Single crystal or polycrystalline substrates, methods of making and electronic devices

Abstract

The embodiment of the present application provides a single crystal or polycrystal substrate, a preparation method thereof and an electronic device. The single crystal or polycrystal substrate has a first surface, a second surface arranged opposite to the first surface, and a side surface connected between the first surface and the second surface; wherein the second surface comprises a central region and an edge region surrounding the central region, the roughness of the central region is greater than the roughness of the edge region; and the roughness of the side surface is Sa <= 50 nm.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic device manufacturing, and in particular to a single crystal or polycrystalline substrate, a preparation method thereof and an electronic device. BACKGROUND

[0002] In recent years, with the progress of technology, smart phones and other mobile communication terminals have been significantly miniaturized and lightened. For filters used in the mobile communication terminals, an elastic wave device capable of miniaturization is used. For example, a surface acoustic wave device mainly includes a general filter and a temperature compensation filter. The general filter includes a piezoelectric substrate made of a material having a piezoelectric effect and an electrode layer provided on the piezoelectric substrate and including interdigital electrodes. The temperature compensation filter generally includes a thin piezoelectric layer and an electrode layer and a substrate layer provided below the piezoelectric layer. For the general filter, the premise of reducing the size is to reduce the thickness of the piezoelectric layer substrate. For the temperature compensation filter, in addition to reducing the thickness of the piezoelectric layer substrate, the thickness of the support substrate also needs to be reduced. The processing difficulty of the substrate increases exponentially with the decrease of the thickness, especially the piezoelectric layer substrate, which generally selects a brittle material such as lithium tantalate and lithium niobate. The hardness is not high and the toughness is general. When the thickness is 300 microns, it still has a certain bending strength, but when the thickness is reduced to 200 microns or less, the processing breakage rate increases significantly, and it is not feasible for mass production. SUMMARY

[0003] The purpose of the present application is to provide a single crystal or polycrystalline substrate, a preparation method thereof and an electronic device, which can reduce the cracking point of the single crystal or polycrystalline substrate, increase the bending strength, and improve the yield of finished products.

[0004] One embodiment of the present application provides a single crystal or polycrystalline substrate having a first surface and a second surface opposite to the first surface, and a side surface connected between the first surface and the second surface; wherein the second surface includes a central region and an edge region surrounding the central region, the roughness of the central region is greater than the roughness of the edge region; and the roughness of the side surface is Sa≤50 nm.

[0005] This invention also provides a method for preparing a single-crystal or polycrystalline substrate, comprising: a first processing step: processing a substrate material to form a first substrate material having a side surface, wherein the roughness Sa of the side surface is ≤ 50 nanometers; a second processing step: polishing the first substrate material to obtain a single-crystal or polycrystalline substrate having opposing first and second surfaces; and a third processing step: processing the second surface to form a central region and an edge region surrounding the central region, wherein the roughness of the central region is greater than the roughness of the edge region.

[0006] This invention also provides an electronic device comprising the single-crystal or polycrystalline substrate described in the foregoing embodiments, or the single-crystal or polycrystalline substrate prepared by the method described in the foregoing embodiments.

[0007] The above embodiments of the present invention have at least one or more of the following beneficial effects: The single-crystal or polycrystalline substrate provided by this embodiment includes a first surface and a second surface opposite to each other, as well as a side surface. The second surface includes a central region and an edge region surrounding the central region. The roughness of the central region is greater than that of the edge region, and the roughness Sa of the side surface is ≤50 nanometers. With this configuration, defects in the first surface, side surface, and edge region can be reduced, cracking points can be reduced, the bending strength of the single-crystal or polycrystalline substrate can be enhanced, and the yield of mass production can be further improved. Furthermore, by improving the strength of the single-crystal or polycrystalline substrate, material loss caused by insufficient strength can be mitigated. Moreover, the thickness of the single-crystal or polycrystalline substrate can be made ultra-thin, increasing the utilization rate of materials, thereby reducing material costs and enhancing the competitiveness of the product. Attached Figure Description

[0008] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0009] Figure 1 This is a schematic diagram of a single-crystal or polycrystalline substrate provided in an embodiment of the present invention.

[0010] Figure 2 for Figure 1 A top view of a single-crystal or polycrystalline substrate.

[0011] Figure 3 This is a schematic flowchart illustrating a method for preparing a single-crystal or polycrystalline substrate according to an embodiment of the present invention.

[0012] Figure 4 for Figure 3 A flowchart illustrating the third processing step in the middle stage.

[0013] [Explanation of Labels in the Attached Image]

[0014] 100. Single-crystal or polycrystalline substrate; 10. First surface; 20. Second surface; 21. Central region; 22. Edge region;

[0015] 30. Side view. Detailed Implementation

[0016] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0017] To enable those skilled in the art to better understand the technical solutions of the present invention, 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, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0018] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0019] It should also be noted that the division of multiple embodiments in this invention is only for the convenience of description and should not constitute a special limitation. Features in various embodiments can be combined and referenced in each other without contradiction.

[0020] One embodiment of the present invention provides a single-crystal or polycrystalline substrate 100. The single-crystal or polycrystalline substrate 100 provided in this embodiment can be, for example, a substrate for an elastic wave device. Specifically, the single-crystal or polycrystalline substrate 100 can be, for example, a piezoelectric substrate, such as a single crystal of a piezoelectric material made of lithium tantalate (LiTaO3), lithium niobate (LiNbO3), or quartz. It can also be, for example, a support substrate for supporting a thin-film piezoelectric layer. The support substrate can be a substrate formed from a material selected from, for example, silicon carbide, alumina, aluminum nitride, sapphire, silicon nitride, silicon, quartz, diamond, cordierite, mullite, talc, forsterite, spinel, and magnesium oxide. Of course, the single-crystal or polycrystalline substrate 100 can also be, for example, other types of substrates, and this embodiment is not limited thereto.

[0021] like Figure 1 As shown, the single-crystal or polycrystalline substrate 100 has a first surface 10, a second surface 20, and a side surface 30. The first surface 10 and the second surface 20 are disposed opposite to each other, and the side surface 30 is connected between the first surface 10 and the second surface 20. The single-crystal or polycrystalline substrate 100 may be, for example, a circular structure, with the first surface 10 and the second surface 20 being two circular surfaces, and the side surface 30 being an edge surface connecting the first surface 10 and the second surface 20; of course, the single-crystal or polycrystalline substrate 100 may also be other shapes.

[0022] See Figure 2 The second surface 20 includes a central region 21 and an edge region 22 surrounding the central region 21. The roughness of the central region 21 is greater than that of the edge region 22. The roughness Sa of the side surface 30 is ≤ 50 nanometers. For example, the central region 21 may be a circular region centered on the center of the single-crystal or polycrystalline substrate 100, with a radius smaller than that of the single-crystal or polycrystalline substrate 100. The edge region 22 is the region from the edge of the single-crystal or polycrystalline substrate 100 to the edge of the central region 21. That is, the central region 21 is a circular region, and the edge region 22 is an annular region. By setting the roughness of the central region 21 to be greater than that of the edge region 22, and the roughness Sa of the side surface 30 to be ≤50 nanometers, defects in the edge region 22 and side surface 30 of the second surface 20 of the monocrystalline or polycrystalline substrate 100 can be reduced, cracking points in the edge region 22 and side surface 30 of the second surface 20 of the monocrystalline or polycrystalline substrate 100 can be reduced, thereby enhancing the bending strength of the monocrystalline or polycrystalline substrate 100; and by improving the strength of the monocrystalline or polycrystalline substrate 100, material loss caused by insufficient strength can be mitigated, and the thickness of the monocrystalline or polycrystalline substrate 100 can be made ultra-thin, increasing material utilization and reducing material costs, thereby enhancing product competitiveness.

