Method of polishing a substrate, substrate and light emitting diode
By employing grinding steps with varying pressures on the substrate, the problem of uneven stress warping is solved, resulting in a smaller damaged layer and a more uniform substrate surface, making it suitable for substrate grinding in semiconductor manufacturing.
Patent Information
- Application Number
- CN202311644388.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-01
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2043-12-01
AI Technical Summary
Existing technologies are difficult to effectively repair substrate warping caused by uneven stress and cannot avoid damage caused by excessive polishing, especially when the warping is greater than 20µm.
The damaged layers on both sides of the substrate are first polished using a first pressure greater than or equal to 3 kPa to reduce stress differences. Then, the damaged layers are thinned using a second pressure less than or equal to 1 kPa to form the target substrate.
It effectively repairs the stress unevenness and warping of the substrate, reduces the thickness of the damaged layer, forms a smaller damaged layer, and improves the flatness and uniformity of the substrate.
Smart Images
Figure CN117912934B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of semiconductor manufacturing, in particular to a substrate grinding method, a substrate and a light emitting diode. BACKGROUND
[0002] At present, a conventional substrate processing method generally comprises grinding, waxing, rough polishing, polishing, waxing, cleaning and testing. The grinding step is to repair the warp of the substrate. The warp of the substrate includes geometric warp and stress uneven warp. The geometric warp is caused by the geometric shape, and the stress uneven warp is caused by the stress uneven on both sides of the substrate.
[0003] In order to repair the warp in the substrate, a conventional substrate grinding method generally adopts a composite pressure operation mode of low pressure first and high pressure later. The conventional substrate grinding method has good repair effect on the warp less than 20 um. However, the conventional substrate grinding method is not applicable to the warp greater than 20 um and cannot effectively repair the stress uneven warp.
[0004] Therefore, how to effectively repair the stress uneven warp of the substrate and form a smaller damage layer of the substrate is still a problem to be solved by those skilled in the art. SUMMARY
[0005] In view of the above, in order to solve the above technical problems, the present application provides a substrate grinding method, a substrate and a light emitting diode.
[0006] To achieve the above object, one of the technical solutions adopted by the present application provides a substrate grinding method, which comprises:
[0007] providing a substrate to be ground, the substrate to be ground comprising a substrate middle layer and damage layers on both sides of the substrate middle layer;
[0008] applying a first pressure to the damage layers on both sides of the substrate to be ground for first grinding, so as to repair the warp of the substrate to be ground and reduce the stress difference of the damage layers on both sides of the substrate middle layer, and form a pre-ground substrate; wherein the first pressure is greater than or equal to 3Kpa;
[0009] applying a second pressure to the damage layers on both sides of the pre-ground substrate for second grinding, so as to thin the damage layers on both sides of the pre-ground substrate, and form a target substrate; wherein the second pressure is less than or equal to 1Kpa.
[0010] Optionally, the substrate to be ground is a 2-inch to 18-inch substrate.
[0011] Optionally, the thickness of the substrate to be ground is 300um to 5000um.
[0012] Optionally, the warpage of the substrate to be ground is 50um-1000um.
[0013] Optionally, the thickness of the damage layer on both sides of the substrate to be ground is 5%-50% of the thickness of the substrate to be ground.
[0014] Optionally, the thickness difference of the substrate to be ground is within ±20% of the thickness of the substrate to be ground.
[0015] Optionally, the thickness of the first grinding removal is 0.8-1.5 times the warpage of the substrate to be ground.
[0016] Optionally, the warpage of the pre-ground substrate is 20um-50um,
[0017] Optionally, the thickness of the damage layer on both sides of the pre-ground substrate is 4%-20% of the thickness of the pre-ground substrate.
[0018] Optionally, the thickness difference of the pre-ground substrate is within ±10%.
[0019] Optionally, the warpage of the target substrate is less than or equal to 20um, and the thickness of the damage layer on both sides of the target substrate is less than or equal to 20um.
[0020] Optionally, the first pressure is less than or equal to 20Kpa, and the second pressure is greater than or equal to 0.1Kpa.
