Method for precisely modulating the microstructure of silicon oxide thin films rich in silicon and products made therefrom
By combining transmission electron microscopy heating with electron beam irradiation, the problem of SiOx film and substrate damage in existing technologies has been solved, enabling the precise preparation and damage-free processing of nanocrystalline silicon.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GUANGDONG INST OF SEMICON IND TECH
- Filing Date
- 2022-10-28
- Publication Date
- 2026-06-02
AI Technical Summary
Existing technologies often cause irreversible damage to the SiOx film and substrate when preparing silicon dioxide films embedded with silicon nanocrystals, making it difficult to achieve precise control and efficient preparation of silicon nanocrystals.
In-situ thermal annealing of SiOx thin films was performed using a combination of transmission electron microscopy heating and electron beam irradiation. By controlling the heating rate, electron beam density, and irradiation time, precise control and rapid thermal annealing at the nanoscale were achieved, avoiding damage.
Precise preparation of nanocrystalline silicon was achieved, avoiding damage to SiOx films and substrates caused by thermal annealing, and improving preparation efficiency and accuracy.
Smart Images
Figure CN115874263B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for modulating the microstructure of silicon-rich silicon oxide thin films, specifically to a method for precisely modulating the microstructure of silicon-rich silicon oxide thin films and the resulting product. Background Technology
[0002] Because silicon with a low-dimensional structure (i.e., nano-silicon) can improve the quantum efficiency of light emission, and silicon dioxide materials containing nano-silicon have good thermal stability, the preparation method of silicon dioxide embedded with nano-silicon has attracted widespread attention.
[0003] Currently, the main method for preparing silicon dioxide containing nano-silicon is through the processing of silicon-rich SiO₂. x The (i.e., silicon-rich silicon oxide) thin film is annealed to bring the metastable SiO2 film to a stable state. x After annealing, it decomposes into two thermodynamically stable phases: nano-silicon and silicon dioxide, with the nano-silicon embedded in the silicon dioxide.
[0004] For SiO x There are two main methods for annealing thin films: thermal annealing and laser annealing.
[0005] Laser annealing is typically used for SiO₂. x During the annealing process of the thin film, the SiO2-bearing film is subjected to... x The substrate of the thin film may absorb a certain amount of energy through molecular vibration and thermal motion, and some SiO2... x The energy absorbed by the thin film is also transferred to the substrate through thermal conduction, causing SiO2 to... x The temperature of the thin film is not high enough to generate silicon nanocrystals. Therefore, high-energy-density lasers are needed to enhance the SiO2 production process. x Annealing temperature of thin films. However, high energy density lasers are used for SiO2. x Annealing the thin film will affect SiO x The thin film caused some irreversible damage, including damage due to laser and SiO2. x Thermal effects between thin films (i.e., SiO2) x After the thin film absorbs laser energy, it generates a non-uniform temperature field, causing SiO2 to... x Changes in the structure and properties of SiO2 lead to x The thin film suffered thermal stress damage and melting failure; and due to laser and SiO x The field effect between thin films makes SiO x The thin film generates plasma on its surface due to the electromagnetic effect of the laser, thereby causing SiO2 to... x The structure of the thin film was damaged.
[0006] And using hot annealing for SiO x During the annealing process of thin films, it is generally necessary to perform the annealing treatment at a relatively high temperature. This is because when the annealing temperature is between 1173K and 1223K, SiO2... x The thin film mainly forms silicon clusters, requiring the annealing temperature to be maintained above 1273K for a period of time in order to achieve the desired effect on SiO₂. x The presence of nanocrystalline silicon was observed in the thin film, whereas existing thermal annealing processes typically involve removing the SiO₂ from the film. x The thin film is placed in an annealing furnace for annealing treatment, which requires the SiO2 film to be annealed. x The thin film undergoes overall thermal annealing; however, thermal annealing requires high annealing temperatures and long annealing times, which is detrimental to the SiO2 film. x Overall thermal annealing of thin films can easily cause SiO2 formation. x Damage to the thin film and substrate. It is evident that thermal annealing makes it difficult to obtain nano-silicon embedded in silica with precise nano-silicon crystal size, good luminescence intensity, and low damage.
