Method and device for micro-nano diode laser additive manufacturing based on organic precursor ceramics

Abstract

The application provides a micro-nano diode laser additive manufacturing method and device based on an organic precursor ceramic, which comprises the following steps: depositing n-type and p-type ceramic precursors on a substrate surface respectively; controlling a first laser beam to perform localized scanning irradiation on the n-type and p-type ceramic precursors according to a preset structure pattern, so that the n-type and p-type ceramic precursors in the corresponding regions are solidified to form n-type and p-type preformed structures respectively; irradiating a first and a second predetermined electrode region by using a second laser beam, so that the first and second conductive metal precursors are respectively converted into a first metal electrode electrically connected with the n-type preformed structure and a second metal electrode electrically connected with the p-type preformed structure; and performing integrated heat treatment on the n-type and p-type preformed structures and the first and second metal electrodes, so that an integrated micro-nano ceramic diode device is obtained. The problems of size shrinkage, structure deformation and heterogeneous material integration difficulty that are prone to occur in traditional ceramic slurry additive manufacturing are solved.

Description

Technical Field

[0001] This application belongs to the field of micro-nano electronic device manufacturing technology, and relates to a method and device for laser additive manufacturing of micro-nano diodes based on organic precursor ceramics. Background Technology

[0002] As a core component of modern electronic technology, semiconductor diodes are manufactured using silicon-based planar lithography. This technology requires multiple steps, including deposition, lithography, etching, and ion implantation, to construct the device structure on a wafer. While it can achieve high-precision device fabrication, it suffers from complex process steps, high costs of specialized equipment, limited compatibility with material systems, and is essentially a two-dimensional planar processing mode. This makes it difficult to adapt to the new application demands of electronic devices for miniaturization, three-dimensionality, customization, and resistance to temperature and chemical corrosion as information technology develops towards fields such as the Internet of Things, wearable devices, and extreme environment detection. As a result, the application scenarios of silicon-based planar lithography are limited.

[0003] To meet the new demands for device fabrication, additive manufacturing technology, with its advantages of strong ability to form complex structures and high material utilization, has been attempted to be applied to the field of electronic device manufacturing. For example, it is used to fabricate electronic components such as transistors and sensors through technologies such as conductive ink direct writing and aerosol spraying. However, existing electronic additive manufacturing technologies mostly use organic polymers or nano-metal particle pastes as functional materials. The devices fabricated have poor electrical performance, narrow operating temperature range, and difficulty in fabricating high-performance semiconductor junctions, which cannot meet the requirements of device applications in high-end and extreme environments.

[0004] Advanced structural ceramics possess excellent high-temperature stability, chemical inertness, and mechanical strength, making them ideal functional materials for fabricating electronic devices resistant to extreme environments. However, the inherent characteristics of ceramic materials—high hardness, high brittleness, and high melting point—pose significant technical challenges to their micro- and nano-scale fabrication and shaping. Currently, mainstream ceramic microfabrication technologies, such as laser ablation and focused ion beam etching, suffer from low processing efficiency, high equipment costs, and a tendency to generate microcracks in the ceramic material during processing. Additive manufacturing technologies based on ceramic slurries require post-processing steps such as debinding and high-temperature sintering, which can easily lead to significant dimensional shrinkage and structural deformation in devices, making it difficult to achieve the integrated molding of heterogeneous materials such as n-type ceramic semiconductors, p-type ceramic semiconductors, and metallic conductive structures. Therefore, in the field of micro- and nano-electronic device manufacturing, especially in niche areas targeting high-temperature and high-reliability applications, a manufacturing technology has yet to emerge that simultaneously achieves precise micro- and nano-scale structural molding of ceramic materials, preparation of high-performance ceramic semiconductor materials, and integrated molding of heterogeneous functional units on a ceramic substrate. Summary of the Invention

[0005] The purpose of this application is to provide a method and device for laser additive manufacturing of micro-nano diodes based on organic precursor ceramics, which solves the problem of the difficulty in achieving integrated molding of heterogeneous materials such as n-type ceramic semiconductors, p-type ceramic semiconductors and metal conductive structures in the prior art.

[0006] In a first aspect, this application provides a method for laser additive manufacturing of micro / nano diodes based on organic precursor ceramics, the method comprising:

[0007] A substrate is provided, an n-type ceramic precursor is deposited on the surface of the substrate, and a first laser beam is controlled to perform localized scanning irradiation on the n-type ceramic precursor according to a preset structural pattern, so that the n-type ceramic precursor in the corresponding region is solidified to form an n-type prefabricated structure; a p-type ceramic precursor is deposited on the surface of the substrate, and the first laser beam is controlled to perform localized scanning irradiation on the p-type ceramic precursor according to a preset structural pattern, so that the p-type ceramic precursor in the corresponding region is solidified to form a p-type prefabricated structure.

[0008] A first conductive metal precursor is deposited in the first predetermined electrode region of the n-type prefabricated structure, and the first predetermined electrode region is irradiated with a second laser beam to transform the first conductive metal precursor into a first metal electrode electrically connected to the n-type prefabricated structure; a second conductive metal precursor is deposited in the second predetermined electrode region of the p-type prefabricated structure, and the second predetermined electrode region is irradiated with a second laser beam to transform the second conductive metal precursor into a second metal electrode electrically connected to the p-type prefabricated structure.

[0009] An integrated heat treatment is performed on the n-type prefabricated structure, p-type prefabricated structure, first metal electrode, and second metal electrode formed on the substrate surface to completely ceramicize the n-type prefabricated structure into an n-type ceramic semiconductor micro / nano structure and the p-type prefabricated structure into a p-type ceramic semiconductor micro / nano structure. A ceramic heterojunction is formed at the contact interface between the n-type ceramic semiconductor micro / nano structure and the p-type ceramic semiconductor micro / nano structure. At the same time, the first metal electrode and the second metal electrode are densified to obtain an integrated micro / nano ceramic diode device.

[0010] In one embodiment, the n-type ceramic precursor includes a metal element source for forming n-type ceramic semiconductor micro / nano structures and an n-type dopant; the p-type ceramic precursor includes a transition metal element source and a p-type dopant.

