Method for laser internal dicing of gallium oxide

Abstract

The application discloses a method for laser internal scribing and segmenting gallium oxide, which comprises the following steps: fixing gallium oxide, covering adhesive film on the processing surface of the gallium oxide, and then performing multi-pass laser stealth cutting, wherein different processing passes and laser parameters are selected according to the thickness of the gallium oxide; after the laser stealth cutting is completed, the adhesive film is expanded to realize the splitting of the gallium oxide, and the segmenting is completed; wherein the loading direction of the laser during the laser cutting and the force direction during the expansion of the adhesive film are regulated according to the crystal face direction of the beta-gallium oxide. The gallium oxide with different thicknesses is scribed and segmented by adopting the laser stealth cutting mode, and the scribing effect is good, and the edge collapse rate is low; the laser direction during the laser cutting and the force direction during the splitting are adjusted for the beta-gallium oxide, and the splitting effect of the beta-gallium oxide is optimized.

Description

Technical Field

[0001] This invention relates to the field of semiconductor material cutting technology, and in particular to a method for laser internal scribing and segmentation of gallium oxide. Background Technology

[0002] Gallium oxide (GaO), as an important member of the next-generation semiconductor family, boasts a larger bandgap (approximately 4.9 eV), higher breakdown voltage (approximately 8 MV / cm), and lower manufacturing costs compared to silicon carbide (SiC) and gallium nitride (GaN). Furthermore, GaO applications can significantly reduce equipment size and effectively minimize energy loss. Therefore, it has become an ideal material for future applications in high-voltage, high-frequency, high-power, and high-radiation devices, showing broad application prospects in power electronics, aerospace, and other fields.

[0003] Compared to mechanical scribing or laser surface scribing, internal laser scribing effectively avoids damage and spatter contamination to the wafer surface during processing. Furthermore, internal laser scribing is highly efficient and precise, capable of cutting multiple wafers at once, completing a large number of cutting tasks in a short time, and offering high-precision control to achieve micro-sizes within 5μm.

[0004] However, there are currently few reported processes for laser internal dicing of gallium oxide, and it is necessary to develop effective methods for laser internal dicing of gallium oxide with different thicknesses and crystal forms. Summary of the Invention

[0005] To address the problems existing in the prior art, the present invention provides a method for laser internal scribing and segmentation of gallium oxide thin films, comprising, Gallium oxide is fixed, and after covering the processed surface of gallium oxide with an adhesive film, multiple laser stealth cutting is performed. The laser stealth cutting selects different processing passes and laser parameters according to the thickness of gallium oxide. After laser stealth cutting is completed, the adhesive film expands to achieve gallium oxide flakes, thus completing the segmentation; Specifically, the laser loading direction and the force direction during the film expansion of β-gallium oxide during laser stealth cutting are controlled according to its crystal plane orientation.

[0006] Furthermore, the laser stealth cutting selects different laser parameters based on the gallium oxide thickness. For gallium oxide with a thickness of 50μm-200μm: The first cut depth is 3 / 5 to 4 / 5 of the thickness of the gallium oxide sheet, and the laser power is 0.08W to 1.0W; The second cutting depth is 3 / 10 to 1 / 2 of the thickness of the gallium oxide sheet, and the laser power is 0.08W to 1.0W; The third cut is made to a depth of 1 / 5 to 3 / 10 of the gallium oxide sheet thickness, with a laser power of 0.08W to 1.0W. For gallium oxide with a thickness of 200μm-400μm: The first cut depth is 7 / 10 to 9 / 10 of the thickness of the gallium oxide sheet, and the laser power is 0.08W to 1.0W; The second cutting depth is 3 / 10 to 1 / 2 of the thickness of the gallium oxide sheet, and the laser power is 0.08W to 1.0W; The third cut is made to a depth of 1 / 5 to 3 / 10 of the gallium oxide sheet thickness, with a laser power of 0.08W to 1.0W. The fourth cut depth is 1 / 10 to 1 / 5 of the thickness of the gallium oxide sheet, and the laser power is 0.08W to 1.0W; For gallium oxide with a thickness of 400μm-600μm: The first cut depth is 4 / 5-9 / 10 of the thickness of the gallium oxide sheet, and the laser power is 0.08W-1.0W; The second cutting depth is 3 / 5-7 / 10 of the thickness of the gallium oxide sheet, and the laser power is 0.08W-1.0W; The third cut is made to a depth of 3 / 10 to 1 / 2 of the gallium oxide sheet thickness, with a laser power of 0.08W to 1.0W. The fourth cut depth is 1 / 5 to 3 / 10 of the thickness of the gallium oxide sheet, and the laser power is 0.08W to 1.0W; The fifth cut depth is 1 / 10 to 1 / 5 of the thickness of the gallium oxide sheet, and the laser power is 0.08W to 1.0W; Each cut involves a laser scan.

