not controlled, the high temperature will cause the metal seals to soften, oxidize, or creep, thereby leading to seal failure, gas leakage, or even vacuum failure.

[0132] To this end, the present invention provides a closed cooling channel within the body of the first connecting flange 71 and / or the second connecting flange 72, forming a cooling pipe 73 surrounding the flange sealing surface. Coolant is pumped into this pipe via an external circulation system, flows inside the flange, and carries away heat conducted to the connection interface, maintaining the temperature of the sealing area within the material's safe operating range. Since the cooling structure is fully integrated inside the flange, it does not occupy additional external space and does not obstruct the X-ray incident or scattering path, thus balancing thermal control performance with compatibility with in-situ characterization.

[0133] Furthermore, as a key interface for modular assembly, the temperature stability of the flange directly affects the mechanical alignment accuracy of the entire device. By actively cooling to suppress differences in thermal expansion, the coaxiality between the spray device 1, the reaction device 2, and the base 3 can be effectively maintained, avoiding sample position displacement or gas flow field distortion caused by thermal deformation, thereby ensuring spatial consistency and process repeatability of long-term in-situ X-ray measurements.

[0134] In summary, this cooling flange design not only improves the sealing reliability and operational safety of the device under high temperature and high pressure conditions, but also provides the necessary thermal and mechanical environment protection for achieving high stability and high precision in-situ coherent X-ray characterization.

[0135] Furthermore, the first connecting flange 71 and / or the second connecting flange 72 include one or more heat dissipation grooves 77 for accommodating cooling pipes 73 through which coolant flows. The cooling pipes 73, acting as heat dissipation elements, are configured to isolate heat around the deposition chamber 21 and sample holder 25, preventing excessive heat transfer to other components of the system (e.g., O-rings and seals), thereby avoiding deformation or damage to the seals due to overheating.

[0136] The cooling pipe 73 has a heat dissipation capacity of approximately 500 W, and can provide higher heat dissipation capacity, such as approximately 750 W, 1000 W or higher, depending on the process requirements, to ensure the thermal stability of the system under high-temperature MOCVD processes.

[0137] like Figure 3 and Figure 6As shown, according to some embodiments of the present invention, an incident window 43 is provided between the X-ray radiation source 41 and the deposition chamber 21, and a scattering window is provided between the X-ray detector 42 and the deposition chamber 21.

[0138] The angle between the incident window 43 and the X-ray radiation source 41 is adjustable, and / or the angle between the scattering window and the X-ray detector 42 is adjustable.

[0139] It is understood that this embodiment significantly enhances the geometric flexibility and experimental adaptability of the in-situ characterization system by setting an adjustable window at a key interface of the X-ray optical path. Both the incident window 43 and the scattering window are made of X-ray transparent material (such as fused silica) and are located on opposite sides of the reaction shell, forming the optical channels for the X-ray beam to enter and exit the deposition chamber 21. Furthermore, the window mounting mechanism is designed to rotate around a specific axis, allowing the angle between the incident window 43 and the incident direction of the X-ray radiation source 41, or between the scattering window and the receiving direction of the X-ray detector 42, to be adjusted as needed.

[0140] The aforementioned adjustable mechanism addresses the limitations of fixed-window systems in grazing incidence or high-angle scattering measurements. Furthermore, the independent adjustment capability of the window angle facilitates alignment and calibration, compensates for optical path offsets caused by cavity assembly errors or thermal deformation, and improves the repeatability and data reliability of long-term experiments. Since the adjustment mechanism acts only on the window itself without disturbing the internal structure of the reaction chamber, sample position, or gas flow field, geometric optimization can be achieved without interrupting epitaxial growth.

[0141] In summary, this adjustable window design maintains the cavity's sealing and high X-ray transmittance while enabling the system to quickly adapt to various X-ray scattering geometries, thus providing key hardware support for a comprehensive analysis of the multi-scale evolution from surface dynamics to bulk structure during the epitaxialization of group III nitrides.

[0142] For example, both the incident window 43 and the scattering window are made of sapphire single crystal and are fixed to a rotatable mounting base by a metal sealing ring. The mounting base can be adjusted within a range of ±45° to enable measurements under different scattering geometries. The window thickness is approximately 0.5–2 mm, allowing it to withstand high-temperature and high-pressure atmospheres while maintaining X-ray transmittance.

