Mask and preparation method of light-emitting diode

Abstract

The invention provides a mask and a preparation method of a light-emitting diode, and belongs to the technical field of photoelectron manufacturing. The mask comprises a light shielding layer and two rigid light-transmitting layers, the two rigid light-transmitting layers are located on the two opposite side faces of the light shielding layer respectively, and the light shielding layer is provided with an opening used for transmitting light. According to the embodiment of the invention, dust or foreign matters on the mask can be conveniently cleaned, and the exposure yield is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of optoelectronic manufacturing technology, and in particular to a method for preparing a mask and a light emitting diode. Background Art

[0002] Micro Light Emitting Diode (Micro LED) refers to an ultra-small light-emitting diode with a side length of 10 to 100 microns. Micro LED is small in size and can be arranged more densely to greatly improve the resolution. It also has self-luminous characteristics and is superior to LCD displays in terms of high brightness, high contrast, high responsiveness and power saving.

[0003] In the related art, when preparing a light-emitting diode, it is often necessary to prepare a photoresist layer with a pattern, and to form a film layer of a desired shape by evaporation in the opening of the photoresist layer through the photoresist layer with a pattern. The mask usually includes a light-shielding layer and a transparent film, the light-shielding layer has an opening for forming a pattern, and the transparent film covers the surface of the light-shielding layer.

[0004] During use, the transparent film is prone to dust or foreign matter, and it is difficult to clean the dust or foreign matter from the transparent film. The dust or foreign matter left on the mask will affect the exposure effect of the mask. In particular, when dust or foreign matter adheres to the opening of the mask, after the mask is exposed, the photoresist layer will be damaged at the position of the pattern, thereby affecting the etching yield. Summary of the invention

[0005] The embodiment of the present disclosure provides a method for preparing a mask and a light-emitting diode, which can facilitate the cleaning of dust or foreign matter on the mask and improve the exposure yield. The technical solution is as follows:

[0006] On the one hand, an embodiment of the present disclosure provides a mask plate, which includes: a light-shielding layer and two rigid light-transmitting layers, wherein the two rigid light-transmitting layers are respectively located on opposite sides of the light-shielding layer, and the light-shielding layer has an opening for transmitting light.

[0007] Optionally, the rigid light-transmitting layer is a quartz glass layer.

[0008] Optionally, the rigid light-transmitting layer has a thickness of 1 nm to 3 nm.

[0009] Optionally, the light shielding layer is a Cr layer.

[0010] Optionally, the light shielding layer has a thickness of 0.1 μm to 0.5 μm.

[0011] Optionally, the mask plate includes a first mask and a second mask, and the first mask and the second mask both include the light-shielding layer and two layers of the rigid light-transmitting layers sandwiching the light-shielding layer; the width of the opening of the light-shielding layer of the first mask is greater than the width of the opening of the light-shielding layer of the second mask.

[0012] Optionally, a difference between a width of an opening of the light shielding layer of the first mask and a width of an opening of the light shielding layer of the second mask is 0.5 μm to 2 μm.

[0013] On the other hand, the embodiment of the present disclosure also provides a method for preparing a light-emitting diode, the preparation method comprising: providing a product to be evaporated; forming a photoresist layer on the surface of the product to be evaporated; exposing the photoresist layer using a mask to form evaporation holes on the surface of the photoresist layer, the mask comprising: a light-shielding layer and two rigid light-transmitting layers, the two rigid light-transmitting layers are respectively located on opposite sides of the light-shielding layer, and the light-shielding layer has an opening for transmitting light; removing the mask to form a soldering pad on the surface of the evaporated product, the soldering pad being electrically connected to the evaporated product through the evaporation holes.

[0014] In one implementation of the present disclosure, the mask plate includes a first mask and a second mask, both of which include the light-shielding layer and two layers of the rigid light-transmitting layers sandwiching the light-shielding layer, and the width of the opening of the light-shielding layer of the first mask is greater than the width of the opening of the light-shielding layer of the second mask; using the mask plate to expose the photoresist layer includes: using the first mask to expose the area to be exposed of the photoresist layer; controlling the orthographic projection of the opening of the second mask on the surface of the photoresist layer to be located within the area to be exposed, and using the second mask to expose the area to be exposed again.

