Crystallization method of amorphous nano-film

Abstract

The invention provides a crystallization method of an amorphous nano-film, which comprises the following steps of: depositing the amorphous nano-film in a reaction cavity by adopting an atomic layer deposition method, performing high-energy laser annealing treatment on the surface of the amorphous nano-film, and converting the amorphous state in the amorphous nano-film into a crystalline state to prepare a crystalline nano-film. According to the method disclosed by the invention, controllable preparation of a crystalline functional film is realized by introducing laser annealing treatment after ALD deposition, a crystallization method of the amorphous nano film is constructed, the problems of poor crystallinity and limited performance after ALD film formation can be effectively solved, and a reliable, efficient and controllable film preparation scheme is provided for a next-generation high-performance device.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor technology and relates to amorphous nanofilms, specifically to a method for crystallizing amorphous nanofilms. Background Technology

[0002] With the rapid development of nanotechnology and advanced manufacturing technology, nanofilm materials have become core components in many cutting-edge fields such as semiconductor devices, micro-nano optoelectronic systems, flexible electronics, sensors, bio-interface materials, and energy conversion and storage. Because their structural dimensions are within the nanoscale, nanofilms exhibit significantly superior physical, electrical, optical, and mechanical properties compared to bulk materials, playing a crucial role in improving device performance, integration density, and reducing energy consumption.

[0003] In the fabrication of modern micro and nano devices, more stringent requirements are placed on thin film materials, encompassing not only controllable thickness, uniform composition, and density, but also surface roughness, interface quality, crystallinity, carrier mobility, defect density, stress state, and process compatibility. Especially in ultrathin nanostructures (such as functional layers less than 10 nanometers thick), minute defects or structural disorder can significantly impact the overall device performance. Therefore, achieving controllable fabrication of high-quality nanofilms at low temperatures, with high precision and high consistency has become a key challenge in current materials preparation technologies. Atomic layer deposition (ALD) is a thin film deposition technique based on a surface self-limiting reaction mechanism. Its greatest advantage lies in its ability to achieve atomic-level thickness control and extremely high surface consistency through layer-by-layer reactions of gaseous molecules on the material surface. Compared to traditional physical vapor deposition (PVD) or chemical vapor deposition (CVD), ALD is more suitable for fabricating ultrathin functional films with uniform thickness, high film quality, and excellent coverage, especially for devices with high aspect ratios and complex three-dimensional structures.

[0004] However, conventional ALD technology is mostly performed at relatively low temperatures (typically 100°C to 300°C). While this is beneficial for process compatibility and flexible substrate applications, it also introduces significant problems: the deposited films often exhibit amorphous or low-crystallinity structures, which limits key properties such as electrical transport, optical response, and thermal stability, making it difficult to meet the material quality requirements of high-performance devices. To improve film performance, ALD processes are usually combined with thermal annealing to enhance the crystallinity and interface quality of the films.

[0005] However, traditional thermal annealing methods, such as furnace annealing or rapid thermal annealing (RTA), have many shortcomings: on the one hand, the annealing temperature is usually high (500℃ to 1100℃), which is incompatible with flexible substrates, low-melting-point materials, or multilayer heterogeneous structures; on the other hand, traditional heat treatment methods involve overall heating, which is slow, has significant heat diffusion, and is prone to introducing stress, defects, and even film peeling. In addition, high thermal inertia leads to high energy consumption and low efficiency, which cannot meet the development requirements of next-generation green and efficient manufacturing technologies. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a method for crystallizing amorphous nanofilms, thereby solving the technical problem that atomic layer deposition (ALD) methods in the prior art cannot prepare high-quality nanocrystalline films.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A method for crystallizing amorphous nanofilms is disclosed. The method first uses atomic layer deposition to deposit amorphous nanofilms in a reaction chamber, and then performs high-energy laser annealing on the surface of the amorphous nanofilms to transform the amorphous amorphous state in the amorphous nanofilms into a crystalline state, thereby obtaining crystalline nanofilms.

[0008] The present invention also has the following technical features: Preferably, the high-energy laser annealing process is performed within the reaction chamber of the atomic layer deposition method, and the amorphous nanofilm does not transfer.

[0009] Preferably, the amorphous nanofilm is isolated from air before the high-energy laser annealing treatment.