[0143] Furthermore, the X-ray radiation source 41 may include a synchrotron radiation source, an undulator, a oscillator, and / or a bending magnet. The incident X-ray beam is used to probe the sample in various ways, including but not limited to X-ray diffraction and X-ray spectroscopy analysis. The detection signal is received by the X-ray detector 42 to detect the scattered or diffracted X-rays. Subsequently, X-ray probe-based analysis can be used to determine the material properties, molecular structure, and atomic-level characteristics of the sample during MOCVD fabrication in the deposition chamber 21.

[0144] According to some embodiments of the present invention, a diffractometer support 75 and an outwardly extending mounting fork 74 are also mounted on the outer side of the base 3. One end of the mounting fork 74 is fixed to the diffractometer support 75, and the other end is used to mount the X-ray radiation source 41. The diffractometer support 75 and the mounting fork 74 are used to precisely position the deposition chamber 21 in the path of the X-ray beam to achieve in-situ measurement of the sample during MOCVD or etching. It can be understood that the above structure can be used to stabilize the reaction device 2, keep it in a fixed position in the X-ray beam direction, and prevent the system from shifting or tilting during the rotation of the sample holder 25.

[0145] like Figure 8 As shown, according to some embodiments of the present invention, the in-situ coherent X-ray characterization apparatus further includes a positioning mechanism 8.

[0146] The positioning mechanism 8 includes a base 81, a positioning base 82, a reaction positioning device 83, and a detector positioning device 84. The positioning base 82 is rotatably mounted on the base 81.

[0147] The reaction positioning device 83 is a six-legged platform, which includes a first platform 831, a second platform 833, and six retractable legs 832 located between the first platform 831 and the second platform 833. The base 3 is mounted on the first platform 831, and the second platform 833 is rotatably mounted on the positioning base 82.

[0148] The X-ray detector 42 is mounted on the detector positioning device 84, which is rotatably mounted on the positioning base 82.

[0149] It is understandable that the positioning mechanism 8 is used to implement high-precision spatial control of the reaction components and the detection components under high temperature, high vacuum and corrosive atmosphere conditions, so as to meet the dual stringent requirements of coherent X-ray characterization for position stability and geometric adjustability.

[0150] Specifically, the positioning mechanism 8 includes a base 81, a positioning base 82, a reaction positioning device 83, and a detector positioning device 84. The positioning base 82 is rotatably mounted on the base 81, serving as a rotational reference platform for the entire positioning system and supporting coarse adjustment of the overall azimuth angle.

[0151] The reaction positioning device 83 adopts a six-legged platform structure, including a first platform 831, a second platform 833, and six independently retractable legs 832 connecting the two. The base 3 is fixed to the first platform 831, thus supporting the entire reaction chamber (including the spray device 1, the reaction device 2, and the sample) on the upper platform of the six-legged platform. The second platform 833 is rotatably mounted on the positioning base 82, giving the entire six-legged platform a rotational degree of freedom about its vertical axis. The six legs 832 are controlled by precision piezoelectric or stepper drivers, allowing for independent length adjustment within the nanometer to micrometer scale, thereby endowing the first platform 831 with six degrees of freedom (including three translational and three rotational) for precise positioning in three-dimensional space. This structure can compensate for sample position drift caused by thermal expansion, mechanical creep, or vibration in real time during epitaxial growth, ensuring that it remains at the X-ray beam focal point and maintaining the sub-micrometer spatial stability required for coherent measurements.

[0152] Meanwhile, the X-ray detector 42 is mounted on the detector positioning device 84, which is also rotatably mounted on the positioning base 82, allowing it to rotate independently of the reaction components around the same vertical axis. By adjusting the angle of the detector positioning device 84, the length of the scattering arm and the scattering angle can be changed, thereby adapting to different X-ray diffraction or scattering experimental modes and realizing a systematic scan of reciprocal space.

[0153] It is understandable that, since both the reaction positioning device 83 and the detector positioning device 84 are mounted on the same rotatable positioning base 82, they share the same rotation reference, which ensures the geometric consistency among the incident, sample, and detector components and avoids the accumulation of errors across multiple axes. Simultaneously, the active pose control capability of the hexapod platform combined with the independent angle adjustment of the detector allows the device to maintain the high-temperature stability of the sample while flexibly switching observation angles, providing a high-dimensional, high-precision spatial manipulation foundation for capturing transient structural evolution during crystal growth.

