Laser grooving method

Abstract

The invention provides a laser grooving method, which comprises the following steps of: providing a semiconductor structure which is provided with at least one grooving region; a mask plate and a laser light source are provided, the laser light source is arranged above the slotting area, a preset distance is reserved between the laser light source and the slotting area, and the mask plate is located between the semiconductor structure and the laser light source; based on the mask plate, using the laser light source to sequentially form a plurality of grooves arranged along the X direction in the grooving area of the semiconductor structure, the laser transmission area of the mask plate forming the current groove and the laser transmission area of the mask plate forming the previous groove are overlapped by a first preset size in the X direction, so that a groove with a second preset size is obtained. According to the laser grooving method, the groove with the second preset size is formed by splicing the formed grooves, and the quality and the yield of the formed groove are improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and particularly to a laser grooving method. Background Art

[0002] During the processing of semiconductor structures, when the thickness of the semiconductor structure reaches a certain level or there are other special process requirements, during the grooving process in the semiconductor structure, there are certain dimensional requirements for the laser light used during grooving and the bottom width of the formed groove. This is because when using a mask plate with a large width dimension for laser operation, since the laser energy is normally distributed, the morphology of the product groove formed by measurement is V-shaped, and the bottom width cannot meet the parameter requirements. For example, Figure 1 As shown, it is a schematic structural diagram of a groove formed in the prior art, including a semiconductor structure 01 and a groove 011. In the existing process, when the opening size of the groove formed in the semiconductor structure is 61.545 μm and the bottom size of the groove is 45.562 μm, which is less than 80% of the opening size and does not meet the parameter requirement that the bottom size is greater than 80% of the opening size.

[0003] In view of this, there is an urgent need for a method that can overcome the problem that the bottom size of the groove formed during the grooving process of the semiconductor structure using the laser process does not meet the requirements. Summary of the Invention

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a laser grooving method for solving the problem that the bottom size of the groove formed during the grooving process of the semiconductor structure using the laser process in the prior art does not meet the requirements.

[0005] To achieve the above purpose and other related purposes, the present invention provides a laser grooving method, including the following steps:

[0006] Provide a semiconductor structure, on which there is at least one grooving area;

[0007] Provide a mask plate and a laser light source, the laser light source is arranged above the grooving area and is spaced from the grooving area by a preset distance, the mask plate is arranged between the semiconductor structure and the laser light source, and at least one laser transmission area is provided on the mask plate;

[0008] Based on the mask plate, use the laser light source to sequentially form a plurality of grooves arranged in the X direction in the grooving area of the semiconductor structure, and the laser transmission area of the mask plate for forming the current groove overlaps with the laser transmission area of the mask plate for forming the previous groove in the X direction by a first preset size, so as to obtain a groove with a second preset size.

[0009] Optionally, the semiconductor structure includes a wafer.

[0010] Optionally, the laser light source includes an ultraviolet laser, a fiber laser, and a CO2 laser.

[0011] Optionally, the depth range of the trench is 9 μm to 11 μm.

[0012] Optionally, the bottom width of the trench is greater than 80% of the width of the laser transmission region.

[0013] Optionally, the width range of the laser transmission region is 25 μm to 65 μm.

[0014] Optionally, the first preset size is greater than 13% and less than 15% of the width of the laser transmission region.

[0015] Optionally, the width of the laser beam emitted by the laser light source is at least 5 μm greater than the width of the laser transmission region.

[0016] Optionally, the center of the laser beam emitted by the laser light source coincides with the midline of the laser transmission region.

[0017] Optionally, the second preset size includes the opening width and the bottom width of the groove.

[0018] Optionally, the bottom width of the formed groove is not less than 80% of the opening width of the groove, and the opening width of the groove is greater than 100 μm.

[0019] As described above, the laser grooving method of the present invention has the following beneficial effects: using the laser light source to sequentially form a plurality of trenches arranged in the X direction in the grooving region of the semiconductor structure based on the mask plate, the laser transmission region of the mask plate for forming the current trench overlaps the laser transmission region of the mask plate for forming the previous trench by a first preset size in the X direction, and the second preset size of the groove is obtained by splicing the formed plurality of trenches, meeting the process requirements for laser grooving of the semiconductor structure, improving the quality and yield of the formed groove. In addition, the laser grooving method of the present invention also broadens the process idea of forming a groove with a preset size in the semiconductor structure by using a laser processing process when the thickness of the semiconductor structure increases or has other process requirements. Description of the Drawings

[0020] Figure 1 A schematic structural diagram of a formed groove shown in the prior art.

