An in-situ optical microscopic imaging high temperature growth system

Abstract

The present application relates to a kind of in-situ optical microscopic imaging high temperature growth system, the system includes: high temperature growth furnace, high temperature microscopic objective lens built in the high temperature growth furnace, very narrow single-wavelength incoherent light source and observation device.Therein, high temperature microscopic objective lens built in the high temperature growth furnace uses high-temperature-resistant material, need not cooling to work normally under high temperature environment;The single-wavelength characteristic of very narrow single-wavelength incoherent light source avoids chromatic aberration, can be close to diffraction limit to imaging resolution, and the incoherence of very narrow single-wavelength incoherent light source can avoid shot noise, to obtain clear imaging picture, so that the system can realize 20-1200 ℃ high temperature under the in-situ optical microscopic imaging of material growth process, to obtain the nucleation rate of material growth process, growth rate, material morphology and structure etc.Experimental data, it has extremely important significance to material high temperature growth research.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of in-situ optical microscopic imaging technology, and particularly relates to an in-situ optical microscopic imaging high-temperature growth system. BACKGROUND

[0002] At present, a high-temperature growth furnace is a commonly used material growth equipment. The in-situ optical microscopic imaging technology is used to observe the material growth process, so that the nucleation rate, growth rate, and the morphology and structure of the material can be directly obtained. However, the prior art cannot realize the in-situ microscopic optical imaging of the material growth process at a high temperature of 20-1200℃, and the key technical difficulties are as follows:

[0003] (1) In the existing objective lens, a plurality of optical lenses made of different materials are used. When heated, the thermal expansion coefficients of different lenses and the lens barrel materials are different, which leads to lens displacement under slight heating and cannot form an image. At a higher temperature, the lenses are broken due to thermal expansion and extrusion, and cannot form an image.

[0004] (2) The glass material (such as BK7) used in the optical lens of the existing objective lens has a very low glass transition temperature, and cannot withstand a high temperature of 500℃ or above.

[0005] (3) The existing objective lens is composed of a plurality of lenses. In order to improve the light transmittance, an optical anti-reflection film is needed. The optical anti-reflection film is a multilayer dielectric film. The thermal expansion coefficients of these dielectric film materials (commonly MgF2, SiO2, etc.) are different, and the high-temperature resistance performance of the dielectric film is limited. Under the heating condition, the film is broken or even melted, the light transmittance is reduced, and the imaging cannot be formed.

[0006] (4) The lens barrel material of the objective lens uses Cu and other materials. Cu is oxidized by air at a temperature of 200℃ or above. At a higher temperature, Cu is softened or even melted, which causes the objective lens to fail to work normally.

[0007] (5) The observation system at a high temperature emits very strong blackbody radiation background light, which makes the existing microscopic optical imaging technology (using wide-spectrum imaging) unable to form an image.

[0008] Therefore, it is particularly important to realize the in-situ optical microscopic imaging of the material growth in the high-temperature growth furnace. CN1721586A discloses a melt crystal real-time observation system. The real-time observation system innovatively combines the microscopic real-time observation method of optical interference and Schliren, and can simultaneously observe the interface dynamics process and the melt flow process. However, the real-time observation system uses the existing optical microscopic system, which can only be placed in a room temperature environment outside the growth furnace, and therefore cannot realize the in-situ optical microscopic imaging of the growth process.

[0009] Therefore, it is very important to realize in-situ optical microscopic imaging of material growth in a high-temperature growth furnace, but there are great challenges. SUMMARY

[0010] The application provides an in-situ optical microscopic imaging high-temperature growth system, which comprises a high-temperature growth furnace, a high-temperature microscopic objective lens built in the high-temperature growth furnace, an extremely narrow single-wavelength incoherent light source and an observation device, and can realize in-situ optical microscopic imaging of material growth under a high-temperature environment (20-1200 DEG C), thereby directly obtaining in-situ experimental data of nucleation rate, growth rate, growth morphology and structure of the material, and having extremely important significance for material high-temperature growth research.

