Method and apparatus for substrate cleaning in a stack-die hybrid bonding process

Abstract

A brush box cleaning module is introduced as part of the pretreatment process flow within the integrated hybrid bonding platform. The brush box cleaning module addresses the challenge of achieving high cleanliness levels on the front and back surfaces of the die, particularly the technical challenge of achieving high cleanliness levels on the front and back surfaces of the die by removing residues and particles induced by the back surface grinding tape and dicing tape. The brush box cleaning module efficiently removes stubborn residues and particles through both chemical and mechanical removal, resulting in a clean, passivated surface without causing watermarks, scratches, corrosion, or surface roughness. This disclosed method enhances bonding yield and offers significant advantages over existing methods in die-stack hybrid bonding applications.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to semiconductor manufacturing, and more particularly to a hybrid bonding platform including a brush box module for cleaning a substrate in die-stack bonding applications.

Background Art

[0002] Semiconductor devices are widely used in a variety of electronic products and systems ranging from consumer electronics to industrial and military applications. As the demand for increasingly complex and miniaturized electronic devices continues to grow, the semiconductor manufacturing industry has pursued the development of advanced packaging technologies that enable the integration of multiple dies or layers within a single device. Die-stack bonding, a method of stacking dies vertically on top of each other, is one such advanced packaging technology that offers benefits such as increased functionality, reduced form factor, and improved performance.

[0003] In die-stack bonding applications, the cleanliness of the die surface is important for achieving high bonding yields and reliability. Contaminants such as residues and particles incorporated during wafer processing, backgrinding, dicing, or other manufacturing steps can negatively impact the bonding process and lead to defects or failures in the resulting semiconductor device. To address this problem, various cleaning methods have been developed to remove contaminants from the die surface prior to bonding.

[0004] One such cleaning method is wet cleaning, which typically involves using liquid chemicals such as solvents, acids, or bases to remove contaminants from the die surface. Wet cleaning processes may utilize megasonic or atomizer cleaning techniques to enhance contaminant removal. However, these wet cleaning methods have limitations, particularly in their ability to remove stubborn residues and particles induced by back-grinding tape or dicing tape from the die surface. Furthermore, wet cleaning processes can sometimes produce undesirable side effects such as watermarks, scratches, corrosion, or surface roughness, which can negatively impact the bonding process and device performance.

[0005] To overcome the limitations of wet cleaning, various alternative cleaning methods have been proposed in related technologies. These methods include, among others, dry cleaning, plasma cleaning, and laser cleaning. While these alternative cleaning methods offer certain advantages, they are not always effective in all situations or suitable for all substrate materials, and they may have their own limitations and drawbacks.

[0006] Considering the above, there is still a need for improved cleaning methods and systems for die-stack bonding applications that effectively remove residues and particles from the die surface without causing undesirable side effects and are adaptable for use in various bonding embodiments such as die-to-wafer and wafer-to-wafer bonding. This need is addressed by providing an integrated hybrid bonding platform that includes a brushbox cleaning module for enhanced substrate surface cleaning. [Overview of the Initiative]

[0007] Embodiments described herein provide a hybrid bonding platform, a brush box assembly for cleaning substrates, and a method for manufacturing stacked semiconductor structures that address the needs identified above.

[0008] In a first aspect, an embodiment of the present disclosure provides a hybrid bonding platform comprising: a substrate handling system configured to transport a substrate within the platform; a brush box cleaning module configured to clean the surface of the substrate by removing residues and particles; a bonding module configured to bond the die of the substrate; and a controller configured to control the substrate handling system, the brush box cleaning module, and the bonding module.

[0009] In a second aspect, an embodiment of the present disclosure provides a brush box assembly for cleaning a substrate in a hybrid bonding platform, the brush box assembly comprising a housing configured to surround a substrate, a plurality of brushes configured to engage with the surface of the substrate, and a cleaning agent supply system configured to supply a cleaning agent to the plurality of brushes.

[0010] In a third aspect, embodiments of the present disclosure provide a method for manufacturing a stacked semiconductor structure, the method comprising: providing a substrate comprising a plurality of dies; cleaning the surface of the substrate using a brushbox cleaning module to remove residues and particles; and bonding the dies of the substrate using a hybrid bonding process.

[0011] These aspects, features, and advantages of the present disclosure, as well as other aspects, features, and advantages, will become more apparent from the following detailed description when considered together with the accompanying drawings.

[0012] A more detailed description of this disclosure can be obtained by referring to one or more embodiments shown in the accompanying drawings, some of which are used to understand the enumerated features of this disclosure in detail. However, it should be noted that the accompanying drawings show only one or more embodiments of several embodiments, and therefore, one or more embodiments provided in the drawings should not be considered to limit the broadest interpretation of the scope of detail. Other effective embodiments that may be described in the detailed description may be considered part of the imagined scope of detail. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram of an exemplary hybrid bonding platform according to one or more embodiments. [Figure 2A] This is an isometric view of an example of a brush cleaner used in the hybrid bonding platform shown in Figure 1, according to one or more embodiments. [Figure 2B] This is a top view of the brush cleaner shown in Figure 2A, according to one or more embodiments. [Figure 2C] This is an isometric view of a loaded (with a circuit board loaded inside) scrubbing device, arranged inside a brush cleaner, according to one or more embodiments. [Figure 2D] This is an isometric view of an idle scrubbing device (without a circuit board installed) placed inside a brush cleaner, according to one or more embodiments. [Figure 3] This flowchart illustrates an exemplary process for manufacturing a stacked semiconductor structure according to one or more embodiments. [Modes for carrying out the invention]

[0014] To facilitate understanding and better recognition of the scope described, in some examples, the same or related reference numerals have been used to indicate identical or similar elements common to the figures, where possible. Without further mention, those skilled in the art may recognize that elements and features of one embodiment may be usefully incorporated into one or more other embodiments.

