Tray structure for apcvd apparatus and wafer placement method in wafer back sealing process thereof

Abstract

The application relates to the field of semiconductor manufacturing equipment, and discloses a tray structure for an APCVD device and a wafer placement method in a wafer back sealing process of the tray structure. The tray structure comprises a silicon carbide tray body and a support assembly arranged on the upper surface of the silicon carbide tray body and used for supporting a wafer to be processed. The support assembly is composed of at least two high-purity tungsten wires which extend along the same direction and are arranged in parallel to each other. The high-purity tungsten wires are located in a wafer placement area of the silicon carbide tray body, and the high-purity tungsten wires are the only support structure for forming a gap between the wafer to be processed and the upper surface of the silicon carbide tray body. The high-purity tungsten wires form a micro gap between the wafer to be processed and the upper surface of the silicon carbide tray body. The technical problem that the Bernoulli chuck adsorption success rate is low due to the excessive adhesion between the wafer back surface and the tray surface, thereby causing production interruption and wafer loss risk can be solved.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing equipment, and particularly to a tray structure for APCVD equipment and a wafer placement method in the wafer back-sealing process thereof. Background Technology

[0002] In semiconductor chip manufacturing, wafer back-sealing is a crucial step in ensuring the structural integrity and reliability of semiconductor epitaxial wafers or device wafers. By depositing a protective layer of a specific material on the back of the wafer, wafer back-sealing effectively improves the wafer's mechanical strength and electrical balance, and prevents autodoping during subsequent high-temperature processes. Atmospheric pressure chemical vapor deposition (APCVD) equipment, as the core equipment for realizing wafer back-sealing, plays a vital role in semiconductor film deposition production lines, ensuring process compatibility and thin film growth quality.

[0003] During the wafer back-sealing process in APCVD equipment, the wafers to be processed are typically placed horizontally on the upper surface of a silicon carbide tray. The silicon carbide tray, with its high thermal conductivity and chemical stability, supports the wafer during thin film deposition. After the atmospheric pressure chemical vapor deposition process is complete, the semiconductor manufacturing system uses the negative pressure effect generated by a Bernoulli chuck to pick up the wafer from the silicon carbide tray and transfer it to subsequent processes. The Bernoulli chuck achieves non-contact or slight-contact gripping of the wafer by creating a pressure difference through a high-speed airflow above it.

[0004] However, the inventors discovered at least the following technical problems in the relevant technology: After the wafer back-sealing process is completed, the existing APCVD equipment exhibits significant interfacial adhesion between the wafer back side and the silicon carbide tray surface due to excessively tight contact. When the Bernoulli chuck attempts to pick up the wafer, the extremely small gap between the wafer and the silicon carbide tray makes it difficult for gas to be quickly replenished to the bottom of the wafer. This prevents the Bernoulli chuck from generating an upward lifting force sufficient to overcome the interfacial adhesion, leading to frequent wafer adsorption failures. Wafer adsorption failures not only cause frequent shutdowns of the film deposition production line, reducing the operating efficiency of semiconductor manufacturing equipment, but also significantly increase the risk of wafer scratches, breakage, and contamination during manual intervention. Summary of the Invention

[0005] One objective of this application is to provide a tray structure for APCVD equipment and a wafer placement method in the wafer back-sealing process, at least to solve the technical problem in the related art where the high adhesion force between the back of the wafer and the tray surface leads to a low success rate of Bernoulli chuck adsorption, which in turn causes production interruption and wafer loss risk.

[0006] To achieve the above objectives, some embodiments of this application provide the following aspects:

[0007] In a first aspect, some embodiments of this application provide a tray structure for an APCVD equipment, the tray structure comprising: a silicon carbide tray body; and a support component disposed on the upper surface of the silicon carbide tray body for supporting a wafer to be processed; wherein the support component consists of at least two high-purity tungsten wires extending in the same direction and arranged parallel to each other, the high-purity tungsten wires being located within the wafer placement area of ​​the silicon carbide tray body, and the high-purity tungsten wires being the only support structure forming a gap between the wafer to be processed and the upper surface of the silicon carbide tray body, the high-purity tungsten wires forming a micro-gap between the wafer to be processed and the upper surface of the silicon carbide tray body.