[0010] Preferably, the high-energy laser annealing process takes 5 to 50 seconds.

[0011] Preferably, the center wavelength of the high-energy laser is 800nm ​​and the output power is set to 500W.

[0012] Specifically, the materials of the nanofilm include oxides, nitrides, or elemental metals.

[0013] Preferably, the material of the nanofilm is gallium oxide.

[0014] Preferably, the reaction temperature of the atomic layer deposition method is 100℃~300℃.

[0015] Specifically, the substrate for growing nanofilms in the atomic layer deposition method includes single-crystal silicon wafers or sapphire.

[0016] Preferably, the single-crystal silicon wafer is a p-type silicon substrate.

[0017] Furthermore, this method employs a disk-type laser-enhanced atomic layer deposition reactor.

[0018] The disc-type laser-enhanced atomic layer deposition reactor includes an atomic layer deposition reactor body and a laser; the atomic layer deposition reactor body includes a sample chamber, a sample chamber cover is installed on the top of the sample chamber, a gate valve is installed on the top of the sample chamber cover, and a gate valve vacuum flange interface is provided on the top of the gate valve; a laser high-transparency window assembly is installed on the gate valve vacuum flange interface.

[0019] The laser high-transparency window assembly includes a double-layer vacuum upper flange interface, a sealing gasket, a high-transparency window sheet, and a double-layer vacuum lower flange interface arranged coaxially from top to bottom vertically; the double-layer vacuum upper flange interface and the double-layer vacuum lower flange interface are installed on the vacuum flange interface of the slide valve via sealing studs.

[0020] The laser light generated by the laser enters the sample chamber through a high-transparency window and a gate valve.

[0021] Specifically, the laser includes a laser generating and output system, a laser positioning system, and a laser shaping system connected in sequence, with a red guide light module provided on the laser shaping system.

[0022] Compared with the prior art, the present invention has the following technical effects: (I) The method of the present invention achieves controllable preparation of crystalline functional thin films by introducing laser annealing treatment after ALD deposition, and constructs a crystallization method for amorphous nanofilms. This method can effectively solve the problems of poor crystallinity and limited performance after ALD film formation, and provide a reliable, efficient and controllable thin film preparation scheme for next-generation high-performance devices.

[0023] (II) The method of this invention uses atomic layer deposition to prepare functional material thin films with controllable thickness, and then uses laser annealing technology to crystallize them, thereby realizing the transformation from amorphous to crystalline nanofilms. This invention can prepare high-performance ultrathin nanofilms on various substrate surfaces. The preparation method is efficient and controllable, and can be applied in the field of high-precision semiconductors. Attached Figure Description

[0024] Figure 1 This is a scanning electron microscope image of the surface of the amorphous nanofilm in Example 1.

[0025] Figure 2 This is a scanning electron microscope image of the surface of the crystalline nanofilm of Example 1.

[0026] Figure 3 This is a schematic diagram of the overall structure of the disc-type laser-enhanced atomic layer deposition reactor of the present invention.

[0027] Figure 4This is a schematic diagram of the structure of a laser high-transparency window assembly.

[0028] The meanings of the labels in the figure are as follows: 1-Atomic layer deposition reactor body, 2-Laser, 3-Gate valve, 4-Gate valve vacuum flange interface, 5-Laser high-transparency window assembly.

[0029] 201-Laser generation and output system, 202-Laser positioning system, 203-Laser shaping system, 204-Red guide light module.

[0030] 501 - Double-layer vacuum upper flange interface with viewing window; 502 - Sealing gasket; 503 - High-transparency window; 504 - Double-layer vacuum lower flange interface with viewing window; 505 - Sealing stud.

[0031] The specific content of the present invention will be further explained in detail below with reference to the embodiments. Detailed Implementation

[0032] It should be noted that, unless otherwise specified, all raw materials, reagents, components and equipment used in this invention are known in the prior art and can be obtained commercially.

[0033] In response to the problems mentioned in the background technology, laser annealing technology has been widely used in the local heat treatment process of nanomaterials in recent years. This technology uses high-energy-density pulsed lasers to perform rapid, non-contact local heating treatment on materials in a very short time (nanosecond to microsecond level), which can effectively induce thin film structure reconstruction, grain growth, defect passivation and stress release, significantly improving the functional performance of thin films. Laser annealing has the following significant advantages: (1) Low thermal load: Only the surface layer of the material is heated, avoiding thermal damage to the underlying structure and substrate; (2) Rapid processing: Nanosecond-level energy coupling, short thermal process time; (3) Strong localization and selectivity: It can realize the treatment of specific areas and is suitable for the manufacturing of highly integrated devices; (4) Excellent process compatibility: It can be integrated with low-temperature deposition technology (such as ALD) to improve the overall material performance.

