An etching apparatus, substrate processing system and device manufacturing method
By using an etching technique that combines a movable mask and a base in the etching equipment, the complexity and high cost of multiple process flows in the existing technology are solved, achieving the effects of simplifying the process flow, reducing costs, and improving chip yield.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ADVANCED MICRO FAB EQUIP INC CHINA
- Filing Date
- 2023-08-21
- Publication Date
- 2026-05-12
AI Technical Summary
In existing semiconductor chip manufacturing, the complexity and high cost caused by multiple process flows, especially the need for additional photolithography equipment and processes when forming isolation trenches, affect chip quality and yield.
An etching device combining a relatively movable mask and a base is used. An isolation trench is formed in the etching cavity through a support plate and an elastic dielectric layer, which simplifies the process flow, avoids the need for additional masks and equipment, reduces production input costs, and reduces the lateral etching of the substrate surface by plasma through full contact with the substrate through the elastic dielectric layer.
It simplifies the substrate processing steps, reduces production costs, improves chip yield and processing efficiency, avoids damage to the substrate surface, and ensures precise control and quality of etching.
Smart Images
Figure CN119495544B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor equipment, and more specifically to an etching apparatus, a substrate processing system thereof, and a device fabrication method. Background Technology
[0002] With the rapid development of semiconductor technology, chip sizes are getting smaller and smaller, and device integration is increasing. To ensure chip quality, the requirements for semiconductor processes are becoming increasingly stringent. In the exploration of next-generation power devices, issues such as device integration and size reduction have received widespread attention. Increasing device integration can achieve both cost-effectiveness and improved device performance. The number of stacked layers also increases accordingly. A typical chip requires thousands of process steps from silicon wafer to final packaging. These multiple process steps inevitably create complexity, especially in multi-patterning techniques.
[0003] In chip manufacturing, various factors influence chip quality and yield. These include lattice compatibility, thermal compatibility, stress compatibility, and the number of stacked layers, all of which directly or indirectly determine the quality of the finished chip. For example, the thermal compatibility between the bottom substrate and the device layers above it determines the stress level during chip growth. Excessive stress can lead to bending and cracking during epitaxial film growth on the bottom substrate, resulting in defects in the finished device, affecting its quality and yield, and consequently impacting the output and scale of integrated circuit production. Therefore, improvements to existing production equipment and methods are necessary.
[0004] It is understood that the above statements only provide background information related to the present invention and do not necessarily constitute prior art. Summary of the Invention
[0005] Based on the aforementioned technical problems, the purpose of this invention is to provide an etching apparatus, a substrate processing system, and a device fabrication method thereof. The etching apparatus combines a relatively movable mask and a base, which simplifies the substrate processing steps, eliminates the need for additional masks and equipment, and reduces production input costs.
[0006] To achieve the above objectives, the present invention is implemented through the following technical solution:
[0007] An etching apparatus for forming isolation trenches on a substrate surface, comprising:
[0008] An etching chamber, wherein a gas inlet is provided on the chamber body, and the gas inlet is used to deliver etching gas;
[0009] A base for supporting the substrate is located inside the etching cavity;
[0010] A mask plate is located between the gas inlet and the base, and the distance between the mask plate and the base is adjustable; wherein, the mask plate comprises:
[0011] The support plate has multiple primary gas channels.
[0012] An elastic dielectric layer is located at the bottom of the support plate. The bottom of the support plate is provided with multiple elastic dielectric layer coverage areas and multiple second gas channels located between different elastic dielectric layer coverage areas. The multiple first gas channels pass through the support plate and communicate with the second gas channels to form an etching gas diffusion channel.
[0013] During the process, at least a portion of the bottom of the mask plate is attached to the upper surface of the substrate, and the portion of the upper surface of the substrate that is not attached to the bottom of the mask plate is exposed at the outlet of the second gas channel, so that the etching gas comes into contact with the substrate below when flowing through the second gas channel.
[0014] Optionally, the first gas channel includes a through hole;
[0015] And / or, the second gas channel is a through hole or a through groove.
[0016] Optionally, the width of the first gas channel is in the range of 5μm to 10μm;
[0017] And / or, the width of the second gas channel is less than 15 μm;
[0018] And / or, the width of the second gas channel is greater than or equal to the width of the first gas channel.
[0019] Optionally, the support plate is made of a metal.
[0020] And / or, the material used to prepare the elastic medium layer includes at least one of fluororubber, Teflon, and polymer materials.
[0021] Optional, also includes:
[0022] The gas extraction channel is a gas diffusion space between the mask plate and the gas inlet, and the gas extraction channel is connected to the first gas channel located at the circumferential edge to discharge the reaction waste gas.
[0023] Optionally, an elastic medium layer is provided on the outer periphery of the lower surface of the support plate to form a sealing ring, and the exhaust gas generated in the second gas channel is connected upward to the extraction channel through the first gas channel located at both ends of the second gas channel and adjacent to the sealing ring.
[0024] Optionally, the upper surface of the support plate includes a plurality of connecting pipes, which are connected between the plurality of first gas channels for exhaust and the extraction channel; or the upper surface of the support plate includes an annular extraction ring, which is connected between the plurality of first gas channels for exhaust and the extraction channel.