[0008] Secondly, some embodiments of this application also provide a wafer placement method in a wafer back-sealing process. The method is applied to the tray structure described above. The method includes: setting at least two parallel high-purity tungsten wires within the wafer placement area of ​​the silicon carbide tray body, making the high-purity tungsten wires the sole support structure between the wafer to be processed and the silicon carbide tray body; placing the wafer to be processed on the high-purity tungsten wires, so that the wafer to be processed is supported by the high-purity tungsten wires; performing a back-sealing deposition process on the wafer to be processed in an APCVD device, during which a micro-gap determined by the height of the high-purity tungsten wires is maintained between the back side of the wafer to be processed and the silicon carbide tray body during deposition; after the deposition process is completed, adsorbing and transferring the wafer to be processed using a Bernoulli chuck; wherein the Bernoulli chuck descends to a predetermined height before adsorption, the predetermined height creating an clearance gap between the Bernoulli chuck and the upper surface of the wafer to be processed.

[0009] Compared with related technologies, the solution provided in this application sets the support component as at least two high-purity tungsten wires extending in the same direction and parallel to each other. These high-purity tungsten wires serve as the sole support structure forming a gap between the wafer and the upper surface of the silicon carbide tray body. This creates a stable micro-gap between the wafer and the tray body. This structural design directly changes the contact method between the wafer and the tray: because high-purity tungsten wires have excellent high-temperature resistance, chemical stability, and precise support height, they can maintain a consistent and extremely small contact area in the APCVD process environment. This effectively avoids the problems of uneven local adsorption or air gap blockage caused by traditional large-area contact. Based on this, after the wafer back-sealing process, this micro-gap structure significantly optimizes the uniformity of the airflow field and the consistency of heat transfer, thereby greatly improving the adsorption success rate of silicon wafers on the silicon carbide tray. This fundamentally reduces the risk of process deviation or downtime caused by adsorption failure, ensuring the stable and efficient operation of the semiconductor manufacturing process. Attached Figure Description

[0010] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0011] Figure 1 A top view of a tray structure for an APCVD equipment provided for some embodiments;

[0012] Figure 2 An AA cross-sectional view of a tray structure for an APCVD equipment provided for some embodiments;

[0013] Figure 3 A schematic diagram of the wafer placement state in a wafer back-sealing process provided in some embodiments;

[0014] Figure 4 An exemplary flowchart of a wafer placement method in a wafer back-sealing process is provided for some embodiments;

[0015] Explanation of reference numerals in the attached diagram: 1-Silicon carbide tray body; 2-Positioning microgroove; 3-High-purity tungsten wire; 4-Wafer placement area; 5-Wafer (to be processed), i.e., wafer to be processed; h-Gap (micro-gap); S-Tungsten wire spacing. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0017] In this embodiment of the disclosure, the collection, storage, use, processing, transmission, provision, and disclosure of user personal information comply with relevant laws and regulations and do not violate public order and good morals.

[0018] The following terms are used in this article.

[0019] APCVD: Atmospheric Pressure Chemical Vapor Deposition.

[0020] First Embodiment

[0021] The first embodiment relates to a tray structure for an APCVD device. For example... Figure 1 and2 As shown, the tray structure includes:

[0022] Silicon carbide tray body 1;

[0023] A support component is disposed on the upper surface of the silicon carbide tray body 1 to support the wafer 5 to be processed;

[0024] The support component consists of at least two high-purity tungsten wires 3 extending in the same direction and arranged parallel to each other. The high-purity tungsten wires 3 are located in the wafer placement area 4 of the silicon carbide tray body 1, and the high-purity tungsten wires 3 are the only support structure that forms a gap between the wafer to be processed 5 and the upper surface of the silicon carbide tray body 1. The high-purity tungsten wires 3 form a micro gap between the wafer to be processed 5 and the upper surface of the silicon carbide tray body 1.

[0025] For example, the tray structure for APCVD equipment can be specifically applied to the AMAYA-6300 APCVD equipment. The AMAYA-6300 equipment, as a commonly used atmospheric pressure chemical vapor deposition film deposition equipment in the industry, is widely used in wafer back-sealing processes due to its stable film quality and high process compatibility. It should be noted that the application of this tray structure is not limited to the aforementioned equipment model.

[0026] Optionally, in some embodiments, the two high-purity tungsten wires 3 are symmetrically arranged about the central axis of the wafer placement area 4.