[0021] Optionally, the material of the substrate to be ground includes at least one of oxides, nitrides, carbides, and borides.
[0022] To solve the above technical problems, another technical solution adopted by the present application is to provide a substrate and a processing method of the substrate, which includes the grinding method of the substrate described above.
[0023] To solve the above technical problems, another technical solution adopted by the present application is to provide a light-emitting diode, which includes the substrate described above.
[0024] Beneficial effects: Different from the prior art, in the present application, the damage layers on both sides of the substrate to be ground are ground by the first pressure greater than or equal to 3Kpa, which can make the damage layers on both sides of the substrate middle layer of the pre-ground substrate more symmetrically distributed on both sides of the substrate middle layer and the thickness difference of the damage layers in each region of the pre-ground substrate reduced, so that the stress of each region of the pre-ground substrate is more balanced, which can effectively repair the uneven stress warpage of the substrate to be ground. The damage layers on both sides of the pre-ground substrate are ground by the second pressure less than or equal to 1Kpa, which can thin the thickness of the damage layers on both sides of the substrate middle layer of the target substrate. That is, the present application can effectively repair the uneven stress warpage of the substrate and make the substrate form a smaller damage layer. Attached Figure Description
[0025] Figure 1 This is a schematic flowchart of the substrate polishing method of this application;
[0026] Figure 2 yes Figure 1 A schematic diagram of the structure of the substrate to be polished provided in step S110;
[0027] Figure 3 yes Figure 2 A schematic diagram showing the dimensions of the substrate to be ground.
[0028] Figure 4 yes Figure 1 A schematic diagram of the first grinding process in step S120;
[0029] Figure 5 yes Figure 1 A schematic diagram of the structure of the pre-polished substrate formed in step S120;
[0030] Figure 6 yes Figure 5 A schematic diagram showing the dimensions of the pre-polished substrate;
[0031] Figure 7 yes Figure 1 A schematic diagram of the target substrate formed in step S130;
[0032] Figure 8 yes Figure 7 A schematic diagram showing the dimensions of the target substrate;
[0033] Figure 9 This is a schematic diagram of the structure of the substrate to be polished provided in step S310;
[0034] Figure 10 yes Figure 9 A schematic diagram showing the dimensions of the substrate to be ground.
[0035] Figure 11 This is a schematic diagram of the first grinding process in step S320;
[0036] Figure 12 This is a schematic diagram of the structure of the pre-polished substrate formed in step S320;
[0037] Figure 13 yes Figure 12 A schematic diagram showing the dimensions of the pre-polished substrate;
[0038] Figure 14 This is a schematic diagram of the target substrate formed in step S330;
[0039] Figure 15 yesFigure 14 A schematic view of a dimension of a target substrate;
[0040] Figure 16 A schematic view of a structure of a substrate prepared by the substrate polishing method of the present application.
[0041] Legend of reference numerals:
[0042] 110 - substrate to be polished; 120 - pre-polished substrate; 130 - target substrate; 111 - substrate intermediate layer; 112 - damage layer; 200 - polishing disk;
[0043] hi - first thickness; h2 - second thickness; h3 - third thickness; h4 - fourth thickness; h5 - fifth thickness; h6 - sixth thickness;
[0044] 210 - substrate to be polished; 220 - pre-polished substrate; 230 - target substrate; 211 - substrate intermediate layer; 212 - damage layer.
[0045] h7 - seventh thickness; h8 - eighth thickness; h9 - ninth thickness; h10 - tenth thickness; hi 1 - eleventh thickness; hi 2 - twelfth thickness;
[0046] 10 - substrate; 11 - substrate intermediate layer; 12 - damage layer. DETAILED DESCRIPTION
[0047] For those skilled in the art to have a better understanding of the technical solutions of the present application, the present application will be described in further detail below in combination with the drawings and specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor shall fall within the scope of protection of the present application.
[0048] Please refer to Figure 1 The substrate polishing method of the present application at least includes steps S110 to S130.