[0011] In one embodiment, the n-type ceramic precursor is one or more of the precursor solutions doped with tin oxide, doped with zinc oxide, doped with titanium oxide, and indium tin oxide.

[0012] The p-type ceramic precursor is one or more combinations of precursor solutions doped with nickel oxide, doped with cuprous oxide, copper aluminum oxide, copper gallium oxide, and doped with tin oxide.

[0013] In one embodiment, both the first conductive metal precursor and the second conductive metal precursor are one of a metal nanoparticle slurry and a metal-organic compound solution.

[0014] In one embodiment, the metal nanoparticle slurry is one of silver nanoparticle slurry and gold nanoparticle slurry; the organometallic compound solution is a platinum organometallic compound solution.

[0015] In one embodiment, the first laser beam is a laser in the ultraviolet to visible light band, and the first laser energy of the first laser beam satisfies the curing energy threshold of the n-type ceramic precursor and the curing energy threshold of the p-type ceramic precursor, so as to induce the n-type ceramic precursor and the p-type ceramic precursor to undergo photocuring reaction.

[0016] The second laser beam is a high-energy laser, and the energy of the second laser beam performs photothermal reduction, sintering, or decomposition on the first conductive metal precursor and the second conductive metal precursor.

[0017] In one embodiment, the feature size of both the n-type prefabricated structure and the p-type prefabricated structure is 500 nm to 50 μm.

[0018] In one embodiment, the power of the first laser beam is 50mW to 300mW, and the scanning speed of the first laser beam is 10μm / s to 1000μm / s.

[0019] In one embodiment, the heat treatment temperature is 400℃~900℃, the heat treatment holding time is 0.5h~4h, and the heat treatment heating rate is 3℃ / min~5℃ / min.

[0020] Secondly, this application provides a micro / nano ceramic diode device, the device comprising an n-type ceramic semiconductor micro / nano structure, a p-type ceramic semiconductor micro / nano structure, a first metal electrode, and a second metal electrode integrally formed on a substrate;

[0021] The n-type ceramic semiconductor micro / nanostructure and the p-type ceramic semiconductor micro / nanostructure form a ceramic heterojunction at the contact interface;

[0022] The first metal electrode is electrically connected to the n-type ceramic semiconductor micro / nano structure, and the second metal electrode is electrically connected to the p-type ceramic semiconductor micro / nano structure.

[0023] In one embodiment, the material of the n-type ceramic semiconductor micro / nano structure is one or more of doped tin oxide, doped zinc oxide, doped titanium oxide, or indium tin oxide; the material of the p-type ceramic semiconductor micro / nano structure is one or more of doped nickel oxide, doped cuprous oxide, copper aluminum oxide, copper gallium oxide, or doped tin oxide; and the materials of the first metal electrode and the second metal electrode are one or more of silver, gold, and platinum.

[0024] As described above, the micro / nano diode laser additive manufacturing method and device based on organic precursor ceramics described in this application have the following beneficial effects:

[0025] This application achieves precise alignment of the n-type and p-type prefabricated structures, in-situ laser-induced connection of the first and second metal electrodes, and synchronous functionalization through integrated heat treatment. The entire process is completed on the same platform, realizing the micro-nano-scale integrated integration of three types of heterogeneous materials: n-type ceramic semiconductor micro-nano structures, p-type ceramic semiconductor micro-nano structures, and metal electrodes (first and second metal electrodes). This effectively ensures close contact and good electrical connection at each interface, solves the problems of size shrinkage, structural deformation, and difficulty in integrating heterogeneous materials that are prone to occur in traditional ceramic slurry additive manufacturing, and significantly improves the structural integrity and operational reliability of micro-nano ceramic diode devices. Attached Figure Description

[0026] Figure 1 The diagram shown is a flowchart of a micro / nano diode laser additive manufacturing method based on organic precursor ceramics, provided in an embodiment of this application.

[0027] Figure 2 This diagram illustrates a technical roadmap for a micro / nano diode laser additive manufacturing method based on organic precursor ceramics, as provided in an embodiment of this application.

[0028] Figure 3 The diagram shows a schematic of the structure of a micro / nano diode based on SnO2 / NiO organic precursor ceramic, generated as a specific exemplary embodiment of Embodiment 1 of this application.

[0029] Figure 4 The diagram shown is a schematic diagram of a micro / nano ceramic diode device structure provided as another exemplary embodiment of this application.

[0030] Explanation of reference numerals in the accompanying drawings: 1. Substrate; 101. n-type prefabricated structure; 102. p-type prefabricated structure; 11. n-type ceramic semiconductor micro / nano structure; 12. p-type ceramic semiconductor micro / nano structure; 111. First metal electrode; 121. Second metal electrode; 13. Ceramic heterojunction. Detailed Implementation

[0031] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, unless otherwise specified, the following embodiments and features in the embodiments can be combined with each other.

[0032] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. Therefore, the drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0033] To address the aforementioned technical challenges, this application proposes a laser additive manufacturing method and device for micro / nano diodes based on organic precursor ceramics. This method enables the micro / nano-scale integrated fabrication of three types of heterogeneous materials: n-type ceramic semiconductor micro / nano structures, p-type ceramic semiconductor micro / nano structures, and metal electrodes (first and second metal electrodes). It effectively ensures close contact and good electrical connection between the interfaces, solving the problems of size shrinkage, structural deformation, and difficulties in integrating heterogeneous materials that are prone to occur in traditional ceramic slurry additive manufacturing. This significantly improves the structural integrity and operational reliability of micro / nano ceramic diode devices.

[0034] The technical solutions in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0035] like Figure 1 and Figure 2 As shown, this embodiment provides a method for laser additive manufacturing of micro / nano diodes based on organic precursor ceramics. The method includes:

[0036] Step 100: Provide a substrate 1, deposit an n-type ceramic precursor on the surface of the substrate 1, and control a first laser beam to perform localized scanning irradiation on the n-type ceramic precursor according to a preset structural pattern, so that the n-type ceramic precursor in the corresponding area is solidified to form an n-type prefabricated structure 101; deposit a p-type ceramic precursor on the surface of the substrate 1, and control the first laser beam to perform localized scanning irradiation on the p-type ceramic precursor according to a preset structural pattern, so that the p-type ceramic precursor in the corresponding area is solidified to form a p-type prefabricated structure 102.

