CN-122013309-A - In-situ coherent X-ray characterization device for III-nitride growth

CN122013309ACN 122013309 ACN122013309 ACN 122013309ACN-122013309-A

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, wherein the spraying device is provided with at least three gas inlets and gas channels, the gas inlets, the gas channels and a deposition chamber are communicated, the reaction device comprises a reaction shell and the deposition chamber which adopt transparent materials for X-rays to pass through, a sample support is arranged in the deposition chamber, a heat radiation channel communicated with the sample support is formed in the base, an optical fiber coupler is arranged at the bottom of the base and is connected to a heat radiation source through an optical fiber, the X-ray radiation source and an X-ray detector are respectively arranged on two opposite sides of the reaction device, and the X-ray device and/or a central axis of the sample support relative to the deposition chamber can rotate. The invention overcomes the core contradiction between the traditional MOCVD system and the coherent X-ray in-situ characterization, and realizes the high-resolution, dynamic and nondestructive observation of the whole growth process of the III-nitride under the real epitaxial condition for the first time.

Inventors

JU GUANGXU
WANG JIALE
Ye Yunhao
ZHAO YANG

Assignees

北京大学

Dates

Publication Date: 20260512
Application Date: 20251226

Claims (13)

1. The in-situ coherent X-ray characterization device for III nitride growth is characterized by comprising an X-ray device, a spraying device, a reaction device and a base, wherein the spraying device, the reaction device and the base are sequentially connected in a sealing manner from top to bottom; at least three gas inlets are connected to the outer wall of the spraying device, at least three mutually isolated gas channels are formed in the spraying device, and the gas channels are respectively communicated with the gas inlets in a one-to-one correspondence manner and are communicated to the deposition chambers of the reaction device; The reaction device comprises a reaction shell and a deposition chamber in the reaction shell, wherein the reaction shell is made of transparent materials through which X rays can pass, a sample support for placing a sample is arranged in the deposition chamber, and an exhaust channel which is respectively communicated with the deposition chamber and the outside is also arranged in the reaction shell; a heat radiation channel communicated with the sample support is formed in the base, and an optical fiber coupler is arranged at the bottom of the heat radiation channel and is connected to a heat radiation source through an optical fiber; The X-ray device comprises an X-ray radiation source and an X-ray detector which are respectively arranged on two opposite sides of the reaction device, and at least one of the X-ray device and the sample support is rotatably arranged relative to the central axis of the deposition chamber.
2. The in situ coherent X-ray characterization device for group III nitride growth of claim 1, wherein the reaction housing comprises a first reaction housing and a second reaction housing, both of which are made of transparent materials, the first reaction housing is sleeved outside the second reaction housing and forms a thermal insulation gap therebetween, and the second reaction housing defines the deposition chamber therein and is provided with the sample holder.
3. The in situ coherent X-ray characterization apparatus for group III nitride growth according to claim 2, wherein the base comprises a fixed seat and a rotating seat, the rotating seat being mounted inside the fixed seat and rotatably disposed about a central axis of the fixed seat, the rotating seat being fixedly connected to the sample support by a mounting tube, the mounting tube having the heat radiation passage formed therein, the optical fiber coupler being mounted inside the rotating seat; the central axes of the fixed seat, the rotating seat, the mounting pipe and the deposition chamber are mutually overlapped.
4. The in situ coherent X-ray characterization device for group III nitride growth according to claim 2, wherein the interior of the sample holder forms a hollow heat transfer channel with a sample fixed at its top end and communicating with the heat radiation channel at its bottom end, the heat transfer channel having an inner diameter that decreases from its bottom end to its top end.
5. An in situ coherent X-ray characterization apparatus for group III nitride growth according to claim 3, wherein said second reaction shell defines a continuous said exhaust channel with said sample holder and said mounting tube, respectively; the outer wall of the base is provided with at least one vacuumizing port, and two ends of the vacuumizing port are respectively connected to the exhaust channel and the external vacuumizing equipment.
