Semiconductor device

Abstract

The present invention provides a semiconductor device in which a semiconductor element disposed above an adhesive layer, and the adhesive layer provided with a tapered portion. The semiconductor element includes a semiconductor unit disposed above one of the adhesive layers, and a first cross-sectional area of the semiconductor unit is greater than a second cross-sectional area of the tapered portion. Using the tapered portion of the adhesive layer, when transferring the semiconductor device, the laser only needs to irradiate the tapered portion to reduce the area of the required laser spot, thereby stably transferring the semiconductor device and avoiding damage to the semiconductor device.

Description

[Technical Field]

[0001] The present invention relates to a semiconductor device, particularly a semiconductor device that can reduce the laser irradiation area when transferring a substrate. [Previous Technology]

[0002] In the prior art, the manufacturing and application process of wafers includes several key processes, such as mass transfer, which is an important step in transferring a large number of wafers from the original substrate to the target substrate. In the mass transfer process, selective irradiation by a laser beam is often relied upon to remove the adhesive on the bottom of the wafer through energy transfer, so that the wafer can be smoothly transferred from the original substrate to the target substrate. However, in practical applications, this technology suffers from significant problems in the wafer transfer process due to limitations in laser spot design and adhesive distribution.

[0003] In current laser mass transfer processes, the laser spot design needs to completely cover the adhesive layer at the bottom of the wafer to ensure that the laser energy is uniformly irradiated onto the adhesive layer, causing the adhesive to detach due to heat and release the wafer. Since the adhesive layer is often designed as a planar structure, its area is usually comparable to or even slightly overlaps with the wafer size. Therefore, the size and accuracy of the laser spot are directly limited by the area of ​​the adhesive layer. The spot needs to cover the entire adhesive area to ensure the normal drop and transfer of the wafer.

[0004] However, when a large area of ​​laser light spot is used for irradiation, due to its wide coverage, it may directly affect the wafer body. When the laser light spot not only irradiates the adhesive material but also the wafer structure, it may cause damage to the wafer, such as damage to the surface structure and the generation of internal thermal stress, which affects the luminous efficiency and stability of the wafer. This situation is particularly obvious in large-scale wafer transfer, because the uneven distribution of laser energy may cause local overheating or damage to the wafer.

[0005] Secondly, due to the dense arrangement of wafers, when a large-area laser beam irradiates a designated wafer, it often unintentionally affects neighboring wafers. This is especially pronounced when the wafer size is small and the wafer spacing is narrow. When the laser beam irradiates a neighboring wafer, it can cause the non-target wafer to be accidentally heated, further leading to wafer damage or positioning errors, thereby reducing the overall transfer efficiency and yield. This accidental heating of non-target wafers can cause irreversible damage to subsequent process steps, affecting the performance of the final product.

[0006] In summary, while laser mass transfer technology has the potential to improve wafer transfer efficiency, the design of the laser spot in existing technologies, which requires covering the entire adhesive area, frequently leads to wafer damage and overheating of adjacent wafers. These problems not only increase yield losses during wafer transfer but also pose challenges to the overall stability and reliability of the process. Therefore, improving the accuracy and controllability of the laser spot and reducing the risk of damage to the wafer itself and adjacent wafers are urgent issues that the industry needs to address.

[0007] In view of the problems of the prior art described above, the present invention provides a semiconductor device which uses an adhesive layer having a gradually decreasing area to reduce the area of ​​the desired laser spot during transfer, thereby reducing the risk of damage to the light-emitting chip and adjacent chips. [Summary of the Invention]

[0008] One object of the present invention is to provide a semiconductor device that uses an adhesive layer with a gradually decreasing area to reduce the area of ​​the desired laser spot during transfer, thereby reducing the irradiation area and avoiding laser damage to the semiconductor device.

[0009] To achieve the aforementioned objectives and effects, the present invention provides a semiconductor device comprising: a light-transmitting substrate, an adhesive layer, and a semiconductor element. The adhesive layer is disposed above one of the light-transmitting substrates and has a tapered portion. The semiconductor element is disposed above one of the adhesive layers. The semiconductor element comprises: a semiconductor unit, the lower portion of which has a first cross-sectional area larger than the second cross-sectional area of ​​the tapered portion; an insulating layer covering the outer side of the semiconductor unit; and an electrode layer electrically connected to and disposed below the semiconductor unit. The adhesive layer covers the electrode layer. With this structure, when transferring the semiconductor device, the adhesive layer structure with the tapered portion enables the semiconductor device to be transferred stably, preventing the semiconductor device from being tilted and damaged when dropped.

