LED chip and method for manufacturing LED chip

Abstract

The invention discloses an LED chip and a method for manufacturing the LED chip. The method comprises the following steps: polishing, wet cleaning, photolithography, ion implantation, etching, plasma washing, heat treatment, chemical vapor deposition, physical vapor deposition, electroplating, surface treatment, and testing and packaging. In step 10, a platinum-titanium mesh material is used for electroplating. In step 5, etching comprises dry etching and wet etching. The dry etching is to remove some unnecessary shapes previously photoetched by plasma. The wet etching is to further clean a silicon wafer by using a reagent. In step 11, after impurities and photoresist remaining on the surface of the silicon wafer are stripped off, the surface of the silicon wafer is repeatedly cleaned. After the electroplating is completed, the impurities and photoresist remaining on the surface of the silicon wafer are stripped off again, so as to avoid the phenomenon of difficult solder joints and cold solder joints on the front side or high voltage drop and breakdown on the back side.

Description

Technical Field

[0001] The present invention relates to the field of LED chips, and in particular to an LED chip and a method for manufacturing the LED chip. Background Art

[0002] An LED chip is a solid-state semiconductor device. The heart of an LED is a semiconductor wafer. One end of the wafer is attached to a bracket, with the cathode connected to the positive terminal of a power source. The entire wafer is encapsulated in epoxy resin. Also known as the LED light-emitting chip, it is the core component of an LED light, and refers to the PN junction. Its primary function is to convert electrical energy into light energy. The chip is primarily made of single-crystal silicon. The semiconductor wafer consists of two parts: a P-type semiconductor, where holes predominate, and an N-type semiconductor, where electrons predominate. When these two semiconductors are connected, a PN junction is formed. When current flows through a wire acting on the wafer, electrons are pushed to the P region, where they recombine with holes and emit energy as photons. This is the principle of LED light emission. The wavelength of light, or therefore its color, is determined by the material forming the PN junction.

[0003] In existing technology, the manufacturing process of LED chips requires the use of diamond grinding wheel blades to cut silicon wafers. This leaves a large amount of debris and powder at the chip edge. If this debris adheres to the PN junction of the LED chip, it can cause leakage and even breakdown. In addition, if the photoresist on the chip surface is not stripped cleanly, it will cause problems such as difficult front-side wire bonding and cold solder joints. If it is on the back, it will also cause high voltage drop and poor overall chip light intensity. In view of this, we have proposed an LED chip and an LED chip manufacturing method. Summary of the Invention

[0004] The main purpose of the present invention is to provide an LED chip and a method for manufacturing the LED chip, which solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides a method for manufacturing an LED chip, which comprises the following steps:

[0006] Step 1: Polishing: Select a round silicon wafer, fix the silicon wafer on a substrate, and polish it. This can effectively ensure that the silicon wafer is not easily broken during the polishing process.

[0007] Step 2: Wet cleaning: Use reagents to clean the silicon wafer to ensure that there are no impurities on the surface of the silicon wafer;

[0008] Step 3: Photolithography: Use ultraviolet light to illuminate the silicon wafer through the mask. The exposed areas will be easily washed away, while the unexposed areas will remain as they are, and the corresponding pattern will be engraved on the silicon wafer.

[0009] Step 4: Ion implantation: adding different impurities to different locations on the silicon wafer. Different impurities form field-effect transistors according to their concentration and location.

[0010] Step 5: etching, etching the silicon wafer after ion implantation;

[0011] Step 6: Plasma cleaning: Use plasma cleaning equipment to rinse the silicon wafer to remove surface pollutants and oxide layers, which can effectively improve the surface activity of the silicon wafer;

[0012] Step 7: Heat treatment, heating the silicon wafer after washing;

[0013] Step 8: Chemical vapor deposition, using one or more gaseous compounds or simple substances containing thin film elements to chemically react on the substrate surface to form a thin film;

[0014] Step 9: Physical vapor deposition: Under vacuum conditions, the surface of the silicon wafer is vaporized into gaseous atoms or molecules, or partially ionized into ions, and a thin film with certain special functions is deposited on the surface of the substrate through a low-pressure gas (or plasma) process;

[0015] Step 10: electroplating treatment, electroplating the silicon wafer;

[0016] Step 11: Surface treatment: remove impurities and photoresist remaining on the surface of the silicon wafer to avoid problems such as difficult solder joints on the front side or high voltage drop on the back side.

[0017] Step 12: Test the package. Test the silicon wafer and polish and package it after passing the test.

[0018] Optionally, in step one, hydrogen peroxide is used to clean the silicon wafer.