[0025] Optionally, the mask plate is connected to the top of the etching cavity via an upwardly extending sidewall, and the mask plate, the upwardly extending sidewall of the mask plate, and the top of the etching cavity together form a gas diffusion cavity.
[0026] Optionally, an exhaust port is provided at the bottom of the etching cavity, and the air extraction channel is connected to the exhaust port;
[0027] Alternatively, the evacuation channel passes through an opening in the etching cavity and is connected to a vacuum extraction device located outside the etching cavity.
[0028] Optionally, the projection of the second gas channel onto the substrate coincides with at least a portion of the dicing line of the substrate.
[0029] Optionally, the mask plate can be removed and replaced.
[0030] Optionally, the mask plate is raised and lowered by a lifting rod;
[0031] And / or, the base is raised and lowered by a lifting column.
[0032] Optionally, the mask includes a downwardly extending lower portion that contacts and presses against the outer edge of the upper surface of the base when at least a portion of the bottom of the mask is in contact with the upper surface of the substrate.
[0033] Optionally, at least a portion of the surface of the mask plate is provided with a corrosion-resistant film layer.
[0034] Optional, also includes:
[0035] A remote plasma source that supplies etching gas into the etching chamber through the gas inlet;
[0036] Alternatively, a gas supply device that supplies etching gas into the etching chamber through the gas inlet.
[0037] Optionally, a substrate processing system includes:
[0038] The aforementioned etching equipment is used to form isolation trenches on the substrate surface;
[0039] A thin film deposition chamber, used to deposit thin films on a substrate surface;
[0040] The transfer cavity is connected to both the etching cavity of the etching apparatus and the thin film deposition cavity.
[0041] Optional, also includes:
[0042] The loading and unloading cavity is connected to the transfer cavity and is used for loading and unloading the substrate.
[0043] Optionally, a method for fabricating a device includes:
[0044] A buffer layer is grown on the substrate;
[0045] The substrate with the buffer layer grown is processed using the aforementioned etching equipment to form isolation trenches on the substrate;
[0046] Thin films are deposited on a substrate containing isolation trenches to fabricate the target device.
[0047] Optional, also includes:
[0048] Before depositing a thin film on the substrate, the substrate surface is cleaned with a cleaning gas.
[0049] Compared with the prior art, the present invention has the following advantages:
[0050] In the etching apparatus, substrate processing system, and device fabrication method of the present invention, the etching apparatus combines a relatively movable mask and a base, simplifying the substrate processing steps, eliminating the need for additional masks and equipment, and reducing production input costs. On the other hand, the mask combines a support plate and an elastic dielectric layer. The support plate provides support for the mask, and the elastic dielectric layer makes full contact with the substrate to avoid damage to the substrate surface. At the same time, the elastic dielectric layer makes full contact with the substrate surface during the process, minimizing the lateral etching of the substrate surface by plasma and avoiding unexpected impacts on the substrate surface. Attached Figure Description
[0051] Figure 1 This is a schematic diagram of an etching device according to Embodiment 1 of the present invention;
[0052] Figure 2 for Figure 1 Top view of the support plate in the middle;
[0053] Figure 3 This is a partial schematic diagram of the mask plate being pressed tightly onto the substrate in Embodiment 1 of the present invention;
[0054] Figure 4 This is a schematic diagram of a substrate processing system according to Embodiment 1 of the present invention;
[0055] Figure 5 This is a schematic diagram illustrating the fabrication of a device according to Embodiment 1 of the present invention;
[0056] Figure 6This is a schematic diagram of an etching device according to Embodiment 2 of the present invention;
[0057] Figure 7 for Figure 6 Top view of the support plate in the middle;
[0058] Figure 8 This is a schematic diagram of another etching device in Embodiment 2 of the present invention;
[0059] Figure 9 for Figure 8 Top view of the support plate. Detailed Implementation
[0060] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0061] It should be noted that, in this document, the terms "comprising," "including," "having," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Unless otherwise specified, an element defined by the phrase "comprising..." or "including..." does not exclude the presence of additional elements in the process, method, article, or terminal device that includes said element.
[0062] As used herein, the term "substrate" refers to and includes a base material or structure on which materials are formed. It should be understood that a substrate can include a single material, layers of multiple different materials, one or more layers having regions of different materials or structures thereon, etc. These materials can include semiconductors, insulators, conductors, or combinations thereof. For example, a substrate can be a semiconductor substrate, a base semiconductor layer on a support structure, a metal electrode or semiconductor substrate on which one or more layers, structures, or regions are formed. A substrate can be a conventional silicon substrate or other bulk substrate comprising layers of semiconductor material. A substrate can be doped or undoped.
[0063] It should be noted that the accompanying drawings are all in a very simplified form and use non-precise ratios, and are only used to facilitate and clearly illustrate the purpose of the embodiments of the present invention.