[0010] In one embodiment of the present invention, the semiconductor unit is a light-emitting diode.

[0011] In one embodiment of the present invention, the light-transmitting substrate is a sapphire substrate.

[0012] In one embodiment of the present invention, the tapered portion is disposed in the middle of the adhesive layer, so that the adhesive layer forms a funnel-shaped structure.

[0013] In one embodiment of the present invention, the adhesive layer is connected to the light-transmitting substrate by the tapered portion.

[0014] In one embodiment of the present invention, the first cross-sectional area is the minimum cross-sectional area of ​​the semiconductor unit.

[0015] In one embodiment of the present invention, the adhesive layer is formed by an inductively coupled plasma etching or a reactive ion etching to form the tapered portion.

[0016] In one embodiment of the present invention, the semiconductor element is separated from the light-transmitting substrate by laser stripping of the adhesive layer.

[0017] In one embodiment of the present invention, the material of the insulating layer is silicon nitride or silicon oxide.

[0018] In one embodiment of the present invention, the thickness of the insulating layer is 500nm~1000nm.

Implementation Method

[0019] In view of the problems of the prior art described above, the present invention provides a tapered portion in an adhesive layer, and a semiconductor element including a semiconductor unit is disposed on the adhesive layer. The first cross-sectional area of ​​the bottom of the semiconductor unit is larger than the second cross-sectional area of ​​the tapered portion. When transferring the semiconductor device, the area of ​​the laser spot only needs to cover the tapered portion, thereby reducing the required area of ​​the laser spot. This solves the problem in the prior art where, during mass transfer, the large irradiation area of ​​the laser causes damage to the semiconductor device, resulting in a decrease in yield and an increase in manufacturing costs.

[0020] Please refer to Figure 1, which is a structural schematic diagram of one embodiment of the present invention. As shown in the figure, this embodiment is the first embodiment, which is a semiconductor device that includes a light-transmitting substrate 10, an adhesive layer 20, and a semiconductor element 30.

[0021] Referring again to Figure 1 and Figures 3A to 3B, Figures 3A to 3B are schematic diagrams of the function of the adhesive layer in one embodiment of the present invention. As shown in the figures, this embodiment is the first embodiment. In this embodiment, the adhesive layer 20 is disposed above one of the light-transmitting substrates 10. The adhesive layer 20 is provided with a tapered portion 202. The semiconductor element 30 is disposed above one of the adhesive layer 20. The semiconductor element 30 includes a semiconductor unit 32, an insulating layer 34 and an electrode layer 36. The first cross-sectional area A1 of one of the semiconductor units 32 is larger than the second cross-sectional area A2 of one of the tapered portions 202. The insulating layer 34 covers the outside of one of the semiconductor units 32. The electrode layer 36 is electrically connected to and disposed below one of the semiconductor units 32.

[0022] Continuing from the above, in this embodiment, the tapered portion 202 of the adhesive layer 20 is disposed in the middle of the adhesive layer 20, so that the adhesive layer 20 forms a funnel-shaped structure.

[0023] In one embodiment, the semiconductor unit 32 of the semiconductor element 30 is a light-emitting diode (LED).

[0024] In one embodiment, the light-transmitting substrate 10 is a sapphire substrate.

[0025] In one embodiment, the insulating layer 34 is made of silicon nitride or silicon oxide.

[0026] In one embodiment, the thickness of the insulating layer 34 is 500nm~1000nm. It should be noted that the first cross-sectional area A1 of the bottom surface of the semiconductor unit 32 plus the thickness of the insulating layer 34 is greater than the second cross-sectional area A2 of the tapered portion 202.

[0027] Referring again to Figure 1, Figures 3A to 3B and Figures 2A to 2B, Figures 2A to 2B are schematic diagrams of the transfer of a front substrate according to one embodiment of the present invention. As shown in the figures, when manufacturing the semiconductor element 30, the semiconductor element 30 is first formed on a front substrate S. After the semiconductor unit 32 and the electrode layer 36 of the semiconductor element 30 are formed, the semiconductor unit 32 is covered with an insulating material to form the insulating layer 34. Then the semiconductor element 30 is transferred to the light-transmitting substrate 10 and the adhesive layer 20. The adhesive layer 20 is first etched to form the tapered portion 202. The semiconductor element 30 is then transferred accordingly. After the transfer, as shown in Figure 1, the adhesive layer 20 is further etched to form the tapered portion 202.