[0015] In another implementation of the present disclosure, a difference between a width of an opening of the light shielding layer of the first mask and a width of an opening of the light shielding layer of the second mask is 0.5 μm to 2 μm.

[0016] The beneficial effects brought by the technical solution provided by the embodiments of the present disclosure include at least:

[0017] The mask provided by the embodiment of the present disclosure includes a light-shielding layer and a rigid light-transmitting layer sandwiched between two sides of the light-shielding layer. Compared with the transparent film attached to the light-shielding layer in the related art, since the rigid light-transmitting layer has a certain hardness and is not easy to wrinkle, when dust or foreign matter falls on the mask, it can be directly wiped off from the rigid light-transmitting film, without the problem that when wiping the transparent film, the transparent film will produce wrinkles due to the external force applied by wiping, causing dust or foreign matter to remain in the wrinkles and be difficult to remove. In this way, the problem of dust sticking to the mask can be prevented, thereby improving the exposure yield of the mask and improving the production efficiency of light-emitting diodes. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 is a structural schematic diagram of a mask provided by an embodiment of the present disclosure;

[0020] Figure 2 is a structural schematic diagram of a mask provided by an embodiment of the present disclosure;

[0021] Figure 3 is a structural schematic diagram of a mask provided by an embodiment of the present disclosure;

[0022] Figure 4 is a flow chart of manufacturing a light emitting diode provided by an embodiment of the present disclosure;

[0023] Figure 5 It is a schematic structural diagram of a product to be evaporated provided in an embodiment of the present disclosure.

[0024] The descriptions of the marks in the figure are as follows:

[0025] 10. Substrate;

[0026] 20. epitaxial layer; 21. first semiconductor layer; 22. active layer; 23. second semiconductor layer;

[0027] 30. Electrode;

[0028] 40. Passivation layer;

[0029] 61, light shielding layer; 610, opening; 62, rigid light-transmitting layer; 620, cavity; 621, air blowing hole;

[0030] 601, first mask; 602, second mask. DETAILED DESCRIPTION

[0031] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0032] Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by persons with ordinary skills in the field to which the present disclosure belongs. The words "first", "second", "third" and similar words used in the patent application specification and claims of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "one" do not indicate a quantity limitation, but indicate the existence of at least one. Words such as "include" or "comprise" and similar words mean that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. Words such as "connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right", "top", "bottom" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0033] Figure 1 Schematic diagram of the structure of a mask provided by an embodiment of the present disclosure. Figure 1 As shown, the mask includes: a light shielding layer 61 and two rigid light-transmitting layers 62 . The two rigid light-transmitting layers 62 are respectively located on two opposite sides of the light shielding layer 61 . The light shielding layer 61 has an opening 610 for light transmission.

[0034] The mask provided by the embodiment of the present disclosure includes a light shielding layer 61 and a rigid light-transmitting layer 62 sandwiched between two sides of the light shielding layer 61. Compared with the transparent film attached to the light shielding layer 61 in the related art, since the rigid light-transmitting layer 62 has a certain hardness and is not easy to wrinkle, when dust or foreign matter falls on the mask, it can be directly wiped off from the rigid light-transmitting film, and there will be no problem that when wiping the transparent film, the transparent film will produce wrinkles due to the external force applied by wiping, causing dust or foreign matter to remain in the wrinkles and be difficult to remove. In this way, the problem of easy dust adhesion of the mask can be prevented, thereby improving the exposure yield of the mask and improving the production efficiency of light-emitting diodes.

[0035] Optionally, the rigid light-transmitting layer 62 may be made of a material layer with a hardness of Mohs hardness level 7. Such a rigid light-transmitting layer 62 has high scratch resistance, wear resistance and impact resistance and is not easily damaged.

[0036] Optionally, the rigid light-transmitting layer 62 is a quartz glass layer.

[0037] Since quartz glass has good hardness, it is not easy to deform or wrinkle after wiping, making the mask easy to clean. At the same time, quartz glass has good light transmittance, so although adding quartz glass increases the overall thickness of the mask, quartz glass will not block too much light to ensure the exposure effect.

[0038] Optionally, the thickness of the rigid light-transmitting layer 62 is 1 nm to 3 nm.

[0039] By controlling the thickness of the rigid light-transmitting layer 62 within the above range, it is possible to avoid the rigid light-transmitting layer 62 being too thick and absorbing more exposure light; and it is also possible to avoid the rigid light-transmitting layer 62 being too thin and causing brittle fracture of the rigid light-transmitting layer.