[0007] Furthermore, during laser stealth cutting, the laser power is reduced to 0.03W-0.05W for multiple scans.

[0008] Furthermore, the specific method for adjusting the laser loading direction and the force direction during film expansion in β-gallium oxide laser stealth cutting based on its crystal plane orientation is as follows: Laser stealth cutting: For (100) and (001) single-crystal gallium β-oxide, the laser loading direction is along the (010) crystal plane direction; for (010) single-crystal gallium β-oxide, the laser loading direction is perpendicular to the (100) or (001) crystal plane direction. Film spreading: For (100) single crystal gallium β-oxide, the direction of the force is along the (001) crystal plane direction; for (001) single crystal gallium β-oxide, the direction of the force is along the (100) crystal plane direction; for (010) single crystal gallium β-oxide, the direction of the force is along the (100) or (001) crystal plane direction.

[0009] Furthermore, the laser type used in the laser cutting includes at least one of picosecond laser, femtosecond laser, and attosecond laser.

[0010] Preferably, the lasers are: picosecond lasers: the laser wavelength is 600nm~1500nm, the pulse frequency is 10kHz~100kHz, and the laser scanning speed is 125mm / s~1000mm / s; femtosecond lasers: the laser wavelength is 600nm~1500nm, the pulse frequency is 10MHz~100MHz, and the laser scanning speed is 1000mm / s~10000mm / s; attosecond lasers: the laser wavelength is 10nm~900nm, the pulse frequency is 100MHz~1000MHz, and the laser scanning speed is 10000mm / s~100000mm / s.

[0011] Furthermore, the gallium oxide is fixed using a suction cup.

[0012] Furthermore, if the segmented gallium oxide is used to manufacture a functional device with a fragile structure, a cushioning elastic pad is also provided between the chuck and the gallium oxide.

[0013] The present invention also provides a gallium oxide chip, which is obtained using the above-described method.

[0014] Compared with the prior art, the present invention has the following beneficial effects: This invention employs laser stealth cutting to dicing gallium oxide of different thicknesses, achieving good dicing effect and low edge breakage rate. Furthermore, it optimizes the dicing effect of β-gallium oxide by adjusting the laser direction during laser cutting and the direction of the force during dicing. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A flowchart of the method for laser internal scribing and segmentation of gallium oxide according to the present invention is shown; Figure 2 A schematic diagram of various objects cut by laser stealth cutting according to the present invention is shown; Figure 3 A schematic diagram of gallium oxide cleavage according to the present invention is shown; Figure 4This diagram illustrates the laser loading direction during the segmentation of (001) single-crystal β-Ga2O3 and the force direction during film expansion in Embodiment 5 of the present invention. Figure 5 This diagram illustrates the laser loading direction during the splitting (100) of single-crystal β-Ga2O3 and the force direction during film expansion in Embodiment 6 of the present invention. Figure 6 The diagram shows the direction of laser loading and the direction of force during film expansion when the (010) single-crystal β-Ga2O3 is segmented in Embodiment 7 of the present invention. Detailed Implementation

[0017] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments and 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 are within the scope of protection of the present invention.