[0034] The amorphous nanofilms processed by the crystallization method of the present invention are suitable for applications in semiconductor devices, optoelectronic devices, sensors and energy storage devices where high requirements are placed on film structure and performance.

[0035] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0036] Example 1: This embodiment provides a method for crystallizing amorphous nanofilms, which includes the following steps: Step 1: After ultrasonic cleaning and drying, the p-type silicon substrate (Si(100)) is placed in an ALD reactor. The temperature is controlled at 300℃, the purge gas nitrogen flow rate is 100ml / min, the pressure inside the reactor is 1Torr, the precursor trimethylgallium (TMG) is cooled to -30℃ using a water chiller, and oxygen is reacted through an ozone generator to generate ozone with a gas flow rate of 80ml / min.

[0037] Step 2, ALD growth process of gallium oxide thin film. First, trimethylgallium is injected into the reaction chamber for 1 second, where it undergoes chemical adsorption with the functional groups on the Si surface. After the injection is stopped, nitrogen gas is purged for 10 seconds to remove excess trimethylgallium and products from the reaction chamber. Subsequently, ozone is continuously injected for 15 seconds, where it reacts chemically with the gallium-containing functional groups adsorbed on the substrate surface to generate gallium oxide. After the injection is stopped, nitrogen gas is purged for 10 seconds to remove excess ozone and products from the reaction chamber.

[0038] Repeat the above steps to complete 1000 cycles and obtain an amorphous nanofilm.

[0039] The thickness of the amorphous nanofilm was measured to be 52.47 nm using an ellipsometry, and the surface morphology of the sample was observed using a scanning electron microscope. Figure 1 As shown.

[0040] Step 3: Turn on the laser source. In this embodiment, a continuous-wave infrared laser with a center wavelength of 800nm ​​and an output power of 500W is selected. After being processed by a homogenizing system, the laser beam forms a uniform spot with a size of 2×2cm², without scanning movement, directly covering the entire sample area. The irradiation time is 20s. During laser irradiation, the sample naturally cools to room temperature after laser annealing, resulting in a crystalline nanofilm.

[0041] Scanning electron microscopy observation of sample surface morphology, such as Figure 2 As shown, from Figure 2 and Figure 1 Comparative analysis shows that, for example Figure 1 After the surface of the amorphous nanofilm shown is subjected to high-energy laser annealing, it will be as follows: Figure 1 The amorphous amorphous state in the amorphous nanofilm shown transforms into a crystalline state, thus obtaining a film as shown in the figure. Figure 2 The crystalline nanofilm shown.

[0042] Example 2: This embodiment provides a method for crystallizing amorphous nanofilms, which, based on Example 1, further employs a disk-type laser-enhanced atomic layer deposition reactor.

[0043] Disk-type laser-enhanced atomic layer deposition reactor, such as Figure 3 As shown, it includes an atomic layer deposition reactor body 1 and a laser 2; the atomic layer deposition reactor body 1 includes a sample chamber 101, a sample chamber cover 102 is installed on the top of the sample chamber 101, a gate valve 3 is installed on the top of the sample chamber cover 102, and a gate valve vacuum flange interface 4 is provided on the top of the gate valve 3; a laser high-transparency window assembly 5 is installed on the gate valve vacuum flange interface 4.

[0044] like Figure 4 As shown, the laser high-transparency window assembly 5 includes a double-layer vacuum upper flange interface 501, a sealing gasket 502, a high-transparency window 503, and a double-layer vacuum lower flange interface 504 arranged coaxially from top to bottom vertically; the double-layer vacuum upper flange interface 501 and the double-layer vacuum lower flange interface 504 are installed on the vacuum flange interface 4 of the slide valve through sealing studs 505.

[0045] like Figure 3 As shown, the laser generated by laser 2 enters the sample chamber 101 through the high-transparency window 503 and the insert valve 3.