[0027] Specifically, two high-purity tungsten wires 3 can be fixedly arranged on the upper surface of the silicon carbide tray along the symmetrical direction of the silicon wafer placement area. The purity of the high-purity tungsten wires 3 is not less than 99.95% to ensure that they will not oxidize, deform, or release impurities under the process environment of the APCVD equipment (such as a certain temperature and chemical atmosphere), thereby avoiding contamination of the silicon wafer.

[0028] Optionally, in some embodiments, the length of the high-purity tungsten wire 3 is adapted to the diameter of the wafer placement area 4 on the silicon carbide tray, and the length ranges from 100 mm to 150 mm.

[0029] Specifically, the length of the high-purity tungsten wire 3 is adapted to the diameter of the silicon wafer placement area on the silicon carbide tray, with a length range of 100mm to 150mm. This length can be adjusted according to the actual silicon wafer size to ensure that the tungsten wire can stably support the silicon wafer without exceeding its edge. By matching the tungsten wire length to the wafer placement area 4, effective and uniform support for the wafer can be achieved, avoiding instability due to an excessively short support structure or affecting process uniformity due to excessive length exceeding the edge.

[0030] Optionally, in some embodiments, the diameter of the high-purity tungsten wire 3 ranges from 0.1 mm to 0.3 mm, and the diameter is used to determine the height of the microgap.

[0031] Optionally, in some embodiments, the diameter of the high-purity tungsten wire 3 is matched with the adsorption gap of the Bernoulli chuck, so that the wafer to be processed 5 remains in a non-contact state with the tray body during the adsorption process.

[0032] Specifically, the diameter of the high-purity tungsten wire 3 ranges from 0.1 mm to 0.3 mm, and this diameter determines the height of the micro-gap. Simultaneously, this diameter matches the adsorption gap of the Bernoulli chuck, ensuring that the wafer 5 to be processed remains in a non-contact state with the tray body throughout the adsorption process. By precisely controlling the tungsten wire diameter, on the one hand, a stable and consistent micro-gap can be formed, optimizing the airflow field and heat transfer uniformity during the process; on the other hand, this diameter design, in synergy with the adsorption gap of the Bernoulli chuck, ensures that the wafer remains in a non-contact state with the tray body throughout the adsorption, transport, and processing processes, avoiding backside contamination or scratches caused by contact. This significantly improves the adsorption success rate of silicon wafers on the silicon carbide tray after the wafer back-sealing process, ensuring the stable and efficient operation of the semiconductor manufacturing process.

[0033] Optionally, in some embodiments, the high-purity tungsten wire 3 is positioned within the wafer placement area 4 in the force support area of ​​the wafer to be processed 5, so that the wafer to be processed 5 maintains force balance during deposition and adsorption.

[0034] Specifically, the force-supported region refers to the area where the wafer can form a stable torque balance when subjected to the non-contact adsorption force of the Bernoulli chuck and its own gravity. By arranging high-purity tungsten wire 3 in this region, the supporting force and adsorption force on the wafer during the process can work synergistically, avoiding wafer tilting, local contact, or vibration displacement caused by force point offset. Through this design, the wafer can maintain a stable spatial orientation during the adsorption process after atmospheric pressure chemical vapor deposition and wafer back sealing, thereby improving the adsorption success rate and reducing the risk of process defects or fragmentation caused by uneven force.

[0035] Optionally, in some embodiments, the spacing between the two high-purity tungsten wires 3 is smaller than the diameter of the wafer 5 to be processed.

[0036] Specifically, by setting the spacing between the two high-purity tungsten filaments 3 to be smaller than the wafer diameter, it can be ensured that both tungsten filaments are located within the wafer's orthogonal projection area when the wafer is placed on the tray, thus providing a two-point support structure for the wafer. This spacing design ensures that the support points remain within the wafer contour during deposition and adsorption, preventing excessively large suspended portions or support failure due to support points extending beyond the wafer edge. This spacing configuration, combined with the setting of the stress support area, further ensures wafer stress balance while ensuring uniform distribution of micro-gap between the wafer and the tray body, improving the stability of the airflow and temperature fields during the process, thereby enhancing adsorption consistency and process reliability after the wafer back-sealing process.

