A process for reducing cracks in manual bonding of GaAs-based light-emitting diodes

Abstract

The present invention relates to a process for reducing cracks in the manual bonding process of GaAs-based light-emitting diodes, comprising the following steps: (1) wafer preparation; (2) wafer placement: placing the second reflector layer of the GaAs-based LED wafer upward and flat in a high-temperature resistant bag, then placing a wedge at the edge of the second reflector layer of the GaAs-based LED wafer, and then placing the metal adhesion layer of the silicon wafer prepared in step (1) downward on the GaAs-based LED wafer, so that the wedge separates the GaAs-based LED wafer from the silicon wafer, and aligns the cut edge of the silicon wafer with the cut edge of the GaAs-based LED wafer; (3) vacuuming and chip bonding; (4) chip pressing; (5) high-temperature bonding; (6) tube core structure production. The method provided by the present invention can greatly reduce or eliminate the generation of cracks / splinters in the bonding process, is applicable to the bonding process of all LED wafers, and has low cost and stable quality.

Description

Technical Field

[0001] The invention relates to a process for reducing cracks in a manual bonding process of a GaAs-based light-emitting diode, and belongs to the technical field of semiconductor device processing. Background Art

[0002] Semiconductor light emitting diodes are widely used in communication, information processing, lighting and other fields because of their simple structure, stable performance, small size, low operating current, easy use, low cost, energy saving and environmental protection, long service life and many other advantages. In particular, they are increasingly used in display screens, traffic lights, automotive lights, LCD backlights, lighting, lighting sources and other industries, bringing many conveniences to people's lives and studies.

[0003] In the production of the flip-chip structure of the red light-emitting diode die, silicon wafers are usually used as replacement substrates. The temporary GaAs substrate with an epitaxial layer and the silicon substrate are adhered together at high temperature through metal adhesion. The atomic bonding force of the bonding surface of the two wafers is used. After treatment, the atomic reaction of the bonding surface produces covalent bonding and achieves a certain bonding strength. Wafer bonding methods generally include direct bonding (Direct Bonding) and bonding through an intermediate layer (Bonding with inter-layers). Direct bonding methods include thermal bonding (Fusion Bonding) and anodic bonding (Anodic Bonding); bonding methods through an intermediate layer include metal bonding (Metal Bonding), glass solution bonding (Glass Frit Bonding), and adhesive bonding (Adhersive Bonding). Among them, metal bonding includes eutectic bonding (Eutectic Bonding), solder bonding (Solder Bonding), and metal thermo-compression bonding (Metal Thermo-Compression Bonding). Adhesive bonding is divided into UV Cured polymer Bonding and Thermo Cured polymer Bonding. The quality of bonding directly affects the yield and luminous brightness of the overall tube core. In the bonding process, a high temperature of 200-300℃ is usually required to carry out the alloy process to make the surface bonding adhesion better. The roughness of the surface of the silicon wafer itself varies greatly. The silicon wafer treated by polishing or thermal oxidation is not an ideal mirror, but always has certain ups and downs and surface roughness. At the same time, during the high-temperature bonding process, silicon will undergo elastic deformation, viscous reflux of metal at high temperature, and other phenomena. If there is a lot of residual gas at the interface, holes will be generated at the bonding interface. When the temporary substrate is removed by corrosion method in the subsequent process, such holes will cause drilling of the corrosive liquid and large-area epitaxial layer shedding. The corrosion shedding caused by this abnormal bonding crack will have a great impact on the overall yield.

[0004] Chinese patent document CN102569031A discloses a method for epitaxial wafer / silicon wafer bonding using indium (In), and the specific steps are as follows: evaporate a gold (Au) layer on an epitaxial wafer deposited with a reflector layer, and then place the two wafers opposite to each other (with the indium (In) layer in the middle) in a bonding machine for bonding, which can prepare high-efficiency, high-brightness, low-resistance, and stable-performance LED light-emitting diode devices. The bonding method using a special bonder in this invention patent is a more traditional bonding method, but the bonder is relatively expensive, making the overall production cost higher. At the same time, the traditional bonding method will inevitably produce bonding lines at the bonding interface.