[0064] Example 1
[0065] As mentioned above, the quality of each layer in a semiconductor device is crucial. Therefore, the manufacturing quality of semiconductor devices can be improved by forming isolation trenches on the substrate. Specifically, these isolation trenches divide the entire surface of the substrate into different small epitaxial growth regions, significantly reducing the stress accumulated on the substrate surface and lowering the likelihood of film cracking. Simultaneously, the small size of each small epitaxial growth region allows for effective stress release, preventing excessive stress accumulation that could lead to film cracking, thus effectively improving the yield of the semiconductor device. Furthermore, even if cracks do occur in some small epitaxial growth regions due to certain factors, the cracks will only extend within that region and will not spread to surrounding epitaxial growth regions, thereby ensuring the overall production yield of the semiconductor device. However, based on existing technological concepts, forming isolation trenches requires first forming a mask on the substrate using photolithography. This method necessitates a series of equipment and processes, including photolithography machines, etching machines, photoresist stripping machines, and photoresist coating machines. For large-scale mass production, using photolithography to form the mask not only occupies a large amount of cleanroom space but also requires the additional purchase of these expensive semiconductor processing devices, resulting in excessively high costs. Based on the above, this invention provides an etching apparatus for forming isolation trenches on the substrate surface to divide the substrate surface into multiple epitaxial growth regions.
[0066] Specifically, such as Figures 1 to 3 As shown, the etching apparatus includes: an etching chamber 100, a base 110 for supporting the substrate W, and a mask 120. The etching chamber 100 has a gas inlet 101 for supplying etching gas. The base 110 is located inside the etching chamber 100, and the mask 120 is located between the gas inlet 101 and the base 110. The distance between the mask 120 and the base 110 is adjustable. The mask plate 120 includes a support plate 121 and an elastic dielectric layer 122. The support plate 121 has multiple first gas channels 123. The elastic dielectric layer 122 is located at the bottom of the support plate 121. The bottom of the support plate 121 is provided with multiple elastic dielectric layer coverage areas and multiple second gas channels 124 located between different elastic dielectric layer coverage areas. The elastic dielectric layer 122 is located on the elastic dielectric layer coverage areas. The multiple first gas channels 123 pass through the support plate 121 and communicate with the second gas channels 124 to form an etching gas diffusion channel.
[0067] During the process, at least a portion of the bottom of the mask plate 120 is attached to the upper surface of the substrate W, and the area of the upper surface of the substrate W that is not attached to the bottom of the mask plate 120 is exposed at the outlet of multiple second gas channels 124, so that the etching gas comes into contact with the upper surface of the substrate W below when it flows through the second gas channels 124, thereby forming multiple isolation grooves 130, i.e., isolation trenches, on the surface of the substrate W that are similar to the pattern of the second gas channels 124. This etching equipment allows the substrate W to be etched with a pattern in one step without adding an additional mask. The substrate W does not need to be photolithographically etched to form a mask and then etched to form the isolation trench 130. The substrate W does not need to be taken out of the substrate thin film deposition system and exposed to the atmospheric environment before being transferred to a series of processing equipment such as photolithography machine, coating machine, etching machine, and resist stripper on the production line. The isolation trench 130 can be formed on the substrate W by etching in the etching chamber 100. This one-step processing method simplifies the processing steps of the substrate W, avoids excessive transportation of the substrate W in the atmospheric environment, helps to ensure the cleanliness and processing quality of the substrate W, and thus greatly improves the production yield of the device. On the other hand, the mask 120 combines the support plate 121 and the elastic dielectric layer 122. In practical applications, the support plate 121 provides support for the mask 120, and the elastic dielectric layer 122 is in full contact with the substrate W to avoid damage to the surface of the substrate W (hard damage such as bumps). The etching gas diffusion channel formed by the first gas channel 123 of the support plate 121 and the second gas channel 124 between the elastic dielectric layer 122 provides a stable airflow guide for the etching gas flow, which helps to accurately control the etching to form the isolation trench 130. At the same time, the elastic dielectric layer 122 is in full contact with the surface of the substrate W during the process, and there is no gap between the two. That is, the elastic dielectric layer 122 covers and protects part of the surface of the substrate W, minimizing the lateral etching of the substrate W surface by the plasma and avoiding unexpected impact on the surface of the substrate W.
[0068] like Figure 1 As shown, in this embodiment, the etching apparatus further includes a remote plasma source (RPS) 140. The remote plasma source 140 supplies etching gas into the etching chamber 100 through the gas inlet 101 for etching. The etching gas consists of active groups of the plasma. After being supplied into the etching chamber 100 through the gas inlet 101, the active groups contact the surface of the substrate W through the etching gas diffusion channel of the mask plate 120, thereby etching an isolation trench 130 on the surface of the substrate W. An exhaust port 102 is also provided at the bottom of the etching chamber 100 to discharge reaction byproducts and / or residual etching gas generated during the etching process to the outside of the chamber.