[0037] In some embodiments, the first laser beam may be generated by a diode laser, solid-state laser, fiber laser or femtosecond laser in the ultraviolet-visible band, preferably a 515nm visible diode laser or a 355nm solid-state laser.

[0038] In some embodiments, the substrate 1 is made of materials such as alumina, zirconium oxide, and silicon carbide. The preset structural pattern refers to a two-dimensional / quasi-three-dimensional geometric pattern set in advance in the computer control system according to the structural design requirements of the target micro / nano ceramic diode device. This pattern is used to form the n-type ceramic semiconductor micro / nano structure, the p-type ceramic semiconductor micro / nano structure, and the electrode connection area. It includes the outline dimensions, extension paths, junction contact positions of the n-type prefabricated structure 101 and the p-type prefabricated structure 102, as well as key geometric information such as the connection points between the first predetermined electrode area, the second predetermined electrode area, and the n-type prefabricated structure 101 and the p-type prefabricated structure 102. This information is the core basis for generating the laser scanning path. The design precision of the n-type prefabricated structure 101 and the p-type prefabricated structure 102 matches the micro / nano feature size of the target micro / nano ceramic diode device. It can be flexibly adjusted according to the structural requirements of the diode in different application scenarios. After its generation, it is directly imported into the motion control module of the laser direct writing system. The laser direct writing system automatically generates a precise scanning path for the first laser beam based on the geometric parameters of the preset structural pattern.

[0039] In some embodiments, the laser scanning path of the first laser beam can be flexibly adjusted using a preset structural pattern.

[0040] In this embodiment, a first laser beam is used for localized scanning to solidify the target, thereby achieving precise micro-nano-scale forming of n-type ceramic semiconductor micro-nano structures and p-type ceramic semiconductor micro-nano structures. This enables precise adjustment of the linewidth or dot diameter of the n-type ceramic semiconductor micro-nano structures and p-type ceramic semiconductor micro-nano structures.

[0041] In this embodiment, both the n-type ceramic precursor and the p-type ceramic precursor are liquid ceramic precursors.

[0042] In this embodiment, the n-type ceramic precursor and the p-type ceramic precursor are deposited by one or more of the following methods: drop coating, blade coating, or spin coating.

[0043] In this embodiment, the deposition path of the p-type ceramic precursor can be controlled by a high-precision displacement stage, and the formation position of the p-type prefabricated structure 102 can be monitored by an in-situ optical imaging system to achieve precise alignment between the p-type prefabricated structure 102 and the n-type prefabricated structure 101.

[0044] In some embodiments, the n-type ceramic precursor includes a metal element source for forming an n-type ceramic semiconductor and an n-type dopant; the p-type ceramic precursor includes a transition metal element source and a p-type dopant.

[0045] The metal element source for forming the n-type ceramic semiconductor is preferably a metal element source from Group IVA, Group IIB, or Group IIIA of the periodic table. Examples include tin, zinc, titanium, and indium sources.

[0046] Among them, the n-type dopant is an elemental compound such as antimony, fluorine, aluminum, and gallium that can achieve n-type doping modification.

[0047] Among them, p-type dopants are elemental compounds such as lithium, chlorine, and nitrogen that can achieve p-type doping modification.

[0048] In some embodiments, the n-type ceramic precursor is one or more combinations of precursor solutions doped with tin oxide, zinc oxide, titanium oxide, or indium tin oxide; the p-type ceramic precursor is one or more combinations of precursor solutions doped with nickel oxide, cuprous oxide, copper aluminum oxide, copper gallium oxide, or tin oxide.

[0049] The precursor solution for doped tin oxide is a solution containing a tin source and an antimony dopant, or a tin source and a fluorine dopant; the precursor solution for doped zinc oxide is a solution containing a zinc source and an aluminum dopant, or a zinc source and a gallium dopant, or a zinc source and an indium dopant; the precursor solution for doped titanium oxide is a solution containing a titanium source and a niobium dopant, or a titanium source and a tantalum dopant; and the precursor solution for indium tin oxide is a solution containing an indium source and a tin dopant.

[0050] The precursor solution for doped nickel oxide is a solution containing a nickel source and a lithium dopant; the precursor solution for doped cuprous oxide is a solution containing a copper source and a chlorine dopant or a copper source and a nitrogen dopant; the precursor solution for copper aluminum oxide is a mixed solution containing a copper source and an aluminum source; the precursor solution for copper gallium oxide is a mixed solution containing a copper source and a gallium source; and the precursor solution for doped tin oxide is a solution containing a tin source and a sodium dopant or a tin source and a potassium dopant.

[0051] This embodiment is based on the preparation of an n-type ceramic precursor using a metal element source for n-type ceramic semiconductor formation and the preparation of a p-type ceramic precursor using a transition metal element source. The resulting all-inorganic ceramic semiconductor structure, combined with a densified metal electrode, gives the generated diode device the inherent characteristics of high temperature resistance, high chemical inertness, and high mechanical strength. It can operate stably in harsh environments such as high temperature and corrosion where silicon-based devices and organic-based additive manufacturing devices cannot operate, thus solving the problems of narrow operating temperature range and poor environmental adaptability of existing electronic additive manufacturing devices.

[0052] In this embodiment, the first laser beam is a laser in the ultraviolet to visible light band, and the first laser energy of the first laser beam satisfies the curing energy threshold of the n-type ceramic precursor and the curing energy threshold of the p-type ceramic precursor, so as to induce the photocuring reaction of the n-type ceramic precursor and the p-type ceramic precursor.

[0053] Wherein, the curing energy threshold of the n-type ceramic precursor refers to the minimum unit area laser energy density of the n-type ceramic precursor in this embodiment, which undergoes photocuring reaction to transform from a liquid state into a solid gel-like pre-structure; the curing energy threshold of the p-type ceramic precursor refers to the minimum unit area laser energy density of the p-type ceramic precursor in this embodiment, which undergoes photocuring reaction to transform from a liquid state into a solid gel-like pre-structure.

