Method for preparing thin film based on atomic layer deposition process and semiconductor structure

Abstract

The invention discloses a method for preparing a thin film based on an atomic layer deposition process and a semiconductor structure, relates to the technical field of semiconductor preparation, and provides a technical scheme capable of forming a thin film on the surface of an organic micro-nano crystal without damaging the organic micro-nano crystal structure. The method for preparing the thin film based on the atomic layer deposition technology comprises the following steps that a substrate and organic micro-nano crystals arranged on the substrate are provided; and forming an oxide film on the surface of the organic micro-nano crystal by using an atomic layer deposition process.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor preparation, and in particular to a method for preparing a thin film based on an atomic layer deposition process and a semiconductor structure. Background Art

[0002] Functional organic micro-nano materials, as an important and urgently needed component in the field of chemical engineering, have attracted more and more attention in future optoelectronic devices. As a classic model, organic micro-nano crystalline materials with clear multi-scale structures have made great progress in charge transport, high-density charge storage, nonlinear optics, delayed fluorescence and biological applications.

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

[0004] The purpose of the present invention is to provide a method for preparing a thin film based on an atomic layer deposition process and a semiconductor structure, so as to provide a technical solution that can form a thin film on the surface of an organic micro-nano crystal without damaging the organic micro-nano crystal structure.

[0005] In a first aspect, the present invention discloses a method for preparing a thin film based on an atomic layer deposition process, the method for preparing a thin film based on an atomic layer deposition process comprising the following steps: providing a substrate and organic micro-nanocrystals arranged on the substrate; and forming an oxide thin film on the surface of the organic micro-nanocrystals using an atomic layer deposition process.

[0006] In the case of adopting the above technical solution, the method for preparing a thin film based on an atomic layer deposition process provided by the present invention includes forming an oxide film on the surface of the organic micro-nano crystal using an atomic layer deposition process. It should be understood that the film grown by the atomic layer deposition process (ALD) is dense in quality and controllable in thickness. After being combined with the organic micro-nano crystal, it can be used to study new device configurations, such as electrical devices, photoelectric detection, etc., which have good application prospects. And the oxide film formed on the surface of the organic micro-nano crystal using the atomic layer deposition process shows that the oxide film completely covers the organic crystal through the comparison of fluorescent photos; and the emission spectrum and laser threshold show that the oxide film does not destroy the organic crystal during the growth process.

[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, forming the oxide film on the surface of the organic micro-nano crystal by using an atomic layer deposition process includes:

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

[0010] Purging the atomic layer deposition reaction chamber with an inert gas;

[0011] Introducing water vapor into the atomic layer deposition reaction chamber, the water vapor is adsorbed onto the surface of the organic micro-nano crystals, and an adsorption reaction occurs;

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

[0013] The introduction time of the trimethylaluminum gas is 0.005s-0.02s, the time for the inert gas to purge 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 aluminum oxide film is

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

[0015] Under vacuum conditions, introducing hafnium tetradimethylamine gas into an atomic layer deposition reaction chamber, wherein the hafnium tetradimethylamine 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] Purging the atomic layer deposition reaction chamber with an inert gas;

[0017] Introducing water vapor into the atomic layer deposition reaction chamber, the water vapor is adsorbed onto the surface of the organic micro-nano crystals, and 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 hafnium tetradimethylamine gas is 0.005s-0.02s, the time for the inert gas to purge 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 hafnium oxide 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° C.-300° C.

[0021] Further, the purging of the atomic layer deposition reaction chamber with 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, before providing a substrate and an organic micro-nano crystal disposed on the substrate, the method for preparing a thin film based on an atomic layer deposition process further includes:

[0024] Cleaning the substrate with a cleaning agent and drying it;

[0025] The organic micro-nano crystals are grown by utilizing a physical vapor deposition process.

[0026] In a second aspect, the present invention further provides a semiconductor structure, including an organic micro-nano crystal and at least one layer of a thin film formed on the organic micro-nano crystal and prepared by the method for preparing a thin film based on an atomic layer deposition process.