[0040] Exemplarily, the thickness of the rigid light-transmitting layer 62 is 2 nm.

[0041] Optionally, the light shielding layer 61 is a Cr layer. Metal Cr has a good light shielding effect, which can prevent light from penetrating the light shielding layer 61 during exposure and affecting the exposure effect.

[0042] Optionally, the thickness of the light shielding layer 61 is 0.1 μm to 0.5 μm.

[0043] By controlling the thickness of the shading layer 61 within the above range, it is possible to avoid the shading layer 61 being too thick, which would increase the cost of preparing the mask; and it is also possible to avoid the shading layer 61 being too thin, which would deteriorate the shading effect of the shading layer 61 and cause light to penetrate the shading layer 61 to affect the exposure effect.

[0044] Exemplarily, the thickness of the light shielding layer 61 is 0.2 μm.

[0045] Figure 2 Schematic diagram of the structure of a mask provided by an embodiment of the present disclosure. Figure 2 As shown, the mask plate includes a first mask 601 and a second mask 602 , and the first mask 601 and the second mask 602 both include a light shielding layer 61 and two rigid light-transmitting layers 62 sandwiching the light shielding layer 61 .

[0046] like Figure 2 As shown, the width L1 of the opening 610 of the light shielding layer 61 of the first mask 601 is greater than the width L2 of the opening 610 of the light shielding layer 61 of the second mask 602 .

[0047] In the disclosed embodiment, the mask is a structure used for vapor deposition of pads. Before use, a photoresist layer needs to be formed on the surface of the product to be vapor deposited, and then the mask is used to expose the photoresist layer.

[0048] In the above implementation, by setting the mask plate as the first mask 601 and the second mask 602, the first mask 601 is first used to expose the photoresist layer, and the area to be exposed of the photoresist layer is initially exposed; then, the second mask 602 with a smaller width of the opening 610 is used to perform a secondary exposure on the area to be exposed that has been initially exposed. Since it is difficult for two masks to adhere to dust or foreign matter in the same area, when the first mask 601 is stained with dust or foreign matter, the second mask 602 is used to expose a smaller range of the area to be exposed, thereby overcoming the defects existing in the first light exposure.

[0049] Alternatively, if Figure 2 As shown, the difference between the width of the opening 610 of the light shielding layer 61 of the first mask 601 and the width of the opening 610 of the light shielding layer 61 of the second mask 602 is 0.5 μm to 2 μm.

[0050] By reducing the width of the opening 610 of the light-shielding layer 61 of the second mask 602, when the second mask 602 is used for exposure, since the opening 610 of the second mask 602 is smaller in size, the opening 610 of the second mask 602 can be directly opposite the exposure area, without the need to place the first mask 601 according to the placement position of the first mask 601, that is, the step of positioning the first mask 601 according to the placement position of the first mask 601 is omitted, which can effectively reduce the difficulty of secondary exposure.

[0051] Exemplarily, the difference between the width of the opening 610 of the light shielding layer 61 of the first mask 601 and the width of the opening 610 of the light shielding layer 61 of the second mask 602 is 1 μm.

[0052] Figure 3 Schematic diagram of the structure of a mask provided by an embodiment of the present disclosure. Figure 3 As shown, the rigid light-transmitting layer 62 has a cavity 620 inside, and the surface of the rigid light-transmitting layer 62 away from the light-shielding layer 61 has a plurality of blowing holes 621 , and one end of each blowing hole 621 is connected to the cavity 620 .

[0053] Exemplarily, the blowing holes 621 may be arranged at the edge region of the rigid light-transmitting layer 62 .

[0054] When cleaning dust or foreign matter from the rigid light-transmitting layer, an air pump can be used to blow air through any one or more of the blowing holes to allow air to enter the cavity, and then the dust or foreign matter attached to the surface of the rigid light-transmitting layer away from the light-shielding layer can be blown upward from each blowing hole in the cavity, thereby quickly cleaning the dust or foreign matter and improving the cleaning efficiency of the mask.

[0055] Figure 4 FIG. 1 is a flow chart of manufacturing a light emitting diode according to an embodiment of the present disclosure. Figure 4As shown, the preparation method comprises:

[0056] Step 101: Provide a product to be evaporated.