[0037] Understandably, in related technologies, such as the actual operation of the AMAYA-6300 APCVD equipment, after the wafer completes the back-sealing process, it needs to be removed from the silicon carbide tray using a Bernoulli chuck-based adsorption method to proceed to subsequent manufacturing processes. However, under existing technologies, when the silicon wafer is adsorbed onto the silicon carbide tray by the Bernoulli chuck, a "leak adsorption" phenomenon often occurs, meaning the Bernoulli chuck cannot stably and reliably adsorb the silicon wafer, preventing it from being properly transferred to the next process.

[0038] This issue of unadsorbed silicon wafers can lead to a series of serious consequences: It causes equipment downtime, requiring operators to manually handle unadsorbed wafers and restart production only after equipment readjustment, severely disrupting the continuity of the production process. Frequent downtime and troubleshooting significantly reduce overall production efficiency and increase production time costs. Furthermore, manual handling carries the risk of wafer damage or contamination, further impacting product yield and production efficiency. Currently, this problem has become a key bottleneck restricting the stable operation of APCVD equipment after wafer back-sealing processes, and the industry urgently needs an efficient and reliable solution.

[0039] It is not difficult to see that, compared with related technologies, the solution provided in this application provides a more efficient solution. By setting the support component as at least two high-purity tungsten wires extending in the same direction and parallel to each other, and making the high-purity tungsten wires the only support structure forming a gap between the wafer and the upper surface of the silicon carbide tray, a stable micro-gap is formed between the wafer to be processed and the tray. This structural design directly changes the contact method between the wafer and the tray: because the high-purity tungsten wires have excellent high-temperature resistance, chemical stability, and precise support height, they can maintain a consistent and extremely small contact area in the APCVD process environment, thereby effectively avoiding the problems of uneven local adsorption or air gap blockage caused by traditional large-area contact. Based on this, after the wafer back-sealing process, this micro-gap structure significantly optimizes the uniformity of the airflow field and the consistency of heat transfer, thereby greatly improving the adsorption success rate of silicon wafers on the silicon carbide tray, reducing the risk of process deviation or downtime caused by adsorption failure from the root, and ensuring the stable and efficient operation of the semiconductor production process.

[0040] Compared with the prior art, the improved structure and method of the present invention have at least the following beneficial effects:

[0041] 1. Significantly improve adsorption success rate: The success rate of adsorption on silicon wafers in one step has been increased from 70%-80% in the existing solution to over 98%.

[0042] 2. No adverse effects and strong compatibility: The selected high-purity tungsten wire has excellent high-temperature resistance and corrosion resistance. Under the process temperature (up to about 400℃) and chemical atmosphere (such as gases containing silane and ammonia) of the AMAYA-6300 APCVD equipment, the high-purity tungsten wire will not oxidize, decompose, or release impurities, thus avoiding contamination of the silicon wafer back seal quality. At the same time, the improved structure only requires adding tungsten wire to the original silicon carbide tray, without modifying the mechanical structure and control system of the equipment. It is fully compatible with the original equipment and has the characteristics of low modification difficulty and low modification cost.

[0043] 3. Feasibility verified and easy to promote: The improvement scheme proposed in this application has been horizontally implemented and improved on multiple AMAYA-6300 models internally. After three months of continuous production operation verification, the equipment leakage adsorption failure rate has decreased from the original 3-5 times per day to 0-1 times, production efficiency has increased by approximately 15%, and no silicon wafer quality problems caused by high-purity tungsten wire have occurred. The feasibility, stability, and reliability of this scheme have been fully verified, and it is ready for widespread promotion among similar equipment in the industry.

[0044] Second Embodiment

[0045] The second embodiment relates to a tray structure for an APCVD equipment. The second embodiment is an improvement on the first embodiment, specifically in that: in this embodiment, the upper surface of the silicon carbide tray body 1 is provided with positioning microgrooves 2 for accommodating the high-purity tungsten wire 3.

[0046] Specifically, in some embodiments, the upper surface of the silicon carbide tray body 1 is provided with a positioning microgroove 2 for accommodating the high-purity tungsten wire 3, and the high-purity tungsten wire 3 is embedded in the positioning microgroove 2 to limit the displacement of the high-purity tungsten wire 3 during the process.

[0047] Specifically, through this positioning microgroove 2 structure, the high-purity tungsten wire 3 can maintain a preset fixed position under the process environment of APCVD equipment (including temperature changes, airflow impact, and the force during the adsorption process), avoiding changes in support points or uneven micro-gap caused by the tungsten wire rolling, shifting, or twisting. This structural design can ensure the positional accuracy and repeatability of the tungsten wire in long-term use, and simplify the positioning operation in the assembly process. Thus, it can improve process stability while reducing maintenance difficulty, and provide a reliable structural basis for the efficient and stable adsorption of silicon wafers after the wafer back-sealing process.

