Semiconductor element and manufacturing method thereof

Abstract

To provide a method for manufacturing a semiconductor element with improved wire bonding characteristics.SOLUTION: A method for manufacturing a semiconductor device 1 includes a step of forming a laser scribe line 35a on a wafer surface 9a of a compound semiconductor wafer 9 by irradiating the wafer surface 9a with laser light 34a. A laminated wafer 30 includes a compound semiconductor wafer 9, and a plurality of laminates 5 arranged on the wafer surface 9a. Each of the plurality of laminates 5 includes a wire bonding pad 27. The power of laser light 34a is less than or equal to 0.3 W.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present disclosure relates to semiconductor devices and methods for manufacturing the same. [Background technology]

[0002] Japanese Patent Application Laid-Open No. 2022-49592 (Patent Document 1) discloses a method for manufacturing a light emitting device, which includes a step of forming a plurality of light emitting diode structures on a semiconductor wafer, and a step of cutting the semiconductor wafer using a dicing blade. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-49592 A [Summary]

[0004] An object of the present disclosure is to provide a semiconductor device with improved wire bondability and a method for manufacturing the same.

[0005] The method for manufacturing a semiconductor device according to the present disclosure includes the steps of: irradiating a first wafer surface of a compound semiconductor wafer of a laminate wafer with a first laser light to form a first laser scribe line on the first wafer surface; and breaking the laminate wafer along the first laser scribe line to separate the laminate wafer into a plurality of semiconductor devices. The laminate wafer includes a compound semiconductor wafer and a plurality of laminates disposed on the first wafer surface. Each of the plurality of laminates includes a wire bonding pad. The first power of the first laser light is 0.3 W or less. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic plan view of a semiconductor device according to an embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view of the semiconductor device according to the embodiment taken along the cross-sectional line II-II shown in FIG. [Figure 3]FIG. 3 is a diagram showing a cross-sectional photograph of a compound semiconductor substrate of a semiconductor device according to an embodiment. [Figure 4] FIG. 4 is a schematic plan view showing one step of the method for manufacturing a semiconductor device according to the embodiment. [Figure 5] FIG. 5 is a schematic enlarged partial cross-sectional view showing one step of the method for manufacturing a semiconductor device according to the embodiment. [Figure 6] FIG. 6 is a schematic partially enlarged cross-sectional view showing a step subsequent to the step shown in FIGS. 4 and 5 in the method for manufacturing a semiconductor device according to the embodiment. [Figure 7] FIG. 7 is a schematic, partially enlarged cross-sectional view showing a step subsequent to the step shown in FIG. 6 in the method for manufacturing a semiconductor device according to the embodiment. [Figure 8] FIG. 8 is a schematic plan view showing a step subsequent to the step shown in FIG. 7 in the method for manufacturing a semiconductor device according to the embodiment. [Figure 9] FIG. 9 is a schematic enlarged partial cross-sectional view showing a step subsequent to the step shown in FIG. 7 in the method for manufacturing a semiconductor device according to the embodiment. [Figure 10] FIG. 10 is a schematic, partially enlarged cross-sectional view showing a step subsequent to the step shown in FIGS. 8 and 9 in the method for manufacturing a semiconductor device according to the embodiment. [Figure 11] FIG. 11 is a schematic, partially enlarged cross-sectional view showing a step subsequent to the step shown in FIG. 10 in the method for manufacturing a semiconductor device according to the embodiment. [Figure 12] FIG. 12 is a schematic, partially enlarged cross-sectional view showing a step subsequent to the step shown in FIG. 11 in the method for manufacturing a semiconductor device according to the embodiment. [Figure 13] FIG. 13 is a schematic, partially enlarged cross-sectional view showing a step subsequent to the step shown in FIG. 12 in the method for manufacturing a semiconductor device according to the embodiment. [Figure 14] FIG. 14 is a schematic, partially enlarged cross-sectional view showing a step subsequent to the step shown in FIG. 13 in the method for manufacturing a semiconductor device according to the embodiment. [Figure 15] FIG. 15 is a schematic, partially enlarged cross-sectional view showing a step subsequent to the step shown in FIG. 14 in the method for manufacturing a semiconductor device according to the embodiment. [Figure 16]FIG. 16 is a schematic, partially enlarged cross-sectional view showing a step subsequent to the step shown in FIG. 15 in the method for manufacturing a semiconductor device according to the embodiment. [Figure 17] FIG. 17 is a diagram showing the contamination incidence rates of Samples 1 to 6. [Figure 18] FIG. 18 is a diagram showing a micrograph of a wire bonding pad of a semiconductor element when contamination occurs on the wire bonding pad. [Figure 19] 19 is a graph showing the relationship between the cleaning time and the normalized contamination incidence rate in two-fluid cleaning.

[0007] The details of the embodiments of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and the description thereof will not be repeated. At least some of the configurations of the embodiments described below may be combined in any manner.

[0008] A semiconductor device 1 according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 3. The semiconductor device 1 is, for example, a semiconductor optical device. In this embodiment, the semiconductor device 1 is, for example, a photodiode 2. With reference to FIGS. 1 and 2, the semiconductor device 1 includes a compound semiconductor substrate 10, a stacked body 5, and an n-electrode 25.