[0057] Figure 5 Schematic diagram of the structure of a product to be evaporated provided by an embodiment of the present disclosure. Figure 5 As shown, the product to be evaporated may include a substrate 10, an epitaxial layer 20, an electrode 30 and a passivation layer 40, the epitaxial layer 20 is located on the surface of the substrate 10, the electrode 30 is located on the surface of the epitaxial layer 20, and the electrode 30 is electrically connected to the epitaxial layer 20, the passivation layer 40 is located on the surface of the epitaxial layer 20, and the passivation layer 40 covers the electrode 30, and the surface of the passivation layer 40 has a through hole exposing the electrode 30.

[0058] Exemplarily, the epitaxial layer 20 may include a first semiconductor layer 21, an active layer 22, and a second semiconductor layer 23 sequentially stacked on the substrate 10. The first semiconductor layer 21 has a first conductivity type, the second semiconductor layer 23 has a second conductivity type different from the first conductivity type, and the active layer 22 is used to generate light through electron-hole recombination.

[0059] Step 102: forming a photoresist layer on the surface of the product to be evaporated.

[0060] Step 103: Expose the photoresist layer using a mask to form evaporation holes on the surface of the photoresist layer.

[0061] like Figure 1 As shown, the mask plate includes: a light shielding layer 61 and two rigid light-transmitting layers 62 . The two rigid light-transmitting layers 62 are respectively located on two opposite sides of the light shielding layer 61 . The light shielding layer 61 has an opening 610 for light transmission.

[0062] Step 104: remove the mask, and form a pad on the surface of the vapor-deposited product, wherein the pad is electrically connected to the vapor-deposited product through the vapor-deposited hole.

[0063] The mask provided by the embodiment of the present disclosure includes a light shielding layer 61 and a rigid light-transmitting layer 62 sandwiched between two sides of the light shielding layer 61. Compared with the transparent film attached to the light shielding layer 61 in the related art, since the rigid light-transmitting layer 62 has a certain hardness and is not easy to wrinkle, when dust or foreign matter falls on the mask, it can be directly wiped off from the rigid light-transmitting film, and there will be no problem that when wiping the transparent film, the transparent film will produce wrinkles due to the external force applied by wiping, causing dust or foreign matter to remain in the wrinkles and be difficult to remove. In this way, the problem of easy dust adhesion of the mask can be prevented, thereby improving the exposure yield of the mask and improving the production efficiency of light-emitting diodes.

[0064] In step 101 , one of the first semiconductor layer 21 and the second semiconductor layer 23 is a p-type layer, and the other of the first semiconductor layer 21 and the second semiconductor layer 23 is an n-type layer.

[0065] As an example, the first semiconductor layer 21 is a p-type layer, and the second semiconductor layer 23 is an n-type layer.

[0066] The production of the product to be evaporated can include the following steps:

[0067] The first step is to provide a GaAs wafer.

[0068] In the second step, a second semiconductor layer, an active layer and a first semiconductor layer are grown in sequence on the GaAs wafer.

[0069] For example, the second semiconductor layer may be an n-type AlGaInP layer, and the thickness of the n-type AlGaInP layer may be 0.5 μm to 3 μm.

[0070] Exemplarily, the first semiconductor layer is an indium-doped p-type AlInP layer, and the thickness of the p-type AlInP layer may be 0.5 μm to 3 μm.

[0071] Optionally, the active layer includes an AlGaInP quantum well layer and an AlGaInP quantum barrier layer grown alternately. The Al content in the AlGaInP quantum well layer and the AlGaInP quantum barrier layer is different. The active layer may include 3 to 8 periods of AlGaInP quantum well layers and AlGaInP quantum barrier layers stacked alternately.

[0072] As an example, in the embodiment of the present disclosure, the active layer includes five periods of AlGaInP quantum well layers and AlGaInP quantum barrier layers that are alternately stacked.

[0073] Optionally, the thickness of the active layer may be 150 nm to 200 nm.

[0074] In the second step, an etching stop layer may be grown before growing the second semiconductor layer, and an AlInP carrier confinement layer may be grown before growing the active layer.

[0075] A GaP window layer may be further grown after the first semiconductor layer is grown, wherein the thickness of the GaP window layer is 10,000 angstroms to 50,000 angstroms.