[0007] Therefore, a method for treating SiO2 is sought. x The preparation method of silicon dioxide containing nano-silicon crystals without damaging the thin film and substrate is an urgent problem to be solved in the preparation of silicon dioxide embedded with nano-silicon crystals. Summary of the Invention
[0008] To address at least one of the aforementioned problems, the inventors conducted extensive research and experiments, discovering that simultaneously heating the silicon-rich silicon oxide film and irradiating it with an electron beam effectively improves the silicon oxide film's performance. x Phase decomposition of thin films is promoted, specifically, electron beam irradiation at high temperatures promotes the decomposition of SiO₂. x The phase separation process of the thin film was facilitated; simultaneously, by heating the thermionic source in the transmission electron microscope, the electrons in the thermionic source could gain sufficient energy to overcome the surface barrier preventing them from leaving, thus forming a potential for irradiating SiO2. x Electron beams in thin films. Therefore, SiO₂ irradiated by an electron beam passed through a transmission electron microscope... x Simultaneously, the thin film also affects SiO x The thin film is heated to achieve SiO2. x The thermal annealing of thin films can greatly accelerate the SiO2 process. x The thermal annealing rate of the thin film should be adjusted to avoid SiO2 buildup caused by prolonged annealing. x Damage to the thin film and substrate; moreover, due to the ultra-high resolution of transmission electron microscopy (TEM), its research scale can reach the nanometer scale, by heating SiO in TEM. x Thin film, simultaneously in SiOx Silicon dioxide embedded with nano-silicon crystals can be prepared by irradiating thin films with electron beams. This method allows for precise control of the preparation area of the nano-silicon crystals within the region requiring processing, and the control of the processing area can be precisely controlled down to the nanometer level.
[0009] Therefore, according to one aspect of the present invention, a method for precisely modulating the microstructure of silicon-rich silicon oxide thin films is provided, comprising the following steps:
[0010] S20: In-situ heating of SiO2 in transmission electron microscopy x Simultaneously, the electron beam generated by transmission electron microscopy was used to irradiate the SiO2 thin film sample. x On thin film samples, to achieve SiO x Thermal annealing treatment of thin film samples.
[0011] The method of this invention promotes the growth of SiO2 by combining heating with electron beam irradiation. x The process of decomposing the thin film into nanocrystalline silicon and silicon dioxide allows for precise control of the processing area down to the nanometer scale, and also enables rapid thermal annealing, avoiding damage to SiO₂ during thermal annealing. x Damage caused by thin films and substrates.
[0012] In some embodiments, in step S20, the transmission electron microscope (TEM) is a field emission TEM. Therefore, the field emission TEM generates an electron source by rapidly increasing the electric field strength at the tip, which can significantly reduce the work function of electron tunneling. This promotes the growth of SiO₂. x The process of thin film decomposing into nanocrystalline silicon and silicon dioxide.
[0013] In some embodiments, in step S20, the heating rate of the heating chip of the field emission transmission electron microscope is controlled at 10. 5 ℃ / s. By controlling the heating rate of the heating chip to a high order of magnitude, the heating time can be greatly reduced, avoiding damage caused by SiO. x Damage occurs when the thin film and substrate are exposed to high temperatures for an extended period of time.
[0014] In some embodiments, in step S20, the heating chip of the field emission transmission electron microscope heats the SiO2 chip. x The heating temperature of the thin film sample was controlled between 1000℃ and 1200℃.
[0015] In some embodiments, in step S20, the electron beam density ranges from [specific value missing]. When the heating temperature is constant, the irradiation time of the electron beam can be controlled by adjusting the electron beam density. That is, when the electron beam density is high, a shorter irradiation time is sufficient to decompose the irradiated area of the silicon-rich silicon oxide film into nano-silicon crystals and silicon dioxide; when the electron beam density is low, a longer irradiation time is sufficient to decompose the irradiated area of the silicon-rich silicon oxide film into nano-silicon crystals and silicon dioxide.
[0016] In some embodiments, the electron beam irradiation time in step S20 is 10s to 16s.
[0017] In some implementations, the following steps are included before step S20:
[0018] S10: Preparation of SiO using dual-beam scanning electron microscopy x Cross-sectional samples of the thin film were obtained to obtain SiO2. x Thin film samples. SiO₂ samples were examined using dual-beam scanning electron microscopy. x The thin film is processed to obtain SiO x Thin film samples can be observed using a transmission electron microscope (TEM) to allow for the observation of SiO2. x The thin film samples can be rapidly thermally annealed by in-situ heating combined with electron beam irradiation on a transmission electron microscope; and SiO2 can be observed under a transmission electron microscope. x Precise modulation of the regions on the thin film where nano-silicon crystals and silicon dioxide are formed.