[0011] To achieve the above object, the application adopts the following technical scheme:

[0012] The application aims to provide an in-situ optical microscopic imaging high-temperature growth system, which comprises:

[0013] The high-temperature growth furnace provides a temperature environment of 20-1200 DEG C for a sample and maintains stable temperature;

[0014] The high-temperature microscopic objective lens built in the high-temperature growth furnace is used for focusing incident light on the sample in the high-temperature growth furnace and collecting sample reflected light;

[0015] The extremely narrow single-wavelength incoherent light source has a laser spectral line width of less than or equal to 1 nm, and provides the incident light for in-situ optical microscopic imaging;

[0016] The observation device is used for processing and analyzing the sample reflected light collected by the high-temperature microscopic objective lens.

[0017] In the system, the high-temperature microscopic objective lens built in the high-temperature growth furnace is made of high-temperature resistant material and can work normally under a high-temperature environment without cooling; the single-wavelength characteristic of the extremely narrow single-wavelength incoherent light source avoids chromatic aberration, and the incoherent nature of the extremely narrow single-wavelength incoherent light source avoids shot noise, thereby obtaining a clear imaging picture, so that the system can realize in-situ optical microscopic imaging of material growth process under a high temperature of 20-1200 DEG C, thereby directly obtaining experimental data of nucleation rate, growth rate, material morphology and structure of the material growth process, and having extremely important significance for material high-temperature growth research.

[0018] The temperature environment of the high-temperature growth furnace is preferably 200-1200 DEG C, for example, 200 DEG C, 400 DEG C, 500 DEG C, 600 DEG C, 800 DEG C, 900 DEG C, 1000 DEG C or 1200 DEG C, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0019] As a preferred technical solution of the present application, the high-temperature growth furnace is provided with an observation hole, the high-temperature microscopic objective lens extends into the observation hole and is located directly above the sample, so that the incident light of the extremely narrow single-wavelength incoherent light source can pass through the observation hole and be focused on the sample in the high-temperature growth furnace through the high-temperature microscopic objective lens, and the sample reflected light can be collected by the high-temperature microscopic objective lens and pass through the observation hole into the observation device.

[0020] As a preferred technical solution of the present application, the magnification of the high-temperature microscopic objective lens is 2-50X, for example, 2X, 5X, 10X, 20X, 30X, 40X or 50X, etc., but not limited to the listed values, and other values not listed in this range are also applicable.

[0021] As a preferred technical solution of the present application, the numerical aperture of the high-temperature microscopic objective lens is 0.2-0.9, for example, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9, etc., but not limited to the listed values, and other values not listed in this range are also applicable.

[0022] As a preferred technical solution of the present application, the working distance of the high-temperature microscopic objective lens is >10mm, for example, 15mm, 16mm, 17mm, 18mm, 19mm or 20mm, etc., but not limited to the listed values, and other values not listed in this range are also applicable.

[0023] The three basic parameters of magnification, numerical aperture and working distance of the high-temperature microscopic objective lens mentioned in the present application are designed based on the growth of conventional materials at high temperature, and basically meet the related requirements of in-situ optical observation and spectral measurement of the growth state, morphology and structure of materials at high temperature.

[0024] As a preferred technical solution of the present application, the material of the lens in the high-temperature microscopic objective lens is fused quartz, and the material of the lens barrel is high-temperature resistant alloy and / or high-temperature resistant ceramic.

[0025] As a preferred technical solution of the present application, the high-temperature resistant alloy includes 310S stainless steel and / or 253MA stainless steel.

[0026] Preferably, the high-temperature resistant ceramic includes zirconia ceramic.