[0021] Figure 2 A schematic process flow diagram of the laser grooving method of the present invention.

[0022] Figure 3 A schematic structural diagram of a groove formed by the laser grooving method of the present invention is shown.

[0023] Figure 4 A schematic structural diagram of the mask plate of the laser grooving method of the present invention overlapping in the X direction is shown.

[0024] Figure 5 Another schematic structural diagram of a groove formed by the laser grooving method of the present invention is shown.

[0025] Figure 6 Another schematic structural diagram of the mask plate of the laser grooving method of the present invention overlapping in the X direction is shown.

[0026] Figure 7 A third schematic structural diagram of a groove formed by the laser grooving method of the present invention is shown.

[0027] Figure 8 A third schematic structural diagram of the mask plate of the laser grooving method of the present invention overlapping in the X direction is shown.

[0028] Figure 9 A fourth schematic structural diagram of a groove formed by the laser grooving method of the present invention is shown.

[0029] Description of component labels

[0030] 01 Semiconductor structure

[0031] 011 Groove

[0032] 1 Semiconductor structure

[0033] 11 Groove

[0034] 111 Groove

[0035] 2 Mask plate Detailed implementation manners

[0036] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0037] Please refer to Figures 1 to 9It should be noted that the structures, proportions, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the conditions for the implementation of the present invention. Therefore, they do not have any technical substance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of clear narration and are not used to limit the scope for the implementation of the present invention. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope within which the present invention can be implemented.

[0038] Embodiment 1

[0039] This embodiment provides a laser grooving method. As Figure 2 shown, it is a schematic process flow diagram of laser grooving, including the following steps:

[0040] S1: Provide a semiconductor structure, on which there is at least one grooving area;

[0041] S2: Provide a mask plate and a laser light source. The laser light source is arranged above the grooving area and is spaced from the grooving area by a preset distance. The mask plate is arranged between the semiconductor structure and the laser light source, and there is at least one laser transmission area on the mask plate;

[0042] S3: Based on the mask plate, use the laser light source to sequentially form a plurality of grooves arranged in the X direction in the grooving area of the semiconductor structure. The laser transmission area of the mask plate for forming the current groove overlaps with the laser transmission area of the mask plate for forming the previous groove in the X direction by a first dimension to obtain a groove with a second preset dimension.

[0043] Specifically, when performing step S1, provide a semiconductor structure 1, on which there is at least one grooving area (not shown).

[0044] As an example, the semiconductor structure 1 includes a wafer or other suitable semiconductor structure.

[0045] Specifically, the thickness of the semiconductor structure 1 is greater than 780 μm.

[0046] Specifically, when meeting the performance of the semiconductor structure 1, the width and shape of the semiconductor structure 1 can be selected according to the actual situation and are not limited here.

[0047] Specifically, a grooved area is provided on the semiconductor structure 1. That is, a laser processing technology can be used to groove the grooved area on the semiconductor structure 1 so that the semiconductor structure 1 meets the subsequent process requirements.

[0048] Specifically, when the performance of the groove 11 formed in the semiconductor structure 1 is satisfied, the size of the grooved area 12 can be selected according to the actual situation and is not limited herein.

[0049] Specifically, when the thickness of the semiconductor structure 1 is greater than 780 μm or there are other special process requirements, it is required that the opening width of the groove 11 formed in the grooved area 11 of the semiconductor structure 1 is greater than 100 μm. At a depth of 10 μm of the groove 11, the bottom of the formed groove 11 is flat and the bottom width is greater than 80% of the opening size of the groove 11.

[0050] Specifically, when performing the step S2, a mask plate 2 and a laser light source (not shown) are provided. The laser light source is arranged above the grooved area and is spaced from the grooved area by a preset distance. The mask plate 2 is arranged between the semiconductor structure 1 and the laser light source, and at least one laser transmission area (not shown) is provided on the mask plate 2.