[0048] Optionally, in some embodiments, the positioning microgroove 2 extends along the diameter direction of the wafer placement area 4. By setting the positioning microgroove 2 to extend along the diameter direction of the wafer placement area 4, the high-purity tungsten wire 3 embedded in the positioning microgroove 2 can be aligned with the diameter direction of the wafer, thereby ensuring that the two high-purity tungsten wires 3 are parallel and symmetrically distributed below the wafer, and the support point is located at the optimal position for wafer force balance. This extension direction design facilitates automatic alignment during wafer placement, ensuring uniform force on the wafer during deposition and adsorption, avoiding wafer tilting or local stress concentration due to support direction deviation, and further ensuring adsorption stability and process consistency after wafer back sealing process.

[0049] Third Embodiment

[0050] The third embodiment relates to a wafer placement method in a wafer back-sealing process. The method provided in the third embodiment is applied to a tray structure as described in the first and / or second embodiments.

[0051] Specifically, such as Figures 3-4 As shown, the method may include the following steps:

[0052] Step S1: At least two parallel high-purity tungsten wires 3 are arranged in the wafer placement area 4 of the silicon carbide tray body 1, so that the high-purity tungsten wires 3 serve as the only support structure between the wafer to be processed 5 and the silicon carbide tray body 1.

[0053] Step S2: Place the wafer 5 to be processed on the high-purity tungsten wire 3, so that the wafer 5 to be processed is supported by the high-purity tungsten wire 3.

[0054] Step S3: Perform a back-sealing deposition process on the wafer 5 to be processed in the APCVD equipment. During the deposition process, the back side of the wafer 5 to be processed and the silicon carbide tray body 1 maintain the micro gap determined by the height of the high-purity tungsten wire 3.

[0055] Step S4: After the deposition process is completed, the wafer 5 to be processed is adsorbed and transferred by a Bernoulli chuck; wherein, the Bernoulli chuck is lowered to a predetermined height before adsorption, and the predetermined height creates an clearance gap between the Bernoulli chuck and the upper surface of the wafer 5 to be processed.

[0056] The following sections provide detailed explanations of each step.

[0057] Specifically, for step S1, by setting the high-purity tungsten wire 3 as the only support structure, the problem of uneven contact caused by large-area contact or complex support structure in the traditional solution can be eliminated. This ensures that the wafer only forms point or line contact with the high-purity tungsten wire 3 during the process, thereby providing a stable and consistent support foundation for subsequent deposition processes and adsorption transfer, which is conducive to improving the adsorption success rate after the wafer back sealing process.

[0058] Specifically, step S2 achieves precise positioning and stable placement of the wafer on the silicon carbide tray. Since the high-purity tungsten wires 3 are arranged parallel to the diameter of the wafer placement area 4 and the spacing is smaller than the wafer diameter, the wafer naturally falls on the two tungsten wires under the action of gravity, forming a stable two-point support state. This placement method ensures that a uniform micro-gap determined by the diameter of the tungsten wires is formed between the wafer and the tray body, creating favorable conditions for the uniform distribution of airflow and the consistency of heat transfer in the subsequent deposition process.

[0059] Specifically, regarding step S3, on the one hand, the micro-gap allows the process gas to flow uniformly through the back side of the wafer, avoiding airflow dead zones or uneven deposition caused by the back side being tightly attached to the tray; on the other hand, the micro-gap reduces the direct thermal conduction contact between the wafer and the tray, making the wafer temperature distribution more uniform, thereby improving the film quality of the back seal layer and ensuring the stability of the wafer surface state in subsequent adsorption processes.

[0060] Specifically, regarding step S4, this design pre-forms an clearance gap before adsorption, preventing the Bernoulli chuck from physically colliding or contacting the wafer's upper surface during descent, effectively reducing the risk of wafer damage. Simultaneously, this clearance gap, in conjunction with the micro-gap formed by the high-purity tungsten wire 3, enables the Bernoulli chuck to generate a stable airflow field when adsorption is initiated, thereby achieving smooth wafer lifting and reliable adsorption, significantly improving the transfer success rate after the wafer back-sealing process.