[0076] Exemplarily, the GaP window layer has a thickness of 40,000 angstroms.

[0077] In the third step, a bonding layer is formed between the first semiconductor layer and the sapphire substrate 10, the epitaxial layer is bonded to the sapphire substrate 10, and the GaAs sheet is removed.

[0078] Since the sapphire substrate 10 has a relatively high light transmittance, and the sapphire material is relatively hard and has relatively stable chemical properties, the use of the sapphire substrate 10 can enable the light-emitting diode to have good light-emitting effect and stability.

[0079] Specifically, the process may include: coating silicon oxide liquid on the surface of the second semiconductor layer, placing the sapphire substrate 10 on the surface of the second semiconductor layer, and heating the epitaxial layer to heat and solidify the silicon oxide liquid to form a bonding layer between the second semiconductor layer and the sapphire substrate 10 .

[0080] Optionally, the heating temperature of the epitaxial layer is 250° C. to 350° C. Exemplarily, the heating temperature may be 300° C.

[0081] In step 101 , after forming the epitaxial layer 20 on the substrate 10 , the preparation method may further include: etching the surface of the second semiconductor layer 23 to form a groove exposing the first semiconductor layer 21 . The epitaxial layer 20 is etched to expose the substrate 10 .

[0082] In the fourth step, the electrode 30 is evaporated on the surface of the second semiconductor layer 23 and in the groove.

[0083] The electrode 30 in the groove may have the same conductivity type as the first semiconductor layer 21. For example, if the first semiconductor layer 21 is an n-type layer, the electrode 30 in the groove may be an n-electrode 30.

[0084] The electrode 30 located on the surface of the second semiconductor layer 23 has the same conductivity type as the second semiconductor layer 23. For example, if the second semiconductor layer 23 is a p-type layer, the electrode 30 located on the second semiconductor layer 23 may be a p-electrode 30.

[0085] The evaporation electrode 30 on the surface of the product to be evaporated may specifically include: sequentially evaporating to form an Au layer, an AuGe layer and a Pt layer on the surface of the product to be evaporated.

[0086] Optionally, the electrode 30 includes an Au layer, an AuGe layer, and a Pt layer stacked in sequence.

[0087] Optionally, the thickness of the Au layer is 80 angstroms to 150 angstroms. The Au layer has good electrical conductivity, and setting the metal layer in contact between the electrode 30 and the epitaxial layer 20 as the Au layer can improve the ohmic contact effect between the electrode 30 and the epitaxial layer 20 .

[0088] Illustratively, the Au layer has a thickness of 100 angstroms.

[0089] Optionally, the thickness of the AuGe layer is 800 angstroms to 1500 angstroms. The AuGe layer also has good conductivity, and due to the addition of Ge metal, the ohmic contact can be improved, and the amount of Au metal used can be reduced, thereby reducing the preparation cost of the electrode 30.

[0090] Illustratively, the AuGe layer has a thickness of 1000 angstroms.

[0091] Optionally, the Pt layer has a thickness of 450 angstroms to 600 angstroms.

[0092] The last metal layer of the electrode 30 is set as a Pt layer, and the Pt layer covers the AuGe layer. In this way, the Pt layer can effectively prevent the Ge element from diffusing upward during annealing, thereby ensuring the total amount of elements diffused into the semiconductor, so that the electrode 30 can achieve a better ohmic contact effect.

[0093] Illustratively, the thickness of the Pt layer is 500 angstroms.

[0094] In a fifth step, a passivation layer 40 is formed on the surface of the second semiconductor layer 23 and in the groove. The passivation layer 40 is located on the surface of the electrode 30 .

[0095] The manufactured passivation layer 40 is at least located in the second semiconductor layer 23, the electrode 30 and the groove.

[0096] Optionally, the passivation layer 40 includes a silicon oxide layer.

[0097] When preparing the passivation layer 40, the deposition temperature of the passivation layer 40 is controlled to be 150° C. to 250° C., and the deposition rate of the passivation layer 40 is controlled to be 15 angstroms / second to 25 angstroms / second. The passivation layer 40 prepared according to this process can release stress and improve the preparation quality of the light-emitting diode.

[0098] Exemplarily, the deposition temperature of the passivation layer 40 is 200° C., and the deposition rate of the passivation layer 40 is 20 angstroms / second.