[0005] Chinese patent document CN112053938A discloses a wafer bonding method, including the following steps: plasma activation treatment of the wafer to be bonded; cleaning the wafer after plasma activation treatment; nitrogen drying the cleaned wafer in a gradient heating mode; pre-bonding and bonding the dried wafer. This patent uses hot nitrogen gradient heating and nitrogen drying treatment on the entire wafer to eliminate or reduce the formation of voids between the two wafers after bonding. It has a certain effect, but there is still a large proportion of bonding cracks.

[0006] Chinese patent document CN109712875B discloses a wafer direct bonding method, comprising the following steps: step 1, providing first and second wafers for bonding, with a cutting path at the edge of the first wafer; step 2, pre-cutting, removing a certain depth of the cutting path at the edge of the first surface of the first wafer; step 3, pre-treating the first and second wafers; step 4, pre-bonding the first and second wafers; step 5, bonding the first and second wafers, gas will be generated and discharged from the bonding surface during the bonding process, and the pressure difference of the bonding wavefront at the edge of the first wafer is reduced by increasing the bonding surface spacing in step 2, and bubbles are prevented from being generated at the edge of the first wafer due to excessive pressure difference. Although the invention can reduce the number of bubbles in the bonding process to a certain extent, it is not thorough, the improvement effect is limited, and the yield is still low.

[0007] In view of this, in view of the drawback of the existing traditional bonding method that is prone to cracks, it is necessary to study a process method for manual bonding without generating bonding cracks, so as to improve the wafer bonding yield. Summary of the invention

[0008] In view of the shortcomings of the prior art, the present invention provides a process method for reducing cracks in the manual bonding process of GaAs-based light-emitting diodes. First, a GaAs-based LED chip is placed in a high-temperature resistant bag, and then a wedge is placed between the silicon wafer and the GaAs-based LED chip. Then, vacuuming, chip mounting and high-temperature bonding are performed in sequence. This process can effectively reduce or eliminate bonding cracks, and at the same time can greatly improve the overall yield of the tube core and reduce the production cost.

[0009] The technical solution of the present invention is:

[0010] A process for reducing cracks in a manual bonding process of a GaAs-based light-emitting diode comprises the following steps:

[0011] (1) Wafer preparation: an ohmic contact layer, a current blocking layer, and a second reflector layer are sequentially grown on the surface of a GaAs-based LED wafer, and a first reflector layer and a metal adhesion layer are sequentially grown on a silicon wafer;

[0012] The silicon wafer is used as a permanent substrate and the GaAs-based LED wafer is used as a temporary substrate for bonding;

[0013] (2) Wafer placement: Place the GaAs-based LED wafer prepared in step (1) flatly in a high temperature resistant bag with the second reflector layer facing upward, then place a wedge at the edge of the second reflector layer of the GaAs-based LED wafer, and then place the metal adhesion layer of the silicon wafer prepared in step (1) on the GaAs-based LED wafer with the metal adhesion layer facing downward, so that the wedge separates the GaAs-based LED wafer from the silicon wafer, and aligns the cut edge of the silicon wafer with the cut edge of the GaAs-based LED wafer;

[0014] (3) Vacuuming and patching: Use a film sealing machine to vacuum and seal the high-temperature resistant bag to automatically complete the patching;

[0015] (4) tablet pressing: placing the wafer after the bonding in step (3) on a semi-automatic tablet pressing machine for tablet pressing;

[0016] (5) High temperature bonding: placing the wafer pressed in step (4) in an oven for heating to complete bonding;

[0017] (6) Fabrication of tube core structure: For the wafer bonded in step (5), substrate etching, electrode extension, P-side electrode, surface roughening and grooving, silicon wafer thinning, silicon wafer N-side electrode, and tube core cutting are sequentially performed to complete the tube core fabrication.