[0019] Example 1 like Figure 1 As shown, a method for laser internal scribing to divide gallium oxide into 150 μm thick α-Ga2O3 layers is described below: Step 1: Adsorb α-Ga2O3 onto the chuck; Step 2: Fix the α-Ga2O3 processing surface using a special invisible cutting adhesive film with high light transmittance to laser wavelength; Step 3, as follows Figure 2As shown, the α-Ga₂O₃ processing surface is subjected to multiple laser stealth cuts along each scribe line, generating laser burst points inside the α-Ga₂O₃. These burst points connect under stress, creating penetrating microcracks within the α-Ga₂O₃. These microcracks extend to the α-Ga₂O₃ surface to form a crack. A picosecond laser with a wavelength of 1064 nm and a pulse frequency of 20 kHz is used, with a laser scanning speed of 600 mm / s. The cuts are performed in three stages, with one laser scan per cut: the first cut depth is 100 μm (the thickness of the gallium oxide sheet), with a laser power of 0.09 W; the second cut depth is 70 μm, with a laser power of 0.08 W; and the third cut depth is 40 μm, with a laser power of 0.09 W. Step 4, as follows Figure 3 As shown, α-Ga2O3 after laser stealth cutting is split into segments by direct film expansion.

[0020] Example 2 A method for laser internal scribing to divide gallium oxide into α-Ga2O3 with a thickness of 300 μm is disclosed. The difference from Example 1 is that step 3 involves four cuts: the first cut is 240 μm thick, with a laser power of 0.09 W; the second cut is 120 μm thick, with a laser power of 0.08 W; the third cut is 80 μm thick, with a laser power of 0.09 W; and the fourth cut is 50 μm thick, with a laser power of 0.08 W.

[0021] Example 3 A method for laser internal scribing to divide gallium oxide into α-Ga2O3 sheets with a thickness of 500 μm is disclosed. The difference from Example 1 is that step 3 involves five cuts: the first cut is made to a depth of 430 μm (the thickness of the gallium oxide sheet) with a laser power of 1.0 W; the second cut is made to a depth of 300 μm with a laser power of 0.08 W; the third cut is made to a depth of 200 μm with a laser power of 0.09 W; the fourth cut is made to a depth of 120 μm with a laser power of 0.09 W; and the fifth cut is made to a depth of 70 μm with a laser power of 0.08 W.

[0022] Example 4 A method for laser internal scribing to divide gallium oxide (Ga₂O₃) with a thickness of 150 μm is disclosed. The difference from Example 1 lies in the laser power decreasing during the three cuts in step 3. Each cut involves two back-and-forth laser scans: the first cut reaches a depth of 100 μm (Ga₂O₃ thickness) with a laser power of 0.05 W; the second cut reaches a depth of 70 μm with a laser power of 0.04 W; and the third cut reaches a depth of 40 μm with a laser power of 0.05 W. Example 5 A method for laser internal scribing to divide gallium oxide, specifically for dividing a 500 μm thick (001) single-crystal β-Ga2O3, comprises the following steps: Step 1: Adsorb β-Ga2O3 onto the chuck; Step 2: Fix the β-Ga2O3 processing surface with a special invisible cutting adhesive film that has high light transmittance to laser wavelength; Step 3: Perform multiple laser stealth cuts along each scribe line on the β-Ga2O3 surface using a picosecond laser with a wavelength of 1064nm and a pulse frequency of 20kHz. The laser scanning speed is 600mm / s, and the cuts are performed in five passes, with one laser scan during each cut. Figure 4 As shown, the laser loading direction is along the (010) crystal orientation: the first cutting depth is 430 μm of the gallium oxide sheet thickness, and the laser power is 1.0 W; the second cutting depth is 300 μm, and the laser power is 0.08 W; the third cutting depth is 200 μm, and the laser power is 0.09 W; the fourth cutting depth is 120 μm, and the laser power is 0.09 W; the fifth cutting depth is 70 μm, and the laser power is 0.08 W. Step 4: The β-Ga2O3 after laser stealth cutting is fragmented using a direct film expansion method, such as... Figure 4 As shown, the direction of the force during film expansion is along the (100) crystal direction, thus completing the segmentation.

[0023] Example 6 A method for laser internal scribing of gallium oxide, for slicing a 500 μm thick (100) single-crystal β-Ga₂O₃, such as... Figure 5 As shown, the difference from Example 5 is that in step 4, the direction of the force during film expansion is along the (001) crystal orientation. Example 7 A method for laser internal dicing to divide gallium oxide, specifically for dividing a 500 μm thick (010) single-crystal β-Ga₂O₃, such as... Figure 6 As shown, the difference from Example 5 is that in step 3, the laser loading direction is perpendicular to the (100) or (001) crystal plane direction; and in step 4, the direction of the force during film expansion is along the (100) or (001) crystal plane direction.