6. The in situ coherent X-ray characterization device for group III nitride growth of claim 2, wherein the spray device comprises a first housing, a second housing, and a third housing, each hollow, the third housing being sleeved outside the second housing and defining a third air intake passage therebetween, the second housing being sleeved outside the first housing and defining a second air intake passage therebetween, the interior of the first housing defining a first air intake passage; The first shell and the second shell extend into the second reaction shell so that the first air inlet channel and the second air inlet channel are respectively communicated with the deposition chamber, an overflow gap is defined between the second shell and the second reaction shell, and the third air inlet channel is communicated with the deposition chamber through the overflow gap; The gas inlets comprise a first gas inlet, a second gas inlet and a third gas inlet, and the first gas inlet, the second gas inlet and the third gas inlet are respectively communicated with the first air inlet channel, the second air inlet channel and the third air inlet channel in one-to-one correspondence.
7. The in situ coherent X-ray characterization apparatus for group III nitride growth of claim 6, further comprising: The optical imaging device is arranged at the top end of the spraying device and comprises an optical shell, a dichroic mirror, a beam blocker, a short-wave pass filter and an optical pyrometer, a conduction space is formed in the optical shell, and the beam blocker, the dichroic mirror and the short-wave pass filter are arranged in the conduction space and are communicated with the first air inlet channel through a radiation inlet; The dichroic mirror is located above the radiation inlet and is arranged at a preset included angle compared with the radiation inlet, the beam blocker is arranged opposite to the dichroic mirror and used for blocking blackbody radiation transmitted by the dichroic mirror, the short-wave pass filter is arranged opposite to the dichroic mirror and used for filtering blackbody radiation reflected by the dichroic mirror, and a filtering outlet of the short-wave pass filter faces to the optical pyrometer.
8. An in situ coherent X-ray characterization apparatus for group III nitride growth according to claim 7, wherein the optical pyrometer and the heat radiation source are each connected to a controller for receiving a detection result of the optical pyrometer and adjusting an operating parameter of the heat radiation source according to the detection result.
9. The in situ coherent X-ray characterization apparatus for group III nitride growth of any one of claims 1 to 8, wherein the spray device is sealingly connected to the reaction device by a first connection flange, the reaction device is sealingly connected to the base by a second connection flange, and a cooling conduit for conveying a cooling fluid is provided within at least one of the first connection flange and the second connection flange.
10. The in situ coherent X-ray characterization apparatus for ill-nitride growth according to any one of claims 1 to 8, wherein an entrance 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; Wherein the angle of the entrance window relative to the X-ray radiation source is adjustable and/or the angle of the scattering window relative to the X-ray detector is adjustable.
11. The in situ coherent X-ray characterization apparatus for group III nitride growth of any one of claims 1 to 8, further comprising: The positioning mechanism comprises a substrate, a positioning base, a reaction positioning device and a detector positioning device, wherein the positioning base is rotatably arranged on the substrate; The reaction positioning device is a hexapod platform, the hexapod platform comprises a first platform, a second platform and six telescopic supporting legs positioned between the first platform and the second platform, the base is arranged on the first platform, and the second platform is rotatably arranged on the positioning base; the X-ray detector is arranged on a detector positioning device, and the detector positioning device is rotatably arranged on the positioning base.
12. The in situ coherent X-ray characterization apparatus for ill-nitride growth according to claim 11, wherein said detector positioning apparatus comprises a first bracket having a first slider extending in an up-down direction, a sliding engagement member having a second slider extending in a left-right direction, and a second bracket having a second slider extending in a left-right direction, said sliding engagement member slidably engaging with said first slider and said second slider, respectively, said X-ray detector being mounted on said second bracket.
13. The in situ coherent X-ray characterization apparatus for group III nitride growth of claim 11, wherein the base is removably mounted on the positioning mechanism via a dedicated engagement structure to allow for quick and easy mounting and dismounting of the reaction apparatus relative to the X-ray apparatus, and to enable sharing of the same X-ray apparatus with other types of reaction apparatus to increase efficiency of use.