[0027] The fused quartz, the high-temperature-resistant alloy and the high-temperature-resistant ceramic meet the working temperature requirement of 20-1200 DEG C, and do not need refrigeration. The fused quartz is prepared by melting natural high-purity silicon dioxide in an electric furnace at a temperature higher than 1760 DEG C, and then rapidly cooling, which converts the crystalline silicon dioxide into an amorphous glass melt. The melting temperature of the fused quartz is about 1713 DEG C, the thermal conductivity coefficient is low, and the thermal expansion coefficient is almost the smallest among all refractory materials, so the fused quartz has extremely high thermal shock stability. Moreover, the melting points of the high-temperature-resistant alloy and the high-temperature-resistant ceramic are both greater than 1300 DEG C.

[0028] As a preferred technical scheme of the present application, the central wavelength of the extremely narrow single-wavelength incoherent light source is 400-800 nm, for example, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm or 800 nm, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0029] It is worth noting that the laser spectral line width of the extremely narrow single-wavelength incoherent light source is ≤1 nm, and the central wavelength is 400-800 nm, which can be obtained in the following three ways: (1) performing light splitting treatment on a wide-spectrum incoherent light source; (2) passing a laser beam through a de-coherence module; and (3) using a random laser light source emitted by a random laser. The de-coherence module in the way (2) includes a nanoparticle scattering de-coherence module and / or a mechanical motion de-coherence module.

[0030] As a preferred technical scheme of the present application, the observation device includes a filter set, a lens set and an imaging camera.

[0031] It is worth noting that the filter set is mainly arranged in front of the lens of the imaging camera to suppress the thermal radiation background and stray light background, etc. Moreover, in order to ensure the propagation of the incident light and the sample reflected light on the optical path, a mirror for adjusting the optical path angle, a first focusing lens and a light splitting plate are arranged on the optical path between the high-temperature microscopic objective and the extremely narrow single-wavelength incoherent light source. After adjusting the optical path angle by the light splitting plate, the light will pass through a filter, a second focusing lens in sequence and finally enter the imaging camera on the optical path between the high-temperature microscopic objective and the observation device.

[0032] As a preferred technical scheme of the present application, the system includes:

[0033] The high-temperature growth furnace provides a temperature environment of 20-1200 DEG C for the sample and maintains the temperature stability;

[0034] The high-temperature microscopic objective arranged in the high-temperature growth furnace is used for focusing the incident light on the sample in the high-temperature growth furnace and collecting the sample reflected light.

[0035] a very narrow single-wavelength incoherent light source with a laser spectral line width ≤ 1 nm, which provides the incident light for in-situ optical microscopic imaging;

[0036] an observation device for processing and analyzing the sample reflected light collected by the high-temperature microscopic objective;

[0037] The high-temperature growth furnace is provided with an observation hole, and the high-temperature microscopic objective extends into the observation hole and is located directly above the sample. The magnification of the high-temperature microscopic objective is 2-50X, the numerical aperture is 0.2-0.9, and the working distance is > 10 mm. The material of the lens in the high-temperature microscopic objective is fused quartz, and the material of the lens barrel is high-temperature-resistant alloy and / or high-temperature-resistant ceramic. The center wavelength of the very narrow single-wavelength incoherent light source is 400-800 nm. The observation device includes a filter group, a lens group, and an imaging camera.

[0038] The test method of the system of the present application comprises the following steps:

[0039] (1) Place the sample in the high-temperature growth furnace, keep the sample surface horizontal, and keep the set temperature stable;

[0040] (2) The incident light emitted from the very narrow single-wavelength incoherent light source passes through the light path system, enters the high-temperature microscopic objective built in the high-temperature growth furnace through the observation hole opened on the high-temperature growth furnace, and the high-temperature microscopic objective focuses the incident light on the sample and generates sample reflected light;

[0041] (3) The sample reflected light on the sample in step (2) is collected by the high-temperature microscopic objective and enters the observation device for observation.