[0019] In some implementations, after step S10 and before step S20, the following steps are also included:
[0020] S11: SiO2 is processed by a robotic arm using a dual-beam scanning electron microscope. x The thin film sample was fixed on the heated chip of the field emission transmission electron microscope.
[0021] Therefore, SiO can be removed by a robotic arm. x The thin film sample is fixed on a heating chip to ensure the accuracy of the preparation areas of the nano-silicon crystals and silicon dioxide.
[0022] According to one aspect of the present invention, a silicon dioxide embedded with nano-silicon crystals is provided, which is prepared by the aforementioned method.
[0023] Because this invention uses a combination of heating and electron beam irradiation to treat SiO x Rapid thermal annealing of thin film samples significantly improved the SiO₂ content in the irradiated area. x The process of thin film decomposition into nanocrystalline silicon and silicon dioxide; moreover, by employing in-situ heating combined with electron beam irradiation using transmission electron microscopy, the SiO2 film is decomposed into nanocrystalline silicon and silicon dioxide. xThe method of localized rapid thermal annealing of thin film samples not only allows for precise control of the processing range at the nanoscale, but also enables truly damage-free micro-area processing, resulting in damage-free silicon dioxide embedded with nano-silicon crystals. Attached Figure Description
[0024] Figure 1 This is a flowchart illustrating a method for precisely modulating the microstructure of silicon-rich silicon oxide thin films according to an embodiment of the present invention.
[0025] Figure 2 This is a flowchart illustrating a method for precisely modulating the microstructure of a silicon-rich silicon oxide thin film according to another embodiment of the present invention.
[0026] Figure 3 This is a flowchart illustrating a method for precisely modulating the microstructure of a silicon-rich silicon oxide thin film according to another embodiment of the present invention.
[0027] Figure 4 In a method for precisely modulating the microstructure of silicon-rich silicon oxide thin films according to an embodiment of the present invention, a robotic arm manipulates SiO₂... x TEM image of a thin film sample fixed on a heated chip of a field emission transmission electron microscope;
[0028] Figure 5 The method for precisely modulating the microstructure of silicon-rich silicon oxide thin films according to an embodiment of the present invention includes SiO2 before and after preparation. x TEM image of the thin film sample: where, Figure 5 Figure (a) shows SiO2 before preparation. x TEM images of the thin film sample. Figure 5 Figure (b) shows the SiO₂ x Preparation of SiO₂ containing silicon dioxide nanocrystals in localized areas of thin film samples x TEM image of the thin film sample;
[0029] Figure reference numerals: 20, SiO x Thin film sample; 30. Heating chip; 40. Robotic arm. Detailed Implementation
[0030] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.
[0031] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising" or "including" include not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. The terminology used herein is generally that commonly used by those skilled in the art; in case of any discrepancy with commonly used terminology, the terminology used herein shall prevail.
[0032] In this paper, the term "low-dimensional structure" specifically refers to two-dimensional, one-dimensional, and zero-dimensional structures, which are composed of a small number of atoms or molecules stacked together, with particles on the nanometer scale.
[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0034] Figure 1 The diagram schematically illustrates a method for precisely modulating the microstructure of silicon-rich silicon oxide thin films according to one embodiment of the present invention.
[0035] like Figure 1 As shown, the method for precisely modulating the microstructure of silicon-rich silicon oxide thin films includes the following steps:
[0036] S20: In-situ heating of SiO2 in transmission electron microscopy x Simultaneously, the electron beam generated by transmission electron microscopy was used to irradiate the SiO2 thin film sample. x On thin film samples, to achieve SiO x Thermal annealing treatment of thin film samples.
[0037] The method of this invention promotes the growth of SiO2 by combining heating with electron beam irradiation. x The process of decomposing the thin film into nanocrystalline silicon and silicon dioxide enables rapid thermal annealing, avoiding the damage to SiO2 caused by prolonged thermal annealing. x Damage caused by the thin film and substrate; moreover, due to the ultra-high resolution of transmission electron microscopy, its research scale can reach the nanometer scale, by heating SiO in the transmission electron microscope. xThin film, simultaneously in SiO x The method of preparing silicon dioxide embedded with nano-silicon crystals by irradiating the thin film with an electron beam allows for precise control of the preparation area of the nano-silicon crystals within the area to be processed. Moreover, the control of the processing area can be precisely controlled down to the nanometer level, thereby achieving precise regulation of the microstructure of silicon-rich silicon dioxide thin films.