[0028] Continuing from the above, as shown in Figure 3A, when the semiconductor element 30 is to be transferred, the whole thing is flipped over and laser lift-off is used to irradiate the tapered portion 202 of the adhesive layer 20, causing the material of the tapered portion 202 to vaporize, as shown in Figure 3B, causing the semiconductor element 30 and part of the adhesive layer 20' to fall off.

[0029] Continuing from the above, since the second cross-sectional area A2 of the tapered portion 202 is smaller than the first cross-sectional area A1 of the bottom surface of the semiconductor unit 32, the area of ​​the laser spot can be limited to the size of the second cross-sectional area A2, so as to avoid the laser spot area being too large and causing the laser to irradiate the semiconductor unit 32 or the insulating layer 34, resulting in damage to these components.

[0030] Continuing from the above, the first cross-sectional area A1 is the minimum cross-sectional area of ​​the semiconductor unit 32.

[0031] Continuing from the above, in one embodiment, the adhesive layer 20 is further etched by an inductively coupled plasma etching or a reactive ion etching to form the tapered portion 202.

[0032] In the above embodiments, inductively coupled plasma (ICP) is a plasma generation technology based on electromagnetic induction, which is widely used in chemical analysis, materials processing, and semiconductor manufacturing processes. Its principle is based on the alternating magnetic field generated in the induction coil by a high-frequency alternating current, which induces the movement of electrons in the gas to achieve gas ionization and stable plasma maintenance.

[0033] The generation process of inductively coupled plasma begins with the introduction of a gas (e.g., argon). When a high-frequency current passes through the induction coil, an alternating magnetic field is generated. This magnetic field exerts a force on the free electrons in the gas, causing them to move at high speed. These electrons collide with gas molecules or atoms, triggering a series of ionization processes to form plasma. Due to the continuous action of the induced magnetic field, the electrons in the plasma are continuously accelerated, thereby maintaining a high-temperature and stable plasma environment.

[0034] One of the main features of inductively coupled plasma is its electrode-free design. Traditional plasma generation techniques often rely on direct contact with electrodes, but this method is prone to erosion of electrode materials, leading to impurity contamination. Inductively coupled plasma technology utilizes an induced magnetic field for energy coupling, avoiding this problem and significantly improving the purity and stability of the plasma. In addition, inductively coupled plasma can generate extremely high plasma temperatures, enabling it to effectively decompose and excite various substances in the sample.

[0035] In the above embodiments, reactive-ion etching (RIE) is a plasma etching technology widely used in semiconductor manufacturing and micro-nano processing. It combines chemical reaction and physical etching mechanisms to achieve precise selective removal of material surfaces. With its high directionality, high resolution and excellent material compatibility, reactive-ion etching technology has become a key step in manufacturing fine structures in modern semiconductor processes.

[0036] The working principle of reactive ion etching is based on the generation and control of plasma. In a reactive ion etching system, a specific gas (such as fluoride or chloride gas) is injected into the reaction chamber, and a high-frequency electric field is applied to the gas through a radio frequency power supply to generate plasma. Ions and free radicals in the plasma react chemically with the material surface to generate volatile byproducts. These byproducts are then removed by a vacuum pump, thereby achieving material removal. In addition, ions driven by the electric field will bombard the material surface in a highly directional manner to achieve physical etching, further enhancing the vertical orientation of the etching.

[0037] The combination of chemical reaction and physical etching is the core characteristic of reactive ion etching. Chemical reaction provides high selectivity, which can effectively distinguish the etching target from the mask material based on the material properties and the selection of reactant gas; physical etching brings excellent directionality, which is suitable for manufacturing deep and narrow structural features, such as transistor trenches, microelectromechanical systems (MEMS) structures and fine patterns in optical devices.

[0038] Reactive ion etching technology offers flexible process adjustability. By adjusting the gas composition, gas pressure, radio frequency power, and electrode bias, reactive ion etching systems can precisely control the etching rate, selectivity, and directionality. Different gases produce different reactive ions, making them suitable for processing different materials. For example, fluorine-based gases are commonly used for etching silicon, while chlorine-based gases are suitable for etching metals and compound semiconductors.

[0039] Please refer to Figure 4 and Figures 5A to 5B. Figure 3 is a schematic diagram of the structure manufacturing of the receiving part according to another embodiment of the present invention. Figures 5A to 5B are schematic diagrams of the function of the adhesive layer according to another embodiment of the present invention. As shown in the figures, this embodiment is based on the first embodiment described above. The adhesive layer 20 is connected to the light-transmitting substrate 10 by the tapered portion 202, so that the adhesive layer 20 forms an inverted trapezoidal structure. The first cross-sectional area A1 below the semiconductor unit 32 is larger than the second cross-sectional area A2 of the tapered portion 202.