[0049] Step S110: providing a substrate to be polished, the substrate to be polished including a substrate intermediate layer and damage layers located on both sides of the substrate intermediate layer.
[0050] Please refer to Figure 2 The substrate to be polished 110 includes a substrate intermediate layer 111 and damage layers 112 located on both sides of the substrate intermediate layer. By way of example and not limitation, the substrate to be polished 110 can be any substrate used for semiconductor device manufacturing, including but not limited to a polycrystalline ceramic substrate. The material of the polycrystalline ceramic substrate includes but is not limited to at least one of oxides, nitrides, carbides, and borides.
[0051] Optionally, in combination with Figure 2 Referring to Figure 3 The substrate to be polished 110 can be a 2-inch to 18-inch (e.g., 2-inch, 4-inch, 10-inch, 18-inch) substrate. The thickness of the substrate to be polished 110 can be a first thickness h1, which is 300 um to 5000 um (e.g., 300 um, 400 um, 1000 um, 5000 um). The thickness of the damage layer 112 on both sides of the substrate to be polished 110 can be a second thickness h2, which is 5% to 50% of the first thickness h1 (e.g., 5%, 10%, 30%, 50%). The warpage of the substrate to be polished 110 can be 50 um to 1000 um (e.g., 50 um, 300 um, 600 um, 1000 um). The thickness difference (TTV) of the substrate to be polished 110 is within ±20% of the first thickness h1 (e.g., -20%, -15%, +13%, +20%).
[0052] Step S120: First polishing of the damage layers on both sides of the substrate to be polished using a first pressure to form a pre-polished substrate.
[0053] In combination with Figure 3 And Figure 4 In comparison Figure 5 The first pressure is greater than or equal to 3 KPa, and through the first polishing, the warpage of the substrate to be polished 110 can be repaired and the stress difference of the damage layers 112 on both sides of the middle layer 111 of the substrate can be reduced.
[0054] Specifically, by first polishing the damage layers 112 on both sides of the substrate to be polished 110 using a first pressure greater than or equal to 3 KPa, the damage layers 112 on both sides of the middle layer 111 of the pre-polished substrate 120 formed can be more symmetrically distributed on both sides of the middle layer 111 of the substrate and the thickness difference of each region of the damage layer 112 can be reduced, so that the stress of each region of the pre-polished substrate 120 is more balanced, which can effectively repair the uneven stress warpage of the substrate to be polished 110.
[0055] By way of example and not limitation, the substrate to be polished 110 is polished on both sides using a polishing disc 200, and the processing pressure of the polishing disc 200 on the substrate to be polished 110 is the first pressure.
[0056] Optionally, the first pressure is less than or equal to 20 KPa, which can prevent the pressure from being too large during polishing, thereby avoiding damage to the substrate to be polished 110.
[0057] Optionally, the first grinding removal thickness is 0.8 times to 1.5 times (e.g. 0.8 times, 1 times, 1.2 times, 1.5 times) of the warpage of the to-be-ground substrate 110. After the first grinding, the to-be-ground substrate 110 forms a pre-ground substrate 120, and the thickness of the pre-ground substrate 120 can be a third thickness h3, which is the difference between the first thickness h1 and the first grinding removal thickness. The thickness of the damage layer 112 on both sides of the pre-ground substrate 120 can be a fourth thickness h4, which is 4% to 20% (e.g. 4%, 6%, 12%, 20%) of the third thickness h3. The warpage of the pre-ground substrate 120 can be 20um to 50um. The thickness difference of the pre-ground substrate 120 is within ±10% (e.g. -10%, -5%, +4%, +10%) of the third thickness h3.
[0058] Step S130: The second grinding is performed on the damage layers on both sides of the pre-ground substrate by using a second pressure, to form a target substrate.
[0059] In combination Figure 5 And Figure 6 In comparison Figure 7 , the second grinding includes thinning the damage layers 112 on both sides of the pre-ground substrate 120. The second pressure is less than or equal to 1Kpa. In this way, the damage layers 112 on both sides of the middle layer 111 of the substrate can be ground by using a second pressure smaller than the first pressure, to remove at least part of the thickness of the damage layers 112 in the pre-ground substrate 120. Optionally, to ensure the removal effect of the thickness of the damage layers 112 during grinding, the second pressure is greater than or equal to 0.1Kpa.