[0054] Specifically, when the energy density per unit area of ​​the first laser beam on the surface of the n-type ceramic precursor material is not lower than the curing energy threshold, the n-type ceramic precursor can absorb enough laser energy to trigger the photocuring reaction between molecules, thus achieving the transition from liquid to solid state. If the energy density per unit area on the surface of the n-type ceramic precursor material is lower than the curing energy threshold, the n-type ceramic precursor cannot absorb enough energy, the photocuring reaction cannot occur, and the n-type ceramic precursor remains in a liquid state. Similarly, if the energy density per unit area on the surface of the p-type ceramic precursor material is lower than the curing energy threshold, the p-type ceramic precursor cannot absorb enough energy, the photocuring reaction cannot occur, and the p-type ceramic precursor remains in a liquid state.

[0055] In some embodiments, after the n-type ceramic precursor and the p-type ceramic precursor undergo photocuring, the uncured n-type ceramic precursor and the uncured p-type ceramic precursor are removed to avoid the interference of stray structures on the performance of the subsequently generated micro / nano ceramic diode devices.

[0056] Specifically, a clean insulating substrate is provided. An n-type liquid ceramic precursor is prepared by drop coating, scraping, or spin coating. A first laser beam is controlled to perform localized scanning irradiation on the n-type liquid ceramic precursor according to a preset structural pattern, initiating a photocuring reaction of the n-type liquid ceramic precursor to form an incompletely ceramized n-type prefabricated structure 101 with a defined shape and position. The uncured n-type liquid ceramic precursor is then removed. Near the n-type liquid ceramic precursor, a p-type liquid ceramic precursor is prepared on the insulating substrate by drop coating, scraping, or spin coating. A first laser beam is controlled to perform localized scanning irradiation on the p-type liquid ceramic precursor according to a preset structural pattern, initiating a photocuring reaction of the p-type liquid ceramic precursor to form an incompletely ceramized p-type prefabricated structure 102 with a defined shape and position. The uncured p-type liquid ceramic precursor is then removed.

[0057] In this embodiment, the photocuring reaction is a photopolymerization reaction or a photocrosslinking reaction.

[0058] In this embodiment, photocuring is used to ensure that both n-type and p-type ceramic precursors can be cured efficiently, thereby improving the compatibility of ceramic precursor materials.

[0059] This embodiment uses the characteristic of precise matching of the first laser energy with the curing energy threshold to avoid over-ablation or incomplete curing of the n-type ceramic precursor and p-type ceramic precursor, thus ensuring the morphological integrity and structural compactness of the n-type ceramic semiconductor micro / nano structure and the p-type ceramic semiconductor micro / nano structure.

[0060] In this embodiment, the power and scanning speed of the first laser beam can be adjusted according to the actual needs of those skilled in the art to control the size, morphology and preliminary electrical properties of the n-type ceramic semiconductor micro / nanostructure and the p-type ceramic semiconductor micro / nanostructure.

[0061] The adjustable laser path of the first laser beam in this embodiment, along with the diversity of the n-type and p-type ceramic precursor materials, allows this application to flexibly fabricate micro / nano ceramic diode devices with different functions and configurations by changing the composition of the n-type and p-type ceramic precursors and adjusting the laser scanning path of the first laser beam. This eliminates the need for expensive photolithography masks and vacuum equipment, simplifies the process steps, increases material utilization, and facilitates integration with other micro / nano electronic systems. It has broad application prospects in fields such as flexible electronics, three-dimensional integrated circuits, and on-chip laboratories.

[0062] In this embodiment, the feature size of both the n-type prefabricated structure 101 and the p-type prefabricated structure 102 is 500nm~50um.

[0063] The feature dimension is the range of feature line width or point diameter.

[0064] In this embodiment, the characteristic dimensions of the n-type prefabricated structure 101 and the p-type prefabricated structure 102 are controlled by the unit area energy E of the first laser beam on the surface of the ceramic precursor (n-type ceramic precursor or p-type ceramic precursor) and the scanning speed V of the first laser beam, satisfying the formula d=k*ln(E / E th ), where d is the characteristic dimension (the characteristic dimension of the n-type prefabricated structure 101 or the characteristic dimension of the p-type prefabricated structure 102), k is the proportionality constant, and E th The curing energy threshold (curing energy threshold for n-type ceramic precursors or curing energy threshold for p-type ceramic precursors).

[0065] Wherein, the energy per unit area E satisfies E th <E< the over-ablation energy density of the ceramic precursor, and the formula for calculating the energy per unit area E is: E=P / (v×d), where P is the power of the first laser beam and v is the scanning speed of the first laser beam.

[0066] In this embodiment, the power of the first laser beam is set to 50mW~300mW, and the scanning speed of the first laser beam is set to 10um / s~1000um / s, so that the feature size d can be continuously adjusted to the micro-nano scale range in a logarithmic relationship with the increase of the energy per unit area E.

[0067] In this embodiment, the metal element source and dopant of the p-type ceramic precursor are specifically matched, forming a material complementarity with the n-type ceramic precursor. This ensures that after ceramization, the two can form a ceramic heterojunction with good rectification characteristics, solving the problem that traditional ceramic additive manufacturing is difficult to achieve heterogeneous semiconductor junction formation. At the same time, the formation of both the n-type prefabricated structure 101 and the p-type prefabricated structure 102 is carried out by localized scanning irradiation with the first laser beam, ensuring the matching of the forming accuracy of the n-type prefabricated structure 101 and the p-type prefabricated structure 102. This achieves precise micro-nano scale contact in the heterojunction region, and the contact length can be flexibly adjusted, effectively ensuring the interface bonding quality of the ceramic heterojunction, reducing interface resistance, and improving the electrical conductivity of the integrated micro-nano ceramic diode device.

[0068] Step 200: Deposit a first conductive metal precursor in the first predetermined electrode region of the n-type prefabricated structure 101, and irradiate the first predetermined electrode region with a second laser beam to transform the first conductive metal precursor into a first metal electrode 111 electrically connected to the n-type prefabricated structure 101; deposit a second conductive metal precursor in the second predetermined electrode region of the p-type prefabricated structure 102, and irradiate the second predetermined electrode region with a second laser beam to transform the second conductive metal precursor into a second metal electrode 121 electrically connected to the p-type prefabricated structure 102.