[0061] Optionally, in some embodiments, the back-sealing deposition process is carried out in a reaction environment containing silane gas and ammonia gas at a process temperature of 400°C.

[0062] Specifically, the process conditions are typical back-sealing deposition environments in APCVD equipment. Silane and ammonia react at high temperatures to generate a silicon nitride film, achieving passivation protection for the back side of the wafer. Under this temperature and chemical atmosphere, high-purity tungsten wire 3, with a purity of no less than 99.95% and excellent high-temperature and corrosion resistance, will not oxidize, deform, or release impurities, thus ensuring that the micro-gap structure remains stable during long-term process cycles. This avoids back-sealing contamination or process drift due to tungsten wire material issues, providing a reliable material basis for high-quality film formation and stable adsorption after the wafer back-sealing process.

[0063] Optionally, in some embodiments, during the back-sealing deposition process, the gap between the back side of the wafer and the tray body remains constant throughout the entire process. This constant micro-gap is determined by the precise diameter of the high-purity tungsten wire 3, and thanks to the material properties of the high-purity tungsten wire 3—which does not oxidize, deform, or creep under a process temperature of 400°C and chemical atmospheres such as silane and ammonia—as well as the fixing effect of the positioning microgroove 2 on the position of the tungsten wire, the micro-gap is unaffected by factors such as thermal expansion, airflow impact, or equipment vibration throughout the deposition process. This constancy ensures that the flow path and velocity distribution of the process gas on the back side of the wafer remain consistent, thereby guaranteeing the uniformity and density of the back-sealing layer thickness. Simultaneously, it provides structural assurance for the repeatability of the wafer orientation during subsequent Bernoulli chuck adsorption, further improving the adsorption success rate and process stability after the wafer back-sealing process.

[0064] It is not difficult to see that this embodiment is a method embodiment corresponding to the first embodiment and / or the second embodiment, and this embodiment can be implemented in conjunction with the first embodiment and / or the second embodiment. The relevant technical details mentioned in the first embodiment and / or the second embodiment are still valid in this embodiment, and will not be repeated here to reduce repetition. Accordingly, the relevant technical details mentioned in this embodiment can also be applied to the first embodiment and / or the second embodiment.

[0065] Fourth embodiment

[0066] The fourth embodiment relates to a wafer placement method in a wafer back-sealing process. The fourth embodiment is an improvement upon the third embodiment, specifically in that the predetermined height is dynamically adjusted based on the thickness of the wafer 5 to be processed and the height of the micro-gap.

[0067] Optionally, in some embodiments, the predetermined height is calculated and determined based on the thickness of the wafer 5 to be processed, the height of the micro-gap, the stable distance of the adsorption flow field of the Bernoulli chuck, and a preset safety compensation amount;

[0068] The predetermined height is calculated using the following formula:

[0069] ;

[0070] in, Indicates the predetermined height, Indicates the thickness of the wafer 5 to be processed, Indicates the height of the micro-gap, This represents the stable adsorption flow field distance, which is the minimum working distance required for the Bernoulli chuck to form a stable negative pressure flow field. This indicates the preset safety compensation amount.

[0071] For example, suppose the thickness of wafer 5 to be processed is... The height of the micro-gap is 0.725 mm. The stable adsorption flow distance of the Bernoulli chuck is determined by the diameter of the high-purity tungsten wire, which is set to 0.2 mm. The tolerance is 2.5mm, with a preset safety compensation amount. If we take 0.5mm, then the predetermined height is... =0.725+0.2+2.5+0.5=3.925mm. This formula precisely calculates the predetermined height, ensuring a reasonable clearance between the Bernoulli chuck and the wafer's upper surface during descent, preventing physical contact between the chuck and the wafer. Simultaneously, this predetermined height ensures the chuck is within the stable negative pressure flow field at the start of adsorption, allowing the wafer to be smoothly lifted and detached from the high-purity tungsten wire 3, achieving non-contact adsorption transfer. This quantitative design method avoids the uncertainties associated with experience-based adjustments, significantly improving the reliability and repeatability of the adsorption process, further guaranteeing the success rate of transfer after wafer back-sealing.