[0018] Preferably according to the present invention, in step (2), the shape of the wedge is a right triangular prism, a side surface of the right triangular prism wedge where the right angle side is located is in contact with the second reflector layer, and a side surface of the right triangular prism wedge where the hypotenuse is located is in contact with the metal adhesion layer.

[0019] One side surface of the right-angled triangular prism wedge where the right-angled side is located can gradually and automatically detach as the pressure on the upper surface increases, so that the silicon wafer and the epitaxial wafer are automatically attached together, the interface is evenly stressed, and there is less gas between the interfaces.

[0020] Preferably, according to the present invention, in step (2), the number of wedges is four, two wedges are placed at the end points of the cut edge of the GaAs-based LED chip, and the other two wedges are symmetrically arranged with respect to the center of the GaAs-based LED chip and the two wedges placed at the end points of the cut edge.

[0021] Choose four wedges, two of which are placed at the vertices of the large sides of the epitaxial wafer, so that the epitaxial wafer and the silicon wafer can be aligned, and the other two are placed symmetrically to them to fix them, achieving the best effect. If too many wedges are used, they will occupy a large space in the sealing bag and have a greater impact on vacuuming.

[0022] Preferably according to the present invention, in step (2), the material of the wedge is polytetrafluoroethylene.

[0023] Preferably, in step (3), the vacuuming time of the film sealing machine used is more than 30 seconds, so as to ensure that the air is extracted as much as possible, and sealing is performed immediately after the vacuuming is completed.

[0024] According to the preferred embodiment of the present invention, in step (4), the pressure of the tablet press is 0.4-0.6 MPa, the heating temperature during tableting is 110-130° C., and the tableting time is 30-40 minutes;

[0025] Further preferably, in step (4), the pressure of the tablet press is 0.5 MPa, the heating temperature during tableting is 120° C., and the tableting time is 35 minutes.

[0026] This pressure can make the wafers adhere together relatively firmly without causing cracks. Too much pressure will cause cracks or even splits, while too little pressure will not cause the epitaxial wafer and silicon wafer to adhere together strongly enough.

[0027] Preferably, in step (5), the heating temperature of the oven is 220-230° C. and the heating time is 50-60 min;

[0028] Further preferably, in step (5), the heating temperature of the oven is 225° C. and the heating time is 55 min.

[0029] Preferably, according to the present invention, in step (1), the material of the first reflector is TiAu, and the material of the metal adhesion layer is In.

[0030] Preferably, according to the present invention, in step (1), the GaAs-based LED wafer comprises, from bottom to top, a GaAs substrate, an N-type GaAs ohmic contact layer, an N-type confinement layer, an MQW quantum well active layer, a P-type confinement layer, a P-type GaAs ohmic contact layer, and a current spreading layer.

[0031] According to the preferred embodiment of the present invention, the structure of the ohmic contact layer on the GaAs-based LED chip is AuBe / Au, and the material of the current blocking layer is SiO 2 , the material of the second reflector layer is PtAu.

[0032] Preferably according to the present invention, the purity of the metals used in the ohmic contact layer and the second reflector layer of the GaAs-based LED wafer and the first reflector layer and the metal adhesion layer evaporated on the silicon wafer are all 4N grade or above.

[0033] The beneficial effects of the present invention are:

[0034] 1. In the present invention, the patch method and vacuuming are the core technologies. First, four smaller wedges are placed at four locations of the wafer. Two wedges are placed at the end points of the cut edges for wafer alignment, and the other two wedges are placed at positions symmetrical to the two wedges about the center of the circle. The flat edge of the wedge is placed on the smooth second reflector layer, and the beveled edge of the wedge is placed on the metal adhesion layer. Based on this, during the vacuuming process, the wafer will slowly drop due to the pressure of the high-temperature resistant bag, and the lower surface of the wedge will slowly move outward in contact with the smooth second reflector layer, causing the upper silicon wafer to fall, and the patching action is automatically completed, that is, the wedge is pressed outside the wafer, which is convenient for the subsequent pressing action. In the whole process, the wafer surface is evenly stressed, and there will be very little gas in the wafer. After the vacuuming action, most of the gas inside the wafer will be pumped away. The method provided by the present invention can avoid the problem of uneven wafer stress caused by manual patching.