[0069] In some embodiments, the second laser beam may be generated by a near-infrared fiber laser, femtosecond laser, or diode laser.

[0070] In this embodiment, the second laser beam is a high-energy laser, and the energy of the second laser beam is used to perform photothermal reduction, sintering, or decomposition on the first conductive metal precursor and the second conductive metal precursor.

[0071] The high-energy laser is preferably a near-infrared laser or a femtosecond laser. When the first predetermined electrode region is irradiated, the high-energy effect of the laser enables the first conductive metal precursor to undergo photothermal reduction, sintering, or decomposition, transforming the first conductive metal precursor into a highly conductive first metal electrode 111; similarly, the second conductive metal precursor is transformed into a highly conductive second metal electrode 121.

[0072] This embodiment utilizes the high energy density characteristic of high-energy lasers to achieve rapid and efficient conversion between the first conductive metal precursor and the second conductive metal precursor, avoiding the problems of insufficient forming and poor conductivity of the first metal electrode 111 and the second metal electrode 121 caused by low-energy lasers.

[0073] In this embodiment, the first predetermined electrode region and the second predetermined electrode region are dedicated regions marked on the n-type prefabricated structure 101 and the p-type prefabricated structure 102, respectively, according to the design requirements of the preset structural pattern, for forming metal electrodes. They are also the core contact regions for achieving electrical connection between the metal electrode and the ceramic semiconductor micro / nano structure. The first predetermined electrode region is located at the end of the n-type prefabricated structure 101 away from the ceramic heterojunction, and the second predetermined electrode region is located at the end of the p-type prefabricated structure 102 away from the ceramic heterojunction. The two are symmetrically distributed on the ceramic heterojunction. Both sides of the junction have their outline shape and size pre-designed by a preset structural pattern, and the first predetermined electrode area matches the deposition range of the first conductive metal precursor and the size of the first metal electrode 111; the second predetermined electrode area matches the deposition range of the second conductive metal precursor and the size of the second metal electrode 121. That is, the core function of the first predetermined electrode area and the second predetermined electrode area is to provide a forming substrate 1 for the metal electrode, realize the precise electrical connection between the metal electrode and the n-type and p-type ceramic semiconductor micro-nano structures, and ensure the integrity of the current conduction path of the diode device.

[0074] In some embodiments, the first conductive metal precursor and the second conductive metal precursor are both one of a metal nanoparticle slurry and a metal-organic compound solution.

[0075] The metal nanoparticle slurry is either a silver nanoparticle slurry or a gold nanoparticle slurry; the organometallic compound solution is a platinum organometallic compound solution.

[0076] This embodiment is compatible with various high-performance conductive metal materials such as silver, gold, and platinum, taking into account the conductivity, corrosion resistance, and interfacial bonding of the electrode with ceramic semiconductors.

[0077] In some embodiments, after the first conductive metal precursor is converted into the first metal electrode 111, the method further includes removing the first conductive metal precursor that has not been converted into the first metal electrode 111; after the second conductive metal precursor is converted into the second metal electrode 121, the method further includes removing the second conductive metal precursor that has not been converted into the second metal electrode 121.

[0078] Specifically, a first conductive metal precursor is deposited in the first predetermined electrode region of the n-type ceramic semiconductor micro / nano structure. The first predetermined electrode region is irradiated with a second laser beam. Through photothermal reduction, sintering, or decomposition effects, the first conductive metal precursor is transformed into a highly conductive first metal electrode 111 electrically connected to the n-type ceramic semiconductor micro / nano structure. The first conductive metal precursor that has not been transformed into the first metal electrode 111 is removed. The second conductive metal precursor is transformed into a highly conductive second metal electrode 121 electrically connected to the n-type ceramic semiconductor micro / nano structure using the same process principle. The second conductive metal precursor that has not been transformed into the second metal electrode 121 is removed.

[0079] This embodiment relies on the core process features of laser localized scanning photocuring and high-energy laser metal electrode induced molding, combined with the functionalized material constraints of n-type and p-type ceramic precursors, to realize additive manufacturing from liquid precursors to solid devices. It eliminates the need for subtractive etching or complex post-processing in traditional ceramic processing, and can precisely manufacture micro-nano ceramic diode devices with complete structures. It solves the problem of difficult micro-nano processing caused by the high hardness and brittleness of ceramic materials, and fills the technological gap in additive manufacturing of ceramic-based micro-nano semiconductor devices.

[0080] Step 300: The n-type prefabricated structure 101, p-type prefabricated structure 102, first metal electrode 111 and second metal electrode 121 formed on the surface of the substrate 1 are subjected to integrated heat treatment, so that the n-type prefabricated structure 101 is completely ceramized into an n-type ceramic semiconductor micro / nano structure 11 and the p-type prefabricated structure 102 is completely ceramized into a p-type ceramic semiconductor micro / nano structure 12, and a ceramic heterojunction is formed at the contact interface between the n-type ceramic semiconductor micro / nano structure and the p-type ceramic semiconductor micro / nano structure. At the same time, the first metal electrode 111 and the second metal electrode 121 are densified to obtain an integrated micro / nano ceramic diode device.

[0081] In some embodiments, the equipment for integrated heat treatment can be a muffle furnace or a tube furnace.

[0082] In some embodiments, the heat treatment temperature is 400℃~900℃, the heat treatment holding time is 0.5h~4h, and the heat treatment heating rate is 3℃ / min~5℃ / min.

[0083] In this embodiment, the heat treatment can be performed in air, oxygen, or an inert atmosphere.