[0060] Optionally, half of the second grinding removal thickness is not less than the difference between the fourth thickness h4 and 20um and not greater than the fourth thickness. After the second grinding, the pre-ground substrate 120 forms a target substrate 130. The thickness of the target substrate 130 can be a fifth thickness h5, which is the difference between the third thickness h3 and the second grinding removal thickness. The thickness of the damage layers 112 on both sides of the target substrate 130 can be a sixth thickness h6, which is less than or equal to 20um. The warpage of the target substrate 130 is less than or equal to 20um.
[0061] The steps S110 to S130 are performed. In the present application, the damage layer 112 on both sides of the substrate to be ground 110 is ground by the first pressure greater than or equal to 3 Kpa, so that the damage layer 112 on both sides of the substrate middle layer 111 in the pre-ground substrate 120 formed is more symmetrically distributed on both sides of the substrate middle layer 111, and the thickness difference of each area of the damage layer 112 in the pre-ground substrate 120 formed is reduced, so that the stress of each area of the pre-ground substrate 120 is more balanced, so that the stress uneven warping of the substrate to be ground 110 can be effectively repaired. The damage layer on both sides of the pre-ground substrate 120 is ground by the second pressure less than or equal to 1 Kpa, so that the thickness of the damage layer 112 on both sides of the substrate middle layer 111 in the target substrate 130 formed is thinned. That is, the present application can effectively repair the stress uneven warping of the substrate and form a smaller damage layer.
[0062] Hereinafter, the substrate grinding method of the present application will be further described through specific examples.
[0063] Experimental group
[0064] The experimental group adopts the method of the present application to grind the substrate.
[0065] The substrate grinding method of the experimental group includes steps S210 to S230. Among them, step S210 is a more specific step of step S110. Step S220 is a more specific step of step S120. Step S230 is a more specific step of step S130.
[0066] Step S210: providing a substrate to be ground
[0067] Combined Figure 2 Reference Figure 3 The substrate to be ground 110 includes a substrate middle layer 111 and a damage layer 112 on both sides of the substrate middle layer 111. The substrate to be ground 110 can be a 10-inch substrate, and the thickness of the substrate to be ground 110 is a first thickness h1, and the first thickness h1 is 700um. The thickness of the damage layer 112 of the substrate to be ground 110 is a second thickness h2, and the second thickness h2 of the damage layer 112 on one side of the substrate to be ground 110 is 50um, and the second thickness h2 of the damage layer 112 on the other side of the substrate to be ground 110 is 60um. The warpage of the substrate to be ground 110 can be 100um. The thickness difference of the substrate to be ground 110 is 15% of the first thickness h1.
[0068] Step S220: grinding the damage layer on both sides of the substrate to be ground by the first pressure to form a pre-ground substrate.
[0069] Combined Figure 2 ,Figure 3 and Figure 4 Comparison Figure 5 and Figure 6 The first grinding includes grinding the to-be-ground substrate 110 on both sides of the to-be-ground substrate 110 by using the grinding disc 200. The first pressure is 5 KPa. The thickness removed by the first grinding is 85 um.
[0070] After the first grinding, the to-be-ground substrate 110 forms a pre-ground substrate 120. The thickness of the pre-ground substrate 120 is a third thickness h3, and the third thickness h3 is 615 um. The thickness of the damage layer 112 of the pre-ground substrate 120 is a fourth thickness h4. The fourth thickness h4 of the damage layer 112 on one side of the pre-ground substrate 120 is 65 um, and the fourth thickness h4 of the damage layer 112 on the other side of the pre-ground substrate 120 is 65 um. The warpage of the pre-ground substrate 120 is 25 um. The thickness difference of the pre-ground substrate 120 is 9% of the third thickness h3.