[0009] The compound semiconductor substrate 10 has a main surface 10a, a main surface 10b opposite to the main surface 10a, and a side surface 10c. The main surface 10a and the main surface 10b are both end surfaces of the compound semiconductor substrate 10 in the thickness direction. The side surface 10c extends in the thickness direction of the compound semiconductor substrate 10, i.e., in the direction in which the main surface 10a and the main surface 10b are spaced apart from each other. The compound semiconductor substrate 10 is, for example, an InP substrate. The compound semiconductor substrate 10 may also be a gallium arsenide (GaAs) substrate, a gallium phosphide (GaP) substrate, a gallium nitride (GaN) substrate, an aluminum nitride (AlN) substrate, a gallium oxide (Ga2O3) substrate, or the like.

[0010] Laser processing marks 11a are formed on the periphery (e.g., the entire periphery) of the main surface 10a. The laser processing marks 11a are formed between the main surface 10a and the side surface 10c. Laser processing marks 11b are formed on the periphery (e.g., the entire periphery) of the main surface 10b. The depth of the laser processing marks 11a is 25.6 μm or less. The depth of the laser processing marks 11a may be 15.9 μm or less, or may be 11.2 μm or less. The laser processing marks 11b are formed between the main surface 10b and the side surface 10c. The depth of the laser processing marks 11b is 25.6 μm or less. The depth of the laser processing marks 11b may be 15.9 μm or less, or may be 11.2 μm or less. FIG. 3 shows examples of the laser processing marks 11a and 11b. The laser processing marks 11a are part of a laser scribe line 35a, which will be described later. The laser processing marks 11b are part of laser scribe lines 35a, which will be described later. The laser processing marks 11a and 11b may be grooves or modified regions.

[0011] 1 and 2, a stacked body 5 is disposed on a primary surface 10a of a compound semiconductor substrate 10. The stacked body 5 includes a buffer layer 13, a light absorbing layer 14, a p-type dopant diffusion region 16, a p-type contact layer 18, an insulating layer 21, an anti-reflection film 22, and a wire bonding pad 27. The stacked body 5 may further include a window layer 15.

[0012] The buffer layer 13 is disposed on the major surface 10a of the compound semiconductor substrate 10. The bottom surface of the buffer layer 13 is the bottom surface of the stack 5. The buffer layer 13 is, for example, an i-type semiconductor layer. The thickness of the buffer layer 13 is, for example, 10 nm or more. Therefore, the buffer layer 13 reduces crystal defects in the light absorption layer 14 and can make the top surface of the light absorption layer 14 more flat. The thickness of the buffer layer 13 is smaller than the thickness of the light absorption layer 14. Therefore, the voltage drop in the buffer layer 13 can be reduced, and the reverse bias voltage applied to the light absorption layer 14 can be increased. The buffer layer 13 is formed of, for example, InGaAs.

[0013] The light absorption layer 14 is disposed on the buffer layer 13. The light absorption layer 14 is separated from the compound semiconductor substrate 10 by the buffer layer 13. The light absorption layer 14 is, for example, an i-type semiconductor layer. The light absorption layer 14 absorbs light incident on the photodiode 2. The light absorption layer 14 is formed of, for example, InGaAsP.

[0014] The window layer 15 is disposed on the light absorption layer 14. The window layer 15 may be an n-type semiconductor layer such as an n-InP layer. The bandgap wavelength of the window layer 15 is shorter than the wavelength of the light detected by the photodiode 2. The window layer 15 is transparent to the light detected by the photodiode 2.

[0015] The p-type dopant diffusion region 16 is a region in which a p-type dopant such as zinc (Zn) is diffused, and is a p-type semiconductor region. The p-type dopant diffusion region 16 extends from the top surface of the window layer 15 to the inside of the light absorption layer 14. The p-type dopant diffusion region 16 is formed by doping the light absorption layer 14 and the window layer 15 with a p-type dopant.

[0016] The p-type contact layer 18 is disposed on the window layer 15. The p-type contact layer 18 is in contact with the p-type dopant diffusion region 16. The p-type contact layer 18 is disposed in an opening 21a in the insulating layer 21. The p-type contact layer 18 is in contact with the insulating layer 21. The p-type contact layer 18 is, for example, a p-InGaAs layer. An opening 18a is provided in the p-type contact layer 18. The p-type dopant diffusion region 16 is exposed from the p-type contact layer 18 at the opening 18a. Light enters the light absorption layer 14 through the opening 18a.

[0017] The insulating layer 21 is disposed on the window layer 15. The insulating layer 21 is, for example, a silicon nitride layer. An opening 21a is provided in the insulating layer 21. In a plan view of the main surface 10a, the opening 21a defines the p-type dopant diffusion region 16. The insulating layer 21 functions as a mask that defines a region where a p-type dopant is implanted for the p-type dopant diffusion region 16.

[0018] The anti-reflection film 22 reduces the reflectance of light at the incident surface of the photodiode 2. The anti-reflection film 22 is disposed on the insulating layer 21, the p-type contact layer 18, and the p-type dopant diffusion region 16. The anti-reflection film 22 is, for example, an insulating layer. The anti-reflection film 22 is, for example, a silicon nitride layer. A through-hole 22a is provided in the anti-reflection film 22. The p-type contact layer 18 is exposed from the anti-reflection film 22 at the through-hole 22a.