[0072] Optionally, in some embodiments, the predetermined height is calculated using the following formula:

[0073] ;

[0074] in, Indicates the predetermined height, Indicates the thickness of the wafer 5 to be processed, Indicates the height of the micro-gap, This represents the stable adsorption flow field distance, which is the minimum working distance required for the Bernoulli chuck to form a stable negative pressure flow field. Indicates the preset safety compensation amount, This is the flow field stability correction factor. This is the adsorption safety correction factor; and The process parameters of the APCVD equipment are preset.

[0075] For example, suppose the thickness of wafer 5 to be processed is... The height of the micro-gap is 0.725 mm. The stable adsorption flow distance of the Bernoulli chuck is determined by the diameter of the high-purity tungsten wire, which is set to 0.2 mm. The tolerance is 2.5mm, with a preset safety compensation amount. Take 0.5mm. Based on the process parameters of the APCVD equipment, if the process environment (such as temperature and airflow velocity) interferes with the formation of the Bernoulli chuck flow field, the flow field stability correction factor can be adjusted. The preset value is 1.2 to enhance the weight of the flow field stabilization distance; at the same time, to cope with wafer thickness tolerances and minor fluctuations in equipment operation, the adsorption safety correction factor can be adjusted. The preset value is 1.5 to amplify the safety compensation effect. This determines the preset height. =0.725+0.2+1.2×2.5+1.5×0.5=0.725+0.2+3.0+0.75=4.675mm.

[0076] In this embodiment, a flow field stability correction coefficient is introduced. Adsorption safety correction factor This allows for precise adjustment of the predetermined height based on the specific process characteristics of the equipment, making the descent position of the Bernoulli suction cup more closely match the adsorption requirements under actual process conditions; flow field stability correction coefficient This ensures that the suction cup can still form a stable negative pressure flow field under different process atmospheres, and the adsorption safety correction coefficient is maintained. This design provides redundant protection against factors such as wafer thickness tolerance and equipment positioning errors. It enhances the adaptability of the adsorption process to process fluctuations and equipment differences, further improving the success rate and robustness of adsorption transfer after wafer back-sealing.

[0077] Specifically, the adsorption process of the Bernoulli chuck relies on a stable gas flow field structure, therefore a certain stable flow field distance needs to be maintained between the chuck and the wafer. This stable flow field distance refers to the minimum gap required between the lower surface of the Bernoulli chuck and the upper surface of the wafer when adsorption is initiated. Within this gap range, the airflow ejected by the chuck can form a continuous and uniform negative pressure flow field, thereby generating sufficient and stable adsorption force to lift the wafer. If the gap is too small, the airflow cannot fully expand, easily forming turbulence or local positive pressure zones, resulting in insufficient or unstable adsorption force. If the gap is too large, the flow field intensity will decrease, and effective adsorption will also fail. By incorporating the stable flow field distance into the calculation formula for the predetermined height and precisely reserving this distance during the descent of the Bernoulli chuck, it can be ensured that the chuck is in the optimal flow field formation range each time adsorption is initiated, thereby avoiding adsorption failure or abnormal wafer orientation due to improper distance, and significantly improving the reliability and consistency of adsorption transfer after wafer back-sealing process.

[0078] Specifically, during the descent of the Bernoulli chuck, the equipment control system can adjust the predetermined height in real time based on the wafer surface height detection signal to maintain the clearance. This real-time correction mechanism uses a height sensor (such as a laser displacement sensor or optical distance sensor) integrated into the equipment to measure the actual height position of the wafer's upper surface before or during the descent of the chuck, and feeds the measured value back to the control system. The control system compares the measured height with the preset theoretical height, calculates the height deviation caused by factors such as wafer thickness tolerance, tray installation deviation, slight differences in the height of the high-purity tungsten filament 3, or thermal expansion, and dynamically adjusts the descent endpoint position of the Bernoulli chuck, thereby ensuring that the preset clearance is always maintained between the chuck and the wafer's upper surface. This correction mechanism effectively eliminates dynamic error sources that cannot be covered by static preset parameters, avoids chuck collisions with the wafer due to accumulated tolerances or excessive clearance affecting the adsorption effect, further improves the adaptability and safety of the adsorption process, and provides closed-loop control assurance for high-reliability transfer after wafer back-sealing process.

[0079] The steps of the various methods described above are only for clarity. In practice, they can be combined into one step or some steps can be split into multiple steps. As long as they include the same logical relationship, they are all within the scope of protection of this application. Adding insignificant modifications or introducing insignificant designs to the algorithm or process, but without changing the core design of the algorithm and process, are also within the scope of protection of this application.