[0071] Step S230: The second grinding of the damage layer on both sides of the pre-ground substrate is performed by using a second pressure to form a target substrate.
[0072] Combination Figure 5 and Figure 6 Comparison Figure 7 and Figure 8 The second pressure is 1 KPa, and the thickness removed by the second grinding is 100 um. After the second grinding, the pre-ground substrate 120 forms a target substrate 130. The thickness of the target substrate 130 is a fifth thickness h5, and the fifth thickness h5 is 515 um. The thickness of the damage layer 112 of the target substrate 130 is a sixth thickness h6. The sixth thickness h6 of the damage layer 112 on one side of the target substrate 130 is 15 um, and the sixth thickness h6 of the damage layer 112 on the other side of the target substrate 130 is 15 um. The warpage of the target substrate 130 is 10 um, and the thickness difference of the target substrate 130 is 2% of the fifth thickness h5.
[0073] Control group
[0074] The control group uses a traditional method to grind the substrate.
[0075] The grinding method of the substrate of the control group includes steps S310 to S330.
[0076] Step S310: providing a to-be-ground substrate
[0077] Combination Figure 9 Reference Figure 10The to-be-ground substrate 210 includes a substrate middle layer 211 and damage layers 212 located on both sides of the substrate middle layer 211. The to-be-ground substrate 210 can be a 10-inch substrate, and the thickness of the to-be-ground substrate 210 is a seventh thickness h7, and the seventh thickness h7 is 700 um. The thickness of the damage layer 212 of the to-be-ground substrate 210 is an eighth thickness h8, and the eighth thickness h8 of the damage layer 212 on one side of the to-be-ground substrate 210 is 50 um, and the eighth thickness h8 of the damage layer 212 on the other side of the to-be-ground substrate 210 is 60 um. The warpage of the to-be-ground substrate 210 can be 100 um. The thickness difference of the to-be-ground substrate 210 is 15% of the seventh thickness h7.
[0078] Step S320: First grinding of the damage layers on both sides of the to-be-ground substrate is performed by using a first pressure, and a pre-ground substrate is formed.
[0079] In combination with Figure 9 , Figure 10 and Figure 11 in contrast Figure 12 and Figure 13 , the first grinding includes grinding the to-be-ground substrate 210 on both sides of the to-be-ground substrate 210 by using the grinding disc 200. The first pressure is 1 Kpa. The thickness removed by the first grinding is 100 um.
[0080] After the first grinding, the to-be-ground substrate 210 forms a pre-ground substrate 220. The thickness of the pre-ground substrate 220 is a ninth thickness h9, and the ninth thickness h9 is 600 um. The thickness of the damage layer 212 of the pre-ground substrate 220 is a tenth thickness h10, and the tenth thickness h10 of the damage layer 212 on one side of the pre-ground substrate 220 is 100 um, and the tenth thickness h10 of the damage layer 212 on the other side of the pre-ground substrate 220 is 30 um. The warpage of the pre-ground substrate 220 is 200 um. The thickness difference of the pre-ground substrate 220 is 13% of the ninth thickness h9.
[0081] Step S330: Second grinding of the damage layers on both sides of the pre-ground substrate is performed by using a second pressure, and a target substrate is formed.
[0082] In combination with Figure 12 and Figure 13 in contrast Figure 14 and Figure 15, the second pressure is 5 KPa, and the second polishing removal thickness is 85 um. The pre-polishing substrate 220 after the second polishing forms a target substrate 230. The thickness of the target substrate 230 is an eleventh thickness h11, and the eleventh thickness h11 is 515 um. The thickness of the damage layer 212 of the target substrate 230 is a twelfth thickness h12, the twelfth thickness h12 of the damage layer 212 of one side of the target substrate 230 is 65 um, and the twelfth thickness h12 of the damage layer 212 of the other side of the target substrate 230 is 65 um. The warpage of the target substrate 230 is 120 um, and the thickness difference of the target substrate 230 is 8% of the eleventh thickness h11.