[0023] Furthermore, the maximum width D of the central region 21 can be, for example, greater than the width d of the edge region 22. In one embodiment of this example, the monocrystalline or polycrystalline substrate 100 can be, for example, a circular structure. In this case, the maximum width of the central region 21 is its diameter, and the width of the edge region 22 is its radial width; that is, the diameter of the central region 21 is greater than the radial width of the edge region 22. In this embodiment, the width d of the edge region 22 is greater than or equal to 1 mm. By setting the width d of the edge region 22 to be greater than or equal to 1 mm, the monocrystalline or polycrystalline substrate 100 can have higher strength. Preferably, the width of the edge region 22 ranges from 1 to 6 mm. For example, if the maximum width of the monocrystalline or polycrystalline substrate 100 is 100 mm, then the width d of the edge region 22 ranges from 1 to 6 mm, and the maximum width D of the central region 21 ranges from 94 to 99 mm. By setting the width d of the edge region 22 to 1 to 6 mm, the monocrystalline or polycrystalline substrate 100 has higher strength. More preferably, the width d of the edge region 22 is in the range of 1 to 3 mm. By setting the width d of the edge region 22 to the range of 1 to 3 mm, the strength of the monocrystalline or polycrystalline substrate 100 can be improved. When a chip is disposed on the monocrystalline or polycrystalline substrate 100, such a setting can also avoid affecting the performance of the chip.

[0024] Furthermore, the roughness Sa of the first surface 10 is ≤1 nm, and the roughness Sa of the first surface 10 can be, for example, 0.25 nm, 0.26 nm, 0.27 nm, 0.32 nm, 0.36 nm, 0.39 nm, etc.; the roughness Sa of the edge region 22 is ≤1 nm, and the roughness Sa of the edge region 22 can be, for example, 0.24 nm, 0.26 nm, 0.27 nm, 0.29 nm, 0.32 nm, 0.36 nm, 0.39 nm, etc.; the roughness Sa of the central region 21 is in the range of 0.01 μm ≤ Sa ≤ 0.4 μm, and the roughness Sa of the central region 21 can be, for example, 0.15 μm, 0.16 μm, 0.19 μm, 0.22 μm, 0.25 μm, 0.3 μm, etc. In some embodiments of this example, the roughness Sa of the first surface 10 is ≤0.3 nanometers, the roughness Sa of the edge region 22 is ≤0.3 nanometers, the roughness Sa of the central region 21 is in the range of 0.1 micrometers ≤ Sa ≤0.4 micrometers, and the roughness Sa of the side surface 20 is ≤6 nanometers.

[0025] In one embodiment of this invention, the single-crystal or polycrystalline substrate 100 is a lithium tantalate substrate or a lithium niobate substrate, and the width of the edge region 22 is greater than or equal to 2 mm. Further, the roughness of the edge region 22 is less than 0.4 nm, and the roughness Sa of the side surface 30 is ≤ 25 nm. This configuration allows the lithium tantalate or lithium niobate substrate to possess good strength; for example, when the thickness of the single-crystal or polycrystalline substrate 100 is 250 μm, the strength of the single-crystal or polycrystalline substrate 100 reaches 200 MPa or higher.

[0026] In one embodiment of this invention, the single-crystal or polycrystalline substrate 100 is a magnesium aluminum spinel substrate or a sapphire substrate, and the roughness Sa of the edge region 22 is ≤0.5 nm. Further, the roughness Sa of the side surface 30 is ≤10 nanometers, and the width of the edge region 22 is greater than or equal to 0 millimeters. This configuration allows the magnesium aluminum spinel substrate or sapphire substrate to possess good strength; for example, when the thickness of the single-crystal or polycrystalline substrate 100 is 200 micrometers, the strength of the single-crystal or polycrystalline substrate 100 reaches 200 MPa or higher.

[0027] In this embodiment, roughness is represented by Sa. According to ISO 25178, roughness can be represented by Sa, which stands for Arithmetic Mean Height. Roughness Sa is an important parameter in surface roughness measurement; it represents the arithmetic mean deviation of the surface profile. Roughness Sa is used to describe and quantify the microscopic geometric characteristics of a surface, i.e., the degree of surface unevenness. The smaller the Sa value, the smoother the surface; the larger the value, the rougher the surface. Roughness Sa values ​​can be measured in various ways, including using surface roughness meters, profile measuring instruments, laser scanning equipment, etc.

[0028] See Figure 3 An embodiment of the present invention also provides a method for preparing a single-crystal or polycrystalline substrate, comprising the following steps:

[0029] S10, First processing step: Processing the substrate material to form a first substrate material with side surfaces, wherein the roughness Sa of the side surfaces is ≤50 nanometers;

[0030] S20, Second processing step: Polish the first substrate material to obtain the single crystal or polycrystalline substrate, and the roughness Sa of the first surface of the single crystal or polycrystalline substrate is ≤0.3 nanometers;

[0031] S30, Third processing step: Process the second surface to form a central region and an edge region surrounding the central region, wherein the roughness of the central region is greater than the roughness of the edge region.

[0032] Specifically, suitable single-crystal or polycrystalline substrate materials can be selected for processing. These materials can include, for example, lithium tantalate, lithium niobate, magnesium aluminum spinel, polycrystalline sapphire, and single-crystal sapphire. The ingot (single-crystal or polycrystalline substrate material) is processed by multi-wire cutting to achieve the required thickness of the single-crystal or polycrystalline substrate 100. For example, a chamfering wheel can be used to chamfer the outer periphery, forming a first substrate material with a side surface 30, ensuring that the roughness Sa of the side surface 30 is ≤ 50 nanometers. The outer periphery chamfer (sometimes called edge chamfering or corner chamfering) refers to the process of cutting a beveled surface at the outer edge or corner of an object. This is done to remove sharp edges, reduce the risk of damage caused by sharp edges, and also facilitates component assembly and aesthetics. The first substrate material is then polished, for example, by using a grinding wheel to polish the first surface 10. Then the second surface 20 is processed so that the second surface 20 forms a central region 21 and an edge region 22 surrounding the central region 21, and the roughness of the central region 21 is greater than the roughness of the edge region 22.

[0033] See Figure 4 The third processing step S30 may include, for example, the following steps:

[0034] S31, Polish the second surface;

[0035] S32, covering the edge region of the second surface, dividing the second surface into a central region and the edge region surrounding the central region; and

[0036] S33, the central region is sandblasted to make the roughness of the central region greater than that of the edge region.