[0069] The etching chamber 100 has limited internal space. Plasma is directly supplied into the chamber via a remote plasma source 140, eliminating the need for additional functional components within the chamber to excite the process gas. This reduces the impact on etching. Furthermore, the remote plasma source 140 does not occupy internal space within the etching chamber 100, saving space and allowing for the placement of other process-friendly functional components. It is understood that the etching chamber 100 is not limited to providing etching gas via the remote plasma source 140; other devices can also be used. This invention does not impose any limitations on this, as long as the corresponding etching can be achieved. For example, in another embodiment, the etching apparatus includes a gas supply device that supplies etching gas into the cavity through the gas inlet 101. The etching gas is a process gas. Radio frequency power is applied into the etching cavity 100 through a radio frequency power source (e.g., supplied into the cavity through the base 110) to dissociate the process gas into plasma, thereby generating plasma between the mask 120 and the base 110 for etching. This plasma environment contains a large number of active particles such as electrons, ions, excited-state atoms, molecules, and free radicals. These active particles react with the surface of the substrate W through the second gas channel 124 to etch isolation trenches 130 on the surface of the substrate W.
[0070] As previously mentioned, the distance between the mask plate 120 and the base 110 is adjustable. Optionally, the mask plate 120 can be raised and lowered to adjust the distance between them, and / or the base 110 can be raised and lowered to adjust the distance between them. For example, the mask plate 120 is raised and lowered via a lifting rod; and / or the base 110 is raised and lowered via a lifting column. In this embodiment, as... Figure 1 As shown, the mask 120 is raised and lowered by three movable lifting rods 125. In the actual process, when it is necessary to transfer the substrate W to the etching cavity 100, the mask 120 is moved upward by the lifting rods 125 to provide space for the substrate W to be transferred. After the substrate W is placed on the base 110, the mask 120 is driven downward by the lifting rods 125, so that at least a portion of the elastic dielectric layer 122 at the bottom of the mask 120 is in close contact with the substrate W.
[0071] like Figures 1 to 3As shown, in this embodiment, the first gas channel 123 of the support plate 121 has a through-hole structure, which gives the support plate 121 a grid-like pattern of pores and higher mechanical strength. The second gas channel 124 at the bottom of the support plate 121 has a through-groove structure, which allows the etching gas to fully contact the surface of the substrate W to form a linear isolation groove. The etching gas enters the etching chamber 100 from the gas inlet 101 and flows through the multiple first gas channels 123 of the support plate 121 to each of the second gas channels 124. The through-hole structure of the first gas channel 123 can further constrain the flow rate of the etching gas, so that the gas flow rate of the etching gas flows uniformly to the second gas channel 124. The through-groove structure of the second gas channel 124 provides a uniform gas space for the diffusion of the etching gas, which helps to form a continuous and uniform isolation groove 130 on the surface of the substrate W, so as to divide the substrate W into multiple epitaxial growth regions. It is understood that the first gas channel 123 is not limited to the above-described through-hole structure, and the second gas channel 124 is not limited to the above-described through-slot structure. In other embodiments, they can also be other structural types, which can be set according to actual needs. For example, the first gas channel 123 can also be a through-slot structure, etc., and the second gas channel 124 can also be a through-hole structure, etc. Similarly, the combination of structural types of the first gas channel 123 and the second gas channel 124 is not limited to the above-described combinations, and can also be set according to needs in practical applications.
[0072] Optionally, the lateral width of the first gas channel 123 ranges from 5 μm to 10 μm; and / or, the lateral width of the second gas channel 124 is less than 15 μm. Figure 3 The diagram shows a partial etching schematic of this embodiment. In this embodiment, the width of the second gas channel 124 is greater than the width of the first gas channel 123. Etching gas flows through the elongated second gas channel 124 to etch the surface of the substrate W, forming an isolation trench 130 with a width of 15 μm and a depth at the nanometer level. It should be noted that the width range of the first gas channel 123 and the second gas channel 124, as well as the width relationship between them, are not limited to those described above. In other embodiments, other data or relationships may also be used. For example, in another embodiment, the width of the second gas channel 124 is equal to the width of the first gas channel 123.
[0073] Optionally, the projection pattern of the second gas channel 124 on the substrate W coincides with at least a portion of the dicing lines of the substrate W, so that the substrate W can be cut when separating the substrate into individual devices without affecting the devices on the substrate W due to the isolation trench 130. In some embodiments, multiple epitaxial growth regions are defined by the projection pattern of the second gas channel 124 on the substrate W. During the formation of the isolation trench 130, each epitaxial growth region is covered and protected by an elastic dielectric layer 122, and each epitaxial growth region on the substrate W contains one or more devices. In this embodiment, the projections of the multiple second gas channels 124 on the substrate W coincide with all the dicing lines of the substrate W to facilitate the cutting of the substrate W, while also helping to ensure the device production yield of the multiple epitaxial growth regions on the substrate W. Further, in this embodiment, the mask 120 is removable and replaceable. Optionally, the mask patterns formed by the second gas channels 124 of the multiple mask plates 120 are not exactly the same. According to the actual process or product requirements, the corresponding mask plate 120 can be selected to increase the applicability of the etching equipment and make the etching equipment usable for processing substrates W of various chip sizes.