[0024] The results show that the present invention uses laser stealth cutting to dicing gallium oxide of different thicknesses, with good dicing effect and low edge breakage rate; it also adjusts the laser direction during laser cutting and the direction of force during dicing for β-gallium oxide, thereby optimizing the dicing effect of β-gallium oxide.

[0025] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for laser internal scribing and segmentation of gallium oxide, characterized in that, include, Gallium oxide is fixed, and after covering the processed surface of gallium oxide with an adhesive film, multiple laser stealth cutting is performed. The laser stealth cutting selects different processing passes and laser parameters according to the thickness of gallium oxide. After laser stealth cutting is completed, the adhesive film expands to achieve gallium oxide flakes, thus completing the segmentation; Specifically, the laser loading direction and the force direction during film expansion in β-gallium oxide laser stealth cutting are controlled according to its crystal plane orientation, including: Laser stealth cutting: For (100) and (001) single-crystal gallium β-oxide, the laser loading direction is along the (010) crystal plane direction; for (010) single-crystal gallium β-oxide, the laser loading direction is perpendicular to the (100) or (001) crystal plane direction. Film spreading: For (100) single crystal gallium β-oxide, the direction of the force is along the (001) crystal plane direction; for (001) single crystal gallium β-oxide, the direction of the force is along the (100) crystal plane direction; for (010) single crystal gallium β-oxide, the direction of the force is along the (100) or (001) crystal plane direction.

2. The method for laser internal scribing and segmentation of gallium oxide according to claim 1, characterized in that, The laser stealth cutting process selects different processing passes and laser parameters based on the gallium oxide thickness. For gallium oxide with a thickness of 50μm-200μm: The first cut depth is 3 / 5 to 4 / 5 of the thickness of the gallium oxide sheet, and the laser power is 0.08W to 1.0W; The second cutting depth is 3 / 10 to 1 / 2 of the thickness of the gallium oxide sheet, and the laser power is 0.08W to 1.0W; The third cut is made to a depth of 1 / 5 to 3 / 10 of the gallium oxide sheet thickness, with a laser power of 0.08W to 1.0W. For gallium oxide with a thickness of 200μm-400μm: The first cut depth is 7 / 10 to 9 / 10 of the thickness of the gallium oxide sheet, and the laser power is 0.08W to 1.0W; The second cutting depth is 3 / 10 to 1 / 2 of the thickness of the gallium oxide sheet, and the laser power is 0.08W to 1.0W; The third cut is made to a depth of 1 / 5 to 3 / 10 of the gallium oxide sheet thickness, with a laser power of 0.08W to 1.0W. The fourth cut depth is 1 / 10 to 1 / 5 of the thickness of the gallium oxide sheet, and the laser power is 0.08W to 1.0W; For gallium oxide with a thickness of 400μm-600μm: The first cut depth is 4 / 5-9 / 10 of the thickness of the gallium oxide sheet, and the laser power is 0.08W-1.0W; The second cutting depth is 3 / 5-7 / 10 of the thickness of the gallium oxide sheet, and the laser power is 0.08W-1.0W; The third cut is made to a depth of 3 / 10 to 1 / 2 of the gallium oxide sheet thickness, with a laser power of 0.08W to 1.0W. The fourth cut depth is 1 / 5 to 3 / 10 of the thickness of the gallium oxide sheet, and the laser power is 0.08W to 1.0W; The fifth cut depth is 1 / 10 to 1 / 5 of the thickness of the gallium oxide sheet, and the laser power is 0.08W to 1.0W; Each cut involves a laser scan.

3. The method for laser internal scribing and segmentation of gallium oxide according to claim 2, characterized in that, During laser stealth cutting, the laser power is reduced to 0.03W-0.05W and multiple scans are performed.

4. The method for laser internal scribing and segmentation of gallium oxide according to claim 1, characterized in that, The laser types used in the laser stealth cutting include at least one of picosecond lasers, femtosecond lasers, and attosecond lasers.

5. The method for laser internal scribing and segmentation of gallium oxide according to claim 1, characterized in that, The gallium oxide is fixed using a suction cup.

6. The method for laser internal scribing and segmentation of gallium oxide according to claim 5, characterized in that, A cushioning elastic pad is also provided between the suction cup and the gallium oxide.

7. A gallium oxide chip, characterized in that, Obtained by using the method described in any one of claims 1 to 6.

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