[0027] Compared with the prior art, the beneficial effects of the second aspect of the present invention are the same as the beneficial effects of the method for preparing a thin film based on the atomic layer deposition process according to the above technical solution, and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0029] Figure 1 A flow chart showing the steps of a method for preparing a two-dimensional film layer structure provided by an embodiment of the present invention is shown;

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

[0031] Figure 2 (b) is a fluorescent photograph of an organic micro-nano crystal provided by an embodiment of the present invention;

[0032] Figure 3 (a) is a fluorescent photograph of an organic crystal provided by an embodiment of the present invention;

[0033] Figure 3 (b) is an emission spectrum of an organic crystal not covered with an aluminum oxide film provided by an embodiment of the present invention;

[0034] Figure 3(c) is a fluorescence emission spectrum of an organic crystal provided in an embodiment of the present invention, which is not covered with an aluminum oxide film, at different laser pumping energies, and the inset is a laser threshold diagram of the organic crystal;

[0035] Figure 4 (a) is a fluorescent photograph of an organic crystal provided by an embodiment of the present invention;

[0036] Figure 4 (b) is an emission spectrum of an organic crystal covered with an aluminum oxide film provided by an embodiment of the present invention;

[0037] Figure 4 (c) is a fluorescence emission spectrum of an organic crystal provided by an embodiment of the present invention after being covered with an aluminum oxide film at different laser pumping energies, and the inset is a laser threshold diagram of the organic crystal;

[0038] Figure 5 An XPS analysis chart of aluminum oxide provided by an embodiment of the present invention;

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

[0040] Hereinafter, embodiments of the present disclosure will 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 present disclosure. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0041] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The meaning of "several" is one or more, unless otherwise clearly and specifically defined.

[0042] Functional organic micro-nano materials, as an important and urgently needed component in the field of chemical engineering, have attracted more and more attention in future optoelectronic devices. As a classic model, organic micro-nano crystalline materials with clear multi-scale structures have made great progress in charge transport, high-density charge storage, nonlinear optics, delayed fluorescence and biological applications.

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

[0044] First, refer to Figure 1 The embodiment of the present invention provides a method for preparing a thin film based on an atomic layer deposition process, comprising the following steps:

[0045] S100, providing a substrate and organic micro-nanocrystals disposed on the substrate.

[0046] In an embodiment of the present invention, the substrate may be a sapphire substrate, a quartz substrate or a silicon substrate. Before the organic micro-nano crystal is transferred to the substrate, the substrate is cleaned with a cleaning agent and blown dry. Specifically, the substrate may be ultrasonically cleaned with anhydrous ethanol, and after cleaning, the substrate may be blown dry by spraying nitrogen with a nitrogen gun. Based on this, the substrate can be ensured to be in a clean state, thereby ensuring the effect of the subsequent deposition film layer.

[0047] In practice, the process of preparing organic micro-nano crystals can be: using organic molecules as raw materials, using physical vapor deposition to grow organic micro-nano crystals. Specifically, it includes: taking an appropriate amount of organic powder and placing it in a quartz boat, placing it in a tube furnace; purging and flushing the tube furnace; introducing high-purity nitrogen mixed gas as a carrier gas, heating to the sublimation temperature, keeping the temperature to grow micro-nano crystals, and cooling naturally after a certain period of time to obtain organic micro-nano crystals.

[0048] As a specific example, the process of preparing organic micro-nanocrystals may be:

[0049] Put the organic molecular powder into a quartz boat and put it in the middle of the quartz tube; put the silicon substrate into the quartz tube, about 20 cm away from the quartz boat in the upstream direction of the carrier gas flow; push the quartz tube into the tube furnace; start the mechanical pump to evacuate and purge the pipeline; turn off the mechanical pump, open the vacuum valve, and pass 100sccm, 10% hydrogen and argon mixed gas as carrier gas; heat the quartz tube to 300℃~350℃, and the heating rate is 3~5.8℃ / min. After the temperature reaches 300℃~350℃, keep it warm for 100-500min; stop heating and cool naturally to room temperature to obtain organic micro-nano crystals.

[0050] S200, forming an oxide film on the surface of the organic micro-nano crystal by using an atomic layer deposition process.

[0051] The oxide film may be an aluminum oxide film or a hafnium oxide film.

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

[0053] Under vacuum conditions, trimethylaluminum gas is introduced into an atomic layer deposition reaction chamber, and the trimethylaluminum 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 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° C.-300° C.