[0074] like Figure 1 As shown, in this embodiment, the mask 120 further includes a downwardly extending lower extension 126. When at least a portion of the bottom of the mask 120 is in contact with the upper surface of the substrate W, the lower extension 126 contacts and presses against the outer edge of the upper surface of the base 110. In practical applications, the lifting rod 125 drives the mask 120 to descend so that the elastic dielectric layer 122 at its bottom contacts the surface of the substrate W, and the lower extension 126 contacts and presses against the outer edge of the upper surface of the base 110 to achieve a sealing effect. This confines the plasma within the etching gas diffusion channel on the upper surface of the substrate W, preventing the plasma from diffusing and etching onto the surface of the base 110, ensuring that the plasma reacts completely on the surface of the substrate W, and that reaction byproducts are discharged through the first gas channel 123 in the edge region of the mask 120. In this embodiment, the lower extension 126 surrounds the substrate W, and the bottom of the lower extension 126 includes an elastic dielectric layer 122 to avoid rigid contact between the lower extension 126 and the upper surface of the base 110, thereby reducing damage to the upper surface of the base 110 by the mask 120.
[0075] Optionally, the support plate 121 is made of a metal to form a rigid cover plate, providing sufficient strength support for the mask 120; and / or, the elastic dielectric layer 122 is made of at least one of fluororubber, Teflon, and polymer materials to provide a flexible buffer between the contact surface between the mask 120 and the substrate W. Of course, the support plate 121 and the elastic dielectric layer 122 can also be made of other materials, and the present invention is not limited thereto. Furthermore, at least a portion of the surface of the mask 120 (mainly the area in contact with plasma) is provided with a corrosion-resistant film layer to avoid affecting the mask 120 and to help improve the service life of the mask 120. For example, the corrosion-resistant film layer is a plasma-resistant coating.
[0076] Furthermore, the present invention also provides a substrate processing system comprising: the aforementioned etching apparatus, a thin film deposition chamber, and a transfer chamber (TM). The etching apparatus is used to form isolation trenches 130 on the surface of substrate W, the thin film deposition chamber is used to deposit a thin film on the surface of substrate W, and the transfer chamber is connected to both the etching chamber 100 of the etching apparatus and the thin film deposition chamber. Figure 4 As shown, in this embodiment, the substrate processing system is an MOCVD processing system, which includes an etching apparatus, a transfer cavity 300, and multiple thin film deposition cavities 200 (MOCVD cavities). The transfer cavity 300 is connected to the etching cavity 100 of the etching apparatus and the thin film deposition cavities 200, respectively. The substrate W can be directly etched in the etching cavity 100 to form isolation trenches 130 in a single step. Since the transfer cavity 300 is connected to both the etching cavity 100 and the thin film deposition cavities 200, after the isolation trenches 130 are formed in the etching cavity 100, the substrate W can be directly transferred from the etching cavity 100 to the thin film deposition cavities 200 via the transfer cavity 300 for a cleaning step (or cleaning can be performed within the etching cavity 100) before the subsequent epitaxial film growth begins, until the desired device (such as an LED, power device, laser device, etc.) is formed. This etching apparatus eliminates the need for the substrate W to undergo multiple transfers in the atmospheric environment, avoiding damage to the substrate W, reducing the number of operation steps, and improving the processing efficiency of the substrate W.
[0077] Furthermore, in this embodiment, the substrate processing system also includes a loading / unloading cavity (LL) 400 and a transfer cavity 500. The transfer cavity 300 is connected to the loading / unloading cavity 400 and the transfer cavity 500 respectively. The loading / unloading cavity 400 is used for loading and unloading the substrate W. The loading / unloading cavity 400 is located between the atmospheric environment and the vacuum chamber, and its vacuum level can be varied. The transfer cavity 500 is used to temporarily store the substrate W.
[0078] It should be noted that the substrate processing system is not limited to the above-described components. In other embodiments, other types or numbers of chambers or devices may be provided according to actual needs, and the present invention does not impose any restrictions on this.
[0079] Based on the same inventive concept, the present invention also provides a method for fabricating a device, the method comprising: growing a buffer layer on a substrate W; processing the substrate W with the buffer layer grown thereon using an etching apparatus as described above to form an isolation trench 130 on the substrate W; and depositing a thin film on the substrate W containing the isolation trench 130 to fabricate a target device.
[0080] Furthermore, the fabrication method of this device also includes cleaning the surface of the substrate W with a cleaning gas before depositing a thin film on the substrate W. Optionally, the surface of the substrate W can be cleaned with a cleaning gas in the etching chamber 100 of the etching apparatus, or the surface of the substrate W can be cleaned with a cleaning gas in the thin film deposition chamber 200. During the cleaning process in the etching chamber 100, a cleaning gas (such as H2) can be supplied into the chamber through the gas inlet 101 of the etching chamber 100. After etching the substrate W to form the isolation trench 130, the introduced etching gas is converted into a cleaning gas to remove residual etching gas and reaction byproducts in the etching gas diffusion channel. Then, the distance between the mask 120 and the base 110 is adjusted to allow the substrate W to detach from the mask 120.