[0046] In this embodiment, the atomic layer deposition reactor body 1 adopts an atomic layer deposition reactor body known in the art.

[0047] As a preferred embodiment of this invention, such as Figure 3 As shown, the high-transparency window 503 is coaxially arranged with the sample cavity 101.

[0048] As a preferred embodiment, the sealing gasket 502 is made of polytetrafluoroethylene.

[0049] In this embodiment, the high-transparency window 503 is made of a material with high transmittance and low absorptivity, the atomic layer deposition reaction pressure in the sample cavity 101 is 0-1000 Pa, and the laser high-transparency window assembly 5 has good vacuum sealing and mechanical strength.

[0050] In this embodiment, the sample chamber 101 is connected to the laser high-transparency window assembly 5 via the insert valve 3. During the ALD process without laser annealing, the insert valve 3 is closed to protect the high-transparency window 503. Conversely, the insert valve 3 is opened to allow the laser to enter the sample chamber 101 through the insert valve 3, which can effectively prevent vapor deposition from contaminating the high-transparency window 503.

[0051] As one specific solution in this embodiment, such as Figure 3As shown, laser 2 includes a laser generating and output system 201, a laser positioning system 202, and a laser shaping system 203 connected in sequence. A red guiding light module 204 is provided on the laser shaping system 203. In this embodiment, laser 2 uses a laser known in the art. The laser generating and output system 201, laser positioning system 202, laser shaping system 203, and red guiding light module 204 all employ laser generating and output systems, laser positioning systems, laser shaping systems, and red guiding light modules known in the art. The laser output from the laser shaping system 203 enters the sample chamber 101 through a high-transparency window 503 and a valve 3.

[0052] As a preferred embodiment, the maximum output power of the laser generating and output system 201 is 1000W, and the power output can be adjusted within the range of 10% to 100%.

[0053] As a preferred embodiment, the maximum travel of the laser positioning system 202 in the X, Y and Z axes is 80mm, 100mm and 300mm respectively.

[0054] In this embodiment, the laser itself is usually invisible. For safety and ease of operation, the laser has a built-in red guide light module 204 that directly outputs a visible red light spot to indicate the optical path or spot position of the high-power laser. This is used to calibrate the optical path and accurately locate the laser action point on the sample, effectively improving the safety and convenience of laser operation while reducing the risk of accidents.

[0055] In a preferred embodiment, the atomic layer deposition reactor body 1 supplies power to the laser generation and output system 201 via a 24V DC power supply from the ALD valve controller. Laser output / off status is controlled using known ALD control software, achieving in-situ coupling of laser annealing and atomic layer deposition.

[0056] In a preferred embodiment, the atomic layer deposition reactor body 1 supplies power to the circuitry of the gate valve 3 and the carrier gas path via a 24V DC power supply from the ALD valve controller. The gate valve 3 is automatically controlled by known ALD valve control software to drive the carrier gas, thus achieving automatic opening and closing control.

[0057] The implementation of the disc-type laser-enhanced atomic layer deposition reactor in this embodiment includes two laser enhancement modes: layer-by-layer laser annealing enhancement and laser-assisted deposition.

[0058] Layer-by-layer laser annealing enhancement includes: In the first step, the slide gate valve 3 is electrically opened, driving the carrier gas to close. With the slide gate valve 3 in the closed state, the laser generation and output system 201 is shut down, and the atomic layer deposition process is executed.

[0059] In the second step, the slide gate valve 3 is electrically opened, driving the carrier gas to open. The slide gate valve 3 is opened, the laser generation and output system 201 is turned on, and the laser enters the sample chamber 101 through the high-transparency window 503 and the slide gate valve 3 to perform laser in-situ annealing.

[0060] Third, the laser generation and output system 201 is turned off, the gate valve 3 is electrically opened, the driving carrier gas is turned off, and the gate valve 3 is closed; repeat the above steps to obtain a high-quality crystalline thin film with controllable thickness.

[0061] Laser-assisted deposition includes: The first step involves electrically opening the gate valve 3, driving the carrier gas to close, and placing the gate valve 3 in the closed state. The laser generation and output system 201 is then shut down, and the first reaction precursor is pulsed. After the pulse ends, a purging step is performed to remove the remaining precursor.