[0037] For example, the second surface 20 can be polished first. The first surface 10 and the second surface 20 can be polished simultaneously or separately. Then, the edge region 22 of the second surface 20 is covered, specifically by applying a film to the edge region 22, dividing the second surface 20 into a central region 21 and an edge region 22 surrounding the central region 21. The central region 21 can then be sandblasted to make its roughness greater than that of the edge region 22. Further, the maximum width D of the central region 21 can be greater than the width d of the edge region 22. The single-crystal or polycrystalline substrate 100 provided in the above embodiment is obtained by the single-crystal or polycrystalline substrate preparation method provided in this embodiment. The roughness Sa of the first surface 10 is ≤ 1 nanometer, the roughness Sa of the edge region 22 is ≤ 1 nanometer, and the roughness Sa of the central region 21 is in the range of 0.01 micrometers ≤ Sa ≤ 0.4 micrometers. In some embodiments of this example, the roughness Sa of the first surface 10 is ≤0.3 nanometers, the roughness Sa of the edge region 22 is ≤0.3 nanometers, the roughness Sa of the central region 21 is in the range of 0.1 micrometers ≤ Sa ≤0.4 micrometers, and the roughness Sa of the side surface 20 is ≤6 nanometers.

[0038] For example, the specific steps of the method for preparing a single-crystal or polycrystalline substrate provided in the embodiments of the present invention are as follows:

[0039] The ingot (monocrystalline or polycrystalline substrate material) can be cut into wire slices, for example, by multi-wire cutting. Then, it can be polished on both sides, for example, using 1000-1500# silicon carbide powder, to obtain a polishing sheet of the target thickness, which can be, for example, the thickness of the monocrystalline or polycrystalline substrate of 100.

[0040] For example, a chamfering grinding wheel of 2000 to 4000# can be used to chamfer the outer periphery of the grinding disc. The roughness Sa of the side surface 30 of the chamfered single crystal or polycrystalline substrate obtained after processing can reach below 50 nanometers.

[0041] Then, the chamfered single-crystal or polycrystalline substrate can be subjected to double-sided thinning, preferably using a grinding wheel with a grit number of 2000 to 4000#, followed by double-sided polishing. At this point, the surface roughness Sa of the first surface 10 and the second surface 20 of the obtained single-crystal or polycrystalline substrate 100 is less than 1 nanometer. In this step, the same grinding wheel grit number of 2000 to 4000# can be used simultaneously for double-sided polishing, or different grinding wheels can be used for polishing. The surface roughness of the first surface 10 and the second surface 20 can be the same or different.

[0042] A film is applied to the second surface 20 of the monocrystalline or polycrystalline substrate 100. For example, the film can be applied only to the edge region 22 of the second surface 20. The film application range can be greater than or equal to 1 mm depending on the actual needs. Then, the second surface 20 of the monocrystalline or polycrystalline substrate 100 is sandblasted. For example, the particle size of the sandblasting can be selected as 1000 to 1200# silicon carbide powder. At this time, due to the difference in roughness between the film-coated area and the uncoated area, the second surface 20 will form a central region 21 and an edge region 22. The roughness Sa of the central region 21 is between 0.01 and 0.4 micrometers, and the roughness Sa of the edge region 22 is between 0 and 1 nanometer.

[0043] The single-crystal or polycrystalline substrate 100 prepared above is subjected to etching. The acid used for etching is preferably HF (hydrofluoric acid) or H2NO3 (nitric acid), or a mixed solution of HF and H2NO3. The etching time depends on the stress release state of the single-crystal or polycrystalline substrate 100, preferably 2 to 6 hours. After cleaning, the finished ultrathin single-crystal or polycrystalline substrate 100 is obtained.

[0044] The specific processes for the aforementioned steps, such as cutting, chamfering, polishing, applying film, sandblasting, and cleaning, can be adjusted according to actual needs.

[0045] This invention also provides an electronic device, comprising the single-crystal or polycrystalline substrate 100 described in any of the foregoing embodiments, or the single-crystal or polycrystalline substrate 100 prepared by the method described in any of the foregoing embodiments. The electronic device can be an elastic wave device, specifically, for example, a SAW device, more specifically, an N-SAW device or a Tc-SAW device. Of course, the electronic device can also be, for example, an LED device or other devices.

[0046] The following experiments, from Experiment 1 to Experiment 36, illustrate the beneficial effects of the single-crystal or polycrystalline substrate 100, the preparation method of the single-crystal or polycrystalline substrate 100, and the electronic devices provided in the embodiments of the present invention.

[0047] Experiment 1

[0048] Lithium tantalate ingots can be obtained by multi-wire cutting, for example, to produce wire slices. These slices can then be double-sided ground using, for example, 1000-1500# silicon carbide powder to obtain 250-micron grinding discs. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.26 nm on the first surface 10, a roughness Sa of 0.25 nm on the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.18 microns. Using 2... A chamfering wheel of 000-4000# is used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 107.6 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 has a thickness of 250 μm, a roughness Sa of 0.26 nm on the first surface 10, a roughness Sa of 107.6 nm on the side surface 30, a width d of 3 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.25 nm on the edge region 22, and a roughness Sa of 0.18 μm on the central region 21. Test experiment one yielded a strength of 144 MPa for the single-crystal or polycrystalline substrate 100.

[0049] Experiment 2

[0050] Lithium tantalate ingots can be obtained by multi-wire cutting, for example, to produce wire slices. These slices can then be double-sided ground using silicon carbide powder of 1000-1500# to obtain a 250-micron grinding disc. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.25 nanometers for the first surface 10, a roughness Sa of 0.27 nanometers for the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.18 micrometers. The outer periphery of the grinding disc was chamfered using a 2000-4000# chamfering wheel, resulting in a roughness Sa of 87 nm on side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 250 μm, a roughness Sa of 0.25 nm on the first surface 10, a roughness Sa of 87 nm on side surface 30, a width d of 3 mm for the edge region 22 of the second surface 20, a roughness Sa of 0.27 nm on the edge region 22, and a roughness Sa of 0.18 μm on the central region 21. Test experiment two showed that the strength of the single-crystal or polycrystalline substrate 100 was 175 MPa.

[0051] Experiment 3

[0052] Lithium tantalate ingots can be obtained by multi-wire cutting to produce wire slices. These slices can then be double-sided ground using silicon carbide powder (1000-1500#) to obtain a 250-micron polishing disc. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.27 nm on the first surface (10). The outer periphery of the polishing disc is then chamfered using a 2000-4000# chamfering wheel to achieve a roughness Sa of 49 nm on the side surface (30). This process yields a single-crystal or polycrystalline substrate (1). The thickness of the substrate 100 is 250 micrometers. The roughness Sa of the first surface 10 is 0.27 nanometers, the roughness Sa of the edge region of the second surface 20 is 0.24 nanometers, and the central region 21 is sandblasted to achieve a roughness Sa of 0.16 micrometers. The roughness Sa of the side surface 30 is 49 nanometers. The width d of the edge region 22 of the second surface 20 is 3 millimeters, the roughness Sa of the edge region 22 is 0.24 nanometers, and the roughness Sa of the central region 21 is 0.16 micrometers. Test experiment three yielded a strength of 201 MPa for the single-crystal or polycrystalline substrate 100.