[0081] like Figure 5 The diagram illustrates the fabrication of a semiconductor device, which comprises a substrate layer 610, a buffer layer 620, and a power device layer 640 arranged sequentially from bottom to top. Specifically, in this embodiment, the semiconductor device is a GaN power device, comprising a silicon substrate (substrate layer 610), a buffer layer 620, a super lattice layer 630, and a GaN device layer (power device layer 640) stacked sequentially from bottom to top. Due to the large lattice and thermal mismatch between the silicon substrate and the GaN thin film, significant stress is easily introduced during growth. To buffer the mismatch between the silicon substrate and the GaN thin film, a buffer layer 620 and a super lattice layer 630 are provided between them. The buffer layer 620 contains AlN, and the super lattice layer 630 contains alternating AlN / GaN material layers. This multilayer structure releases the stress of the device, reducing the overall device deformation.
[0082] like Figure 5As shown, in this embodiment, during actual fabrication: A. A buffer layer 620 is first grown on the substrate layer 610; B. The substrate layer 610 with the buffer layer 620 is cooled and then transferred into the etching chamber 100 of the etching equipment to form an isolation trench 130. Specifically, in the etching chamber 100, a mask plate 120 with an etching pattern (etching gas diffusion channel) is pressed against the substrate layer 610 with the buffer layer 620, and etching gas for the buffer layer 620 is supplied into the chamber through the gas inlet 101 of the etching chamber 100 to etch and form the isolation trench 130 on the surface of the buffer layer 620. The etched substrate W is transferred from the etching chamber 100 to the thin film deposition chamber 200 via the transfer chamber 300; C. Clean gas H2 is introduced into the thin film deposition chamber 200 to remove residual organic matter; D. Then, the subsequent MOCVD process is continued to epitaxially grow a superseed layer 630 and a GaN device layer. As can be seen from the figure, when the device layer is further epitaxially grown on the substrate W with isolation trench 130, the cross-section of the epitaxial layer grown on the isolation trench 130 is V-shaped or U-shaped. The thickness of the epitaxial layer at the isolation trench 130 is slightly different from the thickness of the corresponding device layer on the epitaxial growth region (slightly thinner), which helps to reduce the correlation between devices in adjacent epitaxial growth regions, reduce the influencing factors of devices in the epitaxial growth region, and improve the yield of device production.
[0083] It is understood that the present invention can form isolation trenches 130 not only by etching the buffer layer 620 of the semiconductor device, but also by etching other layers. The choice can be made according to actual needs, as long as it can improve the overall surface stress of the substrate W.
[0084] Example 2
[0085] Based on the structural characteristics of the plasma processing device in Embodiment 1, this embodiment mainly makes some changes to the structure of the mask plate 720.
[0086] like Figure 6As shown, in this embodiment, the mask 720 includes a support plate 721 and a plurality of elastic dielectric layers 722. Similar to Embodiment 1, the mask 720 includes an etching gas diffusion channel composed of a first gas channel 723 of the support plate 721 and a plurality of second gas channels 724 between the coverage areas of different elastic dielectric layers 722. Unlike Embodiment 1, in this embodiment, the mask 720 further includes an extraction channel 726. A gas diffusion space exists between the mask 720 and the gas inlet 701. The extraction channel 726 is connected to a first gas channel 723 located at the radial edge of the plurality of second gas channels 724. That is, the extraction port 727 of the extraction channel 726 is connected to at least a portion of the first gas channel 723 located at the upper edge of the mask 720. Because the second gas channels 724 formed between the elastic dielectric layers 722 are interconnected, the extraction channel 726 can discharge the reaction waste gas (including residual etching gas and / or reaction byproducts) formed on the upper surface of the substrate, and promote the downward flow of reaction gas from the gas diffusion space 740.
[0087] In practical applications, the thickness of the support plate 721 and the elastic dielectric layer 722 is not very high (it may only need a few millimeters). After the etching gas molecules diffuse from the gas inlet 701 to the second gas channel 724 and come into contact with the surface of the substrate W, the residual etching gas or reaction byproducts in the second gas channel 724 are difficult to pass through the etching gas diffusion channel on the mask plate 720 and be discharged in a short time by free diffusion alone. The residual etching gas or reaction byproducts will corrode the areas on the substrate W that do not want to be etched (such as the areas where devices need to be fabricated) and multiple components in the etching cavity 700. That is, if the etching gas and reaction byproducts stay on the substrate W or in the etching cavity 700 for too long, there will also be some negative effects. Based on this, this embodiment provides a gas extraction channel 726 at the edge of the mask plate 720. The auxiliary gas extraction method can accelerate the gas flow rate and quickly discharge the residual etching gas and reaction byproducts, so as not to leave residual etching gas and reaction byproducts on the substrate W, thereby ensuring precise control of etching and avoiding over-etching of the substrate W, which would affect the device performance.
[0088] Optionally, the extraction channel 726 passes through an opening in the etching chamber 700 and connects to a vacuum extraction device located outside the etching chamber 700 to discharge reaction waste gas. Figure 6As shown, in this embodiment, the opening on the etching cavity 700 is the opening at the top of the cavity. Further, the mask plate 720 is connected to the top of the etching cavity 700 via an upwardly extending sidewall. The mask plate 720, its upwardly extending sidewall, and the top of the etching cavity 700 together constitute a gas diffusion cavity 740. This ensures that the etching gas diffuses only within the gas diffusion cavity 740 and the etching gas diffusion channel during the process, preventing leakage to other areas within the etching cavity 700. This improves the utilization rate of the etching gas and further ensures that other areas within the cavity are not affected by the etching gas. Optionally, a corrosion-resistant film layer can be provided only within the gas diffusion cavity 740 and the etching gas diffusion channel. Further, in this embodiment, the base 710 is raised and lowered via a lifting column 725.