[0154] like Figure 8 As shown, the detector positioning device 84 further includes a first bracket 841, a sliding engagement member 842, and a second bracket 843. The first bracket 841 is provided with a first sliding member extending in the vertical direction, and the second bracket 843 is provided with a second sliding member extending in the horizontal direction. The sliding engagement member 842 is slidably engaged with the first sliding member and the second sliding member respectively. The X-ray detector 42 is mounted on the second bracket 843.

[0155] Specifically, the first bracket 841 is fixed on the positioning base 82 and has a first sliding member extending in the up-down direction (i.e., vertical direction) on it; the second bracket 843 is used to install the X-ray detector 42 and has a second sliding member extending in the left-right direction (i.e., horizontal direction) on it; the sliding mating member 842 serves as an intermediate connecting member and forms a slidable mating relationship with the first sliding member and the second sliding member respectively, thereby coupling the two orthogonal directions of movement freedom together.

[0156] Through this sliding fit structure, the X-ray detector 42 can be adjusted independently or in conjunction with other components in both horizontal and vertical dimensions. Furthermore, all sliding parts are made of vacuum-compatible materials and equipped with precision guide rails and locking mechanisms, ensuring smooth movement while maintaining high rigidity and long-term stability. The entire detector positioning device 84 is integrated onto the rotatable positioning base 82, sharing the same rotational reference with the reaction components carried by the hexapod platform, ensuring that the spatial relationship between the incident, sample, and detector remains controllable and repeatable when adjusting the detector's position or angle.

[0157] In summary, the detector positioning device 84 achieves high-precision and high-stability two-dimensional positioning of the X-ray detector 42 in the vertical and horizontal directions through an orthogonal sliding structure, effectively supporting the experimental requirements of multi-mode and multi-angle in-situ coherent X-ray characterization.

[0158] According to some embodiments of the present invention, the base 3 is detachably mounted on the positioning mechanism 8 via a dedicated connecting structure, so that the reaction device 2 can be quickly and conveniently installed and disassembled relative to the X-ray device, and can share the same X-ray device with other types of reaction devices 2, thereby improving the utilization efficiency of the X-ray device.

[0159] like Figure 9 As shown in some specific embodiments, this invention provides a temperature and reactant concentration distribution diagram within the growth chamber obtained through computational fluid dynamics (CFD) simulation. This diagram comprises three sub-diagrams, each illustrating the key physical field distribution along the symmetry axis of the growth chamber. Sub-diagram (a) reveals the temperature distribution and airflow streamlines within the chamber, clearly showing the thermal uniformity and gas flow path in the reaction region; sub-diagram (b) specifically illustrates the concentration distribution of the reactant NH3; and sub-diagram (c) correspondingly displays the concentration distribution of the group III precursor. These simulation results comprehensively reveal the transport and distribution patterns of reactants under controlled thermal and flow fields, intuitively demonstrating the superior performance of the system of this invention in maintaining a stable reaction environment and optimizing reactant mixing efficiency, providing crucial basis for optimizing chamber structure and process parameters.

[0160] To optimize the cavity geometry and airflow conditions, the applicant conducted a systematic study combining simulation analysis and experimental testing. For example... Figure 9As shown, the internal airflow structure of the chamber is dominated by the input gas entering from the top, which flows downwards along the sample and its carrier (i.e., the "support block"). Test results show that, under high-temperature conditions and without forming convective vortices, the maximum total pressure at which the system can operate stably is 200 Torr, and the corresponding total flow rate matches the overall reactor design. Under 200 Torr conditions, the optimized airflow parameters are: window purge gas 5.6 slpm, annular Group V gas flow 3.8 slpm, and central Group III gas flow 0.9 slpm. Under typical high NH3 conditions, 2.7 slpm of the Group V gas flow is NH3, with the remainder being carrier gas (which can be 100% N2 or a 50% / 50% N2 / H2 mixture). Group III precursors (e.g., TEGa) are introduced into the reaction chamber via N2 or H2 carrier gas during growth, and growth is controlled by precisely adjusting the flow rate.