[0051] As an example, the laser light source includes ultraviolet laser, fiber laser, CO2 laser or other suitable laser light sources.

[0052] Specifically, when the performance of the semiconductor structure 1 is satisfied, the model and power of the laser light source can be selected according to the actual situation and are not limited herein.

[0053] Specifically, the range of the laser light rays emitted by the laser light source is 350 nm to 1100 nm.

[0054] Specifically, when the performance of the groove 11 formed in the semiconductor structure 1 is satisfied, the distance between the laser light source and the semiconductor structure 1 can be selected according to the actual situation and is not limited herein.

[0055] Specifically, the mask plate 2 is located on the upper surface of the semiconductor structure 1.

[0056] Specifically, the laser transmission area corresponds to the grooved area on the semiconductor structure 1.

[0057] Specifically, when the groove 11 formed in the semiconductor structure 1 is satisfied, the thickness and material of the mask plate 2 can be selected according to the actual situation and are not limited herein.

[0058] Specifically, the non-laser-transmissive area on the mask plate 2 serves as a laser-blocking area (not shown).

[0059] Specifically, the laser-blocking area is used to prevent the laser light from damaging the non-grooved area of the semiconductor structure 1 during the laser processing process.

[0060] Specifically, the size of the laser-transmissive area is not less than the opening size of the trench 111.

[0061] As an example, the width of the laser light emitted by the laser light source is at least 5 μm greater than the width of the laser-transmissive area.

[0062] As an example, the center of the laser light emitted by the laser light source coincides with the midline of the laser-transmissive area.

[0063] Specifically, when the width of the laser light emitted by the laser light source is at least 5 μm greater than the width of the laser-transmissive area and the center of the laser light emitted by the laser light source coincides with the midline of the laser-transmissive area, it can meet the requirement that the bottom width of the groove 11 formed subsequently is greater than 80% of the opening width of the groove 11.

[0064] Specifically, the laser-transmissive area should be able to transmit the laser light emitted by the laser light source without causing a large loss of the energy of the laser light emitted by the laser light source.

[0065] Specifically, please refer to Figures 3 to 9 , perform the step S3. Based on the mask plate 2, use the laser light source to sequentially form a plurality of trenches 111 arranged in the X direction in the grooved area of the semiconductor structure 1. The laser-transmissive area of the mask plate 2 for forming the current trench 111 overlaps the laser-transmissive area of the mask plate for forming the previous trench 111 by a first preset size to obtain a groove 11 with a second preset size.

[0066] As an example, the depth range of the trench 111 is 9 μm to 11 μm. In this embodiment, the depth of the trench 111 is 10 μm, and the depth here refers to the vertical distance between the opening of the trench 111 and the bottom of the trench 111.

[0067] Specifically, the bottom width of each non-overlapping trench 111 formed by the laser light source is greater than 80% of the width of the laser-transmissive area.

[0068] Specifically, as Figure 3As shown, it is a schematic structural diagram of the formed groove 11. Forming the groove 11 with a preset size in the semiconductor structure 1 includes the following steps: Using the laser light source to form a trench 111 in the semiconductor structure 1 based on the mask plate 2, where both the opening size and the bottom size of the trench 111 are smaller than the preset size. The laser transmission area of the mask plate 2 for forming the current trench 111 intersects with the laser transmission area of the mask plate 2 for forming the previous trench 111 by a first preset size. Repeat the above step of forming the trench 111 based on the mask plate 2 until the opening width and the bottom width of the groove 11 formed by splicing the trenches 111 meet the second preset size. For example, when two trenches 111 are formed in the semiconductor structure 1 based on the mask plate 2, the opening width of the groove 11 formed by splicing the two trenches 111 is 107.819 μm, and the bottom width is 92.914 μm. That is, when the thickness of the semiconductor structure 1 is greater than 780 μm, that is, when the opening size of the groove 11 formed by splicing the trenches 111 is greater than 100 μm, and the bottom size of the groove 11 is greater than 80% of the opening size of the groove 11, the process requirements are met.

[0069] Specifically, when the performance of the groove 11 formed in the semiconductor structure 1 is satisfied, the number of laser light rays emitted by the laser light source is selected according to the actual situation, and there is no limitation here. For example, the number of laser light rays emitted by the laser light source is two, that is, two trenches 111 are formed; the number of laser light rays emitted by the laser light source is three, that is, three trenches 111 are formed, and so on.