[0019] The p-electrode 26 is disposed on the anti-reflection film 22, in the through-hole 22a, and on the p-type contact layer 18 exposed from the through-hole 22a. The p-electrode 26 is electrically connected to the p-type dopant diffusion region 16 through the p-type contact layer 18. An opening 26a is provided in the p-electrode 26, and the p-electrode 26 has a ring shape.

[0020] The wire bonding pad 27 is disposed on the anti-reflection film 22 and is connected to the p-electrode 26. A conductive wire (not shown), such as a gold (Au) wire, a copper (Cu) wire, or an aluminum (Al) wire, is bonded to the wire bonding pad 27.

[0021] The p-electrode 26 and the wire bonding pad 27 are, for example, a laminate of a titanium (Ti) layer, a platinum (Pt) layer, and a gold (Au) layer, and the gold layer is the outermost layer of the laminate.

[0022] The n-electrode 25 is disposed on the main surface 10b of the compound semiconductor substrate 10. The n-electrode 25 is, for example, a laminate of a titanium (Ti) layer, a platinum (Pt) layer, and a gold (Au) layer, with the gold layer being the outermost layer of the laminate. No wire bonding pad is formed on the main surface 10b side of the compound semiconductor substrate 10.

[0023] The operation of the photodiode 2 of this embodiment will be described. A reverse bias voltage is applied between the p electrode 26 and the n electrode 25. That is, a bias voltage is applied between the p electrode 26 and the n electrode 25 so that the potential of the n electrode 25 is higher than the potential of the p electrode 26. Light passes through the openings 26a and 18a and is incident on the light absorbing layer 14. Electrons and holes are generated in the light absorbing layer 14. The reverse bias voltage causes the electrons to move to the p electrode 26 and the holes to move to the n electrode 25. A photocurrent is generated according to the intensity of light incident on the photodiode 2. The photocurrent is extracted from the photodiode 2 through a conductive wire (not shown) bonded to the wire bonding pad 27. The intensity of light incident on the photodiode 2 is detected from the photocurrent.

[0024] A method for manufacturing semiconductor device 1 of this embodiment will be described with reference to FIGS.

[0025] 4 and 5, a laminate wafer 30 is prepared. The laminate wafer 30 includes a compound semiconductor wafer 9, multiple laminates 5, and a backside conductive film 25b. The compound semiconductor wafer 9 includes a wafer surface 9a and a wafer surface 9b opposite to the wafer surface 9a. The compound semiconductor wafer 9 is, for example, an InP wafer. The compound semiconductor wafer 9 may also be a GaAs wafer, a GaP wafer, a GaN wafer, an AlN wafer, or a Ga2O3 wafer. The multiple laminates 5 are disposed on the wafer surface 9a. Each of the multiple laminates 5 has the configuration already described. For example, each of the multiple laminates 5 includes a wire bonding pad 27 (see FIG. 1). The backside conductive film 25b is disposed on the wafer surface 9b. The backside conductive film 25b is formed of the same material as the n-electrode 25 (see FIG. 2). No wire bonding pad is formed on the wafer surface 9b side of the compound semiconductor wafer 9.

[0026] Referring to Fig. 6, protective films 31 and 32 are formed on the laminate wafer 30. The protective film 31 covers the wafer surface 9a and the multiple laminates 5. The protective film 32 covers the wafer surface 9b and the back surface conductive film 25b. The protective films 31 and 32 are resin films such as TLDP-300 manufactured by Tokyo Ohka Kogyo Co., Ltd. Referring to Fig. 7, a dicing tape 33 is attached to the protective film 32.

[0027] 8 and 9, a laser beam 34a is irradiated onto the wafer surface 9a to form a laser scribe line 35a on the wafer surface 9a (laser scribing process). The laser scribe line 35a is, for example, an ablation mark formed by ablating the compound semiconductor wafer 9 with the laser beam 34a. The laser scribe line 35a may be a linear groove or a linear modified region. The laser beam 34a is, for example, an ultraviolet (UV) laser beam. The power of the laser beam 34a is 0.3 W or less. The power of the laser beam 34a may be 0.2 W or less, 0.1 W or less, or 0.05 W or less.

[0028] To form the laser scribe line 35a, the compound semiconductor wafer 9 is scanned with the laser beam 34a. The scanning speed of the laser beam 34a is significantly higher than the feed speed (typically 3 mm / sec) of a blade used to form the scribe line or cut the compound semiconductor wafer 9. The scanning speed of the laser beam 34a relative to the compound semiconductor wafer 9 may be 100 mm / sec or higher, 150 mm / sec or higher, or 200 mm / sec or higher. Therefore, even if the size of the compound semiconductor wafer 9 is large, the time required for the laser scribing process shown in FIGS. 8 and 9 is significantly shorter than the time required for scribing using a blade and the time required for cutting the compound semiconductor wafer 9 using a blade.

[0029] The protective film 31 protects the multiple stacks 5 and the wafer surface 9a from debris generated in the process of forming the laser scribe lines 35a. The protective film 32 protects the back surface conductive film 25b and the wafer surface 9b from debris generated in the process of forming the laser scribe lines 35a.

[0030] Dicing tape 33 is peeled off from protective film 32. With reference to FIG.

