A method of fabricating a thin film based on an atomic layer deposition process and a semiconductor structure

Abstract

The application discloses a method for preparing a thin film based on an atomic layer deposition process and a semiconductor structure, and relates to the technical field of semiconductor preparation, to provide a technical scheme capable of forming a thin film on the surface of an organic micro-nanocrystal without damaging the organic micro-nanocrystal structure. The method for preparing the thin film based on the atomic layer deposition process comprises the following steps: providing a substrate and an organic micro-nanocrystal arranged on the substrate; and forming an oxide thin film on the surface of the organic micro-nanocrystal by using the atomic layer deposition process.

Description

Technical Field

[0001] This invention relates to the field of semiconductor fabrication technology, and in particular to a method for fabricating thin films based on atomic layer deposition (ALD) and a semiconductor structure. Background Technology

[0002] Functional organic micro and nanomaterials, as an essential component urgently needed in the field of chemical engineering, are receiving increasing attention in future optoelectronic devices. Organic micro and nanocrystal materials with well-defined multi-scale structures, as a classic model, have made significant progress in areas such as charge transport, high-density charge storage, nonlinear optics, delayed fluorescence, and biological applications.

[0003] When organic micro- and nano-crystals are applied to laser devices, a thin film needs to be formed on the surface of the organic micro- and nano-crystals. However, most of the current methods of forming thin films will damage the crystal structure of the organic micro- and nano-crystals. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing thin films based on atomic layer deposition (ALD) and a semiconductor structure, so as to provide a technical solution that can form thin films on the surface of organic micro / nano crystals without damaging the organic micro / nano crystal structure.

[0005] In a first aspect, the present invention discloses a method for preparing thin films based on atomic layer deposition (ALD) technology, the method comprising the following steps: providing a substrate and organic micro / nano crystals disposed on the substrate; and forming an oxide thin film on the surface of the organic micro / nano crystals using an ALD process.

[0006] With the above-described technical solution, the present invention provides a method for preparing thin films based on atomic layer deposition (ALD) technology, which includes forming an oxide thin film on the surface of the organic micro / nano crystal using ALD. It should be understood that thin films grown by ALD are dense and have controllable thickness. When combined with organic micro / nano crystals, they can be used to study novel device configurations, such as electrical devices and photoelectric detection, showing promising applications. Furthermore, the oxide thin film formed on the surface of the organic micro / nano crystal using ALD, as shown by fluorescence imaging comparison, completely covers the organic crystal; and the emission spectrum and laser threshold indicate that the oxide thin film did not damage the organic crystal during its growth.

[0007] Furthermore, the oxide film includes an aluminum oxide film or a hafnium oxide film.

[0008] Furthermore, when the oxide film is an aluminum oxide film, the process of forming the oxide film on the surface of the organic micro / nano crystal using atomic layer deposition includes:

[0009] Under vacuum conditions, trimethylaluminum gas is introduced into the atomic layer deposition reaction chamber, and the trimethylaluminum gas is adsorbed on the surface of the organic micro / nano crystals; wherein the substrate and the organic micro / nano crystals are placed in the atomic layer deposition reaction chamber;

[0010] The atomic layer deposition reaction chamber is purged with an inert gas;

[0011] Water vapor is introduced into the atomic layer deposition reaction chamber, and the water vapor is adsorbed onto the surface of the organic micro / nano crystals, where an adsorption reaction occurs.

[0012] Repeat the above steps at least once to obtain the alumina film.

[0013] The introduction time of the trimethylaluminum gas is 0.005s-0.02s, the purging time of the inert gas in the atomic layer deposition reaction chamber is 30s-60s, the introduction time of the water vapor is 0.005s-0.02s, and the growth rate of the alumina film is [missing information].

[0014] Furthermore, when the oxide film is a hafnium oxide film, the process of forming the oxide film on the surface of the organic micro / nano crystal using atomic layer deposition includes:

[0015] Under vacuum conditions, tetramethylaminohafnium gas is introduced into the atomic layer deposition reaction chamber, and the tetramethylaminohafnium gas is adsorbed on the surface of the organic micro / nano crystal; wherein, the substrate and the organic micro / nano crystal are placed in the atomic layer deposition reaction chamber;

[0016] The atomic layer deposition reaction chamber is purged with an inert gas;

[0017] Water vapor is introduced into the atomic layer deposition reaction chamber, and the water vapor is adsorbed onto the surface of the organic micro / nano crystals, where an adsorption reaction occurs.

[0018] Repeat the above steps at least once to obtain the hafnium oxide thin film.