[0035] 2. In the present invention, it is extremely important to use a suitable force to press the wafer. Pressing the wafer works in conjunction with the patch. After the patch is completed, the adhesion between the wafers is relatively small. Pressing the wafer must be performed to further strengthen the adhesion of the metal adhesion layer to the metal on both sides. Then, a eutectic is formed through subsequent high temperature, thereby obtaining a bonded wafer with good adhesion.

[0036] 3. The method provided by the present invention can significantly reduce or eliminate the generation of cracks / splinters during the bonding process, is applicable to the bonding process of all LED chips, and has low cost and stable quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic diagram of the structure after the first reflector layer and the metal adhesion layer are evaporated on the silicon wafer in step (1) of the present invention;

[0038] Figure 2 This is a schematic diagram of the structure after an ohmic contact layer, a current blocking layer, and a reflector layer are grown on the surface of a GaAs-based LED wafer in step (1) of the present invention;

[0039] Figure 3 This is a schematic diagram of the structure after step (2) is completed in the present invention;

[0040] Figure 4 This is a schematic diagram of the structure after step (3) is completed in the present invention;

[0041] Figure 5 This is a schematic diagram of the top view of the wafer after step (2) is completed in the present invention.

[0042] 001, silicon wafer, 002, first reflector layer, 003, metal adhesion layer; 004, GaAs-based LED wafer; 005, current blocking layer, 006, ohmic contact layer, 007, second reflector layer, 008, wedge, 009, high temperature resistant bag. DETAILED DESCRIPTION

[0043] The present invention will be further described below in conjunction with the embodiments and the accompanying drawings, but is not limited thereto.

[0044] Example 1

[0045] A process for reducing cracks in a manual bonding process of a GaAs-based light-emitting diode comprises the following steps:

[0046] (1) Wafer preparation: Figure 2 As shown, an ohmic contact layer 006, a current blocking layer 005 and a second reflector layer 007 are sequentially grown on the surface of a GaAs-based LED wafer 004, and the ohmic contact layer 006 is evenly distributed in the current blocking layer 005, the upper surfaces of the current blocking layer 005 and the ohmic contact layer 006 are connected to the second reflector layer 007, and the lower surfaces of the current blocking layer 005 and the ohmic contact layer 006 are connected to the GaAs-based LED wafer 004; Figure 1 As shown, a first reflector layer 002 and a metal adhesion layer 003 are sequentially grown on a silicon wafer 001;

[0047] The silicon wafer 001 is used as a permanent substrate and the GaAs-based LED wafer 004 is used as a temporary substrate for bonding;

[0048] (2) Wafer placement: Figure 3 and Figure 5As shown, the second reflector layer 007 of the GaAs-based LED wafer 004 prepared in step (1) is placed flatly with the second reflector layer 007 facing upward in a high-temperature resistant bag 009, and then a wedge 008 is placed on the edge of the second reflector layer 007 of the GaAs-based LED wafer 004, and then the metal adhesion layer 003 of the silicon wafer 001 prepared in step (1) is placed downward on the GaAs-based LED wafer 004, so that the wedge 008 separates the GaAs-based LED wafer 004 from the silicon wafer 001, and aligns the cut edge of the silicon wafer 001 with the cut edge of the GaAs-based LED wafer 004; the material of the high-temperature resistant bag 009 is polytetrafluoroethylene, which can withstand high temperatures during the high-temperature bonding process.