[0161] Figure 10 This diagram illustrates the sample temperature calibration using optical interferometry provided by this invention, along with the resulting graph. Assuming the support and sample are at the same ambient temperature before heating, the sample temperature can be extracted from the measured phase change using an inversion formula. As shown in sub-figure (a), it depicts the curve of the interference signal intensity of the probe laser changing over time during sample heating and cooling; this curve exhibits a clear periodic oscillation characteristic. Based on this interference oscillation signal, the real-time temperature difference between the sample and the sample holder can be further extracted. Figure 10 (b) shows typical calibration results between the sapphire sample temperature and the support temperature, plotted as temperature differences corresponding to heating and cooling processes, respectively. The absolute value of the temperature difference is smaller during heating than during cooling. This is achieved by averaging the heating and cooling values ​​using a polynomial fit (…). Figure 10 (b) shows the smoothed center curve, obtaining a calibration curve of the sample temperature under constant carrier temperature. The above analysis neglects the temperature gradient along the thickness of the reference sample, which can be estimated through thermal analysis. Of the typical total heating power of 550 W required to reach a carrier temperature of 1100 °C (sample temperature approximately 1025 °C), approximately 150 W is lost through radiation, and approximately 400 W is conducted to the surrounding gas. Assuming uniform heat transfer across the top, bottom, and sides of the carrier, the heat flux through the sample is approximately 0.08 W / mm². 2 The thermal conductivity of sapphire at 1025℃ is approximately 7.5 W·m. -1 ·K -1 Therefore, the temperature difference along the thickness direction of the reference sample is calculated to be approximately 5°C. Figure 10 (c) The calibration results obtained for sapphire samples were compared under carrier gas compositions of 50% N2 / 50% H2 and pure N2. The presence of hydrogen typically reduces the temperature difference by approximately 10 K.

[0162] Furthermore, Figures 11 to 15 The accompanying figures showcase a series of representative X-ray scattering experimental results obtained using the device of this invention. Specifically, the results include, but are not limited to: high-resolution rocking curves, whose peak shape and full width at half maximum (FWHM) directly demonstrate the excellent angular resolution of the device; scattering intensity distribution measurements of the crystal truncated bar, reflecting the device's ability to detect surface / interface structures; X-ray intensity oscillation curves monitored in real-time during homoepitaxial growth, where the oscillation period corresponds to the growth of a single molecular layer, thus proving that this invention possesses the real-time monitoring capability to achieve single-molecular-layer resolution; and microbeam diffraction experimental data, the results of which clearly demonstrate the spatial resolution performance of the device. These figures collectively confirm that the device of this invention possesses high performance and high reliability across multiple detection modes, as detailed below: Figure 11 This is one of the representative X-ray scattering experimental results provided by this invention. To verify the accuracy of sample rotation, the rocking curves of the out-of-plane and in-plane Bragg peaks of a GaN crystal with a (0001) surface orientation were measured. The full width at half maximum (FWHM) of the (0002) reflection was 0.0022°, used to characterize the Eta motion of the hexapod platform; while the FWHM of the (2020) reflection was 0.0022°, used to characterize the Phi motion and the rotational transmission performance of the cavity.

[0163] Figure 12 This is the second representative X-ray scattering experimental result provided by the present invention, which demonstrates a surface-sensitive scattering example of a GaN single crystal with a semi-polar (2021) surface orientation. The sample was tested at 476°C under standard N2 and NH3 atmosphere conditions. Figure 12 (a) is crystal truncated rod (CTR) scattering, characterized by striped scattering extending in a direction perpendicular to the crystal surface. Figure 12 (b) The in-plane scanning results obtained under grazing incidence conditions. Both types of scanning show that, while keeping the incident angle α constant, accurate tracking and measurement can be achieved along the predicted reciprocal space path by coordinating multi-axis angular motion.

[0164] Figure 13 This is the third representative X-ray scattering experimental result provided by this invention. During the GaN homoepitaxy growth process, the oscillation behavior of the crystal cutoff bar (CTR) intensity was monitored in real time, with each oscillation cycle corresponding to the growth of one single-atom layer. The measurements in this embodiment were performed using a transversely coherent beam. This result verifies the feasibility of using this system to study dynamic growth modes under coherent X-ray irradiation conditions.