[0083] In summary, compared with the target substrate 130 of the experimental group and the target substrate 230 of the control group, the thickness of the damage layer 112 of one side of the target substrate 130 of the experimental group is 50 um less than the thickness of the damage layer 212 of one side of the target substrate 230 of the control group; the warpage of the target substrate 130 of the experimental group is 110 um less than the warpage of the target substrate 230 of the control group; and the percentage of the thickness difference of the target substrate 130 of the experimental group in the thickness of the target substrate 230 is 6% less than the percentage of the thickness difference of the target substrate 230 of the control group in the thickness of the target substrate 230. Therefore, compared with the control group, the polishing method of the substrate of the experimental group has a better repair effect on warpage and thickness difference.
[0084] In addition, the present application further provides a substrate 10, and a processing method of the substrate 10 includes the polishing method of the substrate of the present application. The substrate 10 includes a substrate intermediate layer 11 and damage layers 12 located on both sides of the substrate intermediate layer 11. The thickness of the damage layers 12 on both sides of the substrate 10 is less than or equal to 20 um. The warpage of the substrate 10 is less than or equal to 20 um. The thickness difference of the substrate 10 is less than or equal to 6 um. The specific structure of the substrate 10 can refer to the specific structure of the target substrate 130 described above, and will not be described here.
[0085] In addition, the present application further provides a light emitting diode (not shown in the figure), which includes the substrate 10 described above.
[0086] The above is only an embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation using the content of the specification and drawings of the present application, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.
Claims
1. A method for polishing a substrate, characterized in that, The grinding method includes: A substrate to be polished is provided, the substrate to be polished including a substrate intermediate layer and a damage layer located on both sides of the substrate intermediate layer; A first pressure is applied to the damaged layers on both sides of the substrate to be polished to repair the warping of the substrate and reduce the stress difference between the damaged layers on both sides of the middle layer of the substrate, thereby forming a pre-polished substrate; wherein the first pressure is greater than or equal to 3 kPa. A second pressure is applied to the damaged layers on both sides of the pre-polished substrate to thin the damaged layers on both sides of the pre-polished substrate and form a target substrate; wherein the second pressure is less than or equal to 1 kPa.
2. The grinding method according to claim 1, characterized in that, The substrate to be ground is a 2-inch to 18-inch substrate.
3. The grinding method according to claim 1, characterized in that, The thickness of the substrate to be ground is 300μm~5000μm.
4. The grinding method according to claim 1, characterized in that, The warpage of the substrate to be polished is 50μm~1000μm.
5. The grinding method according to claim 1, characterized in that, The thickness of the damaged layer on both sides of the substrate to be polished is 5% to 50% of the thickness of the substrate to be polished.
6. The grinding method according to claim 1, characterized in that, The thickness difference of the substrate to be polished is within ±20% of the thickness of the substrate to be polished.
7. The grinding method according to claim 1, characterized in that, The thickness removed by the first grinding is 0.8 to 1.5 times the warpage of the substrate to be ground.
8. The grinding method according to claim 1, characterized in that, The warpage of the pre-polished substrate is 20μm~50μm.
9. The grinding method according to claim 1, characterized in that, The thickness of the damaged layer on both sides of the pre-polished substrate is 4% to 20% of the thickness of the pre-polished substrate.
10. The grinding method according to claim 1, characterized in that, The thickness difference of the pre-polished substrate is within ±10% of the thickness of the pre-polished substrate.
11. The grinding method according to claim 1, characterized in that, The warpage of the target substrate is less than or equal to 20 μm, and the thickness of the damage layer on both sides of the target substrate is less than or equal to 20 μm.
12. The grinding method according to claim 1, characterized in that, The first pressure is less than or equal to 20 kPa, and the second pressure is greater than or equal to 0.1 kPa.
13. The grinding method according to claim 1, characterized in that, The material of the substrate to be ground includes at least one of oxides, nitrides, carbides, and borides.
14. A substrate, characterized in that, The substrate processing method includes the grinding method of the substrate according to any one of claims 1-13.
15. A light-emitting diode, characterized in that, The light-emitting diode includes the substrate as described in claim 14.
Citation Information
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