Description

In-situ coherent X-ray characterization device for III-nitride growth Technical Field The invention relates to the technical field of semiconductors, in particular to an in-situ coherent X-ray characterization device for III nitride growth. Background Group III nitride semiconductors are key materials for the fabrication of high brightness LEDs, lasers, high frequency high power electronics, and deep ultraviolet optoelectronic devices, whose performance is highly dependent on the crystal quality, interface abruptness, and strain control level of the epitaxial thin film, which are determined by atomic scale dynamics during metal organic vapor phase epitaxy (MOCVD). In order to understand the transient processes of surface step flow, two-dimensional nucleation, island coalescence, dislocation motion, strain relaxation, etc., in depth, development of technical means capable of in-situ, real-time, non-destructive observation under real growth conditions is needed. Synchrotron radiation X-ray technology is considered an ideal tool for studying the mechanism of epitaxial growth because of its nanoscale spatial resolution, sub-second time resolution, and high sensitivity to crystal defects and surface fluctuations. However, successful application of such techniques to MOCVD environments presents multiple serious challenges. First, conventional MOCVD reactor chambers have fundamental conflict with X-ray penetration requirements. The prior commercial MOCVD equipment commonly adopts a closed cavity made of stainless steel or thick-wall quartz to bear high temperature, high pressure and corrosive atmosphere. However, the metal material has extremely strong absorption to high-energy X-rays, and common quartz is easy to corrode or devitrify under the long-term high-temperature NH 3 environment, so that the transmittance is rapidly attenuated. In addition, most of cavity windows are fixed in angle, the incident and scattering geometry cannot be adjusted, the detection capability of different areas of the reciprocal space is severely limited, and the requirement of Coherent Diffraction Imaging (CDI) or XPCS on large-solid-angle scattering signals is difficult to meet. Second, sample position stability at high temperatures is difficult to meet coherent measurement requirements. Coherent X-ray techniques are extremely sensitive to the positional stability of the sample relative to the incident beam, often requiring drift control on the sub-micron or even nanometer scale. However, conventional MOCVD systems mostly employ a circumferential resistive heating or hot wall design, which causes the entire cavity structure to expand by heating, and the sample is displaced by several micrometers to tens of micrometers during the temperature rising process. This thermal drift not only de-correlates the speckle pattern, but also renders the long-term observations unreliable, essentially preventing XPCS from quantitatively analyzing the surface dynamics. Thirdly, the multicomponent precursor delivery mode is prone to pre-reaction and window contamination. The group III organometallic source and ammonia are extremely susceptible to thermal decomposition or pre-reaction in the gas phase to produce nanoparticles. If a single-channel mixed spray head is adopted, the gas can react before entering a deposition area, so that the purity of the film is reduced, the film can be deposited on an X-ray window, and the transmittance is continuously reduced. Meanwhile, the traditional exhaust structure often needs to introduce an additional pipeline, so that an X-ray path is easily blocked, and the signal to noise ratio is further reduced. Finally, flexible X-ray geometry adjustment mechanisms are lacking. In-situ CVD devices which are rarely tried to integrate X-rays are mostly adopting fixed incidence/detection angles, and only limited information in the reciprocal space can be obtained. The crystal growth involves the evolution of a surface, an interface, an equal multi-scale structure, and the crystal growth needs to be cooperatively characterized by various geometric configurations such as grazing incidence, transmission, high-angle reflection and the like. The inability of fixed geometry designs to accommodate this requirement results in the difficulty of efficient capture of critical physical processes. In summary, the prior art has not provided an integrated device that can meet the severe process conditions of group III nitride MOCVD and is compatible with high-sensitivity coherent X-ray in-situ characterization. The technical blank severely restricts the deep understanding of the microscopic mechanism of semiconductor epitaxial growth and also prevents rational design and process optimization of high-performance devices. Disclosure of Invention The invention provides an in-situ coherent X-ray characterization device for the vapor phase epitaxy growth of a group III nitride metal, which is used for solving the defects existing in the prior a