[0053] Experiment 4

[0054] Lithium tantalate ingots can be obtained by multi-wire cutting, for example, to produce wire slices. These slices can then be double-sided ground using silicon carbide powder of 1000-1500# to obtain a 250-micron grinding disc. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.26 nanometers for the first surface 10, a roughness Sa of 0.29 nanometers for the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.17 micrometers. The outer periphery of the grinding disc was chamfered using a 2000-4000# chamfering wheel, resulting in a roughness Sa of 24 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 250 μm, a roughness Sa of 0.26 nm on the first surface 10, a roughness Sa of 24 nm on the side surface 30, a width d of 3 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.29 nm on the edge region 22, and a roughness Sa of 0.17 μm on the central region 21. Test experiment four yielded a strength of 238 MPa for the single-crystal or polycrystalline substrate 100.

[0055] Experiment 5

[0056] Lithium tantalate ingots can be obtained by multi-wire cutting to produce wire slices. These slices can then be double-sided ground using silicon carbide powder (1000-1500#) to obtain a 250-micron grinding disc. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.27 nm on the first surface 10. A chamfering wheel (2000-4000#) is then used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 6.5 nm on the side surface 30. The roughness of the edge region of the second surface 20 is also improved. The roughness Sa of the central region 21 is 0.26 nm. Sandblasting of the central region 21 reduces the roughness Sa to 0.19 μm. The resulting single-crystal or polycrystalline substrate 100 has a thickness of 250 μm. The roughness Sa of the first surface 10 is 0.27 nm, the roughness Sa of the side surface 30 is 6.5 nm, the width d of the edge region 22 of the second surface 20 is 3 mm, the roughness Sa of the edge region 22 is 0.26 nm, and the roughness Sa of the central region 21 is 0.19 μm. Test experiment five yielded a strength of 261 MPa for the single-crystal or polycrystalline substrate 100.

[0057] Experiment Six

[0058] Lithium tantalate ingots can be obtained by multi-wire cutting, for example, to produce wire slices. These slices can then be double-sided ground using silicon carbide powder (1000-1500#) to obtain a 250-micron grinding disc. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.26 nm on the first surface 10, a roughness Sa of 0.25 nm on the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.16 microns. The outer periphery of the grinding disc was chamfered using a 2000-4000# chamfering wheel, resulting in a roughness Sa of 2.3 nm on side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 250 μm, a roughness Sa of 0.26 nm on the first surface 10, a roughness Sa of 2.3 nm on side surface 30, a width d of 3 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.25 nm on the edge region 22, and a roughness Sa of 0.16 μm on the central region 21. Test experiment six yielded a strength of 267 MPa for the single-crystal or polycrystalline substrate 100.

[0059] Table 1

[0060]

[0061] Referring to Table 1, based on Experiments 1 to 6, it is evident that when the thickness of the lithium tantalate substrate is the same (all 250 μm), the roughness Sa of the first surface 10 is essentially the same, the width d of the edge region 22 of the second surface 20 is the same, the roughness Sa of the edge region 22 is essentially the same, and the roughness Sa of the central region 21 is essentially the same, the smaller the roughness Sa of the side surface 30, the higher the strength of the single-crystal or polycrystalline substrate 100. However, when the roughness Sa of the side surface 30 is less than 6 nm, the strength of the single-crystal or polycrystalline substrate 100 no longer increases. Therefore, when the thickness of the lithium tantalate substrate is 250 μm and the roughness Sa of the side surface 30 is ≤ 25 nm, the strength of the lithium tantalate substrate is greater than 200 MPa. When the roughness Sa of the side surface 30 is ≤ 6 nm, the single-crystal or polycrystalline substrate 100 exhibits high strength. Improving the strength of monocrystalline or polycrystalline substrates can mitigate material loss caused by insufficient strength, and it also allows for ultra-thin substrates, increasing material utilization, reducing material costs, and enhancing product competitiveness.

[0062] Experiment 7

[0063] Lithium tantalate ingots can be obtained by multi-wire cutting, for example, to produce wire slices. These slices can then be double-sided ground using silicon carbide powder (1000-1500#) to obtain 250-micron grinding discs. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.26 nm on the first surface 10, a roughness Sa of 0.25 nm on the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.17 microns. A chamfering wheel of 2000-4000# was used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 5.71 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 250 μm, a roughness Sa of 0.26 nm on the first surface 10, a roughness Sa of 5.71 nm on the side surface 30, a width d of 0 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.25 nm on the edge region 22, and a roughness Sa of 0.17 μm on the central region 21. Test experiment seven showed that the strength of the single-crystal or polycrystalline substrate 100 was 185 MPa.

[0064] Experiment 8

[0065] Lithium tantalate ingots can be obtained by multi-wire cutting, for example, to produce wire slices. These slices can then be double-sided ground using silicon carbide powder (1000-1500#) to obtain 250-micron grinding discs. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.25 nm on the first surface 10, a roughness Sa of 0.24 nm on the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.16 microns. A chamfering wheel of 2000-4000# was used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 5.65 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 250 μm, a roughness Sa of 0.25 nm on the first surface 10, a roughness Sa of 5.65 nm on the side surface 30, a width d of 2 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.24 nm on the edge region 22, and a roughness Sa of 0.16 μm on the central region 21. Test experiment eight showed that the strength of the single-crystal or polycrystalline substrate 100 was 233 MPa.

[0066] Experiment Nine

[0067] Lithium tantalate ingots can be obtained by multi-wire cutting, for example, to produce wire slices. These slices can then be double-sided ground using silicon carbide powder (1000-1500#) to obtain 250-micron grinding discs. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.27 nm on the first surface 10 and 0.27 nm on the edge region of the second surface 20. The central region 21 is then sandblasted to achieve a roughness Sa of 0.15 microns. A chamfering wheel of 2000-4000# was used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 5.75 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 250 μm, a roughness Sa of 0.27 nm on the first surface 10, a roughness Sa of 5.75 nm on the side surface 30, a width d of 4 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.27 nm on the edge region 22, and a roughness Sa of 0.15 μm on the central region 21. Test experiment nine showed that the strength of the single-crystal or polycrystalline substrate 100 was 256 MPa.

[0068] Experiment 10

[0069] Lithium tantalate ingots can be obtained by multi-wire cutting, for example, to produce wire slices. These slices can then be double-sided ground using silicon carbide powder (1000-1500#) to obtain 250-micron grinding discs. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.26 nm on the first surface 10, a roughness Sa of 0.27 nm on the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.17 microns. A chamfering wheel of 2000-4000# was used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 5.72 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 250 μm, a roughness Sa of 0.26 nm on the first surface 10, a roughness Sa of 5.72 nm on the side surface 30, a width d of 6 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.27 nm on the edge region 22, and a roughness Sa of 0.17 μm on the central region 21. Test experiment 10 showed that the strength of the single-crystal or polycrystalline substrate 100 was 266 MPa.

[0070] Experiment Eleven

[0071] Lithium tantalate ingots can be obtained by multi-wire cutting, for example, to produce wire slices. These slices can then be double-sided ground using silicon carbide powder (1000-1500#) to obtain 250-micron grinding discs. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.27 nm on the first surface 10, a roughness Sa of 0.24 nm on the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.17 microns. A chamfering wheel of 2000-4000# was used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 5.76 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 250 μm, a roughness Sa of 0.27 nm on the first surface 10, a roughness Sa of 5.76 nm on the side surface 30, a width d of 8 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.24 nm on the edge region 22, and a roughness Sa of 0.17 μm on the central region 21. Test experiment eleven showed that the strength of the single-crystal or polycrystalline substrate 100 was 267 MPa.