[0031] Referring to FIG. 11, a laser beam 34b is irradiated onto the wafer surface 9b to form a laser scribe line 35b on the wafer surface 9b (laser scribing). The laser scribe line 35b is, for example, an ablation mark formed by ablating the compound semiconductor wafer 9 with the laser beam 34b. The laser scribe line 35b may be, for example, a linear groove or a linear modified region. The laser beam 34b is, for example, a UV laser beam. The power of the laser beam 34b is 0.3 W or less. The power of the laser beam 34b may be 0.2 W or less, 0.1 W or less, or 0.05 W or less.

[0032] To form laser scribe lines 35b, laser beam 34b is scanned across compound semiconductor wafer 9. The scanning speed of laser beam 34b is significantly higher than the feed speed (typically 3 mm / sec) of a blade used to form scribe lines or cut compound semiconductor wafer 9. The scanning speed of laser beam 34b across compound semiconductor wafer 9 may be 100 mm / sec or higher, 150 mm / sec or higher, or even 200 mm / sec or higher. Therefore, even if the size of compound semiconductor wafer 9 is large, the time required for the laser scribing process shown in FIG. 11 is significantly shorter than the time required for scribing using a blade and the time required for cutting compound semiconductor wafer 9 using a blade.

[0033] The protective film 32 protects the back surface conductive film 25b and the wafer surface 9b from debris generated in the process of forming the laser scribe lines 35b. The protective film 31 protects the multiple stacks 5 and the wafer surface 9a from debris generated in the process of forming the laser scribe lines 35b.

[0034] 12, the back surface conductive film 25b, the wafer surface 9b, and the laser scribe line 35b are cleaned by two-fluid cleaning. The protective film 32 is washed away and removed by this two-fluid cleaning. In this specification, two-fluid cleaning refers to cleaning the object by spraying a mixed fluid 36, which is a mixture of a cleaning liquid such as water and a gas such as air, onto the object (in the process shown in FIG. 12, the wafer surface 9b, the laser scribe line 35b, and the back surface conductive film 25b).

[0035] The dicing tape 37 is peeled off from the protective film 31. Referring to Fig. 13, the laminated wafer 30 is turned over, and a dicing tape 38 is attached to the wafer front surface 9b and the back surface conductive film 25b.

[0036] 14 and 15, the laminate wafer 30 is broken along the laser scribe lines 35a and 35b, thereby dividing the laminate wafer 30 into a plurality of semiconductor elements 1. Specifically, referring to Fig. 14, a breaking tool 40 is pressed against the laminate wafer 30 (for example, the compound semiconductor wafer 9) along the laser scribe lines 35a and 35b. The compound semiconductor wafer 9 is slightly curved, and cracks 39 are generated in the compound semiconductor wafer 9, starting from the laser scribe lines 35a and 35b.

[0037] Referring to FIG. 15 , the dicing tape 38 is stretched. The compound semiconductor wafer 9 is divided into a plurality of compound semiconductor substrates 10 along the laser scribe lines 35a, 35b and the cracks 39. Each of the compound semiconductor substrates 10 includes a main surface 10a, a main surface 10b opposite the main surface 10a, and a side surface 10c extending in a direction in which the main surface 10a and the main surface 10b are spaced apart from each other. The main surface 10a is a part of the wafer surface 9a. The main surface 10b is a part of the wafer surface 9b. The laser processing trace 11a is formed between the main surface 10a and the side surface 10c and is a part of the laser scribe line 35a. The laser processing trace 11b is formed between the main surface 10b and the side surface 10c and is a part of the laser scribe line 35b. The back surface conductive film 25b is divided into a plurality of n-electrodes 25. In this way, the laminate wafer 30 is singulated into a plurality of semiconductor elements 1.

[0038] Referring to FIG. 16, multiple semiconductor elements 1 are cleaned by two-fluid cleaning. Specifically, the main surface 10a, side surface 10c, and laser processing marks 11a and 11b of each of the multiple semiconductor elements 1 are cleaned by two-fluid cleaning. The protective film 31 is washed away and removed by two-fluid cleaning. The time required to clean the multiple semiconductor elements 1 by two-fluid cleaning shown in FIG. 16 is longer than the time required to wash away the protective film 32 shown in FIG. The time required to clean the multiple semiconductor elements 1 by two-fluid cleaning is, for example, 800 seconds or more.

[0039] Then, the dicing tape 38 is peeled off from the main surface 10b of each of the plurality of semiconductor elements 1. In this way, a plurality of semiconductor elements 1 are obtained.

[0040] The operation of the semiconductor device 1 and the manufacturing method thereof according to the present disclosure will be described with reference to FIGS.

[0041] Samples 1 to 6 shown in Fig. 17 are photodiodes 2 obtained by laser scribing an InP wafer as a compound semiconductor wafer 9 using UV laser light as the laser light 34a and 34b under the conditions shown in Table 1. In Samples 1 to 6, the protective films 31 and 32 were removed by performing the two-fluid cleaning shown in Figs. 12 and 16 for 400 seconds. [Table 1]

[0042] Samples 1 to 6 were subjected to a high-temperature, high-humidity test as an accelerated test, and the contamination incidence rates for Samples 1 to 6 shown in FIG. 17 were obtained. The contamination incidence rate for Sample 1 indicates the proportion of multiple Samples 1 in which contamination occurred on wire bonding pads 27. The contamination incidence rates for each of Samples 2 to 6 are defined in the same way. Whether or not contamination occurred on wire bonding pads 27 was determined by observing wire bonding pads 27 at a magnification of 1000 times using a microscope. FIG. 18 shows a micrograph of when contamination occurred on wire bonding pads 27.