[0084] Specifically, the n-type ceramic semiconductor micro / nanostructure, p-type ceramic semiconductor micro / nanostructure, first metal electrode 111, and second metal electrode 121, solidified on the surface of substrate 1, undergo integrated heat treatment. During the heat treatment process, the organic components in the n-type ceramic semiconductor micro / nanostructure are completely decomposed, inorganicized, and crystallized to form a high-performance n-type ceramic semiconductor micro / nanostructure; the organic components in the p-type ceramic semiconductor micro / nanostructure are also completely decomposed, inorganicized, and crystallized to form a high-performance p-type ceramic semiconductor micro / nanostructure. Simultaneously, the first metal electrode 111 and the second metal electrode 121 are further densified, resulting in an integrated, fully functional micro / nano ceramic diode device.

[0085] This embodiment utilizes the integrated heat treatment technology to simultaneously densify the prefabricated structure and the metal electrode, avoiding device structure deformation and interface separation caused by step-by-step heat treatment. It achieves integrated integration of the prefabricated structure and the metal electrode, solving the problem of difficult integration of heterogeneous materials in traditional ceramic processing. During the heat treatment process, atomic-level interdiffusion of the ceramic heterojunction is achieved, strengthening the metallurgical bonding of the junction region (referring to the interface between the n-type ceramic semiconductor micro / nanostructure and the p-type ceramic semiconductor micro / nanostructure), forming a ceramic heterojunction with excellent interface characteristics. At the same time, the densification of the metal electrode significantly reduces its resistivity, ensuring the rectification performance and electrical stability of the generated micro / nano ceramic diode device.

[0086] In a specific exemplary embodiment, an alumina ceramic substrate with dimensions of 20 mm × 20 mm is provided after being ultrasonically cleaned and dried with acetone, ethanol and deionized water.

[0087] A SnO2:Sb liquid precursor was deposited on the surface of the alumina ceramic substrate. A first laser beam with a power of 100mW, a wavelength of 515nm, and a scanning speed of 100μm / s was used to scan the SnO2:Sb liquid precursor, inducing a photocuring reaction that rapidly gelled and solidified the precursor, forming brown n-type SnO2:Sb gel lines attached to the alumina ceramic substrate. The alumina ceramic substrate with the n-type SnO2:Sb gel lines was then ultrasonically cleaned in anhydrous ethanol for 30 seconds, followed by drying with a nitrogen gun to remove the uncured SnO2:Sb liquid precursor, leaving only clearly defined brown n-type SnO2:Sb gel lines on the alumina ceramic substrate.

[0088] A first laser beam with the same power, wavelength, and scanning speed is used to scan the NiO:Li liquid precursor, inducing a photocuring reaction that rapidly gels and solidifies the precursor, forming green p-type NiO:Li gel lines attached to the alumina ceramic substrate. A high-precision displacement stage is used to precisely position the n-type SnO2:Sb gel lines and the p-type NiO:Li gel lines, ensuring their ends are in contact with each other at a length of approximately 3 μm. The alumina ceramic substrate with the p-type NiO:Li gel lines is then ultrasonically cleaned in anhydrous ethanol for 30 seconds, followed by drying with a nitrogen gun to remove the uncured p-type NiO:Li liquid precursor, leaving only clearly defined green p-type NiO:Li gel lines on the alumina ceramic substrate, forming a clean contact interface with the n-type SnO2:Sb gel lines, i.e., a ceramic heterojunction.

[0089] The SnO2:Sb liquid precursor was formed by dissolving 0.5 mol / L tin acetate in ethylene glycol methyl ether, stirring until dissolved, and then adding antimony trichloride at 5% of the tin molar ratio as an n-type dopant, followed by continuous stirring for 2 hours. The NiO:Li liquid precursor was formed by dissolving 0.5 mol / L nickel acetate tetrahydrate in ethylene glycol methyl ether, stirring until dissolved, and then adding lithium acetate at 2% of the nickel molar ratio as a p-type dopant, followed by continuous stirring for 2 hours.

[0090] The process parameters for SnO2:Sb liquid precursor and NiO:Li liquid precursor meet the following requirements: dynamic viscosity range of 5~80 mPa·s (25℃), curing threshold energy density E th The range is 0.05~0.2J / cm², and the energy density E required for stable curing is in the range of 0.2~1.5J / cm²; or the solid content of the conductive metal precursor in the organometallic compound solution is controlled between 10~40wt%, and the solvent system is ethylene glycol methyl ether or an organic solvent with a similar evaporation rate.

[0091] Silver nanoparticle ink was coated at the ends of SnO2:Sb gel lines away from the ceramic heterojunction, and at the ends of NiO:Li gel lines away from the ceramic heterojunction. A femtosecond laser with a power of 1.5W, a scanning speed of 10mm / s, and a wavelength of 1064nm was used to scan the areas coated with silver nanoparticle ink. The photothermal effect of the femtosecond laser caused the silver nanoparticles to sinter and fuse instantaneously, forming dense silver metal electrodes at the ends of the SnO2:Sb and NiO:Li gel lines away from the ceramic heterojunction, respectively. These silver metal electrodes formed good mechanical and preliminary electrical contacts with the SnO2:Sb and NiO:Li gel lines below. The solid content of the silver nanoparticle ink was 20wt%, the dynamic viscosity range was 50~500mPa·s (25℃), and the curing threshold energy density E0 was [not specified]. th The range is 0.3~0.8 J / cm², and the energy density E required for stable curing ranges from 0.8~3 J / cm².

[0092] The samples of NiO:Li gel lines, SnO2:Sb gel lines, and silver metal electrodes formed on the surfaces of the NiO:Li gel lines and SnO2:Sb gel lines respectively, which were cured on the surface of the alumina ceramic substrate in the above steps, were placed in a tube furnace. The tube furnace was heated to 600°C at a rate of 5°C / min under an air atmosphere and held at that temperature for 1 hour. Then, the samples were cooled to room temperature along with the tube furnace. During this process, the organic components in the n-type SnO2:Sb gel wire and the p-type NiO:Li gel wire are completely decomposed and volatilized. The acetates of Sn and Ni are converted into crystallized oxides, and the dopants are activated, forming polycrystalline SnO2:Sb semiconductor wires and polycrystalline NiO:Li semiconductor wires, respectively. In the junction region where the ceramic heterojunction is formed, the polycrystalline SnO2:Sb semiconductor wires and polycrystalline NiO:Li semiconductor wires form a tight SnO2 / NiO heterojunction at high temperature. The silver metal electrode is further sintered, the resistivity is significantly reduced, and an ohmic contact is formed with the polycrystalline SnO2:Sb semiconductor wires and polycrystalline NiO:Li semiconductor wires. The schematic diagram of the generated micro / nano diode based on the SnO2 / NiO organic precursor ceramic is shown below. Figure 3 As shown.