[0042] Compared with the prior art, the present application has at least the following beneficial effects:

[0043] (1) The system of the present application can efficiently, accurately and directly observe the growth state, morphology and structure of materials at high temperatures of 20-1200℃ in-situ under optical observation;

[0044] (2) The system of the present application can study material growth at high temperatures, such as two-dimensional material growth, nanometer film growth, fiber material growth, and can realize carbon nanotube growth observation by combining with other imaging technologies;

[0045] (3) The built-in high-temperature microscopic objective in the system of the present application adopts high-temperature-resistant materials and will not be deformed or damaged at high temperatures, and can work normally in a high-temperature environment without cooling;

[0046] (4) The system of the present application utilizes the single wavelength characteristic of the extremely narrow single wavelength incoherent light source to avoid chromatic aberration, and can approach the diffraction limit in imaging resolution, and the incoherence of the extremely narrow single wavelength incoherent light source can avoid shot noise, thereby obtaining a clear imaging picture. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 is a schematic diagram of the in-situ optical microscopic imaging high-temperature growth system of the present application;

[0048] Figure 2 is an observation picture of the sample of application example 1 of the present application;

[0049] Figure 3 is an observation picture of the sample of application example 2 of the present application;

[0050] In the figure, 1 is a laser illumination light source; 2 is a de-coherence module; 3 is a reflecting mirror; 4 is a first focusing lens; 5 is a light splitting plate; 6 is a high-temperature microscopic objective; 7 is a sample; 8 is a filter; 9 is a second focusing lens; 10 is an imaging camera; and 11 is a high-temperature growth furnace. DETAILED DESCRIPTION

[0051] The technical solutions of the present application will be further described below in combination with the drawings and through specific embodiments. Those skilled in the art should understand that the embodiments are only to help understand the present application and should not be regarded as specific limitations of the present application.

[0052] The following are typical but non-limiting embodiments of the present application:

[0053] Embodiment 1

[0054] This embodiment provides an in-situ optical microscopic imaging high-temperature growth system, as shown in Figure 1 The straight-line connecting part represents the optical path, and the system comprises:

[0055] A high-temperature growth furnace 11 provides a temperature environment of 20-1200℃ for the sample 7 and maintains the temperature stable;

[0056] A high-temperature microscopic objective 6 built-in in the high-temperature growth furnace 11 is used to focus the incident light on the sample 7 in the high-temperature growth furnace 11 and collect the sample reflected light;

[0057] An extremely narrow single-wavelength incoherent light source with a laser spectral line width of 1 nm and a central wavelength of 488 nm, the incident light is provided for in-situ optical microscopic imaging, the laser beam emitted by the laser illumination light source 1 is processed by the de-coherence module 2 to obtain the extremely narrow single-wavelength incoherent light source, the de-coherence module uses a water solution of cerium dioxide nanoparticles with a particle size of 50 nm, and the concentration is controlled to be 1.2 wt.%, which is used to eliminate the shot noise in laser imaging;

[0058] An observation device for processing and analyzing the sample reflected light collected by the high-temperature microscopic objective 6;

[0059] The high-temperature growth furnace 11 is provided with an observation hole, and the high-temperature microscopic objective 6 extends into the observation hole and is located directly above the sample 7; the magnification of the high-temperature microscopic objective 6 is 50X, the numerical aperture is 0.4, and the working distance is 15 mm; the material of the lens in the high-temperature microscopic objective 6 is fused quartz, and the material of the lens barrel is 310S stainless steel; the observation device includes a filter group, a lens group and an imaging camera 10, the laser beam from the laser illumination light source 1 is first adjusted by the mirror 3 after passing through the de-coherence module 2, then converges through the first focusing lens 4, then enters the high-temperature growth furnace 11 through the light splitting plate 5 and irradiates on the sample 7, and the sample reflected light is first adjusted by the light splitting plate 5 after passing through the observation hole on the high-temperature growth furnace 11, then sequentially passes through the filter 8 and the second focusing lens 9, and finally enters the imaging camera 10.