[0019] Optionally, in step 10, platinum titanium mesh material is used for electroplating. When power is applied between the platinum titanium mesh (anode) and the silicon wafer (cathode), the solution will generate current and form an electric field. An oxidation reaction occurs at the anode to release electrons, while the cathode obtains electrons to undergo a reduction reaction. The complexed gold ions near the cathode combine with the electrons and are deposited on the surface of the silicon wafer in the form of gold atoms. Under the action of an external electric field, the complexed gold ions in the plating solution move toward the cathode and replenish the concentration consumption near the cathode. The main purpose of electroplating is to deposit a dense, uniform, hole-free, seamless, and other defect-free layer of gold on the silicon wafer.

[0020] Optionally, the heat treatment in step seven includes:

[0021] Rapid thermal annealing, heating the entire silicon wafer to over 1200°C using high-power heating equipment and then slowly cooling it, can better activate and thermally oxidize the implanted ions;

[0022] Thermal oxidation, after the silicon wafer slowly cools down, produces silicon dioxide.

[0023] Optionally, the etching in step five includes dry etching and wet etching.

[0024] Optionally, the dry etching is to wash away some unnecessary shapes previously photoetched by plasma.

[0025] Optionally, the wet etching further cleans the silicon wafer with a reagent, and this step needs to be repeated until the cleaning requirement is met.

[0026] Optionally, after the impurities and photoresist remaining on the surface of the silicon wafer are stripped off in step eleven, the surface of the silicon wafer is roughened and scratched into an inverted trapezoidal structure, which can effectively increase the light intensity.

[0027] Optionally, the LED chip is manufactured by the above steps, and the LED chip includes a substrate, a bonding area, an adhesive layer, an expansion area, a transparent conductive layer and a transparent barrier layer.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The LED chip and the manufacturing method of the LED chip are to repeatedly clean the surface of the silicon wafer, and after the electroplating is completed, the impurities and photoresist remaining on the surface of the silicon wafer are stripped again to avoid the phenomenon of difficult welding and cold welding on the front side or high voltage drop and breakdown on the back side.

[0030] (2) The LED chip and its manufacturing method: When power is applied between the platinum titanium mesh (anode) and the silicon wafer (cathode), the solution generates a current and forms an electric field. The anode undergoes an oxidation reaction to release electrons, while the cathode receives electrons and undergoes a reduction reaction. The complexed gold ions near the cathode combine with the electrons and are deposited on the silicon wafer surface in the form of gold atoms, resulting in a good electroplating effect.

[0031] (3) The LED chip and the method for manufacturing the LED chip can effectively improve the light intensity by roughening and dividing the surface of the silicon wafer into an inverted trapezoidal structure after the impurities and photoresist remaining on the surface of the silicon wafer are stripped off. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0033] Figure 1 This is a schematic diagram of the process structure of the present invention;

[0034] Figure 2 Schematic diagram of the structure of the LED chip of the present invention.

[0035] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0037] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0038] In addition, the descriptions of "first", "second", etc. in the present invention are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0039] Reference Figure 1-Figure 2 The present invention provides a method for manufacturing an LED chip, which includes the following steps:

[0040] Step 1: Polishing: Select a round silicon wafer, fix the silicon wafer on a substrate, and polish it. This can effectively ensure that the silicon wafer is not easily broken during the polishing process.

[0041] Step 2: Wet cleaning: Use reagents to clean the silicon wafer to ensure that there are no impurities on the surface of the silicon wafer;

[0042] Step 3: Photolithography: Use ultraviolet light to illuminate the silicon wafer through the mask. The exposed areas will be easily washed away, while the unexposed areas will remain as they are, and the corresponding pattern will be engraved on the silicon wafer.

[0043] Step 4: Ion implantation: adding different impurities to different locations on the silicon wafer. Different impurities form field-effect transistors according to their concentration and location.

[0044] Step 5: etching, etching the silicon wafer after ion implantation;

[0045] Step 6: Plasma cleaning: Use plasma cleaning equipment to rinse the silicon wafer to remove surface pollutants and oxide layers, which can effectively improve the surface activity of the silicon wafer;

[0046] Step 7: Heat treatment, heating the silicon wafer after washing;

[0047] Step 8: Chemical vapor deposition, using one or more gaseous compounds or simple substances containing thin film elements to chemically react on the substrate surface to form a thin film;

[0048] Step 9: Physical vapor deposition: Under vacuum conditions, the surface of the silicon wafer is vaporized into gaseous atoms or molecules, or partially ionized into ions, and a thin film with certain special functions is deposited on the surface of the substrate through a low-pressure gas (or plasma) process;

[0049] Step 10: electroplating the silicon wafer;

[0050] Step 11: Surface treatment: remove impurities and photoresist remaining on the surface of the silicon wafer to avoid problems such as difficult solder joints on the front side or high voltage drop on the back side.

[0051] Step 12: Test the package. Test the silicon wafer and polish and package it after passing the test.

[0052] In step 1, hydrogen peroxide is used to clean the silicon wafer.