[0093] In another specific exemplary embodiment, a quartz glass substrate is provided after being ultrasonically cleaned and dried with acetone, ethanol and deionized water.

[0094] A ZnO:Al sol precursor was deposited on the surface of the quartz glass substrate. A first laser beam with a power of 80mW, a wavelength of 515nm, and a scanning speed of 80μm / s was used to scan the ZnO:Al sol precursor, inducing a photocuring reaction that rapidly gelled and solidified the precursor, forming transparent n-type ZnO:Al gel lines attached to the quartz glass substrate. The quartz glass substrate with the n-type ZnO:Al gel lines was then ultrasonically cleaned in anhydrous ethanol for 30 seconds, followed by drying with a nitrogen gun to remove the uncured ZnO:Al liquid precursor, leaving only clearly defined n-type ZnO:Al gel lines on the quartz glass substrate.

[0095] A first laser beam with the same power, wavelength, and scanning speed is used to scan the basic copper complex precursor of Cu2O, initiating a photocuring reaction that rapidly gels and solidifies the precursor, forming a brownish-red p-type Cu2O gel line attached to the quartz glass substrate. A high-precision displacement stage is used to precisely position the n-type ZnO:Al gel line and the p-type Cu2O gel line, ensuring their ends are in contact with each other for approximately 3 μm. Simultaneously, in-situ optical monitoring ensures that the n-type ZnO:Al gel line and the p-type Cu2O gel line are precisely parallel and aligned at one end. A quartz glass substrate with p-type Cu2O gel lines attached to its surface was ultrasonically cleaned in anhydrous ethanol for 30 seconds, and then dried with a nitrogen gun to remove the uncured alkaline copper complex precursor of Cu2O, leaving only clearly outlined green p-type Cu2O gel lines on the quartz glass substrate, forming a clean contact interface with the n-type ZnO:Al gel lines, i.e., a ceramic heterojunction.

[0096] The ZnO:Al sol precursor is formed by dissolving 0.4 mol / L zinc acetate dihydrate in ethanol, adding aluminum chloride at 3% of the zinc molar ratio as an n-type dopant, and adding acetylacetone at 1-10% of the zinc molar ratio as a stabilizer, followed by stirring. The basic copper complex precursor of Cu2O is formed by dissolving 0.3 mol / L copper acetate (II) in a mixed solvent of deionized water and ethanol, adding glucose at 2-10 times the molar amount of copper ions as a reducing agent, and adjusting the pH to acidic with hydrochloric acid.

[0097] The process parameters for the ZnO:Al sol precursor and the Cu2O alkaline copper complex precursor meet the following requirements: dynamic viscosity range of 5~60 mPa·s (25℃), and curing threshold energy density E. thThe range is 0.04~0.15J / cm², the energy density E required for stable curing is in the range of 0.15~1.5J / cm², or the solid content of the organometallic precursor is controlled between 5~30wt%, and the volume fraction of ethanol is in the range of 30~70%.

[0098] Silver nanoparticle ink was coated at one end of the ZnO:Al gel line away from the ceramic heterojunction, and at the other end of the Cu2O gel line away from the ceramic heterojunction. A pulsed laser with a power of 0.8W and a wavelength of 515nm was used to irradiate the area coated with silver nanoparticle ink. The photothermal effect of the pulsed laser caused the silver nanoparticles to undergo redox reactions with Cu2O and ZnO:Al, respectively, transforming Au... 3+ Ions are reduced to Au atoms and aggregate to form a film, creating a gold metal electrode. Even though dense gold metal electrodes are formed at the ends of the ZnO:Al gel lines and Cu2O gel lines respectively, away from the ceramic heterojunction, these gold metal electrodes form good mechanical and preliminary electrical contacts with the underlying Cu2O and ZnO:Al gel lines. The silver nanoparticle ink is a 0.1 mol / L triethylene glycol solution of chloroauric acid; the precursor concentration of the silver nanoparticle ink ranges from 0.05 to 0.2 mol / L, the dynamic viscosity ranges from 10 to 120 mPa·s (25℃), and the curing threshold energy density E0 is [not specified]. th The range is 0.2~0.6 J / cm², and the energy density E required for stable curing ranges from 0.5~2.5 J / cm².

[0099] The ZnO:Al gel wires, Cu2O gel wires, and gold metal electrodes formed on the surfaces of the ZnO:Al gel wires and Cu2O gel wires respectively, which were cured on the surface of the alumina ceramic substrate in the above steps, were placed in a tube furnace. The sample was heated to 500°C at a rate of 3°C / min under a flowing nitrogen atmosphere and held at that temperature for 2 hours. Then, the sample was cooled to room temperature with the tube furnace. In this process, the organic components in the n-type ZnO:Al gel wire and the p-type Cu2O gel wire are completely decomposed and volatilized. The acetates of Zn and Cu are transformed into crystallized oxides, and the dopants are activated to form polycrystalline ZnO:Al semiconductor wires and polycrystalline Cu2O semiconductor wires, respectively. In the junction region where the ceramic heterojunction is formed, the polycrystalline ZnO:Al semiconductor wires and polycrystalline Cu2O semiconductor wires form a compact ZnO:Al / Cu2O heterojunction at high temperature. The gold metal electrode is further purified and densified, and the resistivity is significantly reduced, generating micro / nano diodes based on ZnO / Cu2O organic precursor ceramics.