[0072] Experiment Twelve

[0073] Lithium tantalate ingots can be obtained by multi-wire cutting, for example, to produce wire slices. These slices can then be double-sided ground using, for example, 1000-1500# silicon carbide powder to obtain 250-micron grinding discs. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.26 nm on the first surface 10, a roughness Sa of 0.25 nm on the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.19 microns. Using 2... A chamfering wheel of 000-4000# was used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 5.66 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 250 μm, a roughness Sa of 0.26 nm on the first surface 10, a roughness Sa of 5.66 nm on the side surface 30, a width d of 10 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.25 nm on the edge region 22, and a roughness Sa of 0.19 μm on the central region 21. Test experiment twelve showed that the strength of the single-crystal or polycrystalline substrate 100 was 259 MPa.

[0074] Table 2

[0075]

[0076] Referring to Table 2, based on Experiments 7 to 12, it is evident that when the thickness of the lithium tantalate substrate is the same (all 250 micrometers), the roughness Sa of the first surface 10 is essentially the same, the roughness Sa of the side surface 30 is also essentially the same, the roughness Sa of the edge region 22 is essentially the same, and the roughness Sa of the central region 21 is also essentially the same, the larger the width d of the edge region 22 of the second surface 20, the higher the strength of the monocrystalline or polycrystalline substrate 100. However, when the width d of the edge region 22 is greater than 6 millimeters, the strength of the monocrystalline or polycrystalline substrate 100 no longer increases. Therefore, when the thickness of the lithium tantalate substrate is 250 micrometers and the width d of the edge region 22 is greater than or equal to 2 millimeters, the strength of the lithium tantalate substrate is greater than 200 MPa. When the width d of the edge region 22 is in the range of 1–6 millimeters, the monocrystalline or polycrystalline substrate 100 exhibits high strength, further improving the yield in mass production. Improving the strength of monocrystalline or polycrystalline substrates can mitigate material loss caused by insufficient strength, and it also allows for ultra-thin substrates, increasing material utilization, reducing material costs, and enhancing product competitiveness.

[0077] Experiment Thirteen

[0078] Magnesium aluminum spinel ingots can be, for example, multi-wire cut to obtain wire slices, which can then be double-sided ground using, for example, 1000-1500# silicon carbide powder to obtain 200-micron grinding discs. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.36 nm on the first surface 10, a roughness Sa of 0.4 nm on the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.27 microns. A chamfering wheel of 2000-4000# was used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 100.7 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 200 μm, a roughness Sa of 0.36 nm on the first surface 10, a roughness Sa of 100.7 nm on the side surface 30, a width d of 3 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.4 nm on the edge region 22, and a roughness Sa of 0.27 μm on the central region 21. Test experiment thirteen showed that the strength of the single-crystal or polycrystalline substrate 100 was 187 MPa.

[0079] Experiment Fourteen

[0080] Magnesium aluminum spinel ingots can be, for example, cut into wire slices using multi-wire cutting. Then, they can be double-sided ground using, for example, 1000-1500# silicon carbide powder to obtain 200-micron grinding discs. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.36 nanometers on the first surface 10, and a roughness Sa of 0.32 nanometers on the edge region of the second surface 20. The central region 21 is then sandblasted to achieve a roughness Sa of 0.26 micrometers. The outer periphery of the grinding disc was chamfered using a 2000-4000# chamfering grinding wheel, resulting in a roughness Sa of 81.3 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 200 μm, a roughness Sa of 0.36 nm on the first surface 10, a roughness Sa of 81.3 nm on the side surface 30, a width d of 3 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.32 nm on the edge region 22, and a roughness Sa of 0.26 μm on the central region 21. Test experiment fourteen showed that the strength of the single-crystal or polycrystalline substrate 100 was 232 MPa.

[0081] Experiment 15

[0082] Magnesium aluminum spinel ingots can be cut into wire slices, for example, using multi-wire cutting. These slices can then be double-sided ground using silicon carbide powder (1000-1500#) to obtain 200-micron grinding discs. Polishing with a 2000-4000# grinding wheel results in a roughness Sa of 0.33 nm on the first surface 10 and 0.29 nm on the edge region of the second surface 20. The central region 21 is then sandblasted to achieve a roughness Sa of 0.29 microns. The outer periphery of the grinding disc was chamfered using a 2000-4000# chamfering grinding wheel, resulting in a roughness Sa of 46.8 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 200 μm, a roughness Sa of 0.33 nm on the first surface 10, a roughness Sa of 46.8 nm on the side surface 30, a width d of 3 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.29 nm on the edge region 22, and a roughness Sa of 0.29 μm on the central region 21. Test experiment fifteen yielded a strength of 261 MPa for the single-crystal or polycrystalline substrate 100.

[0083] Experiment Sixteen

[0084] Magnesium aluminum spinel ingots can be, for example, cut into wire slices using multi-wire cutting. Then, they can be double-sided ground using, for example, 1000-1500# silicon carbide powder to obtain 200-micron grinding discs. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.32 nanometers for the first surface 10, and a roughness Sa of 0.35 nanometers for the edge region of the second surface 20. The central region 21 is then sandblasted to achieve a roughness Sa of 0.3 micrometers. The outer periphery of the grinding disc was chamfered using a 2000-4000# chamfering wheel, resulting in a roughness Sa of 19.9 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 200 μm, a roughness Sa of 0.32 nm on the first surface 10, a roughness Sa of 19.9 nm on the side surface 30, a width d of 3 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.35 nm on the edge region 22, and a roughness Sa of 0.3 μm on the central region 21. Test experiment sixteen showed that the strength of the single-crystal or polycrystalline substrate 100 was 273 MPa.

[0085] Experiment 17

[0086] Magnesium aluminum spinel ingots can be cut into wire slices, for example, by multi-wire cutting. Then, double-sided grinding with 1000-1500# silicon carbide powder can be performed to obtain 200-micron grinding discs. Polishing with a 2000-4000# grinding wheel results in a roughness Sa of 0.31 nm on the first surface 10 and 0.31 nm on the edge region of the second surface 20. Sandblasting of the central region 21 reduces its roughness Sa to 0.25 microns. The outer periphery of the grinding disc was chamfered using a 2000-4000# chamfering wheel, resulting in a roughness Sa of 5.44 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 200 μm, a roughness Sa of 0.31 nm on the first surface 10, a roughness Sa of 5.44 nm on the side surface 30, a width d of 3 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.31 nm on the edge region 22, and a roughness Sa of 0.25 μm on the central region 21. Test experiment seventeen showed that the strength of the single-crystal or polycrystalline substrate 100 was 289 MPa.