[0060] Application Example 1

[0061] In this application example, the system described in Example 1 is used to perform high-temperature in-situ optical microscopic imaging on an aluminum film sample with scratches, wherein a quartz piece coated with an aluminum film with a thickness of 100 nm is used as the aluminum film sample with scratches to be observed, and the scratches are made on the aluminum film using tweezers. The specific steps include the following:

[0062] (1) Put the aluminum film sample with scratches into the high-temperature growth furnace, and keep the surface of the aluminum film sample with scratches horizontal;

[0063] (2) The incident light from the laser light source is processed by the de-coherence module to obtain an extremely narrow single-wavelength incoherent light source, and the incident light passing through the observation hole on the high-temperature growth furnace enters the high-temperature microscopic objective built in the high-temperature growth furnace, and the high-temperature microscopic objective focuses the incident light on the sample to excite the sample reflected light;

[0064] (3) The sample reflected light on the sample in step (2) is collected by the high-temperature microscopic objective and enters the observation device for observation;

[0065] The temperature rising procedure of the high-temperature growth furnace is as follows: 20 min from normal temperature to 550 DEG C, 10 min from 550 DEG C to 590 DEG C, 30 min from 590 DEG C to 620 DEG C, starting the high-temperature growth furnace to heat, and observing the change of the aluminum film sample with scratches in the temperature rising process. Figure 2 The pictures of the aluminum film sample with scratches at room temperature (a), 600 DEG C (b) and 602 DEG C (c) are shown in the following figure. Figure 2 It can be seen that the aluminum film sample with scratches starts to melt near 602 DEG C.

[0066] Embodiment 2

[0067] The embodiment provides a high-temperature growth system for in-situ optical microscopic imaging, wherein, in addition to replacing the de-coherence module by the nanoparticle scattering de-coherence module with the mechanical motion de-coherence module, the mechanical rotation module adopts a scattering sheet with a thickness of 1 mm and a rotation speed of 300 rpm, and other conditions are completely same as those in embodiment 1.

[0068] Application Example 2

[0069] The application example adopts the system in embodiment 2 to perform high-temperature in-situ optical microscopic imaging on a gold film sample with scratches, wherein, a quartz sheet plated with a gold film with a thickness of 100 nm is taken, a scratch is drawn on the gold film by using a forceps as a sample with scratches to be observed, and the specific steps include the following steps.

[0070] (1) the gold film sample with scratches is placed into the high-temperature growth furnace, so that the surface of the gold film sample with scratches is kept horizontal;

[0071] (2) the incident light emitted from the laser light source passes through the de-coherence module to obtain an extremely narrow single-wavelength incoherent light source, the incident light passing through the observation hole arranged on the high-temperature growth furnace enters the high-temperature microscopic objective lens arranged in the high-temperature growth furnace, and the high-temperature microscopic objective lens focuses the incident light on the sample to excite sample reflection light;

[0072] (3) the sample reflection light on the sample in step (2) is collected by the high-temperature microscopic objective lens and enters the observation device to be observed;

[0073] The temperature rising procedure of the high-temperature growth furnace is as follows: 40 min from normal temperature to 950 DEG C, 10 min from 950 DEG C to 990 DEG C, 30 min from 990 DEG C to 1020 DEG C, starting the high-temperature growth furnace to heat, and observing the change of the gold film sample with scratches in the temperature rising process. Figure 3 The pictures of the gold film sample with scratches at room temperature (a), 950 DEG C (b), 990 DEG C (c) and 1002 DEG C (d) are shown in the following figure. Figure 3It can be seen that the gold film sample with scratches starts to melt in part of the area near 950℃, and almost completely melts near 1002℃.