[0080] The flowcharts or block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of devices, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-specific system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0081] The scope of this application is defined by the appended claims rather than the foregoing description, and is therefore intended to encompass all variations falling within the meaning and scope of equivalents of the claims. No reference numerals in the claims should be construed as limiting the scope of the claims. Furthermore, it is clear that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units or devices recited in a device claim may also be implemented by a single unit or device in software or hardware. Terms such as "first," "second," etc., are used only for distinguishing descriptions and do not indicate any particular order, nor should they be construed as indicating or implying relative importance.

[0082] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily made by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims, and the above embodiments should be regarded as exemplary and non-limiting.

Claims

1. A tray structure for APCVD equipment, characterized in that, The tray structure includes: Silicon carbide tray body; A support component is disposed on the upper surface of the silicon carbide tray body for supporting the wafer to be processed; The support component consists of at least two high-purity tungsten wires extending in the same direction and arranged parallel to each other. The high-purity tungsten wires are located in the wafer placement area of ​​the silicon carbide tray body, and the high-purity tungsten wires are the only support structure that forms a gap between the wafer to be processed and the upper surface of the silicon carbide tray body. The high-purity tungsten wires form a micro gap between the wafer to be processed and the upper surface of the silicon carbide tray body.

2. The pallet structure according to claim 1, characterized in that, The diameter of the high-purity tungsten wire ranges from 0.1 mm to 0.3 mm, and the diameter is used to determine the height of the microgap.

3. The pallet structure according to claim 1, characterized in that, The spacing between the two high-purity tungsten wires is smaller than the diameter of the wafer to be processed.

4. The pallet structure according to claim 1, characterized in that, The two high-purity tungsten wires are symmetrically arranged about the central axis of the wafer placement area.

5. The pallet structure according to any one of claims 1-4, characterized in that, The upper surface of the silicon carbide tray body is provided with a positioning microgroove for accommodating the high-purity tungsten wire. The high-purity tungsten wire is embedded in the positioning microgroove to limit the displacement of the high-purity tungsten wire during the process.

6. The pallet structure according to claim 5, characterized in that, The positioning microgroove extends along the diameter of the wafer placement area.

7. A wafer placement method in a wafer back-sealing process, characterized in that, The method is applied to the tray structure as described in any one of claims 1-6, and the method includes: At least two parallel high-purity tungsten wires are arranged in the wafer placement area of ​​the silicon carbide tray body, so that the high-purity tungsten wires serve as the only support structure between the wafer to be processed and the silicon carbide tray body. The wafer to be processed is placed on the high-purity tungsten wire, so that the wafer to be processed is supported by the high-purity tungsten wire; In the APCVD equipment, the wafer to be processed is subjected to a back-sealing deposition process. During the deposition process, the back side of the wafer to be processed and the silicon carbide tray body maintain the micro gap determined by the height of the high-purity tungsten wire. After the deposition process is completed, the wafer to be processed is adsorbed and transferred by a Bernoulli chuck; wherein, the Bernoulli chuck is lowered to a predetermined height before adsorption, and the predetermined height creates an clearance gap between the Bernoulli chuck and the upper surface of the wafer to be processed.

8. The method according to claim 7, characterized in that, The predetermined height is dynamically adjusted based on the thickness of the wafer to be processed and the height of the micro-gap.

9. The method according to claim 7, characterized in that, The predetermined height is calculated and determined based on the thickness of the wafer to be processed, the height of the micro-gap, the stable distance of the adsorption flow field of the Bernoulli chuck, and the preset safety compensation amount. The predetermined height is calculated using the following formula: ； in, Indicates the predetermined height, Indicates the thickness of the wafer to be processed, Indicates the height of the micro-gap, This represents the stable adsorption flow field distance, which is the minimum working distance required for the Bernoulli chuck to form a stable negative pressure flow field. This indicates the preset safety compensation amount.

10. The method according to claim 7, characterized in that, The predetermined height is calculated using the following formula: ； in, Indicates the predetermined height, Indicates the thickness of the wafer to be processed, Indicates the height of the micro-gap, This represents the stable adsorption flow field distance, which is the minimum working distance required for the Bernoulli chuck to form a stable negative pressure flow field. Indicates the preset safety compensation amount, This is the flow field stability correction factor. This is the adsorption safety correction factor; and The process parameters of the APCVD equipment are preset.

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