[0019] The introduction time of the tetramethylaminohafnium gas is 0.005s-0.02s, the purging time of the inert gas in the atomic layer deposition reaction chamber is 30s-60s, the introduction time of water vapor is 0.005s-0.02s, and the growth rate of the hafnium oxide thin film is...

[0020] Furthermore, the process pressure of the atomic layer deposition reaction chamber includes 0.1 torr-0.3 torr, and the process temperature of the atomic layer deposition reaction chamber includes 100℃-300℃.

[0021] Furthermore, the purging of the atomic layer deposition reaction chamber using an inert gas includes:

[0022] The atomic layer deposition reaction chamber is purged multiple times with nitrogen gas, wherein the flow rate of the nitrogen gas is 180 sccm-220 sccm.

[0023] Furthermore, prior to providing the substrate and the organic micro / nano crystals disposed on the substrate, the method for preparing the thin film based on atomic layer deposition further includes:

[0024] The substrate was cleaned with a cleaning agent and then dried.

[0025] The organic micro / nano crystals were grown using physical vapor deposition.

[0026] In a second aspect, the present invention also provides a semiconductor structure comprising an organic micro / nano crystal and at least one thin film formed on the organic micro / nano crystal using the method for preparing thin films based on atomic layer deposition.

[0027] Compared with the prior art, the beneficial effects of the second aspect of the present invention are the same as those of the method for preparing thin films based on atomic layer deposition process described above, and will not be repeated here. Attached Figure Description

[0028] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0029] Figure 1 A flowchart illustrating the steps of a method for preparing a two-dimensional film structure according to an embodiment of the present invention is shown.

[0030] Figure 2 (a) is a schematic diagram of an organic micro / nano crystal physical vapor deposition provided in an embodiment of the present invention;

[0031] Figure 2 (b) A fluorescence photograph of an organic micro / nano crystal provided in an embodiment of the present invention;

[0032] Figure 3 (a) A fluorescence photograph of an organic crystal provided in an embodiment of the present invention;

[0033] Figure 3 (b) An emission spectrum of an organic crystal without an aluminum oxide film provided in an embodiment of the present invention;

[0034] Figure 3(c) The fluorescence emission spectrum of an organic crystal without an aluminum oxide film provided in an embodiment of the present invention at different laser pump energies. The inset is a laser threshold diagram of the organic crystal.

[0035] Figure 4 (a) A fluorescence photograph of an organic crystal provided in an embodiment of the present invention;

[0036] Figure 4 (b) An emission spectrum of an organic crystal covered with an alumina film according to an embodiment of the present invention;

[0037] Figure 4 (c) The fluorescence emission spectrum of an organic crystal after being covered with an alumina film according to an embodiment of the present invention at different laser pump energies. The inset is a laser threshold diagram of the organic crystal.

[0038] Figure 5 An XPS analysis chromatogram of alumina provided in an embodiment of the present invention;

[0039] Figure 6 A cross-sectional SEM image is provided for an embodiment of the present invention. Detailed Implementation

[0040] Embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0041] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0042] Functional organic micro and nanomaterials, as an essential component urgently needed in the field of chemical engineering, are receiving increasing attention in future optoelectronic devices. Organic micro and nanocrystal materials with well-defined multi-scale structures, as a classic model, have made significant progress in areas such as charge transport, high-density charge storage, nonlinear optics, delayed fluorescence, and biological applications.

[0043] When organic micro- and nano-crystals are applied to laser devices, a thin film needs to be formed on the surface of the organic micro- and nano-crystals. However, most of the current methods of forming thin films will damage the crystal structure of the organic micro- and nano-crystals.

[0044] Firstly, referring to Figure 1 This invention provides a method for preparing thin films based on atomic layer deposition, comprising the following steps:

[0045] S100 provides a substrate and organic micro / nano crystals disposed on the substrate.

[0046] In this embodiment of the invention, the substrate can be a sapphire substrate, a quartz substrate, or a silicon substrate. Before transferring the organic micro / nano crystals to the substrate, the substrate is cleaned with a cleaning agent and then dried. Specifically, anhydrous ethanol can be used to ultrasonically clean the substrate, and after cleaning, nitrogen gas is sprayed from a nitrogen gun to dry the substrate. This ensures that the substrate is in a clean state, thereby guaranteeing the effectiveness of subsequent film deposition.

[0047] In practice, the process for preparing organic micro / nano crystals can be as follows: using organic molecules as raw materials, organic micro / nano crystals are grown by physical vapor deposition. Specifically, this includes: placing an appropriate amount of organic powder in a quartz boat and placing it in a tube furnace; purging and rinsing the tube furnace; introducing a high-purity nitrogen mixture as a carrier gas; heating to the sublimation temperature; holding at this temperature to grow micro / nano crystals; and then allowing it to cool naturally after a certain period of time to obtain organic micro / nano crystals.