[0054] The atomic layer deposition reaction chamber is purged with an inert gas. Specifically, the inert gas may be nitrogen. The atomic layer deposition reaction chamber is purged with an inert gas, including: purging the atomic layer deposition reaction chamber with nitrogen for multiple times, 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, and an adsorption reaction occurs.

[0056] Repeat the above steps at least once to obtain the aluminum oxide 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 aluminum oxide film, and the embodiment of the present invention does not make any specific limitation.

[0057] The introduction time of the trimethylaluminum gas is 0.005s-0.02s, the time for the inert gas to purge 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 aluminum oxide film is

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

[0059] Under vacuum conditions, tetrakis(dimethylamino)hafnium gas is introduced into an atomic layer deposition reaction chamber, and the tetrakis(dimethylamino)hafnium 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 process pressure of the atomic layer deposition reaction chamber includes 0.1torr-0.3torr, and the process temperature of the atomic layer deposition reaction chamber includes 100°C-300°C.

[0060] The atomic layer deposition reaction chamber is purged with an inert gas; specifically, the inert gas may be nitrogen. The purging of the atomic layer deposition reaction chamber with an inert gas includes: purging the atomic layer deposition reaction chamber with nitrogen for multiple times, 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, and an adsorption reaction occurs.

[0062] Repeat the above steps at least once to obtain the hafnium oxide 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 film, and the embodiment of the present invention does not make any specific limitation.

[0063] The introduction time of the hafnium tetradimethylamine gas is 0.005s-0.02s, the time for the inert gas to purge 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 hafnium oxide film is

[0064] In practice, the embodiment of the present invention uses trimethylaluminum and water as precursors and adopts atomic layer deposition to grow an aluminum oxide film on a silicon substrate, including: placing the substrate in a reaction chamber, and under vacuum conditions and the presence of a carrier gas, introducing trimethylaluminum gas into the reaction chamber in a pulsed form for adsorption; introducing an inert gas into the reaction chamber for purging; in the presence of a carrier gas, introducing water into the reaction chamber in a pulsed form to react with the adsorbed groups to obtain an aluminum oxide film; introducing an inert gas into the reaction chamber for purging to complete an ALD cycle; repeating the above steps to prepare aluminum oxide films of different thicknesses by depositing different numbers of cycles.

[0065] As a complete implementation, the method for preparing a thin film based on an atomic layer deposition process provided in an embodiment of the present invention includes the following steps:

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

[0067] Step 2: Put the organic molecular powder into the quartz boat and put it in the middle of the quartz tube; put the silicon substrate into the quartz tube, about 20 cm away from the quartz boat in the upstream direction of the carrier gas flow; push the quartz tube into the tube furnace; start the mechanical pump to evacuate and purge the pipeline; turn off the mechanical pump, open the vacuum valve, and pass 100sccm, 10% hydrogen and argon mixed gas as carrier gas; heat the quartz tube to 300℃~350℃, and the heating rate is 3~5.8℃ / min. After the temperature reaches 300℃~350℃, keep it warm for 300min; stop heating and cool naturally to room temperature to obtain organic micro-nano crystals.

[0068] Figure 2To take an appropriate amount of organic compound powder, place it at the front end of the tubular furnace, set the first temperature zone to 320℃, the second temperature zone to 220℃, heat and sublimate for 2-4 hours, and keep warm for 10-15 hours. After the insulation is completed, we can obtain organic micro-nano crystals at the circle marked in this figure.

[0069] Step three: Place the substrate in a reaction chamber, and under vacuum conditions and in the presence of a carrier gas, introduce trimethylaluminum into the reaction chamber in a pulsed form for adsorption; introduce an inert gas into the reaction chamber for purging; in the presence of a carrier gas, introduce water into the reaction chamber in a pulsed form to react with the adsorbed groups to obtain an aluminum oxide film. A total of 400 cycles of deposition were performed to deposit about 90 nm of aluminum oxide.

[0070] Reference Figure 3 and Figure 4 , Figure 3 (a)-(c) are fluorescence photos of the organic crystal in the embodiment of the present invention and the emission spectrum and laser threshold value without the aluminum oxide film. Figure 4 (a)-(c) are fluorescence photos of the organic crystal in the embodiment of the present invention and the emission spectrum and laser threshold after being covered with an aluminum oxide film. Figure 3 and Figure 4 It can be shown that the atomic layer deposition method will not damage the structure of organic microcrystals and will not destroy their optical properties.