[0099] For example, the thickness of the passivation layer 40 may be 3000 angstroms to 6000 angstroms. For example, the thickness of the passivation layer 40 is 5000 angstroms.

[0100] In the sixth step, two via holes are made on the passivation layer 40 to expose the two electrodes 30 respectively.

[0101] Specifically, the method may include: forming a photoresist layer on the surface of the passivation layer 40 , opening a hole in the photoresist layer in a region corresponding to the via hole, and then etching the passivation layer 40 with a buffered oxide etching solution to form the via hole on the passivation layer 40 .

[0102] The buffered oxide etching solution is a mixture of hydrofluoric acid and water, or a mixture of ammonium fluoride and water.

[0103] Optionally, the mask plate includes a first mask 601 and a second mask 602, each of which includes a light-shielding layer 61 and two rigid light-transmitting layers 62 sandwiching the light-shielding layer 61, and the width of the opening 610 of the light-shielding layer 61 of the first mask 601 is greater than the width of the opening 610 of the light-shielding layer 61 of the second mask 602.

[0104] In the disclosed embodiment, the mask is a structure used for evaporating the pad. Before use, a photoresist layer needs to be formed on the surface of the passivation layer 40 and then exposed using a mask.

[0105] Alternatively, if Figure 2 As shown, the difference between the width of the opening 610 of the light shielding layer 61 of the first mask 601 and the width of the opening 610 of the light shielding layer 61 of the second mask 602 is 0.5 μm to 2 μm.

[0106] By reducing the width of the opening 610 of the light-shielding layer 61 of the second mask 602, when the second mask 602 is used for exposure, since the opening 610 of the second mask 602 is smaller in size, the opening 610 of the second mask 602 can be directly opposite the exposure area, without the need to place the first mask 601 according to the placement position of the first mask 601, that is, the step of positioning the first mask 601 according to the placement position of the first mask 601 is omitted, which can effectively reduce the difficulty of secondary exposure.

[0107] Exemplarily, the difference between the width of the opening 610 of the light shielding layer 61 of the first mask 601 and the width of the opening 610 of the light shielding layer 61 of the second mask 602 is 1 μm.

[0108] Exposing the photoresist layer using a mask in step 103 may include:

[0109] First, the first mask 601 is used to expose the area to be exposed of the photoresist layer.

[0110] Exemplarily, when the photoresist layer is a positive photoresist, the area to be exposed is opposite to the through hole on the passivation layer 40 .

[0111] Exemplarily, when the photoresist layer is a negative photoresist layer, the orthographic projection of the area to be exposed on the passivation layer 40 is located outside the through hole.

[0112] Then, the orthographic projection of the opening 610 of the second mask 602 on the surface of the photoresist layer is controlled to be located in the area to be exposed, and the area to be exposed is exposed again using the second mask 602 .

[0113] In the above implementation, by setting the mask plate as the first mask 601 and the second mask 602, the first mask 601 is first used to expose the photoresist layer, and the area to be exposed of the photoresist layer is initially exposed; then, the second mask 602 with a smaller width of the opening 610 is used to perform a secondary exposure on the area to be exposed that has been initially exposed. Since it is difficult for two masks to adhere to dust or foreign matter in the same area, when the first mask 601 is stained with dust or foreign matter, the second mask 602 is used to expose a smaller range of the area to be exposed, thereby overcoming the defects existing in the first light exposure.

[0114] In the embodiment of the present disclosure, after the photoresist layer is exposed, it can be heated on a hot plate at 100 degrees for 3 minutes, and then developed. After development, it should be baked in an oven at 100 degrees for 10 minutes to harden the photoresist layer.

[0115] Optionally, the pad evaporated on the surface of the passivation layer 40 is connected to the electrode 30 through a via hole.

[0116] Specifically, it may include: sequentially evaporating a Cr layer, an Al layer, a Ti layer, a Ni layer and an Au layer on the surface of the passivation layer 40 to form a pad on the surface of the passivation layer 40 .

[0117] The pad is connected to the electrode 30 through a via hole.

[0118] Exemplarily, the thickness of the Cr layer is 50 angstroms to 150 angstroms. For example, the thickness of the Cr layer is 100 angstroms.