[0053] In step 10, platinum titanium mesh material is used for electroplating. When power is applied between the platinum titanium mesh (anode) and the silicon wafer (cathode), the solution will generate current and form an electric field. The anode undergoes an oxidation reaction to release electrons, while the cathode obtains electrons to undergo a reduction reaction. The complexed gold ions near the cathode combine with the electrons and are deposited on the surface of the silicon wafer in the form of gold atoms. Under the action of the external electric field, the complexed gold ions in the plating solution move toward the cathode and replenish the concentration consumption near the cathode. The main purpose of electroplating is to deposit a dense, uniform, hole-free, seamless, and other defect-free layer of gold on the silicon wafer.

[0054] The heat treatment in step seven includes:

[0055] Rapid thermal annealing, heating the entire silicon wafer to over 1200°C using high-power heating equipment and then slowly cooling it, can better activate and thermally oxidize the implanted ions;

[0056] Thermal oxidation, after the silicon wafer slowly cools down, produces silicon dioxide.

[0057] The etching in step five includes dry etching and wet etching.

[0058] Dry etching is the process of removing some unwanted shapes previously photoetched by plasma.

[0059] Wet etching further cleans the silicon wafer through reagents, and this step needs to be repeated until the requirements are met.

[0060] After the impurities and photoresist remaining on the surface of the silicon wafer are stripped off in step eleven, the surface of the silicon wafer is roughened and scratched into an inverted trapezoidal structure, which can effectively increase the light intensity.

[0061] An LED chip is manufactured by the above steps and comprises a substrate, a bonding area, an adhesive layer, an expansion area, a transparent conductive layer and a transparent barrier layer.

[0062] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for manufacturing an LED chip, characterized in that: The manufacturing method of the LED chip comprises the following steps: Step 1: polishing: select a circular silicon wafer, fix the silicon wafer on the substrate, and polish it; Step 2: Wet cleaning: Use reagents to clean the silicon wafer to ensure that there are no impurities on the surface of the silicon wafer; Step 3: Photolithography: Use ultraviolet light to illuminate the silicon wafer through the mask. The exposed areas will be easily washed away, while the unexposed areas will remain as they are, and the corresponding pattern will be engraved on the silicon wafer. Step 4: Ion implantation: adding different impurities to different locations on the silicon wafer. Different impurities form field-effect transistors according to their concentration and location. Step 5: etching, etching the silicon wafer after ion implantation; Step 6: Plasma cleaning: Use plasma cleaning equipment to clean the silicon wafer to remove surface contaminants and oxide layers; Step 7: Heat treatment, heating the silicon wafer after washing; Step 8: Chemical vapor deposition, using one or more gaseous compounds or simple substances containing thin film elements to chemically react on the substrate surface to form a thin film; Step 9: Physical vapor deposition: Under vacuum conditions, the surface of the silicon wafer is vaporized into gaseous atoms or molecules, or partially ionized into ions, and a thin film with certain special functions is deposited on the surface of the substrate through a low-pressure gas (or plasma) process; Step 10: electroplating treatment, electroplating the silicon wafer; Step 11: Surface treatment, stripping off impurities and photoresist remaining on the surface of the silicon wafer; Step 12: Test the package. Test the silicon wafer and polish and package it after passing the test.

2. The method for manufacturing an LED chip according to claim 1, wherein: In the step 1, hydrogen peroxide is used to clean the silicon wafer.

3. The method for manufacturing an LED chip according to claim 1, wherein: In the step 10, platinum titanium mesh material is used for electroplating.

4. The method for manufacturing an LED chip according to claim 1, wherein: The heat treatment in step seven includes: Rapid thermal annealing, heating the entire silicon wafer to over 1200°C using high-power heating equipment and then slowly cooling it, can better activate and thermally oxidize the implanted ions; Thermal oxidation, after the silicon wafer slowly cools down, produces silicon dioxide.

5. The method for manufacturing an LED chip according to claim 1, wherein: The etching in step five includes dry etching and wet etching.

6. The method for manufacturing an LED chip according to claim 5, wherein: The dry etching is to wash away some unnecessary shapes previously photoetched by plasma.

7. The method for manufacturing an LED chip according to claim 5, wherein: The wet etching further cleans the silicon wafer through reagents, and this step needs to be repeated until the cleaning requirements are met.

8. The method for manufacturing an LED chip according to claim 1, wherein: After the impurities and photoresist remaining on the surface of the silicon wafer are stripped off in the step eleven, the surface of the silicon wafer is roughened and scratched into an inverted trapezoidal structure.

9. An LED chip, characterized in that: The invention comprises an LED chip, wherein the LED chip is prepared by the manufacturing method of the LED chip according to claims 1-8, and the LED chip comprises a substrate, a bonding area, an adhesive layer, an expansion area, a transparent conductive layer and a transparent barrier layer.

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