[0040] Continuing from the above, as shown in Figure 5A, when the semiconductor element 30 is to be transferred, the whole thing is flipped over and laser lift-off is used to irradiate the tapered portion 202 of the adhesive layer 20, causing the material of the tapered portion 202 to vaporize, as shown in Figure 4B, so that the semiconductor element 30 and the adhesive layer 20 fall off.

[0041] The structure of this embodiment can further enable the adhesive layer 20 to fall off completely along with the semiconductor element 30. The other elements and their operating relationships in this embodiment are the same as those in the above embodiments, so they will not be described again.

[0042] In the above embodiments, the semiconductor device is exemplified by a light-emitting device. The semiconductor element can be a light-emitting element, and the semiconductor unit can be a light-emitting unit, such as a light-emitting diode.

[0043] In summary, the present invention provides a semiconductor device in which an adhesive layer is provided with a tapered portion whose area gradually decreases in one direction, a semiconductor element is disposed above the adhesive layer, and the area of ​​the bottom of the semiconductor element is larger than the area of ​​the tapered portion. When transferring the semiconductor element, the area of ​​the laser spot only needs to cover the tapered portion, thereby reducing the required area of ​​the laser spot. This solves the problem in the prior art that, during mass transfer, the laser spot needs to cover the entire bottom area of ​​the semiconductor element, causing the laser to irradiate the semiconductor element or the insulating layer, resulting in wafer damage or local overheating, which increases manufacturing costs.

[0044] Therefore, this invention is indeed novel, inventive and industrially usable, and should undoubtedly meet the requirements for patent application under the Patent Law of our country. Therefore, we have filed a patent application in accordance with the law and earnestly pray that the Bureau will grant the patent as soon as possible.

[0045] However, the above description is only one embodiment of the present invention and is not intended to limit the scope of the present invention. Therefore, all equivalent changes and modifications made to the shape, structure, features and spirit described in the claims of the present invention should be included in the scope of the claims of the present invention. [Simplified Explanation of the Diagram]

[0046] Figure 1: It is a structural schematic diagram of one embodiment of the present invention; Figures 2A to 2B: It is a schematic diagram of the transfer of the front substrate in one embodiment of the present invention; Figures 3A to 3B: It is a schematic diagram of the function of the adhesive layer in one embodiment of the present invention; Figure 4: It is a schematic diagram of the manufacturing of the receiving part structure in another embodiment of the present invention; and Figures 5A to 5B: It is a schematic diagram of the function of the adhesive layer in another embodiment of the present invention.

Claims

1. A semiconductor device comprising: a light-transmitting substrate; an adhesive layer disposed above one of the light-transmitting substrates, the adhesive layer having a tapered portion; and a semiconductor element disposed above one of the adhesive layers, the semiconductor element comprising: a semiconductor cell having a first cross-sectional area at its lower portion larger than a second cross-sectional area at one of the tapered portions; an insulating layer covering the outer side of one of the semiconductor cells; and an electrode layer electrically connected to and disposed below one of the semiconductor cells, the adhesive layer covering the electrode layer.

2. The semiconductor device as claimed in claim 1, wherein the semiconductor unit is a light-emitting diode.

3. The semiconductor device as claimed in claim 1, wherein the light-transmitting substrate is a sapphire substrate.

4. The semiconductor device as claimed in claim 1, wherein the tapered portion is disposed in the middle of the adhesive layer, such that the adhesive layer forms a funnel-shaped structure.

5. The semiconductor device as claimed in claim 1, wherein the adhesive layer is connected to the light-transmitting substrate via the tapered portion.

6. The semiconductor device as claimed in claim 1, wherein the first cross-sectional area is the minimum cross-sectional area of ​​the semiconductor unit.

7. The semiconductor device as claimed in claim 1, wherein the adhesive layer is formed by an inductively coupled plasma etching or a reactive ion etching of the tapered portion.

8. The semiconductor device as claimed in claim 1, wherein the semiconductor element is separated from the light-transmitting substrate by laser stripping of the adhesive layer.

9. The semiconductor device as claimed in claim 1, wherein the insulating layer is made of silicon nitride or silicon monoxide.

10. The semiconductor device as claimed in claim 1, wherein the thickness of the insulating layer is 500 nm to 1000 nm.

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