[0089] Furthermore, in this embodiment, an elastic dielectric layer 722 is provided around the outer periphery of the lower surface of the support plate 721 to form a sealing ring. The exhaust gas generated in the second gas channel 724 is connected upward to the extraction channel 726 through the first gas channel 723 located at both ends of the second gas channel 724 and adjacent to the sealing ring. The sealing ring on the lower surface of the support plate 721 can confine the etching gas to the area where the substrate W is located, and prevent it from diffusing to the surrounding area of the substrate W.
[0090] In this embodiment, the upper surface of the support plate 721 includes a plurality of connecting pipes 728. The plurality of connecting pipes 728 are connected between the plurality of first gas channels 723 for exhaust and the exhaust channel 726. The connection port of the plurality of connecting pipes 728 and the first gas channel 723 is equivalent to the exhaust port 727 of the exhaust channel 726. After the etching gas enters the grid-shaped second gas channel 724 through the first gas channel 723, it flows along the long groove-shaped second gas channel 724 until it enters the exhaust channel 726 from the first gas channel 723 at the edge of the support plate 721, and then exits the etching cavity 700 from the exhaust channel 726.
[0091] Preferably, the air extraction ports 727 of the air extraction channel 726 are uniformly arranged circumferentially along the edge of the mask plate 720 (see [link]). Figure 7 This ensures that the driving or extraction effect of the gas on the mask plate 720 is the same in all directions, which helps to guarantee the uniformity of the surface treatment of the substrate W, that is, the isolation trench structure formed at all locations on the surface of the substrate W is the same. Of course, the arrangement of the gas extraction port 727 of the gas extraction channel 726 is not limited to the above-described manner, and can be configured in other ways as needed. For example, the arrangement of the gas extraction channel 726 can make the driving or extraction effect of the gas at a specific location different from that at other locations, and the present invention does not limit this.
[0092] It should be noted that the present invention does not limit the communication method between the exhaust channel 726 and the outside of the cavity, as long as it enables exhaust to the outside of the cavity. For example, in another embodiment, an exhaust port 702 is provided at the bottom of the etching cavity 700, and the exhaust channel 726 is connected to the exhaust port 702. Furthermore, the present invention does not limit the communication method between the first gas channel 723 for exhaust and the exhaust channel 726 in the support plate 721, as long as it can achieve the corresponding function. For example, as... Figure 8 and Figure 9 As shown, in another embodiment, the upper surface of the support plate 821 includes an annular suction ring 825, which connects the plurality of first gas channels 823 and the suction channel 826 for exhaust. In this embodiment, the suction channel 826 is an exhaust pipe disposed on the outer wall of the support plate 821, which extends downward from the suction ring to the bottom of the reaction chamber (which can communicate with the exhaust port 802) to prevent etching gas and reaction byproducts from contaminating the sides and bottom of the substrate W. Furthermore, the etching apparatus can also deliver purified gas into the chamber through the gas inlet 801 to purify the surface of the substrate W after etching. During the etching process, the suction ring around the support plate 821 can slowly extract gas, allowing the etching gas to remain in the etching gas diffusion channel for a longer time to produce a sufficient amount of etching on the surface of the substrate W. After etching is completed, the etching gas delivered by the gas inlet 801 can be switched to high-speed purified gas and sprayed downwards. At the same time, the gas extraction ring also becomes a high-speed gas extraction ring. This can quickly extract the residual etching gas and reaction byproducts in the etching gas diffusion channel. Then, the base 810 is lowered to separate the substrate W from the mask plate 820 above it.
[0093] In addition, other structures and the operating modes of each component in this embodiment, such as the structure of the first gas channel 723 and the structure of the second gas channel 724, are similar to or the same as those in Embodiment 1, and will not be described in detail here.
[0094] In summary, the etching apparatus, substrate processing system, and device fabrication method of the present invention combine a mask 120 with a support plate 121 and an elastic dielectric layer 122 with a base 110. During the process, at least a portion of the bottom area of the mask 120 is brought into contact with the upper surface of the substrate W, allowing etching gas to contact the surface of the substrate W within the etching gas diffusion channel of the mask 120 to etch isolation trenches 130 on the substrate W surface. This apparatus simplifies the substrate W surface processing steps, forming patterned etching in a single step without the need for additional masks, resulting in multiple isolation trenches 130 on the substrate W surface. This reduces the overall stress on the substrate W surface and improves the yield of device production. Furthermore, this etching apparatus eliminates the need for additional expensive equipment such as lithography machines and photoresist coating machines in the entire substrate processing system, reducing production input costs and significantly improving the economic efficiency of device production. On the other hand, the mask 120 contacts the substrate W through the elastic dielectric layer 122 at the bottom of the support plate 121, which avoids causing hard damage to the surface of the substrate W and helps to ensure the quality of device fabrication.