[0074] In summary, in the system of the present application, the high-temperature microscope objective lens built in the high-temperature growth furnace is made of high-temperature resistant material and can work normally at high temperature without cooling; the single-wavelength characteristic of the extremely narrow single-wavelength incoherent light source avoids chromatic aberration, and the incoherence of the extremely narrow single-wavelength incoherent light source can avoid shot noise, thereby obtaining a clear imaging picture, so that the system can realize in-situ optical microscopic imaging of the material growth process at 20-1200℃, thereby directly obtaining experimental data such as nucleation rate, growth rate, material morphology and structure of the material growth process, which has extremely important significance for the study of material high-temperature growth.

[0075] The applicant declares that the present application is illustrated by the above-mentioned embodiments to show the detailed structural features of the present application, but the present application is not limited to the above-mentioned detailed structural features, i.e. it does not mean that the present application must rely on the above-mentioned detailed structural features to be implemented. It should be understood by those skilled in the art that any improvement of the present application, equivalent replacement of the components selected by the present application, addition of auxiliary components, selection of specific modes, etc. fall within the protection scope and disclosure scope of the present application.

[0076] The preferred embodiments of the present application are described in detail above, but the present application is not limited to the specific details in the above-mentioned embodiments, and various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application.

[0077] In addition, it should be noted that each specific technical feature described in the above-mentioned specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present application will not further describe various possible combination manners.

[0078] In addition, various different embodiments of the present application can also be combined in any manner, as long as it does not deviate from the idea of the present application, and it should be considered as disclosed by the present application.

Claims

1. An in-situ optical microscopic imaging high temperature growth system, comprising: The system comprises: a high-temperature growth furnace providing a temperature environment of 200-1200℃ for a sample and maintaining the temperature stable; a high-temperature microscopic objective lens built in the high-temperature growth furnace, used for focusing incident light on the sample in the high-temperature growth furnace and collecting sample reflected light; the sample reflected light is used for microscopic imaging of the sample surface; the magnification of the high-temperature microscopic objective lens is 5-50X; the working distance of the high-temperature microscopic objective lens is >10mm; the material of the lens in the high-temperature microscopic objective lens is fused quartz, and the material of the lens barrel is high-temperature-resistant alloy and / or high-temperature-resistant ceramic; the numerical aperture of the high-temperature microscopic objective lens is 0.2-0.9; the high-temperature growth furnace is provided with an observation hole, and the high-temperature microscopic objective lens extends into the observation hole and is located directly above the sample; an extremely narrow single-wavelength incoherent light source, the spectral line width of the extremely narrow single-wavelength incoherent light source is ≤1nm, and the incident light is provided for in-situ optical microscopic imaging; the central wavelength of the extremely narrow single-wavelength incoherent light source is 400-800nm; the method for obtaining the extremely narrow single-wavelength incoherent light source comprises: processing a laser beam through a de-coherence module; the de-coherence module uses a water solution of cerium dioxide nanoparticles with a particle size of 50nm, and controls the concentration thereof to be 1.2wt.% for eliminating shot noise in laser imaging; an observation device used for processing and analyzing the sample reflected light collected by the high-temperature microscopic objective lens.

2. The system of claim 1, wherein, The magnification of the high-temperature microscopic objective lens is 10-50X.

3. The system of claim 1, wherein, The high-temperature-resistant alloy comprises 310S stainless steel and / or 253MA stainless steel.

4. The system of claim 1, wherein, The high-temperature-resistant ceramic comprises zirconia ceramic.

5. The system of claim 1, wherein, The observation device comprises a filter set, a lens set and an imaging camera; the optical path of the observation device is as follows: after the laser beam from the laser illumination light source passes through the de-coherence module, the laser beam is first adjusted in the optical path by a mirror, then converges through a first focusing lens, and then enters the high-temperature growth furnace through a light splitting plate and irradiates on the sample; after the sample reflected light passes through the observation hole on the high-temperature growth furnace, the sample reflected light is first adjusted in the optical path angle by the light splitting plate, then passes through a filter and a second focusing lens in sequence, and finally enters the imaging camera.

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