[0038] In some preferred embodiments, in step S20, the transmission electron microscope (TEM) is preferably a field emission transmission electron microscope (FET). This is because the electron source of a FET is generated by rapidly increasing the electric field strength at the tip of the needle. This method can significantly reduce the work function of electron tunneling, enabling the generation of an electron beam in the electron source at a relatively low heating temperature, and further avoiding damage to SiO2 caused by high temperatures. x Damage caused by thin films and substrates.
[0039] In some preferred embodiments, in step S20, the heating rate of the heating chip of the field emission transmission electron microscope is controlled at 10. 5 ℃ / s. For example, the heating rate of the heating chip can be controlled by the control software of a field emission transmission electron microscope. By controlling the heating rate of the heating chip to a high order of magnitude, the heating time can be significantly reduced, avoiding damage to SiO₂. x Damage occurs when the thin film and substrate are exposed to high temperatures for an extended period of time.
[0040] In some preferred embodiments, in step S20, the heating chip of the field emission transmission electron microscope (FET) heats the SiO2 chip. x The heating temperature of the thin film sample was controlled between 1000℃ and 1200℃ to ensure that, at this temperature, combined with electron beam irradiation, SiO2 could be heated. x The irradiated areas in the thin film sample decomposed into nano-silicon crystals and silicon dioxide.
[0041] In some preferred embodiments, in step S20, the electron beam density ranges from [specific value missing]. When the heating temperature is constant, the irradiation time of the electron beam can be controlled by adjusting the electron beam density. That is, when the electron beam density is high, a shorter irradiation time is sufficient to decompose the irradiated area of the silicon-rich silicon oxide film into nano-silicon crystals and silicon dioxide; when the electron beam density is low, a longer irradiation time is sufficient to decompose the irradiated area of the silicon-rich silicon oxide film into nano-silicon crystals and silicon dioxide.
[0042] In some preferred embodiments, in step S20, the electron beam irradiation time is 10s to 16s.
[0043] In some implementations, the following steps are included before step S20:
[0044] S10: Preparation of SiO using dual-beam scanning electron microscopy x Cross-sectional samples of the thin film were obtained to obtain SiO2. x Thin film sample.
[0045] Due to the general SiO x Thin films cannot be observed using a transmission electron microscope (TEM). Therefore, in-situ heating with a TEM is used to heat SiO₂. x Before thermal annealing, the SiO2 thin film sample needs to be... x The thin film is processed to become SiO2 that can be observed using a transmission electron microscope. x Thin film samples for in-situ heating of SiO2 using transmission electron microscopy. x When examining thin film samples, SiO2 can be observed. x The formation of nanocrystalline silicon in thin film samples to achieve SiO x Precise modulation of regions on the thin film where microstructures such as nanocrystalline silicon are formed. In this embodiment, a dual-beam scanning electron microscope is used to study the SiO₂ film. x The thin film is processed to obtain SiO x Thin film samples can be observed using a transmission electron microscope (TEM) to allow for the observation of SiO2. x The thin film samples can be rapidly thermally annealed by in-situ heating combined with electron beam irradiation on a transmission electron microscope.
[0046] In some implementations, after step S10 and before step S20, the following steps are also included:
[0047] S11: SiO2 is processed by a robotic arm using a dual-beam scanning electron microscope. x The thin film sample was fixed on the heated chip of the field emission transmission electron microscope.
[0048] Therefore, SiO can be removed by a robotic arm. x The thin film sample is fixed on a heating chip to ensure the accuracy of the preparation areas of the nano-silicon crystals and silicon dioxide.
[0049] According to one aspect of the present invention, a silicon dioxide embedded with nano-silicon crystals is provided, which is prepared by the aforementioned method.
[0050] The specific technical solutions of the invention will be described in detail below with reference to specific embodiments. Unless otherwise specified, the features in the following embodiments can be combined with each other.
[0051] Example 1
[0052] The first step was to prepare SiO2 using a dual-beam scanning electron microscope. x Cross-sectional samples of the thin film were obtained to obtain SiO₂ that could be observed using field emission transmission electron microscopy. x Thin film sample.
[0053] The second step involves using a robotic arm of a dual-beam scanning electron microscope to separate SiO₂. x Thin film samples are fixed on the heated chip of a field emission transmission electron microscope (PES) (e.g., Figure 4 (As shown).