[0048] As a specific example, the process for preparing organic micro / nano crystals can be described as follows:

[0049] Organic molecular powder was placed in a quartz boat and positioned in the center of a quartz tube. A silicon substrate was placed in the quartz tube, approximately 20 cm upstream of the carrier gas flow from the quartz boat. The quartz tube was then pushed into a tube furnace. A mechanical pump was turned on to create a vacuum and purge the tubing. The mechanical pump was then turned off, and a vacuum valve was opened to introduce a 100 sccm mixture of 10% hydrogen and argon as the carrier gas. The quartz tube was heated to 300℃–350℃ at a rate of 3–5.8℃ / min. After reaching 300℃–350℃, the temperature was held for 100–500 min. Heating was then stopped, and the tube was allowed to cool naturally to room temperature to obtain organic micro / nano crystals.

[0050] S200 utilizes atomic layer deposition (ALD) to form an oxide film on the surface of the organic micro / nano crystals.

[0051] The oxide film mentioned above can be an aluminum oxide film or a hafnium oxide film.

[0052] As a specific implementation, when the oxide film is an aluminum oxide film, the process of forming the oxide film on the surface of the organic micro / nano crystal using atomic layer deposition includes:

[0053] Under vacuum conditions, trimethylaluminum gas is introduced into the atomic layer deposition (ALD) reaction chamber, and the trimethylaluminum gas is adsorbed on the surface of the organic micro / nano crystals; wherein the substrate and the organic micro / nano crystals are placed in the ALD reaction chamber. The process pressure of the ALD reaction chamber includes 0.1 torr-0.3 torr, and the process temperature of the ALD reaction chamber includes 100℃-300℃.

[0054] The atomic layer deposition reaction chamber is purged using an inert gas. Specifically, the inert gas can be nitrogen, and purging the atomic layer deposition reaction chamber with an inert gas includes purging the atomic layer deposition reaction chamber multiple times with nitrogen, wherein the flow rate of the nitrogen is 180 sccm-220 sccm.

[0055] Water vapor is introduced into the atomic layer deposition reaction chamber, and the water vapor is adsorbed onto the surface of the organic micro / nano crystals, where an adsorption reaction occurs.

[0056] Repeat the above steps at least once to obtain the alumina film. It should be understood that the number of times the above steps are repeated can be specifically set according to the actual thickness requirements of the alumina film, and the embodiments of the present invention do not impose specific limitations.

[0057] The trimethylaluminum gas is introduced for 0.005 s to 0.02 s, the inert gas purging time of the atomic layer deposition reaction chamber is 30 s to 60 s, the water vapor introduction time is 0.005 s to 0.02 s, and the alumina film growth rate is [missing information].

[0058] In another specific example, when the oxide film is a hafnium oxide film, the formation of the oxide film on the surface of the organic micro / nano crystal using atomic layer deposition includes:

[0059] Under vacuum conditions, tetramethylaminohafnium gas is introduced into the atomic layer deposition (ALD) reaction chamber, and the tetramethylaminohafnium gas is adsorbed on the surface of the organic micro / nano crystals; wherein the substrate and the organic micro / nano crystals are placed in the ALD reaction chamber. The process pressure of the ALD reaction chamber includes 0.1 torr-0.3 torr, and the process temperature of the ALD reaction chamber includes 100℃-300℃.

[0060] The atomic layer deposition reaction chamber is purged with an inert gas; specifically, the inert gas can be nitrogen. Purging the atomic layer deposition reaction chamber with an inert gas includes purging the atomic layer deposition reaction chamber multiple times with nitrogen, wherein the flow rate of the nitrogen is 180 sccm-220 sccm.

[0061] Water vapor is introduced into the atomic layer deposition reaction chamber, and the water vapor is adsorbed onto the surface of the organic micro / nano crystals, where an adsorption reaction occurs.

[0062] Repeat the above steps at least once to obtain the hafnium oxide thin film. It should be understood that the number of times the above steps are repeated can be specifically set according to the actual thickness requirements of the hafnium oxide thin film, and the embodiments of the present invention do not impose specific limitations.

[0063] The introduction time of the tetramethylaminohafnium gas is 0.005s-0.02s, the purging time of the inert gas in the atomic layer deposition reaction chamber is 30s-60s, the introduction time of water vapor is 0.005s-0.02s, and the growth rate of the hafnium oxide thin film is...