[0100] In another exemplary embodiment, such as Figure 4As shown, this application also provides a micro / nano ceramic diode device, which is fabricated by the above-described laser additive manufacturing method for micro / nano diodes based on organic precursor ceramics. The device includes an n-type ceramic semiconductor micro / nano structure 11, a p-type ceramic semiconductor micro / nano structure 12, a first metal electrode 111, and a second metal electrode 121 integrally formed on a substrate 1. The n-type ceramic semiconductor micro / nano structure 11 and the p-type ceramic semiconductor micro / nano structure 12 form a ceramic heterojunction 13 at the contact interface. The first metal electrode 111 is electrically connected to the n-type ceramic semiconductor micro / nano structure 11, and the second metal electrode 121 is electrically connected to the p-type ceramic semiconductor micro / nano structure 12. The n-type ceramic semiconductor micro / nano structure 11, the p-type ceramic semiconductor micro / nano structure 12, the first metal electrode 111, and the second metal electrode 121 are integrally formed through laser additive manufacturing and integrated heat treatment.

[0101] The micro / nano ceramic diode device is an all-inorganic ceramic / metal composite structure, the ceramic heterojunction is a pn-type heterojunction, the overall feature size of the micro / nano ceramic diode device is 1μm~100μm, and the contact length between the n-type ceramic semiconductor micro / nano structure 11 and the p-type ceramic semiconductor micro / nano structure 12 is 1μm~5μm.

[0102] In some embodiments, the material of the n-type ceramic semiconductor micro / nano structure 11 is one or more of doped tin oxide, doped zinc oxide, doped titanium oxide, or indium tin oxide; the material of the p-type ceramic semiconductor micro / nano structure 12 is one or more of doped nickel oxide, doped cuprous oxide, copper aluminum oxide, copper gallium oxide, or doped tin oxide; and the material of the first metal electrode 111 and the second metal electrode 121 is one of silver, gold, or platinum.

[0103] The micro-nano ceramic diode device generated in this embodiment realizes the micro-nano scale integrated molding of ceramic semiconductor and metal electrode, which solves the problems of difficult micro-nano molding of traditional ceramic processing and difficulty in integrated integration of heterogeneous materials.

[0104] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. A method for laser additive manufacturing of micro / nano diodes based on organic precursor ceramics, characterized in that, The method includes: A substrate is provided, an n-type ceramic precursor is deposited on the surface of the substrate, and a first laser beam is controlled to perform localized scanning irradiation on the n-type ceramic precursor according to a preset structural pattern, so that the n-type ceramic precursor in the corresponding region is solidified to form an n-type prefabricated structure; a p-type ceramic precursor is deposited on the surface of the substrate, and the first laser beam is controlled to perform localized scanning irradiation on the p-type ceramic precursor according to a preset structural pattern, so that the p-type ceramic precursor in the corresponding region is solidified to form a p-type prefabricated structure. A first conductive metal precursor is deposited in the first predetermined electrode region of the n-type prefabricated structure, and the first predetermined electrode region is irradiated with a second laser beam to transform the first conductive metal precursor into a first metal electrode electrically connected to the n-type prefabricated structure; a second conductive metal precursor is deposited in the second predetermined electrode region of the p-type prefabricated structure, and the second predetermined electrode region is irradiated with a second laser beam to transform the second conductive metal precursor into a second metal electrode electrically connected to the p-type prefabricated structure. An integrated heat treatment is performed on the n-type prefabricated structure, p-type prefabricated structure, first metal electrode, and second metal electrode formed on the substrate surface to completely ceramicize the n-type prefabricated structure into an n-type ceramic semiconductor micro / nano structure and the p-type prefabricated structure into a p-type ceramic semiconductor micro / nano structure. A ceramic heterojunction is formed at the contact interface between the n-type ceramic semiconductor micro / nano structure and the p-type ceramic semiconductor micro / nano structure. At the same time, the first metal electrode and the second metal electrode are densified to obtain an integrated micro / nano ceramic diode device.

2. The method according to claim 1, characterized in that, The n-type ceramic precursor includes a metal element source for forming n-type ceramic semiconductor micro / nano structures and an n-type dopant; the p-type ceramic precursor includes a transition metal element source and a p-type dopant.

3. The method according to claim 2, characterized in that, The n-type ceramic precursor is one or more of the precursor solutions doped with tin oxide, zinc oxide, titanium oxide, and indium tin oxide. The p-type ceramic precursor is one or more combinations of precursor solutions doped with nickel oxide, doped with cuprous oxide, copper aluminum oxide, copper gallium oxide, and doped with tin oxide.

4. The method according to claim 1, characterized in that, Both the first conductive metal precursor and the second conductive metal precursor are one of metal nanoparticle slurry and metal-organic compound solution.

5. The method according to claim 4, characterized in that, The metal nanoparticle slurry is one of silver nanoparticle slurry and gold nanoparticle slurry; the organometallic compound solution is a platinum organometallic compound solution.

6. The method according to claim 1, characterized in that, The first laser beam is a laser in the ultraviolet to visible light band, and the first laser energy of the first laser beam satisfies the curing energy threshold of the n-type ceramic precursor and the curing energy threshold of the p-type ceramic precursor, so as to induce the photocuring reaction of the n-type ceramic precursor and the p-type ceramic precursor. The second laser beam is a high-energy laser, and the energy of the second laser beam performs photothermal reduction, sintering, or decomposition on the first conductive metal precursor and the second conductive metal precursor.

7. The method according to claim 1, characterized in that, The characteristic dimensions of both the n-type prefabricated structure and the p-type prefabricated structure are 500 nm to 50 μm.

8. The method according to claim 7, characterized in that, The power of the first laser beam is 50mW~300mW, and the scanning speed of the first laser beam is 10μm / s~1000μm / s.

9. The method according to claim 1, characterized in that, The heat treatment temperature is 400℃~900℃, the heat treatment holding time is 0.5h~4h, and the heat treatment heating rate is 3℃ / min~5℃ / min.

10. A micro / nano ceramic diode device, characterized in that, The device includes an n-type ceramic semiconductor micro / nano structure, a p-type ceramic semiconductor micro / nano structure, a first metal electrode, and a second metal electrode integrally formed on a substrate. The n-type ceramic semiconductor micro / nanostructure and the p-type ceramic semiconductor micro / nanostructure form a ceramic heterojunction at the contact interface; The first metal electrode is electrically connected to the n-type ceramic semiconductor micro / nano structure, and the second metal electrode is electrically connected to the p-type ceramic semiconductor micro / nano structure.

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