[0054] The third step is to control the heating rate of the field emission transmission electron microscope to be 10. 5 ℃ / s, chip heating temperature is 1100℃, electron beam density is The heating time is 16 seconds, so that SiO2... x The electron beam-irradiated area of the thin film sample decomposes into silicon dioxide containing nanocrystalline silicon.
[0055] Figure 5 This shows the SiO2 before and after preparation in this embodiment. x TEM (Transmission Electron Microscopy) images of thin film samples, where... Figure 5 Figure (a) shows SiO x TEM image of the thin film sample before electron beam irradiation. The image shows SiO₂. x The thin film sample contains only SiO x It lacks a nanocrystalline silicon structure; Figure 5 Figure (b) shows SiO₂ after rapid thermal annealing using the method of Example 1. x TEM images of the thin film sample show that the method in Example 1 allows for precise rapid thermal annealing of the area encircled by the dashed line coil, thereby accurately generating nanocrystalline silicon (e.g., silicon nanoparticles) within the encircled area. Figure 5 As shown in Figure (b), SiO x The portion of the thin film sample outside the area circled by the dashed line, since it was not treated by the method of Example 1, still retains SiO₂. x Structure; moreover, as can be seen from the TEM images before and after processing, the method of Example 1 was used in SiO2. x Preparing nanocrystalline silicon in thin film samples will not affect SiO2. x The thin film and the prepared silicon nanocrystals were damaged, i.e., the SiO2 was treated using the method of Example 1. x Thin film samples can be prepared to obtain undamaged silicon dioxide thin films containing nano-silicon crystals.
[0056] Example 2
[0057] The main difference between this embodiment and Embodiment 1 is that:
[0058] The third step is to control the heating rate of the field emission transmission electron microscope to be 10.5 ℃ / s, chip heating temperature is 1100℃, electron beam density is The heating time is 10 seconds, so that SiO2... x The electron beam-irradiated area of the thin film sample decomposes into silicon dioxide containing nanocrystalline silicon.
[0059] Example 3
[0060] The main difference between this embodiment and Embodiment 1 is that:
[0061] The third step is to control the heating rate of the field emission transmission electron microscope to be 10. 5 ℃ / s, chip heating temperature is 1000℃, electron beam density is The heating time is 10 seconds, so that SiO2... x The electron beam-irradiated area of the thin film sample decomposes into silicon dioxide containing nanocrystalline silicon.
[0062] Example 4
[0063] The main difference between this embodiment and Embodiment 1 is that:
[0064] The third step is to control the heating rate of the field emission transmission electron microscope to be 10. 5 ℃ / s, chip heating temperature is 1200℃, electron beam density is The heating time is 16 seconds, so that SiO2... x The electron beam-irradiated area of the thin film sample decomposes into silicon dioxide containing nanocrystalline silicon.
[0065] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.
Claims
1. A method for precisely modulating the microstructure of silicon-rich silicon oxide thin films, characterized in that, Includes the following steps: S20: In-situ heating of SiO in a transmission electron microscope x Simultaneously, the electron beam generated by the transmission electron microscope is irradiated on the SiO x thin film sample to achieve the thermal annealing treatment of the SiO x thin film sample; In step S20, the heating chip of the field emission transmission electron microscope (FET) heats the SiO2 chip. x The heating temperature of the thin film sample was controlled at 1000℃~1200℃; In step S20, the density range of the electron beam is: ; In step S20, the heating rate of the heating chip of the field emission transmission electron microscope is controlled at 10. 5 ℃ / s; In step S20, the electron beam irradiation time is 10s~16s.
2. The method for precisely modulating the microstructure of silicon-rich silicon oxide thin films according to claim 1, characterized in that, In step S20, the transmission electron microscope is a field emission transmission electron microscope.
3. The method for precisely modulating the microstructure of silicon-rich silicon oxide thin films according to any one of claims 1 to 2, characterized in that, Before step S20, the following steps are also included: S10: Preparation of SiO using dual-beam scanning electron microscopy x Cross-sectional samples of the thin film were obtained to obtain SiO2. x Thin film sample.
4. The method for precisely modulating the microstructure of silicon-rich silicon oxide thin films according to claim 3, characterized in that, After step S10 and before step S20, the following steps are also included: S11: SiO2 is processed by a robotic arm using a dual-beam scanning electron microscope. x The thin film sample was fixed on the heated chip of the field emission transmission electron microscope.
5. Silica embedded with nano-silicon crystals, characterized in that, It is prepared by any one of claims 1 to 4.