[0087] Experiment 18

[0088] Magnesium aluminum spinel ingots can be cut into wire slices, for example, by multi-wire cutting. Then, double-sided grinding with 1000-1500# silicon carbide powder can be performed to obtain a 200-micron grinding disc. Polishing with a 2000-4000# grinding wheel results in a roughness Sa of 0.39 nm for the first surface 10, a roughness Sa of 0.37 nm for the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.22 microns. The outer periphery of the grinding disc was chamfered using a 2000-4000# chamfering wheel, resulting in a roughness Sa of 2.2 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 200 μm, a roughness Sa of 0.39 nm on the first surface 10, a roughness Sa of 2.2 nm on the side surface 30, a width d of 3 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.37 nm on the edge region 22, and a roughness Sa of 0.22 μm on the central region 21. Test experiment eighteen yielded a strength of 291 MPa for the single-crystal or polycrystalline substrate 100.

[0089] Table 3

[0090]

[0091] Experiment Nineteen

[0092] Magnesium aluminum spinel ingots can be cut into wire slices, for example, using multi-wire cutting. These slices can then be double-sided ground using silicon carbide powder (1000-1500#) to obtain a 200-micron grinding disc. Polishing with a 2000-4000# grinding wheel results in a roughness Sa of 0.34 nanometers on the first surface 10, a roughness Sa of 0.38 nanometers on the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.25 micrometers. The outer periphery of the grinding disc was chamfered using a 2000-4000# chamfering wheel, resulting in a roughness Sa of 5.12 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 200 μm. The roughness Sa of the first surface 10 was 0.34 nm, the roughness Sa of the side surface 30 was 5.12 nm, the width d of the edge region 22 of the second surface 20 was 0 mm, the roughness Sa of the edge region 22 was 0.38 nm, and the roughness Sa of the central region 21 was 0.25 μm. Test experiment nineteen showed that the strength of the single-crystal or polycrystalline substrate 100 was 266 MPa.

[0093] Experiment 20

[0094] Magnesium aluminum spinel ingots can be cut into wire slices, for example, using multi-wire cutting. These slices can then be double-sided ground using silicon carbide powder (1000-1500#) to obtain 200-micron grinding discs. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.38 nm on the first surface 10 and 0.37 nm on the edge region of the second surface 20. The central region 21 is then sandblasted to achieve a roughness Sa of 0.27 microns. The outer periphery of the grinding disc was chamfered using a 2000-4000# chamfering grinding wheel, resulting in a roughness Sa of 5.34 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 200 μm, a roughness Sa of 0.38 nm on the first surface 10, a roughness Sa of 5.34 nm on the side surface 30, a width d of 2 mm for the edge region 22 of the second surface 20, a roughness Sa of 0.37 nm on the edge region 22, and a roughness Sa of 0.27 μm on the central region 21. Test experiment 20 showed that the strength of the single-crystal or polycrystalline substrate 100 was 279 MPa.

[0095] Experiment 21

[0096] Magnesium aluminum spinel ingots can be cut into wire slices, for example, using multi-wire cutting. These slices can then be double-sided ground using silicon carbide powder (1000-1500#) to obtain a 200-micron grinding disc. Polishing with a 2000-4000# grinding wheel reduces the roughness Sa of the first surface 10 to 0.33 nanometers, and the roughness Sa of the edge region of the second surface 20 to 0.36 nanometers. The central region 21 is then sandblasted to reduce its roughness Sa to 0.27 micrometers. The outer periphery of the grinding disc was chamfered using a 2000-4000# chamfering grinding wheel, resulting in a roughness Sa of 5.44 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 200 μm, a roughness Sa of 0.33 nm on the first surface 10, a roughness Sa of 5.44 nm on the side surface 30, a width d of 4 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.36 nm on the edge region 22, and a roughness Sa of 0.27 μm on the central region 21. Test experiment nineteen showed that the strength of the single-crystal or polycrystalline substrate 100 was 292 MPa.

[0097] Experiment 22

[0098] Magnesium aluminum spinel ingots can be, for example, cut into wire slices using multi-wire cutting. Then, they can be double-sided ground using, for example, 1000-1500# silicon carbide powder to obtain 200-micron grinding discs. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.37 nanometers on the first surface 10, and a roughness Sa of 0.35 nanometers on the edge region of the second surface 20. The central region 21 is then sandblasted to achieve a roughness Sa of 0.26 micrometers. The outer periphery of the grinding disc was chamfered using a 2000-4000# chamfering grinding wheel, resulting in a roughness Sa of 5.77 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 200 μm, a roughness Sa of 0.37 nm on the first surface 10, a roughness Sa of 5.77 nm on the side surface 30, a width d of 6 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.35 nm on the edge region 22, and a roughness Sa of 0.26 μm on the central region 21. Test experiment nineteen showed that the strength of the single-crystal or polycrystalline substrate 100 was 296 MPa.

[0099] Experiment 23

[0100] Magnesium aluminum spinel ingots can be, for example, cut into wire slices using multi-wire cutting. Then, they can be double-sided ground using, for example, 1000-1500# silicon carbide powder to obtain 200-micron grinding discs. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.37 nanometers on the first surface 10, and a roughness Sa of 0.32 nanometers on the edge region of the second surface 20. The central region 21 is then sandblasted to achieve a roughness Sa of 0.27 micrometers. The outer periphery of the grinding disc was chamfered using a 2000-4000# chamfering wheel, resulting in a roughness Sa of 5.25 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 200 μm, a roughness Sa of 0.37 nm on the first surface 10, a roughness Sa of 5.25 nm on the side surface 30, a width d of 8 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.32 nm on the edge region 22, and a roughness Sa of 0.27 μm on the central region 21. Test experiment twenty-three showed that the strength of the single-crystal or polycrystalline substrate 100 was 300 MPa.

[0101] Experiment 24

[0102] Magnesium aluminum spinel ingots can be, for example, multi-wire cut to obtain wire slices, which can then be double-sided ground using, for example, 1000-1500# silicon carbide powder to obtain 200-micron grinding discs. Polishing is then performed using a 2000-4000# grinding wheel to achieve a roughness Sa of 0.33 nm on the first surface 10, a roughness Sa of 0.35 nm on the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.24 microns. A chamfering wheel of 2000-4000# was used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 5.36 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 200 μm, a roughness Sa of 0.33 nm on the first surface 10, a roughness Sa of 5.36 nm on the side surface 30, a width d of 10 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.35 nm on the edge region 22, and a roughness Sa of 0.24 μm on the central region 21. Test experiment nineteen showed that the strength of the single-crystal or polycrystalline substrate 100 was 298 MPa.

[0103] Table 4

[0104]

[0105] Experiment 25

[0106] Sapphire ingots can be cut into wire slices, for example, using multi-wire cutting. Then, double-sided grinding with 1000-1500# silicon carbide powder can be performed to obtain 200-micron grinding discs. Polishing with a 2000-4000# grinding wheel results in a roughness Sa of 0.33 nanometers for the first surface 10 and 0.33 nanometers for the edge region of the second surface 20. The central region 21 is then sandblasted to achieve a roughness Sa of 0.25 micrometers. Using 2... A chamfering wheel of 000-4000# is used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 102.3 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 has a thickness of 200 μm, a roughness Sa of 0.33 nm on the first surface 10, a roughness Sa of 102.3 nm on the side surface 30, a width d of 3 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.33 nm on the edge region 22, and a roughness Sa of 0.25 μm on the central region 21. Test experiment twenty-five yielded a strength of 243 MPa for the single-crystal or polycrystalline substrate 100.

