A method for fabricating a light emitting diode chip

Abstract

The application discloses a preparation method of a light emitting diode chip, which comprises the following steps of: preparing an ITO layer on an epitaxial wafer, growing an Al2O3 layer, depositing a SiN x layer, spin-coating a positive photoresist mask layer, carbonizing the photoresist mask layer by means of high-energy ion beam bombardment to form nanoscale mountain-shaped textures, etching the SiN x passivation layer and the carbonized photoresist mask layer distributed on the surface of the SiN x layer to form nanoscale mountain-shaped textures, and finally, selectively etching the epitaxial wafer to the n-GaN layer to form a step, and depositing p-type and n-type metal electrodes to obtain an LED device with nanoscale mountain-shaped textures formed on the surface. The method can improve the light emitting efficiency of the LED device and is also beneficial to improving the anti-static capability of the LED device.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor chip manufacturing, and more particularly, to a method for manufacturing a light emitting diode chip. Background Art

[0002] A light-emitting diode (LED) is a semiconductor electronic device that converts electrical energy into light energy. LEDs are widely used in lighting, mobile phone / TV backlight displays, and sterilization and disinfection due to their low operating voltage, low operating current, good shock and vibration resistance, high reliability, long life, and environmental friendliness.

[0003] With the rapid development of third-generation semiconductor technology, semiconductor LED lighting, with its advantages of energy saving, environmental protection, high brightness, and long life, has become a focus of social development. In recent years, LED performance has significantly improved, and production costs have continued to decline, making a significant contribution to the widespread adoption of semiconductor lighting in thousands of households. However, to accelerate the application of high-end applications such as sterilization and disinfection, as well as mobile phone and TV backlighting, LED devices need to further improve their luminous efficiency. How to further enhance the luminous efficiency of LED chips is a hot research topic in this field.

[0004] Therefore, improving the luminous efficiency of light-emitting diodes is an urgent problem to be solved in this field. Summary of the Invention

[0005] The present invention aims to provide a method for fabricating a light-emitting diode chip to improve the light extraction efficiency and anti-static properties of LED devices. This technical solution does not require nanoscale photolithography, is simple to manufacture, is low-cost, and is compatible with traditional manufacturing processes, making it suitable for industrial applications.

[0006] The present invention discloses a method for manufacturing a light emitting diode chip, which is characterized by comprising the following steps:

[0007] Step 1: Using sputtering coating method to make ITO layer on epitaxial wafer;

[0008] Step 2: Using atomic layer deposition to grow an Al2O3 layer on the ITO layer to improve the light transmittance of the material layer;

[0009] Step 3: Deposit SiN on the Al2O3 layer using plasma enhanced chemical vapor deposition x The SiN layer is used as a passivation layer to reduce the leakage current of the device and prevent the device from oxidation failure. x During the deposition process of the SiN layer, the flow ratio of SiH4 and NH3 is controlled to increase gradually to improve the SiN x Density and uniformity of the membrane material;

[0010] Step 4: In SiN x Spin-coating a positive photoresist mask layer on the layer;

[0011] Step 5: bombarding the photoresist mask layer with a high-energy ion beam of ion beam etching to carbonize the photoresist mask layer, and forming a nanoscale mountain-like texture on the surface of the photoresist mask layer after carbonization;

[0012] Step 6: Etch SiN using dry etching method x The passivation layer and the carbonized photoresist mask layer covering it are used to transfer the nanoscale mountain texture pattern on the surface of the carbonized photoresist mask layer to the SiN x layer surface, on the SiN x The surface distribution of the layer forms a nanoscale mountain-like texture;

[0013] Step 7: Selectively etch the epitaxial wafer to the n-GaN layer by ICP etching;

[0014] Step 8: Deposit p-type and n-type metal electrodes, and finally obtain an LED device with a nano-scale mountain-like texture on the surface. The nano-scale mountain-like texture increases the scattering effect on the surface of the LED device to reduce the internal Fresnel reflection and the total internal reflection of the top interface, thereby improving the light output efficiency of the LED device.

[0015] Furthermore, the thickness of the ITO layer in step 1 is 100-300 nm.

[0016] Furthermore, the thickness of the Al2O3 layer in step 2 is 5-20 nm.

[0017] Furthermore, the step 3 of depositing SiN x Layer, further:

[0018] The temperature is controlled at 200-300℃, the RF power is 50-70W, the flow ratio of SiH4 to NH3 is gradually increased from 1:2 to 2:1, the N2 gas flow rate is 800-1200sccm, and a 1-2um thick SiN layer is deposited on the Al2O3 layer. x layer, where X ranges from 0.05 to 1.