[0070] As an example, the width range of the laser transmission area is 25 μm to 65 μm. That is, in this embodiment, when the opening size of the groove 11 to be formed is greater than 100 μm, at least two trenches 111 with an opening size range of 50 μm to 65 μm need to be formed, at least three trenches 111 with an opening size range of 35 μm to 65 μm need to be formed, at least four trenches 111 with an opening size range of 25 μm to 65 μm need to be formed, and so on.

[0071] Specifically, when the performance of the formed groove 11 is satisfied, the number of trenches 111 in the groove 11 can be selected according to the actual situation, and there is no limitation here.

[0072] Specifically, the laser transmission regions of the mask plate 2 forming the current trench 111 overlap with the laser transmission regions of the mask plate 2 forming the previous trench 111 in the X direction by a first preset size, which can offset part of the laser light, and then the adjacent trenches 111 can be spliced to obtain the groove 11 with a second preset size.

[0073] Specifically, the interval width range between the laser transmission region of the mask plate 2 forming the previous trench 111 and the laser transmission region of the mask plate 2 forming the next trench 111 is 4.5 μm to 5.5 μm. In this embodiment, the interval width between the laser transmission region of the mask plate 2 forming the previous trench 111 and the laser transmission region of the mask plate 2 forming the next trench 111 is 5 μm.

[0074] Specifically, the shape of each non - overlapping trench 111 formed includes an inverted trapezoid or other suitable shapes.

[0075] As an example, the first preset size is greater than 13% of the width of the laser transmission region and less than 15% of the width of the laser transmission region. In this embodiment, the width of the overlapping part between the laser transmission region of the mask plate 2 forming the current trench 111 and the laser transmission region of the mask plate 2 forming the previous trench 111 is 14% of the width of the laser transmission region, as Figures 4 to 9As shown, they are respectively a schematic structural diagram of the mask plate 2 overlapping in the X direction, another schematic structural diagram of the formed groove 11, another schematic structural diagram of the mask plate 2 overlapping in the X direction, a third schematic structural diagram of the formed groove 11, a third schematic structural diagram of the mask plate 2 overlapping in the X direction, and a fourth schematic structural diagram of the formed groove 11. When the width ratio of the overlapping part of the laser transmission area of the mask plate 2 used to form the current groove 111 to the mask plate 2 used to form the previous groove 111 accounts for 13% of the width of the mask plate 2, that is, when the width of the overlapping part of two adjacent grooves 111 is 13% of the width of the groove 111, there is a protrusion in the middle overlapping part at the bottom of the spliced groove 11; when the width ratio of the overlapping part of the mask plate 2 used to form the current groove 111 to the mask plate 2 used to form the previous groove 111 accounts for 14% of the width of the mask plate 2, that is, when the width of the laser transmission area of the overlapping part of two adjacent grooves 111 is 14% of the width of the groove 111, the bottom of the spliced groove 11 is flat; when the width ratio of the overlapping part of the laser transmission area of the mask plate 2 used to form the current groove 111 to the mask plate 111 used to form the previous groove 11 accounts for 15% of the width of the mask plate 2, that is, when the width of the overlapping part of two adjacent grooves 111 is 15% of the width of the groove 111, the middle overlapping part at the bottom of the spliced groove 11 is concave.

[0076] Specifically, when there is a protrusion or a concavity in the middle overlapping part at the bottom of the groove 11, it will affect the yield of the groove 11.

[0077] Specifically, under the condition of meeting the performance of the formed groove 11, the first preset size can also be selected according to the actual situation.

[0078] Specifically, the optical path of the laser light is perpendicular to the grooving area of the semiconductor structure 1.

[0079] Specifically, under the condition of meeting the performance of the groove 11 formed in the semiconductor structure 1, the laser temperature of the laser light can be selected according to the actual situation, and no limitation is made here.

[0080] Specifically, the shape of the groove 11 includes an inverted trapezoid or other suitable shapes.

[0081] As an example, the second preset size includes the opening width of the groove 11 and the bottom width of the groove 11.

[0082] As an example, the bottom width of the formed groove 11 is not less than 80% of the opening width of the groove 11, and the opening width of the groove 11 is greater than 100 μm.