[0043] 17 and Table 1, it can be seen that as the output power of the laser beams 34a and 34b decreases, the depth of the laser processing marks 11a and 11b decreases, and the contamination incidence rate decreases. For example, the contamination incidence rate decreases when the power of each of the laser beams 34a and 34b is set to 0.3 W or less. The contamination incidence rate further decreases when the power of each of the laser beams 34a and 34b is set to 0.05 W or less.

[0044] When the inventor analyzed the contaminants adhering to the wire bonding pad 27, it was found that the contaminants contained elements constituting the compound semiconductor wafer 9 and the compound semiconductor substrate 10. Therefore, it is presumed that the contamination incidence rate decreases as the output of the laser beams 34a and 34b decreases for the following reason.

[0045] When the compound semiconductor wafer 9 is laser scribed using the laser beams 34a and 34b, the compound semiconductor constituting the compound semiconductor wafer 9 is decomposed by the laser beams 34a and 34b, and debris such as the decomposed material or its oxides adheres to the laser scribe lines 35a and 35b. In the dicing process shown in FIG. 15, the debris spreads over the side surface 10c of the compound semiconductor substrate 10. When an accelerated test is performed on the photodiode 2, which is the semiconductor element 1, the debris moves from the side surface 10c of the compound semiconductor substrate 10 to the wire bonding pad 27 and adheres to the wire bonding pad 27 as contaminants. In this way, the wire bonding pad 27 is contaminated.

[0046] Reducing the output of the laser beams 34a and 34b reduces or inhibits decomposition of the compound semiconductor that constitutes the compound semiconductor wafer 9 by the laser beams 34a and 34b. This reduces the depth of the laser processing marks 11a and 11b. This reduces the amount of debris generated during the laser scribing process of the compound semiconductor wafer 9 using the laser beams 34a and 34b, thereby reducing the rate of contamination of the wire bonding pads 27. This makes it possible to manufacture a semiconductor device 1 that includes wire bonding pads 27 that have good wire bonding properties to conductive wires.

[0047] FIG. 19 shows the relationship between the time for which Sample 1 is subjected to the two-fluid cleaning shown in FIGS. 12 and 16 and the normalized contamination incidence rate. The normalized contamination incidence rate is the contamination incidence rate when Sample 1 is subjected to two-fluid cleaning for a predetermined time, normalized by the contamination incidence rate when Sample 1 is subjected to two-fluid cleaning for 400 seconds. By subjecting Sample 1 to two-fluid cleaning for 800 seconds or more, the contamination incidence rate is further reduced. By subjecting Sample 1 to two-fluid cleaning for 2000 seconds or more, the contamination incidence rate becomes zero. By performing two-fluid cleaning, debris generated by the laser scribing process is washed away from the laser scribe lines 35a and 35b and the side surface 10c of the compound semiconductor substrate 10, thereby reducing or eliminating adhesion of contaminants to the wire bonding pad 27. A semiconductor device 1 can be manufactured that includes a wire bonding pad 27 with even better wire bonding properties to conductive wires.

[0048] The effects of the semiconductor element 1 of this embodiment and the manufacturing method thereof will be described.

[0049] The method for manufacturing a semiconductor device 1 according to the present embodiment includes the steps of: irradiating a first wafer surface (wafer surface 9a) of a compound semiconductor wafer 9 of a laminate wafer 30 with a first laser beam (laser beam 34a) to form first laser scribe lines (laser scribe lines 35a) on the first wafer surface; and breaking the laminate wafer 30 along the first laser scribe lines to separate the laminate wafer 30 into a plurality of semiconductor devices 1. The laminate wafer 30 includes a compound semiconductor wafer 9 and a plurality of laminates 5 disposed on the first wafer surface. Each of the plurality of laminates 5 includes a wire bonding pad 27. The first power of the first laser beam is 0.3 W or less.

[0050] This makes it possible to reduce contaminants that adhere to the wire bonding pad 27 due to the process of forming the first laser scribe line (laser scribe line 35a). According to the method for manufacturing the semiconductor element 1 of this embodiment, it is possible to manufacture the semiconductor element 1 having improved wire bonding properties with a higher yield.

[0051] Furthermore, a first laser scribe line (laser scribe line 35a) is formed using a first laser beam (laser beam 34a). The scanning speed of the first laser beam is significantly faster than the feed speed of a blade used to form the scribe line or cut compound semiconductor wafer 9. Therefore, according to the manufacturing method for semiconductor device 1 of this embodiment, the manufacturing time for semiconductor device 1 can be significantly reduced compared to when a blade is used to form a scribe line or cut compound semiconductor wafer 9.

[0052] In the method for manufacturing semiconductor device 1 of the present embodiment, the first power is 0.05 W or less.

[0053] It is possible to further reduce contaminants that are generated in the process of forming the first laser scribe line (laser scribe line 35a) and that adhere to the wire bonding pad 27. According to the manufacturing method of the semiconductor element 1 of this embodiment, it is possible to manufacture semiconductor elements 1 having improved wire bonding properties with a higher yield.