[0095] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.
Claims
1. An etching apparatus, characterized in that, It is used to form isolation trenches on the surface of a substrate, and includes: An etching chamber, wherein a gas inlet is provided on the chamber body, and the gas inlet is used to deliver etching gas; A base for supporting the substrate is located inside the etching cavity; A mask plate is located between the gas inlet and the base, the distance between the mask plate and the base is adjustable, and the mask plate is detachable and replaceable; wherein, the mask plate comprises: The support plate has multiple primary gas channels. An elastic dielectric layer is located at the bottom of the support plate. The bottom of the support plate is provided with multiple elastic dielectric layer coverage areas and multiple second gas channels located between different elastic dielectric layer coverage areas. The multiple first gas channels pass through the support plate and communicate with the second gas channels to form an etching gas diffusion channel. During the process, at least a portion of the bottom of the mask plate is attached to the upper surface of the substrate, and the portion of the upper surface of the substrate that is not attached to the bottom of the mask plate is exposed at the outlet of the second gas channel, so that the etching gas comes into contact with the substrate below when flowing through the second gas channel.
2. The etching apparatus as described in claim 1, characterized in that, The first gas channel includes a through hole; And / or, the second gas channel is a through hole or a through groove.
3. The etching apparatus as described in claim 1, characterized in that, The width of the first gas channel ranges from 5 μm to 10 μm; And / or, the width of the second gas channel is less than 15 μm; And / or, the width of the second gas channel is greater than or equal to the width of the first gas channel.
4. The etching apparatus as described in claim 1, characterized in that, The material used to prepare the support plate includes metal; And / or, the material used to prepare the elastic medium layer includes at least one of fluororubber, Teflon, and polymer materials.
5. The etching apparatus as described in claim 1, characterized in that, Also includes: The gas extraction channel is a gas diffusion space between the mask plate and the gas inlet, and the gas extraction channel is connected to the first gas channel located at the circumferential edge to discharge the reaction waste gas.
6. The etching apparatus as described in claim 5, characterized in that, An elastic medium layer is provided on the outer periphery of the lower surface of the support plate to form a sealing ring. The exhaust gas generated in the second gas channel is connected upward to the extraction channel through the first gas channel located at both ends of the second gas channel and near the sealing ring.
7. The etching apparatus as described in claim 6, characterized in that, The upper surface of the support plate includes multiple connecting pipes, which are connected between multiple first gas channels for exhaust and extraction channels; or the upper surface of the support plate includes an annular extraction ring, which is connected between multiple first gas channels for exhaust and extraction channels.
8. The etching apparatus as described in claim 5, characterized in that, The mask plate is connected to the top of the etching cavity through an upwardly extending sidewall. The mask plate, the upwardly extending sidewall of the mask plate, and the top of the etching cavity together form a gas diffusion cavity.
9. The etching apparatus as described in claim 5, characterized in that, The bottom of the etching cavity is provided with an exhaust port, and the air extraction channel is connected to the exhaust port; Alternatively, the evacuation channel passes through an opening in the etching cavity and is connected to a vacuum extraction device located outside the etching cavity.
10. The etching apparatus as claimed in claim 1, characterized in that, The projection of the second gas channel onto the substrate coincides with at least a portion of the dicing line of the substrate.
11. The etching apparatus as claimed in claim 1, characterized in that, The mask plate is raised and lowered by a lifting rod; And / or, the base is raised and lowered by a lifting column.
12. The etching apparatus as described in claim 1, characterized in that, The mask includes a downwardly extending lower portion that contacts and presses against the outer edge of the upper surface of the base when at least a portion of the bottom of the mask is in contact with the upper surface of the substrate.
13. The etching apparatus as claimed in claim 1, characterized in that, At least a portion of the surface of the mask plate is provided with a corrosion-resistant film layer.
14. The etching apparatus as claimed in claim 1, characterized in that, Also includes: A remote plasma source that supplies etching gas into the etching chamber through the gas inlet; Alternatively, a gas supply device that supplies etching gas into the etching chamber through the gas inlet.
15. A substrate processing system, characterized in that, Include: The etching apparatus according to any one of claims 1 to 14 is used to form isolation trenches on the surface of a substrate; A thin film deposition chamber, used to deposit thin films on a substrate surface; The transfer cavity is connected to both the etching cavity of the etching apparatus and the thin film deposition cavity.
16. The substrate processing system as claimed in claim 15, characterized in that, Also includes: The loading and unloading cavity is connected to the transfer cavity and is used for loading and unloading the substrate.
17. A method for fabricating a device, characterized in that, Include: A buffer layer is grown on the substrate; The substrate with the buffer layer grown is processed using the etching apparatus as described in any one of claims 1 to 14 to form an isolation trench on the substrate; Thin films are deposited on a substrate containing isolation trenches to fabricate the target device.
18. The method for fabricating the device as described in claim 17, characterized in that, Also includes: Before depositing a thin film on the substrate, the substrate surface is cleaned with a cleaning gas.