[0019] Furthermore, the thickness of the positive photoresist mask layer in step 4 is 1-3 μm.

[0020] Furthermore, the nanoscale mountain-like texture in step five is further as follows: the distance between two adjacent mountain-like textures is 200-1200 nm.

[0021] Furthermore, in step six, the SiN xThe surface of the layer is distributed to form a nano-scale mountain-like texture, further comprising: a distance between two adjacent mountain-like textures is 200-900 nm, and a height of the mountain-like texture is 200-700 nm.

[0022] Compared with the prior art, the method for preparing a light-emitting diode chip of the present invention achieves the following beneficial effects:

[0023] 1. Compared with growing SiN directly on the ITO layer x Thin film layer, the present invention first grows Al2O3 layer on the ITO layer, and then grows SiN x The layer can improve the light transmittance of the material layer and improve the light extraction efficiency of the LED. This is because SiH4 gas is used to deposit SiN on ITO by PECVD. x When the Al2O3 layer is grown on the ITO layer, H-containing free radicals will reduce In2O3 to metallic In on the film surface, resulting in a decrease in the transmittance of the ITO layer in the visible light range. The present application can effectively avoid the problem of decreased transmittance by growing an Al2O3 layer on the ITO layer.

[0024] 2. Through SiN x During the deposition process of the SiN layer, the flow rate ratio of SiH4 and NH3 is gradually increased, which can improve the x The density and uniformity of the film material, thereby improving the SiN x The refractive index of the film layer makes SiN x The refractive index of the film layer is close to that of the ITO layer, thereby reducing the total internal reflection of light and reducing the photons emitted from the active area from the ITO layer to the SiN layer. x The light loss of the layer is reduced, so that the light extraction efficiency of the LED device is improved.

[0025] 3. The technical solution of the method of the present invention is to use high energy ions to bombard the photoresist to carbonize and form a nano texture as a mask pattern, directly on the SiN x The passivation layer is dry-etched to create a nanoscale, mountainous texture on the LED surface. This texture enhances the scattering effect on the LED surface, reducing internal Fresnel reflection and total internal reflection at the top interface, thereby improving the LED's light output efficiency. Because the nanotexture is achieved on the LED's surface passivation layer, this new self-masking surface roughening solution causes minimal damage to the device and helps improve the LED's anti-static capabilities.

[0026] 4. The technical solution of this application does not require nano-scale lithography, has a simple process, low cost, and is compatible with traditional manufacturing processes, making it very suitable for industrial applications.

[0027] Of course, any product implementing the present invention does not necessarily need to achieve all of the technical effects described above at the same time.

[0028] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0030] Figure 1 This is step 1 of the light emitting diode according to an embodiment of the present application.

[0031] Figure 2 This is step 2 of the light emitting diode according to the embodiment of the present application.

[0032] Figure 3 This is step three of the light emitting diode of the embodiment of the present application.

[0033] Figure 4 This is step 4 of the light emitting diode according to the embodiment of the present application.

[0034] Figure 5 This is step five of the light emitting diode manufacturing process according to the embodiment of the present application.

[0035] Figure 6 This is step six of the light emitting diode of the embodiment of the present application.

[0036] Figure 7 Shown are steps seven to eight of the light emitting diode of the embodiment of the present application.

[0037] Illustration: 1. Epitaxial wafer, 2. ITO layer, 3. Al2O3 layer, 4. SiN x layer, 5, photoresist mask layer, 6, P-type metal electrode, 7, N-type metal electrode. DETAILED DESCRIPTION

[0038] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention.

[0039] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0040] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0041] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0042] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0043] The method for preparing a light-emitting diode chip described in this embodiment includes the following steps:

[0044] Step 101: A 100-300 nm thick ITO layer 2 is formed on the epitaxial wafer 1 by a sputtering coating method to enhance current spreading.

[0045] Step 102: Using an atomic layer deposition method, a 5-20 nm thick Al2O3 layer 3 is grown on the ITO layer 2 to improve the light transmittance of the material layer and enhance the light extraction efficiency of the LED.

[0046] Step 103: Deposit 1-2 μm thick SiN on the Al2O3 layer 3 using plasma enhanced chemical vapor deposition. x Layer 4 is used as a passivation layer to reduce the leakage current of the device and prevent the device from oxidation failure. x Layer 4, further includes:

[0047] The temperature is controlled at 200-300℃, the RF power is 50-70W, the flow ratio of SiH4 to NH3 is gradually increased from 1:2 to 2:1, the N2 gas flow rate is 800-1200sccm, and a 1-2um thick SiN layer is deposited on the Al2O3 layer 3. x Layer 4, where X ranges from 0.05 to 1.