[0054] The method for manufacturing a semiconductor element 1 according to the present embodiment further includes a step of cleaning the plurality of semiconductor elements 1 by two-fluid cleaning for 800 seconds or more.

[0055] Therefore, debris generated in the process of forming the first laser scribe lines (laser scribe lines 35a) is washed away from the plurality of semiconductor elements 1. This can further reduce or eliminate contaminants adhering to the wire bonding pads 27. According to the method for manufacturing the semiconductor element 1 of this embodiment, semiconductor elements 1 having improved wire bonding properties can be manufactured with a higher yield.

[0056] In the manufacturing method of the semiconductor device 1 of this embodiment, the compound semiconductor wafer 9 is divided into a plurality of compound semiconductor substrates 10 by the step of singulating the laminate wafer 30 into a plurality of semiconductor devices 1. Each of the plurality of compound semiconductor substrates 10 includes a first main surface (main surface 10a) that is a part of the first wafer surface (wafer surface 9a), a second main surface (main surface 10b) opposite to the first main surface, a side surface 10c extending in a direction in which the first main surface and the second main surface are spaced apart from each other, and laser processing marks 11a formed between the first main surface and the side surface 10c. The step of cleaning the plurality of semiconductor devices 1 by two-fluid cleaning includes cleaning the first main surface, the side surface 10c, and the laser processing marks 11a.

[0057] Therefore, debris generated in the process of forming the first laser scribe line (laser scribe line 35a) is washed away from the first main surface (main surface 10a), the side surface 10c, and the laser processing marks 11a. This can further reduce or eliminate contaminants adhering to the wire bonding pad 27. According to the manufacturing method of the semiconductor element 1 of this embodiment, semiconductor elements 1 having improved wire bondability can be manufactured with a higher yield.

[0058] The method for manufacturing a semiconductor element 1 according to the present embodiment further includes the step of forming a first protective film (protective film 31) on the first wafer surface (wafer surface 9a). The first protective film protects the first wafer surface and the plurality of stacked bodies 5 from debris generated in the step of forming the first laser scribe lines (laser scribe lines 35a). The step of cleaning the plurality of semiconductor elements 1 includes rinsing away the first protective film.

[0059] By using two-fluid cleaning, the first protective film (protective film 31) can be removed while debris generated in the process of forming the first laser scribe lines (laser scribe lines 35a) is washed away from the semiconductor elements 1. This allows the manufacturing time of the semiconductor elements 1 to be shortened.

[0060] The method for manufacturing a semiconductor device 1 according to the present embodiment further includes the steps of: forming a second laser scribe line (laser scribe line 35b) on a second wafer surface (wafer surface 9b) of the compound semiconductor wafer 9 opposite to the first wafer surface (wafer surface 9a) by irradiating the second wafer surface with a second laser beam (laser beam 34b); and cleaning the second wafer surface and the second laser scribe line by two-fluid cleaning. The second power of the second laser beam is 0.3 W or less. The time required to clean the multiple semiconductor devices 1 is longer than the time required to clean the second wafer surface and the second laser scribe line.

[0061] This makes it possible to reduce contaminants that adhere to the wire bonding pad 27 due to the process of forming the second laser scribe line (laser scribe line 35b). According to the method for manufacturing the semiconductor element 1 of this embodiment, it is possible to manufacture the semiconductor element 1 having improved wire bonding properties with a higher yield.

[0062] Furthermore, a second laser scribe line (laser scribe line 35b) is formed using a second laser beam (laser beam 34b). The scanning speed of the second laser beam is significantly faster than the feed speed of a blade used to form the scribe line or cut compound semiconductor wafer 9. Therefore, according to the manufacturing method for semiconductor device 1 of this embodiment, the manufacturing time for semiconductor device 1 can be significantly reduced compared to when a blade is used to form a scribe line or cut compound semiconductor wafer 9.

[0063] By making the time for cleaning the multiple semiconductor elements 1 longer than the time for cleaning the second wafer surface (wafer surface 9b) and the second laser scribe line (laser scribe line 35b), it is possible to prevent the manufacturing time for the semiconductor elements 1 from becoming excessively long while reducing the amount of contaminants adhering to the wire bonding pads 27.

[0064] The method for manufacturing a semiconductor device 1 according to the present embodiment further includes the step of forming a second protective film (protective film 32) on the second wafer surface (wafer surface 9b). The second protective film protects the second wafer surface from debris generated in the step of forming the second laser scribe line (laser scribe line 35b). The step of cleaning the second wafer surface and the second laser scribe line includes rinsing away the second protective film.

[0065] By using two-fluid cleaning, the second protective film (protective film 32) can be removed while debris generated in the process of forming the second laser scribe lines (laser scribe lines 35b) is washed away from the second wafer surface (wafer surface 9b) and the second laser scribe lines (laser scribe lines 35b), thereby shortening the manufacturing time of the semiconductor device 1.

[0066] The semiconductor device 1 of this embodiment includes a compound semiconductor substrate 10 including a first main surface (main surface 10a), and a laminate 5 disposed on the first main surface. The laminate 5 includes a wire bonding pad 27. A first laser processing mark (laser processing mark 11a) is formed on the periphery of the first main surface. The depth of the first laser processing mark is 25.6 μm or less.