[0049] (3) Vacuuming and patching: Figure 4 As shown, a film sealing machine is used to evacuate and seal the high temperature resistant bag 009, and the patch is automatically completed;

[0050] (4) tablet pressing: placing the wafer after the bonding in step (3) on a semi-automatic tablet pressing machine for tablet pressing;

[0051] (5) High temperature bonding: placing the wafer pressed in step (4) in an oven for heating to complete bonding;

[0052] (6) Fabrication of tube core structure: For the wafer bonded in step (5), substrate etching, electrode extension, P-side electrode, surface roughening and grooving, silicon wafer 001 thinning, silicon wafer 001N-side electrode, and tube core cutting are sequentially performed to complete the tube core fabrication.

[0053] 200 GaAs-based LED wafers 004 were bonded by the method provided by the present invention, of which 0 had bonding lines, and the proportion of bonding lines was 0%; 1 had abnormal bonding, and the proportion of abnormal bonding was 0.5%.

[0054] Example 2

[0055] According to a process method for reducing cracks in a manual bonding process of a GaAs-based light-emitting diode provided in Example 1, the difference is that:

[0056] In step (1), the material of the first reflector is TiAu, and the material of the metal adhesion layer 003 is In.

[0057] In step (1), the GaAs-based LED chip 004 is composed of a GaAs substrate, an N-type GaAs ohmic contact layer, an N-type confinement layer, an MQW quantum well active layer, a P-type confinement layer, a P-type GaAs ohmic contact layer, and a current spreading layer from bottom to top; MQW, Multiple Quantum Well.

[0058] In step (2), the shape of wedge 008 is a right-angled triangular prism, and one side of the right-angled side of the right-angled triangular prism wedge 008 is in contact with the second reflector layer 007, and the side of the right-angled triangular prism wedge 008 is in contact with the metal adhesion layer 003.

[0059] In step (2), there are four wedges 008, two of which are placed at the end points of the cut edge of the GaAs-based LED chip 004, and the other two wedges 008 are symmetrically arranged with respect to the center of the GaAs-based LED chip 004 and the two wedges 008 arranged at the end points of the cut edge.

[0060] In step (2), the material of wedge 008 is polytetrafluoroethylene.

[0061] In step (3), the vacuuming time of the film sealing machine used is more than 30 seconds to ensure that the air is extracted as much as possible, and the sealing is performed immediately after the vacuuming is completed.

[0062] In step (4), the pressure of the tablet press is 0.4-0.6 MPa, the heating temperature during tableting is 110-130° C., and the tableting time is 30-40 minutes;

[0063] In step (5), the heating temperature of the oven is 220-230° C., and the heating time is 50-60 min;

[0064] The structure of the ohmic contact layer 006 on the GaAs-based LED wafer 004 is AuBe / Au, the material of the current blocking layer 005 is SiO2, and the material of the second reflector layer 007 is PtAu.

[0065] The purity of the metals used in the evaporation of the ohmic contact layer 006 and the second reflector layer 007 of the GaAs-based LED wafer 004 and the first reflector layer 002 and the metal adhesion layer 003 evaporated on the silicon wafer 001 are all 4N grade or above.

[0066] 200 GaAs-based LED wafers 004 were bonded by the method provided by the present invention, of which 0 had bonding lines, and the proportion of bonding lines was 0%; 0 had abnormal bonding, and the proportion of abnormal bonding was 0%.

[0067] Example 3

[0068] According to a process method for reducing cracks in the manual bonding process of GaAs-based light-emitting diodes provided in Example 2, the difference is that:

[0069] In step (5), the heating temperature of the oven is 220° C. and the heating time is 60 min.

[0070] In step (4), the pressure of the tablet press is 0.5 MPa, the heating temperature during tableting is 120° C., and the tableting time is 35 minutes.

[0071] 200 GaAs-based LED wafers 004 were bonded by the method provided by the present invention, of which 0 had bonding lines, and the proportion of bonding lines was 0%; 1 had abnormal bonding, and the proportion of abnormal bonding was 0.5%.