[0107] Experiment 26

[0108] Sapphire ingots can be cut into wire slices, for example, using multi-wire cutting. Then, double-sided grinding with 1000-1500# silicon carbide powder can be performed to obtain a 200-micron grinding disc. Polishing with a 2000-4000# grinding wheel results in a roughness Sa of 0.31 nanometers for the first surface 10, a roughness Sa of 0.37 nanometers for the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.27 micrometers. A chamfering wheel of 2000-4000# was used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 85.4 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 200 μm, a roughness Sa of 0.31 nm on the first surface 10, a roughness Sa of 85.4 nm on the side surface 30, a width d of 3 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.37 nm on the edge region 22, and a roughness Sa of 0.27 μm on the central region 21. Test experiment twenty-six showed that the strength of the single-crystal or polycrystalline substrate 100 was 276 MPa.

[0109] Experiment 27

[0110] Sapphire ingots can be cut into wire slices, for example, using multi-wire cutting. Then, double-sided grinding with 1000-1500# silicon carbide powder can be performed to obtain 200-micron grinding discs. Polishing with a 2000-4000# grinding wheel results in a roughness Sa of 0.35 nanometers for the first surface 10, a roughness Sa of 0.36 nanometers for the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.27 micrometers. A chamfering wheel of 2000-4000# was used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 50.9 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 200 μm, a roughness Sa of 0.35 nm on the first surface 10, a roughness Sa of 50.9 nm on the side surface 30, a width d of 3 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.36 nm on the edge region 22, and a roughness Sa of 0.27 μm on the central region 21. Test experiment 27 showed that the strength of the single-crystal or polycrystalline substrate 100 was 302 MPa.

[0111] Experiment 28

[0112] Sapphire ingots can be cut into wire slices, for example, using multi-wire cutting. Then, double-sided grinding with 1000-1500# silicon carbide powder can be performed to obtain 200-micron grinding discs. Polishing with a 2000-4000# grinding wheel results in a roughness Sa of 0.34 nanometers for the first surface 10 and 0.34 nanometers for the edge region of the second surface 20. Sandblasting of the central region 21 reduces its roughness Sa to 0.26 micrometers. A chamfering wheel of 2000-4000# was used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 23.4 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 200 μm, a roughness Sa of 0.34 nm on the first surface 10, a roughness Sa of 23.4 nm on the side surface 30, a width d of 3 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.34 nm on the edge region 22, and a roughness Sa of 0.26 μm on the central region 21. Test experiment 28 showed that the strength of the single-crystal or polycrystalline substrate 100 was 322 MPa.

[0113] Experiment 29

[0114] Sapphire ingots can be cut into wire slices, for example, using multi-wire cutting. Then, double-sided grinding with 1000-1500# silicon carbide powder can be performed to obtain 200-micron grinding discs. Polishing with a 2000-4000# grinding wheel results in a roughness Sa of 0.34 nm on the first surface 10, a roughness Sa of 0.36 nm on the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.27 microns. A chamfering wheel of 2000-4000# was used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 5.67 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 200 μm, a roughness Sa of 0.34 nm on the first surface 10, a roughness Sa of 5.67 nm on the side surface 30, a width d of 3 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.36 nm on the edge region 22, and a roughness Sa of 0.27 μm on the central region 21. Test experiment 29 showed that the strength of the single-crystal or polycrystalline substrate 100 was 336 MPa.

[0115] Experiment Thirty

[0116] Sapphire ingots can be cut into wire slices, for example, using multi-wire cutting. Then, double-sided grinding with 1000-1500# silicon carbide powder can be performed to obtain 200-micron grinding discs. Polishing with a 2000-4000# grinding wheel results in a roughness Sa of 0.36 nanometers for the first surface 10, a roughness Sa of 0.35 nanometers for the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.24 micrometers. The outer periphery of the grinding disc was chamfered using a 2000-4000# chamfering wheel, resulting in a roughness Sa of 2.3 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 200 μm, a roughness Sa of 0.36 nm on the first surface 10, a roughness Sa of 2.3 nm on the side surface 30, a width d of 3 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.35 nm on the edge region 22, and a roughness Sa of 0.24 μm on the central region 21. Test experiment 30 showed that the strength of the single-crystal or polycrystalline substrate 100 was 341 MPa.

[0117] Table 5

[0118]

[0119]

[0120] Experiment 31

[0121] Sapphire ingots can be cut into wire slices, for example, using multi-wire cutting. Then, double-sided grinding with 1000-1500# silicon carbide powder can be performed to obtain 200-micron grinding discs. Polishing with a 2000-4000# grinding wheel results in a roughness Sa of 0.35 nanometers for the first surface 10 and 0.35 nanometers for the edge region of the second surface 20. Sandblasting of the central region 21 reduces its roughness Sa to 0.22 micrometers. A chamfering wheel of 2000-4000# is used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 5.25 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 has a thickness of 200 μm. The roughness Sa of the first surface 10 is 0.35 nm, the roughness Sa of the side surface 30 is 5.25 nm, the width d of the edge region 22 of the second surface 20 is 0 mm, the roughness Sa of the edge region 22 is 0.35 nm, and the roughness Sa of the central region 21 is 0.22 μm. Test experiment thirty-one shows that the strength of the single-crystal or polycrystalline substrate 100 is 311 MPa.

[0122] Experiment 32

[0123] Sapphire ingots can be cut into wire slices, for example, using multi-wire cutting. Then, double-sided grinding with 1000-1500# silicon carbide powder can be performed to obtain a 200-micron grinding disc. Polishing with a 2000-4000# grinding wheel results in a roughness Sa of 0.32 nm on the first surface 10, a roughness Sa of 0.33 nm on the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.21 microns. A chamfering wheel of 2000-4000# is used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 5.43 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 has a thickness of 200 μm, a roughness Sa of 0.32 nm on the first surface 10, a roughness Sa of 5.43 nm on the side surface 30, a width d of 2 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.33 nm on the edge region 22, and a roughness Sa of 0.21 μm on the central region 21. Test experiment thirty-two yielded a strength of 332 MPa for the single-crystal or polycrystalline substrate 100.

[0124] Experiment 33

[0125] Sapphire ingots can be cut into wire slices, for example, using multi-wire cutting. Then, double-sided grinding with 1000-1500# silicon carbide powder can be performed to obtain 200-micron grinding discs. Polishing with a 2000-4000# grinding wheel results in a roughness Sa of 0.37 nm on the first surface 10, a roughness Sa of 0.32 nm on the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.27 microns. A chamfering wheel of 2000-4000# was used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 5.14 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 had a thickness of 200 μm, a roughness Sa of 0.37 nm on the first surface 10, a roughness Sa of 5.14 nm on the side surface 30, a width d of 4 mm on the edge region 22 of the second surface 20, a roughness Sa of 0.32 nm on the edge region 22, and a roughness Sa of 0.27 μm on the central region 21. Test experiment thirty-three showed that the strength of the single-crystal or polycrystalline substrate 100 was 346 MPa.