[0067] This makes it possible to reduce contaminants that adhere to the wire bonding pad 27 due to the step of forming the first laser processing marks (laser processing marks 11a). The semiconductor element 1 of this embodiment has improved wire bonding properties.

[0068] Furthermore, the first laser processing marks (laser processing marks 11a) formed to divide the compound semiconductor wafer 9 into a plurality of compound semiconductor substrates 10 are formed using the first laser light (laser light 34a). The scanning speed of the first laser light is significantly faster than the feed speed of a blade used to form scribe lines or cut the compound semiconductor wafer 9. Therefore, the manufacturing time of the semiconductor device 1 can be significantly reduced compared to when the processing marks on the compound semiconductor substrate 10 are processing marks formed by using a blade to form scribe lines or by using a blade to cut the compound semiconductor wafer 9.

[0069] In the semiconductor device 1 of this embodiment, the compound semiconductor substrate 10 includes a second main surface (main surface 10b) opposite to the first main surface (main surface 10a). A second laser processing mark (laser processing mark 11b) is formed on the periphery of the second main surface. The depth of the second laser processing mark is 25.6 μm or less.

[0070] This makes it possible to reduce contaminants that adhere to the wire bonding pad 27 due to the process of forming the second laser processing marks (laser processing marks 11b). The semiconductor element 1 of this embodiment has improved wire bonding properties.

[0071] Furthermore, the second laser processing marks (laser processing marks 11b) formed to divide the compound semiconductor wafer 9 into a plurality of compound semiconductor substrates 10 are formed using a second laser beam (laser beam 34b). The scanning speed of the second laser beam is significantly faster than the feed speed of a blade used to form scribe lines or cut the compound semiconductor wafer 9. Therefore, the manufacturing time of the semiconductor device 1 can be significantly reduced compared to when the processing marks on the compound semiconductor substrate 10 are processing marks formed by using a blade to form scribe lines or by using a blade to cut the compound semiconductor wafer 9.

[0072] Various aspects of the present disclosure are summarized below as appendices. (Appendix 1) forming a first laser scribe line on a first wafer surface of a compound semiconductor wafer of the laminate wafer by irradiating the first wafer surface with a first laser light; breaking the laminated wafer along the first laser scribe line to separate the laminated wafer into a plurality of semiconductor elements; the laminate wafer includes the compound semiconductor wafer and a plurality of laminates disposed on a surface of the first wafer, each of the plurality of laminates including a wire bonding pad; A method for manufacturing a semiconductor device, wherein the first power of the first laser light is 0.3 W or less. (Appendix 2) 2. The method for manufacturing a semiconductor device according to claim 1, wherein the first power is 0.05 W or less. (Appendix 3) cleaning the semiconductor elements by two-fluid cleaning; 3. The method for manufacturing a semiconductor element according to claim 1, wherein the time for cleaning the semiconductor elements by the two-fluid cleaning is 800 seconds or more. (Appendix 4) the compound semiconductor wafer is divided into a plurality of compound semiconductor substrates by the step of singulating the laminate wafer into the plurality of semiconductor elements; each of the plurality of compound semiconductor substrates includes a first main surface that is a part of the first wafer surface, a second main surface opposite to the first main surface, a side surface extending in a direction in which the first main surface and the second main surface are spaced apart from each other, and a laser processing mark formed between the first main surface and the side surface; 4. The method for manufacturing a semiconductor element according to claim 3, wherein the step of cleaning the plurality of semiconductor elements by two-fluid cleaning includes cleaning the first main surface, the side surface, and the laser processing marks. (Appendix 5) forming a first protective film on the surface of the first wafer; the first protective film protects the first wafer surface and the plurality of stacked bodies from debris generated in the step of forming the first laser scribe line; 5. The method for manufacturing a semiconductor element according to claim 3, wherein the step of cleaning the semiconductor elements includes washing away the first protective film. (Appendix 6) forming a second laser scribe line on a second wafer surface of the compound semiconductor wafer opposite to the first wafer surface by irradiating the second wafer surface with a second laser light; cleaning the second wafer surface and the second laser scribe line by two-fluid cleaning; a second power of the second laser light is 0.3 W or less; 4. The method for manufacturing a semiconductor element according to claim 3, wherein the time for cleaning the plurality of semiconductor elements is longer than the time for cleaning the second wafer surface and the second laser scribe line. (Appendix 7) forming a second protective film on the surface of the second wafer; the second protective film protects the surface of the second wafer from debris generated in the step of forming the second laser scribe line; 7. The method for manufacturing a semiconductor device according to claim 6, wherein the step of cleaning the second wafer surface and the second laser scribe lines includes washing away the second protective film. (Appendix 8) 8. The method for manufacturing a semiconductor device according to any one of claims 1 to 7, wherein the compound semiconductor wafer is an InP wafer, a GaAs wafer, a GaP wafer, a GaN wafer, an AlN wafer, or a Ga2O3 wafer. (Appendix 9) 9. The method for manufacturing a semiconductor element according to claim 1, wherein the plurality of semiconductor elements are photodiodes. (Appendix 10) a compound semiconductor substrate including a first main surface; a laminate disposed on the first main surface, the laminate includes a wire bonding pad; a first laser processing mark is formed on a periphery of the first main surface, A semiconductor element, wherein the depth of the first laser processing mark is 25.6 μm or less. (Appendix 11) the compound semiconductor substrate includes a second main surface opposite the first main surface, a second laser processing mark is formed on a periphery of the second main surface, 11. The semiconductor element according to claim 10, wherein the depth of the second laser processing mark is 25.6 μm or less. (Appendix 12) 12. The semiconductor device according to claim 10, wherein the compound semiconductor substrate is an InP substrate, a GaAs substrate, a GaP substrate, a GaN substrate, an AlN substrate, or a Ga2O3 substrate. (Appendix 13) 13. The semiconductor element according to any one of claims 10 to 12, wherein the semiconductor element is a photodiode.