[0062] In the second step, the slide gate valve 3 is electrically opened, driving the carrier gas to open. The slide gate valve 3 is opened, the laser generation and output system 201 is turned on, and the laser enters the sample chamber 101 through the high-transparency window 503 and the slide gate valve 3, introducing the second type of reaction precursor.

[0063] The third step involves shutting down the laser generation and output system 201, electrically opening the gate valve 3, shutting down the drive carrier gas, closing the gate valve 3, and performing the purging step.

[0064] Repeat the above steps to obtain a high-quality crystalline thin film with controllable thickness.

[0065] The reactor of this invention deeply couples atomic layer deposition (ALD) system with laser annealing technology, providing hardware support for the precise preparation mode of "layer-by-layer deposition-layer-by-layer annealing" and the idea of ​​strengthening the surface reaction of laser-enhanced deposition. It can perform in-situ (non-transfer) layer-by-layer annealing during the atomic layer deposition process of thin films, effectively avoiding the introduction of impurities into the sample during sample transfer, thus avoiding the introduction of defects and achieving the preparation of high-quality crystalline thin films.

[0066] The reactor of this invention deeply couples laser enhancement with atomic layer deposition technology, has a high degree of automation, can be applied to the controllable deposition of high-quality crystalline nanofilms, and is easy to mass-produce.

Claims

1. A method for crystallizing amorphous nanofilms, wherein the method first employs atomic layer deposition to deposit an amorphous nanofilm in a reaction chamber, characterized in that, The surface of the amorphous nanofilm is then subjected to high-energy laser annealing to transform the amorphous amorphous state in the amorphous nanofilm into a crystalline state, thus obtaining a crystalline nanofilm.

2. The crystallization method for amorphous nanofilms as described in claim 1, characterized in that, The high-energy laser annealing process is carried out in the reaction chamber of the atomic layer deposition method, and the amorphous nanofilm does not transfer.

3. The crystallization method for amorphous nanofilms as described in claim 1, characterized in that, Before the high-energy laser annealing treatment, the amorphous nanofilm is isolated from the air.

4. The crystallization method for amorphous nanofilms as described in claim 1, characterized in that, The high-energy laser annealing process takes 5 to 50 seconds.

5. The crystallization method for amorphous nanofilms as described in claim 1, characterized in that, The high-energy laser has a center wavelength of 800nm ​​and an output power of 500W.

6. The crystallization method for amorphous nanofilms as described in claim 1, characterized in that, The materials of the nanofilm include oxides, nitrides, or elemental metals.

7. The crystallization method for amorphous nanofilms as described in claim 6, characterized in that, The material of the nanofilm is gallium oxide.

8. The crystallization method for amorphous nanofilms as described in claim 1, characterized in that, The reaction temperature of the atomic layer deposition method is 100℃~300℃; the substrate for the growth of the nanofilm in the atomic layer deposition method includes a single crystal silicon wafer or sapphire.

9. The crystallization method for amorphous nanofilms as described in any one of claims 1 to 8, wherein the method employs a disk-type laser-enhanced atomic layer deposition reactor; The disk-type laser-enhanced atomic layer deposition reactor includes an atomic layer deposition reactor body (1) and a laser (2); the atomic layer deposition reactor body (1) includes a sample chamber (101), and a sample chamber cover (102) is installed on the top of the sample chamber (101). The reactor body is characterized in that... A slide gate valve (3) is installed on the top of the sample chamber cover (102), and a slide gate valve vacuum flange interface (4) is provided on the top of the slide gate valve (3); a laser high-transparency window assembly (5) is installed on the slide gate valve vacuum flange interface (4). The laser high-transparency window assembly (5) includes a double-layer vacuum upper flange interface (501), a sealing gasket (502), a high-transparency window (503), and a double-layer vacuum lower flange interface (504) arranged coaxially from top to bottom vertically; the double-layer vacuum upper flange interface (501) and the double-layer vacuum lower flange interface (504) are installed on the vacuum flange interface (4) of the slide valve through sealing studs (505); The laser generated by the laser (2) enters the sample chamber (101) through the high-transparency window (503) and the insert valve (3).

10. The crystallization method for amorphous nanofilms as described in claim 9, characterized in that, The laser (2) includes a laser generating and output system (201), a laser positioning system (202) and a laser shaping system (203) connected in sequence. A red guide light module (204) is provided on the laser shaping system (203).

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