[0048] By controlling SiN x During the deposition of layer 4, the flow ratio of SiH4 to NH3 gradually increases to improve the SiN x The density and uniformity of the film material, thereby improving the SiN x The refractive index of the film 4 makes SiN x The refractive index of the film layer 4 is close to that of the ITO layer 2, thereby reducing the total internal reflection of light and reducing the photons emitted from the active area from the ITO layer 2 to the SiN layer. x The light loss of layer 4 improves the light extraction efficiency of the LED device.

[0049] Step 104: In SiN x A 1-3 μm thick positive photoresist mask layer 5 is spin-coated on the layer 4 .

[0050] Step 105: bombarding the photoresist mask layer 5 with a high-energy ion beam of ion beam etching to carbonize the photoresist mask layer 5. After carbonization, a nanoscale mountain-like texture is formed on the surface of the photoresist mask layer 5, wherein the distance between two adjacent mountain-like textures is 200-1200 nm.

[0051] Step 106: Etch SiN using dry etching method x layer 4 and the carbonized photoresist mask layer 5 covering it, so as to transfer the nanoscale mountain texture pattern on the surface of the carbonized photoresist mask layer to the SiN x layer surface, on the SiN x The surface of the layer is distributed to form a nanoscale mountain-like texture, where the distance between two adjacent mountain-like textures is 200-900nm, and the height of the mountain-like texture is 200-700nm. This nanoscale mountain-like texture can reduce internal Fresnel reflection and total internal reflection at the top interface by increasing the scattering effect on the surface of the LED device, thereby improving light extraction efficiency.

[0052] Step 107 : selectively etching the epitaxial wafer to the n-GaN layer by ICP etching to form a step.

[0053] Step 108 : depositing a p-type metal electrode 6 and an n-type metal electrode 7 , and finally obtaining an LED device having a nanoscale mountain-like texture on the surface.

[0054] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A method for manufacturing a light-emitting diode chip, comprising the following steps: Step 1: Using sputtering coating method to make ITO layer on epitaxial wafer; Step 2: growing an Al2O3 layer on the ITO layer using an atomic layer deposition method; Step 3: Deposit SiN on the Al2O3 layer using plasma enhanced chemical vapor deposition x layer as a passivation layer, wherein SiN x During the layer deposition process, the flow ratio of SiH4 and NH3 is controlled to increase gradually; Step 4: In SiN x Spin-coating a positive photoresist mask layer on the layer; Step 5: bombarding the photoresist mask layer with a high-energy ion beam of ion beam etching to carbonize the photoresist mask layer, and forming a nanoscale mountain-like texture on the surface of the photoresist mask layer after carbonization; Step 6: Etch SiN using dry etching method x The passivation layer and the carbonized photoresist mask layer covering it are used to transfer the nanoscale mountain texture pattern on the surface of the carbonized photoresist mask layer to the SiN x layer surface, on the SiN x The surface distribution of the layer forms a nanoscale mountain-like texture; Step 7: Etch the epitaxial wafer to the n-GaN layer by ICP etching to form a step; Step 8: Deposit p-type and n-type metal electrodes, and finally obtain an LED device with a nanoscale mountain-like texture on the surface.

2. The method for manufacturing a light emitting diode chip according to claim 1, wherein: The thickness of the ITO layer in step 1 is 100-300 nm.

3. The method for manufacturing a light emitting diode chip according to claim 1, wherein: The thickness of the Al2O3 layer in step 2 is 5-20 nm.

4. The method for manufacturing a light emitting diode chip according to claim 1, wherein: The deposition of SiN in step 3 x Layer, further: The temperature is controlled at 200-300℃, the RF power is 50-70W, the flow ratio of SiH4 to NH3 is gradually increased from 1:2 to 2:1, the N2 gas flow rate is 800-1200sccm, and a 1-2um thick SiN layer is deposited on the Al2O3 layer. x layer, where X ranges from 0.05 to 1.

5. The method for manufacturing a light emitting diode chip according to claim 1, wherein: The thickness of the positive photoresist mask layer in step 4 is 1-3 μm.

6. The method for manufacturing a light emitting diode chip according to claim 1, wherein: The nanoscale mountain-like texture in step five is further characterized in that the distance between two adjacent mountain-like textures is 200-1200 nm.

7. The method for manufacturing a light emitting diode chip according to claim 1, wherein: The SiN x The surface of the layer is distributed to form a nano-scale mountain-like texture, further comprising: a distance between two adjacent mountain-like textures is 200-900 nm, and a height of the mountain-like texture is 200-700 nm.

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