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

[0072] Figure 5 An XPS analysis chart of aluminum oxide provided by an embodiment of the present invention is shown. Figure 5 The characterization results show that the aluminum oxide film contains elements such as Al, C, and O, among which the Al2p absorption peak is 74.48 ev, the half-peak width is 1.6 ev, the O1s absorption peak is 530.41 ev, and the half-peak width is 2.11 ev, which is very close to the theoretical values ​​of Al2p and O1s energy levels of 72.9 ev and 531.1 ev in the standard Al2O3 XPS. Therefore, it can be proved that Al-O bonds are formed in the A4 sample film, and the molar ratio of Al / O is about 1:1.5, which is consistent with the molar ratio of Al2O3 in the standard material, indicating that the embodiment of the present invention successfully achieves the preparation of Al2O3 film by ALD method.

[0073] Figure 6 A cross-sectional SEM image provided for an embodiment of the present invention shows that an aluminum oxide film is generated on a substrate; a comparison of fluorescent photographs shows that the aluminum oxide film completely covers the organic crystals; and the emission spectrum and laser threshold show that the aluminum oxide film does not destroy the organic crystals during the growth process.

[0074] Based on this, the embodiment of the present invention successfully prepared a high-quality and dense aluminum oxide film on the surface of organic micro-nano crystals, providing a theoretical reference for preparing OLED and OFET devices with excellent performance.

[0075] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by reviewing the drawings, the disclosure, and the appended claims.

[0076] The word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality of components. A single processor or other unit can implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0077] Although the present invention has been described in conjunction with specific features and embodiments thereof, it is apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the present invention. Accordingly, this specification and the accompanying drawings are merely exemplary illustrations of the present invention as defined by the appended claims and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the present invention. Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, the present invention is intended to include such modifications and variations if they fall within the scope of the claims of the present invention and their equivalents.

Claims

1. A method for preparing a thin film based on an atomic layer deposition process, characterized in that: The method for preparing a thin film based on an atomic layer deposition process comprises the following steps: Providing a substrate and organic micro-nanocrystals disposed on the substrate; An oxide film is formed on the surface of the organic micro-nano crystals by utilizing an atomic layer deposition process.

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

4. The method for preparing a thin film based on an atomic layer deposition process according to claim 3, characterized in that: The introduction time of the trimethylaluminum gas is 0.005s-0.02s, the time for the inert gas to purge 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 aluminum oxide film is 5. The method for preparing a thin film based on an atomic layer deposition process according to claim 2, characterized in that: When the oxide film is a hafnium oxide film, the step of forming the oxide film on the surface of the organic micro-nano crystal by using an atomic layer deposition process comprises: Under vacuum conditions, introducing hafnium tetradimethylamine gas into an atomic layer deposition reaction chamber, wherein the hafnium tetradimethylamine 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; Purging the atomic layer deposition reaction chamber with an inert gas; Introducing water vapor into the atomic layer deposition reaction chamber, the water vapor is adsorbed onto the surface of the organic micro-nano crystals, and an adsorption reaction occurs; Repeat the above steps at least once to obtain the hafnium oxide thin film.

6. The method for preparing a thin film based on an atomic layer deposition process according to claim 5, characterized in that: The introduction time of the hafnium tetradimethylamine gas is 0.005s-0.02s, the time for the inert gas to purge 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 hafnium oxide film is 7. The method for preparing a thin film based on an atomic layer deposition process 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° C.-300° C.

8. The method for preparing a thin film based on an atomic layer deposition process according to claim 3 or 5, characterized in that: The step of purging the atomic layer deposition reaction chamber with an inert gas comprises: 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 a thin film based on an atomic layer deposition process according to claim 1, characterized in that: Before providing a substrate and an organic micro-nano crystal disposed on the substrate, the method for preparing a thin film based on an atomic layer deposition process further includes: Cleaning the substrate with a cleaning agent and drying it; The organic micro-nano crystals are grown by utilizing a physical vapor deposition process.

10. A semiconductor structure, characterized in that: The invention comprises an organic micro-nano crystal and at least one layer of a thin film formed on the organic micro-nano crystal and prepared by the method for preparing a thin film based on an atomic layer deposition process according to any one of claims 1 to 9.

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