[0064] In practice, embodiments of the present invention use trimethylaluminum and water as precursors to grow alumina thin films on silicon substrates using atomic layer deposition (ALD). The process includes: placing the substrate in a reaction chamber; under vacuum conditions and in the presence of a carrier gas, introducing trimethylaluminum gas into the reaction chamber in a pulsed manner for adsorption; purging the reaction chamber with an inert gas; introducing water into the reaction chamber in a pulsed manner in the presence of a carrier gas to react with the adsorbed groups, thereby obtaining an alumina thin film; purging the reaction chamber with an inert gas to complete one ALD cycle; and repeating the above steps to prepare alumina films of different thicknesses by depositing different numbers of cycles.

[0065] As a complete implementation, the method for preparing thin films based on atomic layer deposition technology provided in this embodiment of the invention includes the following steps:

[0066] Step 1: Ultrasonically clean the silicon substrate with anhydrous ethanol and dry it with a nitrogen gun.

[0067] Step 2: Place the organic molecular powder into a quartz boat, positioning it in the center of a quartz tube; place the silicon substrate into the quartz tube, approximately 20 cm upstream of the carrier gas flow from the quartz boat; push the quartz tube into the tube furnace; turn on the mechanical pump to create a vacuum and purge the pipeline; turn off the mechanical pump, open the vacuum valve, and introduce a 100 sccm mixture of 10% hydrogen and argon as the carrier gas; heat the quartz tube to 300℃~350℃ at a heating rate of 3~5.8℃ / min. Hold the temperature at 300℃~350℃ for 300 min; stop heating and allow it to cool naturally to room temperature to obtain organic micro / nano crystals.

[0068] Figure 2To obtain an appropriate amount of organic compound powder, place it at the front end of a tube furnace. Set the first temperature zone to 320℃ and the second temperature zone to 220℃. Heat and sublimate for 2-4 hours, then hold for 10-15 hours. After holding, we can obtain organic micro / nano crystals at the area marked by the circle in the figure.

[0069] Step 3: Place the substrate in the reaction chamber. Under vacuum conditions and in the presence of a carrier gas, introduce trimethylaluminum into the reaction chamber in a pulsed manner for adsorption. Purge the reaction chamber with an inert gas. In the presence of a carrier gas, introduce water into the reaction chamber in a pulsed manner to react with the adsorbed groups and obtain an alumina film. A total of 400 cycles were performed, and an alumina film of approximately 90 nm was deposited.

[0070] Reference Figure 3 and Figure 4 , Figure 3 Images (a)-(c) show fluorescence photographs of the organic crystal in the embodiments of the present invention, as well as the emission spectrum and laser threshold without the alumina film covering. Figure 4 Images (a)-(c) show fluorescence photographs of the organic crystal in the embodiments of the present invention, as well as the emission spectrum and laser threshold after being covered with an alumina film. Figure 3 and Figure 4 This demonstrates that atomic layer deposition does not damage the structure of organic microcrystals, nor does it impair their optical properties.

[0071] Step 5: Cut the prepared device in half from the middle and observe its morphology using a scanning tunneling microscope (SEM).

[0072] Figure 5 The figure shows an XPS analysis diagram of alumina provided in an embodiment of the present invention. Figure 5 Characterization results show that the alumina film contains elements such as Al, C, and O. The Al 2p absorption peak is 74.48 eV with a half-maximum width of 1.6 eV, and the O 1s absorption peak is 530.41 eV with a half-maximum width of 2.11 eV. These values ​​are very close to the theoretical values ​​of the Al 2p and O 1s energy levels in the XPS of standard Al 2O 3 (72.9 eV and 531.1 eV, respectively). Therefore, it can be proved that Al-O bonds are formed in the A4 sample film, and the molar ratio of Al / O is approximately 1:1.5, which is consistent with the molar ratio of Al 2O 3 in the standard material. This indicates that the embodiment of the present invention successfully prepared Al 2O 3 film using the ALD method.

[0073] Figure 6 A cross-sectional SEM image provided for an embodiment of the present invention shows the formation of an alumina film on a substrate; a comparison of fluorescence images shows that the alumina film completely covers the organic crystals; the emission spectrum and laser threshold indicate that the alumina film did not damage the organic crystals during the growth process.

[0074] Based on this, the embodiments of the present invention successfully prepared a dense alumina film on the surface of organic micro / nano crystals, providing a theoretical reference for the preparation of OLED and OFET devices with excellent performance.

[0075] Although the invention has been described herein in conjunction with various embodiments, those skilled in the art will understand and implement other variations of the disclosed embodiments by reviewing the accompanying drawings, the disclosure, and the appended claims in carrying out the claimed invention. In the claims, "comprising"

[0076] The word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple components. A single processor or other unit can perform several functions listed in the claims. Although different dependent claims may describe certain measures, this does not mean that these measures cannot be combined to produce a good effect.