[0073] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0074] 1 semiconductor element, 2 photodiode, 5 laminate, 9 compound semiconductor wafer, 9a, 9b wafer surface, 10 compound semiconductor substrate, 10a, 10b main surface, 10c side surface, 11a, 11b laser processing marks, 13 buffer layer, 14 light absorption layer, 15 window layer, 16 p-type dopant diffusion region, 18 p-type contact layer, 18a, 21a, 26a opening, 21 insulating layer, 22 anti-reflection film, 22a through hole, 25 n-electrode, 25b backside conductive film, 26 p-electrode, 27 wire bonding pad, 30 laminate wafer, 31, 32 protective film, 33, 37, 38 dicing tape, 34a, 34b laser light, 35a, 35b laser scribe, 36 mixed fluid, 39 crack, 40 break tool.

Claims

1. forming a first laser scribe line on a first wafer surface of a compound semiconductor wafer of the laminate wafer by irradiating the first wafer surface with a first laser light; breaking the laminated wafer along the first laser scribe line to separate the laminated wafer into a plurality of semiconductor elements; the laminate wafer includes the compound semiconductor wafer and a plurality of laminates disposed on a surface of the first wafer, each of the plurality of laminates including a wire bonding pad; The first power of the first laser light is 0.3 W or less.

2. The method of claim 1 , wherein the first power is 0.05 W or less.

3. cleaning the semiconductor elements by two-fluid cleaning; 3. The method for manufacturing a semiconductor element according to claim 1, wherein the time for cleaning the semiconductor elements by the two-fluid cleaning is 800 seconds or more.

4. the compound semiconductor wafer is divided into a plurality of compound semiconductor substrates by the step of singulating the laminate wafer into the plurality of semiconductor elements; each of the plurality of compound semiconductor substrates includes a first main surface that is a part of the first wafer surface, a second main surface opposite to the first main surface, a side surface extending in a direction in which the first main surface and the second main surface are spaced apart from each other, and a laser processing mark formed between the first main surface and the side surface; 4. The method for manufacturing a semiconductor element according to claim 3, wherein the step of cleaning the plurality of semiconductor elements by two-fluid cleaning includes cleaning the first main surface, the side surface, and the laser processing marks.

5. forming a first protective film on the first wafer surface; the first protective film protects the first wafer surface and the plurality of stacked bodies from debris generated in the process of forming the first laser scribe lines; 4. The method of manufacturing a semiconductor element according to claim 3, wherein the step of cleaning the plurality of semiconductor elements includes washing away the first protective film.

6. irradiating a second wafer surface of the compound semiconductor wafer opposite to the first wafer surface with a second laser light to form a second laser scribe line on the second wafer surface; cleaning the second wafer surface and the second laser scribe line by two-fluid cleaning; a second power of the second laser light is 0.3 W or less; The method of manufacturing a semiconductor element according to claim 3 , wherein the time for cleaning the plurality of semiconductor elements is longer than the time for cleaning the second wafer surface and the second laser scribe lines.

7. forming a second protective film on the surface of the second wafer; the second protective film protects the surface of the second wafer from debris generated in the step of forming the second laser scribe line; 7. The method for manufacturing a semiconductor device according to claim 6, wherein the step of cleaning the second wafer surface and the second laser scribe lines includes washing away the second protective film.

8. The compound semiconductor wafer may be an InP wafer, a GaAs wafer, a GaP wafer, a GaN wafer, an AlN wafer, or a Ga ２ O ３ The method for manufacturing a semiconductor device according to claim 1 or 2, wherein the semiconductor device is a wafer.

9. 3. The method for manufacturing a semiconductor element according to claim 1, wherein the plurality of semiconductor elements are photodiodes.

10. a compound semiconductor substrate including a first main surface; a laminate disposed on the first main surface, the laminate includes a wire bonding pad; a first laser processing mark is formed on a periphery of the first main surface, A semiconductor element, wherein the depth of the first laser processing mark is 25.6 μm or less.

11. the compound semiconductor substrate includes a second main surface opposite the first main surface, a second laser processing mark is formed on a periphery of the second main surface, The semiconductor element according to claim 10 , wherein the depth of the second laser processing mark is 25.6 μm or less.

12. The compound semiconductor substrate is an InP substrate, a GaAs substrate, a GaP substrate, a GaN substrate, an AlN substrate, or a Ga ２ O ３ The semiconductor element according to claim 10 or 11, which is a substrate.

13. The semiconductor element according to claim 10 or 11, wherein the semiconductor element is a photodiode.

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