[0072] Comparative Example 1

[0073] The GaAs-based LED wafer 004 is bonded by manual bonding method. The specific process is as follows:

[0074] (1) An ohmic contact layer 006, a current blocking layer 005 and a second reflector layer 007 are sequentially grown on the surface of a GaAs-based LED wafer 004;

[0075] A first reflector layer 002 and a metal adhesion layer 003 are sequentially grown on a silicon wafer 001;

[0076] In step (1), the material of the first reflector is TiAu, and the material of the metal adhesion layer 003 is In.

[0077] In step (1), the GaAs-based LED wafer 004 comprises, from bottom to top, a GaAs substrate, an N-type GaAs ohmic contact layer, an N-type confinement layer, an MQW quantum well active layer, a P-type confinement layer, a P-type GaAs ohmic contact layer, and a current spreading layer.

[0078] (2) The second reflector layer 007 of the GaAs-based LED wafer 004 prepared in step (1) is facing upward, and the metal adhesion layer 003 of the silicon wafer 001 prepared in step (1) is placed downward on the GaAs-based LED wafer 004, and the cut edge of the silicon wafer 001 is manually aligned with the cut edge of the GaAs-based LED wafer 004; then, a pressure tool, such as a C-type pressing clamp, is used to fix and press the GaAs-based LED wafer 004 and the silicon wafer 001;

[0079] (3) The compressed GaAs-based LED wafer 004 and silicon wafer 001 are then placed in an oven for heating to complete bonding; the heating temperature of the oven is 220° C. and the heating time is 60 minutes.

[0080] This method was used to manually bond 200 GaAs-based LED chips 004, of which 26 had bonding lines, accounting for 13%; 34 had bonding abnormalities, accounting for 17%. Bonding abnormalities were abnormal chips other than bonding lines, such as loose adhesion and falling off of the bonding layer, uneven bonding and metal falling off, etc.

[0081] As can be seen from Examples 1-3 and Comparative Example 1, the present invention provides a process for reducing cracks in the manual bonding process of GaAs-based light-emitting diodes. A wedge 008 is placed between the GaAs-based LED chip 004 and the silicon chip 001, and then transferred to a high-temperature resistant bag 009. During the vacuuming process, the chip will slowly drop due to the pressure of the high-temperature resistant bag 009, and the lower surface of the wedge 008 will contact the smooth second reflector layer 007 and slowly move outward, so that the upper silicon chip 001 falls, and the patch action is automatically completed, that is, the wedge 008 is pressed outside the chip, which is convenient for the subsequent tablet pressing action; and the chip surface is uniformly stressed during the whole process, and there will be very little gas in the chip. After the vacuuming action, most of the gas inside the chip will be pumped away, which can avoid the problem of uneven chip stress caused by manual patching. The method provided by the present invention can avoid the problem of uneven chip stress caused by manual patching. In addition, after the bonding is completed, the adhesion between the wafers is relatively weak, and the metal adhesion layer 003 must be pressed to further strengthen the adhesion with the metal on both sides; and then a eutectic is formed through subsequent high temperature action, so that a well-adhesive bonded wafer is obtained, which can effectively reduce the generation of cracks during the manual bonding process of GaAs-based light-emitting diodes and improve the product yield.

Claims

1. A process for reducing cracks in the manual bonding process of GaAs-based light-emitting diodes. It is characterized in that The steps include: (1) Wafer preparation: an ohmic contact layer, a current blocking layer, and a second reflector layer are sequentially grown on the surface of a GaAs-based LED wafer, and a first reflector layer and a metal adhesion layer are sequentially grown on a silicon wafer; (2) Wafer placement: Place the GaAs-based LED wafer prepared in step (1) flatly in a high temperature resistant bag with the second reflector layer facing upward, then place a wedge at the edge of the second reflector layer of the GaAs-based LED wafer, and then place the metal adhesion layer of the silicon wafer prepared in step (1) on the GaAs-based LED wafer with the metal adhesion layer facing downward, so that the wedge separates the GaAs-based LED wafer from the silicon wafer, and aligns the cut edge of the silicon wafer with the cut edge of the GaAs-based LED wafer; (3) Vacuuming and patching: Use a film sealing machine to vacuum and seal the high-temperature resistant bag to automatically complete the patching; (4) tablet pressing: placing the wafer after the bonding in step (3) on a semi-automatic tablet pressing machine for tablet pressing; (5) High temperature bonding: placing the wafer pressed in step (4) in an oven for heating to complete bonding; (6) Fabrication of tube core structure: For the wafer bonded in step (5), substrate etching, electrode extension, P-side electrode, surface roughening and grooving, silicon wafer thinning, silicon wafer N-side electrode, and tube core cutting are sequentially performed to complete the tube core fabrication.