[0083] Specifically, the depth range of the groove 11 is 9 μm to 11 μm. In this embodiment, the depth of the groove 11 is 10 μm, and the depth here refers to the vertical distance between the opening of the groove 11 and the bottom of the groove 11.

[0084] Specifically, using the laser light source, a plurality of grooves 111 arranged in the X direction are sequentially formed in the grooving area 12 of the semiconductor structure 1 based on the mask plate 2. The laser transmission area of the mask plate 2 for forming the current groove 111 overlaps with the laser transmission area of the mask plate 2 for forming the previous groove 111 by a first preset size in the X direction, and the grooves 111 are spliced to form the groove 11 with a second preset size, improving the quality and yield of the formed groove 11. In addition, the laser grooving method of the present invention also broadens the process idea of using the laser processing technology to form the groove 11 with a preset size in the semiconductor structure 1 when the thickness of the semiconductor structure 1 increases or has other process requirements.

[0085] The laser grooving method of this embodiment uses the laser light source to sequentially form a plurality of grooves 111 in the grooving area of the semiconductor structure 1 based on the mask plate 2. The laser transmission area of the mask plate 2 for forming the current groove 111 overlaps with the laser transmission area of the mask plate 2 for forming the previous groove 111 by a first preset size in the X direction, and the grooves 111 are spliced to form the groove 11 with a second preset size, meeting the process requirements of laser grooving in the semiconductor structure 1, improving the quality and yield of the formed groove 11. In addition, the laser grooving method of the present invention also broadens the process idea of using the laser processing technology to form the groove 11 with a preset size in the semiconductor structure 1 when the thickness of the semiconductor structure 1 increases or has other process requirements.

[0086] In summary, in the laser grooving method of the present invention, the laser light source is used to sequentially form a plurality of grooves in the grooving area of the semiconductor structure based on the mask plate. The laser transmission area of the mask plate for forming the current groove overlaps with the laser transmission area of the mask plate for forming the previous groove by a first preset dimension in the X direction. The formed grooves are spliced to form a groove with a second preset dimension, meeting the process requirements for laser grooving of the semiconductor structure, improving the quality and yield of the formed groove. In addition, the laser grooving method of the present invention also broadens the process idea of forming a groove with a preset dimension in the semiconductor structure by using the laser processing technology when the thickness of the semiconductor structure increases or has other process requirements. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0087] The above embodiments are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A laser grooving method, characterized in that, It includes the following steps: Provide a semiconductor structure with at least one grooved area provided thereon; Provide a mask and a laser light source. The laser light source is arranged above the grooved area and is spaced from the grooved area by a preset distance. The mask is arranged between the semiconductor structure and the laser light source, and at least one laser transmission area is provided on the mask; Based on the mask, use the laser light source to sequentially form a plurality of grooves arranged in the X direction in the grooved area of the semiconductor structure. The laser transmission area of the mask for forming the current groove overlaps the laser transmission area of the mask for forming the previous groove in the X direction by a first preset size to obtain a groove with a second preset size.

2. The laser grooving method according to claim 1, wherein: The semiconductor structure includes a wafer.

3. The laser grooving method according to claim 1, wherein: The laser light source includes ultraviolet laser, fiber laser, and CO2 laser.

4. The laser grooving method according to claim 1, characterized in that: The depth range of the grooves is 9 μm to 11 μm.

5. The laser grooving method according to claim 1, characterized in that: The width range of the laser transmission area is 25 μm to 65 μm.

6. The laser grooving method according to claim 1, wherein: The first preset size is greater than 13% of the width of the laser transmission area and less than 15% of the width of the laser transmission area.

7. The laser grooving method according to claim 1, characterized in that: The width of the laser beam emitted by the laser light source is at least 5 μm greater than the width of the laser transmission area.

8. The laser grooving method according to claim 1, wherein: The center of the laser beam emitted by the laser light source coincides with the midline of the laser transmission area.

9. The laser grooving method according to claim 1, wherein: The second preset size includes the opening width and the bottom width of the groove.

10. The laser grooving method according to claim 9, wherein: The bottom width of the formed groove is not less than 80% of the opening width of the groove, and the opening width of the groove is greater than 100 μm.

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