[0165] Figure 14This is the fourth representative X-ray scattering experimental result provided by this invention. To verify the applicability of this cavity in the study of surface morphology changes at the micrometer scale, we... Figure 14 (a) shows a GaN sample with a patterned structure, for which micro-diffraction measurements were performed. The incident beam size was 5 µm (Y direction) × 50 µm (X direction), and the sample was tested at 476 °C in a typical NH3 / N2 atmosphere. Figure 14 (b) This diagram shows the diffraction intensity distribution near the Bragg peak of GaN (0002) measured on an area detector when the incident beam is aligned with the center of the trench. Two crystal truncated rod (CTR) signals at ±18° angles relative to the horizontal plane are clearly visible, originating from the tilted sidewalls on either side of the trench. By monitoring each CTR during scanning within the sample plane, the scattered signals from the sidewalls can be separated, such as... Figure 14 As shown in (c), the spatial resolution of the measurement is thus characterized. Figure 14 (c) The 5.9 µm spacing between the two peaks is consistent with the groove width measured by scanning electron microscopy after growth. These results demonstrate that this system possesses the high spatial resolution and excellent angular stability required for microdiffraction studies.

[0166] Figure 15 This is the fifth representative X-ray scattering experimental result provided by this invention. For example... Figure 15 As shown in (a), the autocorrelation function of the time series signal was measured when the sample was held in a fixed position. The flat autocorrelation curve indicates that the speckle pattern remains essentially unchanged within a time scale of 1500 s, demonstrating that both the cavity and the diffractometer have extremely high stability. Figure 15 (b) and Figure 15 (c) The autocorrelation functions obtained when scanning the sample along the Y and Z directions are presented. In this case, the time variable corresponds to the spatial displacement, and the speckle pattern is expected to change with the correlation length, which is equal to the transverse coherence length of the X-ray beam. By fitting the measured autocorrelation function to an exponential function (red curve), the coherence lengths in the horizontal (Y) and vertical (Z) directions are found to be 2.8 µm and 2.1 µm, respectively, which are basically consistent with the values ​​calculated based on the light source size and focusing optical model. The small peaks deviating from zero may be artifacts caused by insufficient averaging due to the limited scanning range. These preliminary results indicate that the system has sufficient stability to observe the temporal evolution characteristics of speckle patterns on GaN surfaces under MOCVD conditions, thus providing a feasible basis for carrying out atomic-scale dynamic measurements based on XPCS.

[0167] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "method," "specific method," or "some methods," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or method is included in at least one embodiment or method of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or method. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or methods. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or methods described in this specification, as well as the features of different embodiments or methods.

[0168] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An in-situ coherent X-ray characterization device for the growth of group III nitrides, characterized in that, It includes an X-ray device, and a spray device, a reaction device, and a base that are sealed together from top to bottom; The outer wall of the spray device is connected to at least three gas inlets, and the interior of the spray device forms at least three mutually isolated gas channels. Each gas channel is connected to one of the gas inlets and all of them are connected to the deposition chamber of the reaction device. The reaction apparatus includes a reaction shell and a deposition chamber inside it. The reaction shell is made of a transparent material that allows X-rays to pass through. The deposition chamber is equipped with a sample holder for placing samples. The reaction shell is also equipped with exhaust channels that connect the deposition chamber to the outside. The base has a thermal radiation channel that connects to the sample holder. The bottom of the thermal radiation channel is provided with an optical fiber coupler and is connected to the thermal radiation source through an optical fiber. The X-ray device, including the X-ray radiation source and the X-ray detector, is respectively disposed on opposite sides of the reaction device, and the X-ray device and at least one of the sample holders are rotatably disposed relative to the central axis of the deposition chamber.

2. The in-situ coherent X-ray characterization apparatus for group III nitride growth according to claim 1, characterized in that, The reaction shell includes a first reaction shell and a second reaction shell, both made of transparent material. The first reaction shell is sleeved on the outside of the second reaction shell, and a heat-insulating gap is formed between them. The second reaction shell defines the deposition chamber and is equipped with the sample holder inside.

3. The in-situ coherent X-ray characterization apparatus for group III nitride growth according to claim 2, characterized in that, The base includes a fixed base and a rotating base. The rotating base is installed inside the fixed base and is rotatably arranged around the central axis of the fixed base. The rotating base is fixedly connected to the sample holder through a mounting tube. The thermal radiation channel is formed inside the mounting tube. The optical fiber coupler is installed inside the rotating base. The central axes of the fixed base, the rotating base, the mounting tube, and the deposition chamber all coincide with each other.

4. The in-situ coherent X-ray characterization apparatus for group III nitride growth according to claim 2, characterized in that, The sample holder has a hollow heat transfer channel inside. The sample is fixed at the top of the heat transfer channel and its bottom is connected to the thermal radiation channel. The inner diameter of the heat transfer channel decreases continuously from its bottom to its top.