2. A process for reducing cracks in a manual bonding process of GaAs-based light-emitting diodes according to claim 1, It is characterized in that In step (2), the shape of the wedge is a right-angled triangular prism, a side surface of the right-angled triangular prism wedge where the right-angled side is located is in contact with the second reflector layer, and a side surface of the right-angled triangular prism wedge where the hypotenuse is located is in contact with the metal adhesion layer; In step (2), the wedge is made of polytetrafluoroethylene.

3. A process for reducing cracks in a manual bonding process of GaAs-based light-emitting diodes according to claim 1, It is characterized in that In step (2), there are four wedges, two of which are placed at the end points of the cut edge of the GaAs-based LED chip, and the other two wedges are symmetrically arranged with respect to the center of the GaAs-based LED chip and the two wedges placed at the end points of the cut edge.

4. A process for reducing cracks in a manual bonding process of GaAs-based light-emitting diodes according to claim 1, It is characterized in that In step (3), the vacuuming time of the film sealing machine used is more than 30 seconds, and sealing is performed immediately after the vacuuming is completed.

5. A process for reducing cracks in a manual bonding process of GaAs-based light-emitting diodes according to claim 1, It is characterized in that In step (4), the pressure of the tablet press is 0.4-0.6 MPa, the heating temperature during tableting is 110-130° C., and the tableting time is 30-40 minutes.

6. A process for reducing cracks in a manual bonding process of GaAs-based light-emitting diodes according to claim 5, It is characterized in that In step (4), the pressure of the tablet press is 0.5 MPa, the heating temperature during tableting is 120° C., and the tableting time is 35 minutes.

7. A process for reducing cracks in a manual bonding process of GaAs-based light-emitting diodes according to claim 1, It is characterized in that In step (5), the heating temperature of the oven is 220-230° C., and the heating time is 50-60 min.

8. A process for reducing cracks in a manual bonding process of GaAs-based light-emitting diodes according to claim 7, It is characterized in that In step (5), the heating temperature of the oven is 225° C. and the heating time is 55 min.

9. A process for reducing cracks in a manual bonding process of GaAs-based light-emitting diodes according to claim 1, It is characterized in that In step (1), the material of the first reflector is TiAu, and the material of the metal adhesion layer is In.

10. A process for reducing cracks in a manual bonding process of GaAs-based light-emitting diodes according to claim 1, It is characterized in that In step (1), the GaAs-based LED wafer comprises, from bottom to top, a GaAs substrate, an N-type GaAs ohmic contact layer, an N-type confinement layer, an MQW quantum well active layer, a P-type confinement layer, a P-type GaAs ohmic contact layer, and a current spreading layer.

11. A process for reducing cracks in a manual bonding process of GaAs-based light-emitting diodes according to claim 1, It is characterized in that The structure of the ohmic contact layer on the GaAs-based LED chip is AuBe / Au, the material of the current blocking layer is SiO2, and the material of the second reflector layer is PtAu.

12. A process for reducing cracks in a manual bonding process of GaAs-based light-emitting diodes according to any one of claims 1 to 11, It is characterized in that The purity of the metals used in the ohmic contact layer and the second reflector layer of the GaAs-based LED wafer, as well as the first reflector layer and the metal adhesion layer evaporated on the silicon wafer, are all 4N grade or above.

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