[0126] Experiment Thirty-Four

[0127] Sapphire ingots can be cut into wire slices, for example, using multi-wire cutting. Then, double-sided grinding with 1000-1500# silicon carbide powder can be performed to obtain 200-micron grinding discs. Polishing with a 2000-4000# grinding wheel results in a roughness Sa of 0.36 nm for the first surface 10, a roughness Sa of 0.32 nm for the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.23 microns. A chamfering wheel of 2000-4000# is used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 5.67 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 has a thickness of 200 μm. The roughness Sa of the first surface 10 is 0.36 nm, the roughness Sa of the side surface 30 is 5.67 nm, the width d of the edge region 22 of the second surface 20 is 6 mm, the roughness Sa of the edge region 22 is 0.32 nm, and the roughness Sa of the central region 21 is 0.23 μm. Test experiment thirty-four shows that the strength of the single-crystal or polycrystalline substrate 100 is 349 MPa.

[0128] Experiment Thirty-Five

[0129] Sapphire ingots can be cut into wire slices, for example, using multi-wire cutting. Then, double-sided grinding with 1000-1500# silicon carbide powder can be performed to obtain 200-micron grinding discs. Polishing with a 2000-4000# grinding wheel results in a roughness Sa of 0.31 nanometers for the first surface 10, a roughness Sa of 0.36 nanometers for the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.27 micrometers. A chamfering wheel of 2000-4000# is used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 5.55 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 has a thickness of 200 μm. The roughness Sa of the first surface 10 is 0.31 nm, the roughness Sa of the side surface 30 is 5.55 nm, the width d of the edge region 22 of the second surface 20 is 8 mm, the roughness Sa of the edge region 22 is 0.36 nm, and the roughness Sa of the central region 21 is 0.27 μm. Test experiment thirty-five shows that the strength of the single-crystal or polycrystalline substrate 100 is 351 MPa.

[0130] Experiment Thirty-Six

[0131] Sapphire ingots can be cut into wire slices, for example, using multi-wire cutting. Then, double-sided grinding with 1000-1500# silicon carbide powder can be performed to obtain 200-micron grinding discs. Polishing with a 2000-4000# grinding wheel results in a roughness Sa of 0.34 nanometers for the first surface 10, a roughness Sa of 0.35 nanometers for the edge region of the second surface 20, and sandblasting of the central region 21 to achieve a roughness Sa of 0.25 micrometers. Using 2... A chamfering wheel of 000-4000# is used to chamfer the outer periphery of the grinding disc, resulting in a roughness Sa of 5.46 nm on the side surface 30. The prepared single-crystal or polycrystalline substrate 100 has a thickness of 200 μm. The roughness Sa of the first surface 10 is 0.34 nm, the roughness Sa of the side surface 30 is 5.46 nm, the width d of the edge region 22 of the second surface 20 is 10 mm, the roughness Sa of the edge region 22 is 0.35 nm, and the roughness Sa of the central region 21 is 0.25 μm. Test experiment thirty-one shows that the strength of the single-crystal or polycrystalline substrate 100 is 349 MPa.

[0132] Table Six

[0133]

[0134] Referring to Tables 3 to 6, and based on Experiments 13 to 36, when the thickness of the magnesium-aluminum spinel substrate or sapphire substrate is the same (both 200 micrometers), the roughness Sa of the edge region 22 is ≤0.5 nanometers, the roughness Sa of the side surface 30 is ≤10 nanometers, the width of the edge region 22 is greater than or equal to 0 millimeters, and the strength of the magnesium-aluminum spinel substrate or sapphire substrate is greater than 200 MPa. Improving the strength of single-crystal or polycrystalline substrates 100 can mitigate material loss caused by insufficient strength, and it also allows for ultra-thinning of single-crystal or polycrystalline substrates, increasing material utilization, reducing material costs, and enhancing product competitiveness.

[0135] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A single-crystal or polycrystalline substrate (100), characterized in that, It has a first surface (10) and a second surface (20) disposed opposite to the first surface (10), and a side surface (30) connected between the first surface (10) and the second surface (20); The second surface (20) includes a central region (21) and an edge region (22) surrounding the central region (21), wherein the roughness of the central region (21) is greater than the roughness of the edge region (22); and the roughness Sa of the side surface (30) is ≤50 nanometers.

2. The single-crystal or polycrystalline substrate (100) as described in claim 1, characterized in that, The width of the edge region (22) is greater than or equal to 1 mm.

3. The single-crystal or polycrystalline substrate (100) as described in claim 1, characterized in that, The single-crystal or polycrystalline substrate (100) has a circular structure, and the diameter of the central region (21) is greater than the diameter of the edge region (22).

4. The single-crystal or polycrystalline substrate (100) as described in claim 2, characterized in that, The roughness Sa of the first surface (10) is ≤1 nanometer, the roughness Sa of the edge region (22) is ≤1 nanometer, and the roughness Sa of the central region (21) is in the range of 0.01 micrometer ≤ Sa ≤0.4 micrometer.

5. The single-crystal or polycrystalline substrate (100) as described in claim 1, characterized in that, The single-crystal or polycrystalline substrate (100) is a lithium tantalate substrate or a lithium niobate substrate, and the width of the edge region is greater than or equal to 2 mm.

6. The single-crystal or polycrystalline substrate (100) as described in claim 5, characterized in that, The roughness of the edge region (22) is less than 0.4 nanometers, and the roughness Sa of the side surface (30) is ≤25 nanometers.

7. The single-crystal or polycrystalline substrate (100) as described in claim 1, characterized in that, The single-crystal or polycrystalline substrate (100) is a magnesium aluminum spinel substrate or a sapphire substrate, and the roughness Sa of the edge region is ≤0.5 nanometers.

8. The single-crystal or polycrystalline substrate (100) as described in claim 7, characterized in that, The roughness Sa of the side surface (30) is ≤10 nanometers, and the width of the edge region (22) is greater than or equal to 0 millimeters.

9. A method for preparing a single-crystal or polycrystalline substrate, characterized in that, include: First processing step: The substrate material is processed to form a first substrate material with side surfaces, wherein the roughness Sa of the side surfaces is ≤50 nanometers; The second processing step is to polish the first substrate material to obtain a single crystal or polycrystalline substrate with opposing first and second surfaces. The third processing step is to process the second surface so that the second surface forms a central region and an edge region surrounding the central region, wherein the roughness of the central region is greater than that of the edge region.

10. The method for preparing a single-crystal or polycrystalline substrate as described in claim 9, characterized in that, The third processing step includes: The second surface is polished. The edge region of the second surface is covered, dividing the second surface into a central region and an edge region surrounding the central region; and The central region is sandblasted to make its roughness greater than that of the edge region.

11. The method for preparing a single-crystal or polycrystalline substrate as described in claim 9, characterized in that, The width of the edge region is greater than or equal to 1 millimeter.

12. The method for preparing a single-crystal or polycrystalline substrate as described in claim 11, characterized in that, The roughness Sa of the first surface is ≤1 nanometer, the roughness Sa of the edge region is ≤1 nanometer, and the roughness Sa of the center region is in the range of 0.01 micrometer ≤ Sa ≤0.4 micrometer.

13. An electronic device, characterized in that, include: This includes single-crystal or polycrystalline substrates as described in any one of claims 1 to 8, or single-crystal or polycrystalline substrates prepared by the method described in any one of claims 9 to 12.

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