5. The in-situ coherent X-ray characterization apparatus for group III nitride growth according to claim 3, characterized in that, The second reaction shell defines a continuous exhaust channel between the sample holder and the mounting tube, respectively; The base has at least one vacuum port on its outer wall, and the two ends of the vacuum port are respectively connected to the exhaust channel and an external vacuum device.

6. The in-situ coherent X-ray characterization apparatus for group III nitride growth according to claim 2, characterized in that, The spraying device includes a first shell, a second shell, and a third shell, all of which are hollow. The third shell is sleeved on the outside of the second shell and defines a third air intake channel between them. The second shell is sleeved on the outside of the first shell and defines a second air intake channel between them. The first shell defines a first air intake channel inside. Both the first housing and the second housing extend into the interior of the second reaction housing, such that the first air intake channel and the second air intake channel are respectively connected to the deposition chamber; a flow gap is defined between the second housing and the second reaction housing, and the third air intake channel is connected to the deposition chamber through the flow gap; The gas inlet includes a first gas inlet, a second gas inlet, and a third gas inlet, which are respectively connected to the first air intake channel, the second air intake channel, and the third air intake channel.

7. The in-situ coherent X-ray characterization apparatus for group III nitride growth according to claim 6, characterized in that, Also includes: An optical imaging device is installed at the top of the spray device. The optical imaging device includes an optical housing, a dichroic mirror, a beam blocker, a short-pass filter, and an optical pyrometer. A conduction space is formed inside the optical housing. The beam blocker, the dichroic mirror, and the short-pass filter are installed in the conduction space and are connected to the first air intake channel through a radiation inlet. The dichroic mirror is located above the radiation inlet and is set at a preset angle relative to the radiation inlet. The beam blocker is set opposite to the dichroic mirror to block blackbody radiation transmitted by the dichroic mirror. The short-pass filter is set opposite to the dichroic mirror to filter blackbody radiation reflected by the dichroic mirror. The filter outlet of the short-pass filter is set towards the optical pyrometer.

8. The in-situ coherent X-ray characterization apparatus for group III nitride growth according to claim 7, characterized in that, The optical pyrometer and the thermal radiation source are respectively connected to the controller. The controller is used to receive the detection results of the optical pyrometer and adjust the operating parameters of the thermal radiation source according to the detection results.

9. The in-situ coherent X-ray characterization apparatus for group III nitride growth according to any one of claims 1 to 8, characterized in that, The spraying device is sealed to the reaction device via a first connecting flange, and the reaction device is sealed to the base via a second connecting flange. At least one of the first connecting flange and the second connecting flange is provided with a cooling pipe for conveying coolant.

10. The in-situ coherent X-ray characterization apparatus for group III nitride growth according to any one of claims 1 to 8, characterized in that, An incident window is provided between the X-ray radiation source and the deposition chamber, and a scattering window is provided between the X-ray detector and the deposition chamber; The angle between the incident window and the X-ray radiation source is adjustable, and / or the angle between the scattering window and the X-ray detector is adjustable.

11. The in-situ coherent X-ray characterization apparatus for group III nitride growth according to any one of claims 1 to 8, characterized in that, Also includes: The positioning mechanism includes a base, a positioning base, a reaction positioning device, and a detector positioning device, wherein the positioning base is rotatably mounted on the base; The reaction positioning device is a six-legged platform, which includes a first platform, a second platform, and six retractable legs located between the first platform and the second platform. The base is mounted on the first platform, and the second platform is rotatably mounted on the positioning base. The X-ray detector is mounted on a detector positioning device, which is rotatably mounted on the positioning base.

12. The in-situ coherent X-ray characterization apparatus for group III nitride growth according to claim 11, characterized in that, The detector positioning device includes a first bracket, a sliding engagement component, and a second bracket. The first bracket is provided with a first sliding component extending in the vertical direction, and the second bracket is provided with a second sliding component extending in the horizontal direction. The sliding engagement component is slidably engaged with the first sliding component and the second sliding component, respectively. The X-ray detector is mounted on the second bracket.

13. The in-situ coherent X-ray characterization apparatus for group III nitride growth according to claim 11, characterized in that, The base is detachably mounted on the positioning mechanism via a dedicated connecting structure, enabling the reaction device to be quickly and easily installed and disassembled relative to the X-ray device, and allowing it to share the same X-ray device with other types of reaction devices, thereby improving efficiency.

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