[0077] Although the invention has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made therein without departing from the spirit and scope of the invention. Accordingly, this specification and drawings are merely exemplary descriptions of the invention as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if such modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include such modifications and modifications.

Claims

1. A method for preparing thin films based on atomic layer deposition (ALD) technology, characterized in that, The method for preparing thin films based on atomic layer deposition includes the following steps: A substrate and organic micro / nanocrystalline materials disposed on the substrate are provided; the organic micro / nanocrystalline materials are applied to a laser device; An oxide film is formed on the surface of the organic micro / nano crystal using atomic layer deposition (ALD) without damaging the crystal structure or optical properties of the organic micro / nano crystal.

2. The method for preparing thin films based on atomic layer deposition according to claim 1, characterized in that, The oxide film includes an aluminum oxide film or a hafnium oxide film.

3. The method for preparing thin films based on atomic layer deposition according to claim 2, characterized in that, When the oxide film is an aluminum oxide film, the process of forming the oxide film on the surface of the organic micro / nano crystal using atomic layer deposition includes: Under vacuum conditions, trimethylaluminum gas is introduced into the atomic layer deposition reaction chamber, and the trimethylaluminum gas is adsorbed on the surface of the organic micro / nano crystals; wherein the substrate and the organic micro / nano crystals are placed in the atomic layer deposition reaction chamber; The atomic layer deposition reaction chamber is purged with an inert gas; Water vapor is introduced into the atomic layer deposition reaction chamber, and the water vapor is adsorbed onto the surface of the organic micro / nano crystals, where an adsorption reaction occurs. Repeat the above steps at least once to obtain the alumina film.

4. The method for preparing thin films based on atomic layer deposition according to claim 3, characterized in that, The introduction time of the trimethylaluminum gas is 0.005s-0.02s, the purging time of the inert gas in the atomic layer deposition reaction chamber is 30s-60s, the introduction time of the water vapor is 0.005s-0.02s, and the growth rate of the alumina film is [missing information]. .

5. The method for preparing thin films based on atomic layer deposition according to claim 2, characterized in that, When the oxide film is a hafnium oxide film, the process of forming the oxide film on the surface of the organic micro / nano crystal using atomic layer deposition includes: Under vacuum conditions, tetramethylaminohafnium gas is introduced into the atomic layer deposition reaction chamber, and the tetramethylaminohafnium gas is adsorbed on the surface of the organic micro / nano crystal; wherein, the substrate and the organic micro / nano crystal are placed in the atomic layer deposition reaction chamber; The atomic layer deposition reaction chamber is purged with an inert gas; Water vapor is introduced into the atomic layer deposition reaction chamber, and the water vapor is adsorbed onto the surface of the organic micro / nano crystals, where an adsorption reaction occurs. Repeat the above steps at least once to obtain the hafnium oxide thin film.

6. The method for preparing thin films based on atomic layer deposition according to claim 5, characterized in that, The introduction time of the tetramethylaminohafnium gas is 0.005s-0.02s, the purging time of the inert gas in the atomic layer deposition reaction chamber is 30s-60s, the introduction time of water vapor is 0.005s-0.02s, and the growth rate of the hafnium oxide thin film is... .

7. The method for preparing thin films based on atomic layer deposition according to claim 3 or 5, characterized in that, The process pressure of the atomic layer deposition reaction chamber includes 0.1 torr-0.3 torr, and the process temperature of the atomic layer deposition reaction chamber includes 100℃-300℃.

8. The method for preparing thin films based on atomic layer deposition according to claim 3 or 5, characterized in that, The process of purging the atomic layer deposition reaction chamber with inert gas includes: The atomic layer deposition reaction chamber is purged multiple times with nitrogen gas, wherein the flow rate of the nitrogen gas is 180 sccm-220 sccm.

9. The method for preparing thin films based on atomic layer deposition according to claim 1, characterized in that, Prior to providing a substrate and organic micro / nano crystals disposed on the substrate, the method for preparing thin films based on atomic layer deposition further includes: The substrate was cleaned with a cleaning agent and then dried. The organic micro / nano crystals were grown using physical vapor deposition.

10. A semiconductor structure, characterized in that, The invention includes organic micro / nano crystals and at least one oxide film formed on the organic micro / nano crystals using the method for preparing thin films based on atomic layer deposition as described in any one of claims 1-9. The organic micro / nano crystals are applied to laser devices, and the formation of the oxide film does not damage the crystal structure and optical properties of the organic micro / nano crystals.

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