[0119] Exemplarily, the thickness of the Al layer is 2500 angstroms to 3500 angstroms. For example, the thickness of the Al layer is 3000 angstroms.

[0120] Exemplarily, the thickness of the Ti layer is 400 angstroms to 600 angstroms. For example, the thickness of the Ti layer is 500 angstroms.

[0121] Exemplarily, the thickness of the Ni layer is 1000 angstroms to 3000 angstroms. For example, the thickness of the Ni layer is 2000 angstroms.

[0122] Exemplarily, the thickness of the Au layer is 15000 angstroms to 25000 angstroms. For example, the thickness of the Au layer is 20000 angstroms.

[0123] After the pad is prepared, a protection layer is formed on the surface of the passivation layer 40 , and the protection layer extends from the surface of the passivation layer 40 to the substrate 10 .

[0124] Illustratively, in the embodiment of the present disclosure, the protective layer may be a silicon oxide layer, and the thickness of the silicon oxide layer is 2000 angstroms.

[0125] It should be noted that after the protective layer is grown on the surface of the passivation layer 40 , a through hole exposing the pad can be etched on the surface of the protective layer using photolithography technology to facilitate electrical connection.

[0126] Finally, the sapphire can be cut and scratched by invisible cutting, which can effectively reduce the loss of brightness. Then, the light-emitting diode is obtained by testing.

[0127] The above description is only an optional embodiment of the present disclosure and is not intended to limit the present disclosure. The data therein only represent illustrative examples. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A mask, characterized in that: The mask plate comprises: a light-shielding layer (61) and two rigid light-transmitting layers (62), wherein the two rigid light-transmitting layers (62) are respectively located on two opposite sides of the light-shielding layer (61), and the light-shielding layer (61) has an opening (610) for light transmission.

2. The mask according to claim 1, characterized in that: The rigid light-transmitting layer (62) is a quartz glass layer.

3. The mask according to claim 2, characterized in that: The thickness of the rigid light-transmitting layer (62) is 1 nm to 3 nm.

4. The mask according to any one of claims 1 to 3, characterized in that: The light shielding layer (61) is a Cr layer.

5. The mask according to claim 4, characterized in that: The thickness of the light shielding layer (61) is 0.1 μm to 0.5 μm.

6. The mask according to any one of claims 1 to 3, characterized in that: The mask plate comprises a first mask (601) and a second mask (602), and the first mask (601) and the second mask (602) both comprise the light shielding layer (61) and two layers of the rigid light-transmitting layers (62) sandwiching the light shielding layer (61); The width of the opening (610) of the light shielding layer (61) of the first mask (601) is greater than the width of the opening (610) of the light shielding layer (61) of the second mask (602).

7. The mask according to claim 6, characterized in that: The difference between the width of the opening (610) of the light shielding layer (61) of the first mask (601) and the width of the opening (610) of the light shielding layer (61) of the second mask (602) is 0.5 μm to 2 μm.

8. A method for preparing a light emitting diode, characterized in that: The preparation method comprises: Providing a product to be evaporated; forming a photoresist layer on the surface of the product to be evaporated; The photoresist layer is exposed using a mask to form a vapor deposition hole on the surface of the photoresist layer, wherein the mask comprises: a light shielding layer and two rigid light-transmitting layers, wherein the two rigid light-transmitting layers are respectively located on opposite sides of the light shielding layer, and the light shielding layer has an opening for light transmission; The mask is removed, and a pad is formed on the surface of the vapor-deposited product, wherein the pad is electrically connected to the vapor-deposited product through the vapor-deposited hole.

9. The preparation method according to claim 8, characterized in that: The mask plate comprises a first mask and a second mask, the first mask and the second mask both comprise the light shielding layer and two layers of the rigid light-transmitting layers sandwiching the light shielding layer, and the width of the opening of the light shielding layer of the first mask is greater than the width of the opening of the light shielding layer of the second mask; Exposing the photoresist layer using a mask includes: Exposing the to-be-exposed area of ​​the photoresist layer using the first mask; The orthographic projection of the opening of the second mask on the surface of the photoresist layer is controlled to be located within the area to be exposed, and the area to be exposed is exposed again using the second mask.

10. The preparation method according to claim 9, characterized in that: A difference between a width of an opening of the light shielding layer of the first mask and a width of an opening of the light shielding layer of the second mask is 0.5 μm to 2 μm.

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