[0015] Embodiments described herein provide improved methods and systems for cleaning substrates in die-stack bonding applications by incorporating a brushbox module into an integrated hybrid bonding platform for advanced packaging. The brushbox module effectively removes residues and particles from the die surface without causing watermarks, scratches, corrosion, or surface roughness, which leads to enhanced bonding yield.

[0016] Figure 1 shows a schematic diagram of an exemplary integrated hybrid bonding platform 100 for advanced packaging according to one embodiment of the present disclosure. The hybrid bonding platform 100 is designed to facilitate precise and efficient bonding of semiconductor devices by an automated process. In one embodiment, the hybrid bonding platform 100 comprises an Equipment Front End Module (EFEM) 102 responsible for loading and unloading substrates from a number of substrate cassettes 110; surface preparation modules 104 and 106 designed to clean and activate substrates in preparation for bonding; a bonding module 108 responsible for executing a hybrid bonding process, including bonding a source substrate 110A to a target substrate 110B; and a system controller 112 for managing and coordinating the operation of the various modules within the hybrid bonding platform 100.

[0017] The instrument front-end module (EFEM) 102 disclosed in the integrated hybrid bonding platform 100 comprises a support structure configured to house a plurality of substrate cassettes 110, the substrate cassettes 110 being adapted to hold source substrates 110A and target substrates 110B. The EFEM 102 further includes a housing 111 enclosing a chamber, the chamber providing a controlled environment for substrate handling and processing. The enclosed chamber is configured to maintain the cleanliness and integrity of the substrates by reducing the risk of contamination and exposure to external factors during the bonding process. In addition, the instrument front-end module 102 is equipped with one or more factory interface robots 113, the robots operably connected to the chamber and configured to transfer substrates between the substrate cassettes and various modules of the hybrid bonding platform 100. The factory interface robots 113 ensure precise and efficient movement of substrates within the system by automating substrate transfer, thereby contributing to the overall effectiveness of the hybrid bonding process.

[0018] The surface preparation module 104 is designed to perform a series of cleaning and activation steps on a substrate, such as a semiconductor wafer, using an integrated and automated system. In one embodiment, the surface preparation module 104 comprises an automated modular mainframe (AMM) 130A, a brush box cleaning module 140A, a wet cleaning module 150A, a degassing module 160A, and a plasma module 170A.

[0019] The automated module mainframe (AMM) 130A acts as the central hub of the system, coordinating the transfer of substrates between different submodules. This mainframe utilizes substrate transfer robots to move substrates between various process stations, ensuring precise handling and minimization of the risk of contamination or damage. The automated module mainframe 130A includes a wafer aligner 132A and an in-line measurement system 134A. These components work together to ensure proper substrate alignment and verification of surface characteristics before and after the surface preparation process. The wafer aligner 132A is configured to precisely align the substrates, ensuring that the substrates are precisely positioned according to the requirements of the bonding process. The in-line measurement system 134A is adapted to measure and verify substrate surface characteristics, including cleanliness, activation level, and other relevant parameters, both before and after the surface preparation module 104 performs the cleaning and activation steps.

[0020] The brush box cleaning module 140A provides mechanical cleaning of substrate surfaces by removing particles and contaminants using brushes or other mechanical scrubbing means. To achieve a desired level of cleanliness, this module can be customized to use different brush materials, rotation speeds, and cleaning chemistry.

[0021] The wet cleaning module 150A is responsible for the chemical cleaning of substrates, removing contaminants that may not be effectively removed by mechanical means using a variety of liquid cleaning agents. These cleaning agents may include deionized water, acids, bases, or other specialized chemistry, depending on the specific requirements of the process and substrate material.

[0022] The degassing module 160A is configured to perform outgassing of the substrate by removing residual liquid, gas, and contaminants that may have been adsorbed or trapped on the substrate surface during previous processing steps. This step is important to ensure that the substrate surface is free of contaminants that could interfere with subsequent processing steps.

[0023] The plasma module 170A is designed and configured for effective and efficient radical / plasma RPS / RF cleaning or activation processes. The plasma module 170A includes a remote plasma source (RPS), which can be selectively placed on the top, sidewalls, or any combination thereof of the chamber, providing flexibility in RPS placement. The RPS is further equipped with engineering hardware components such as baffles and / or diffuser plates, which facilitate a uniform distribution of gas or radicals within the chamber, thereby ensuring consistent process control and reproducibility.

[0024] In one or more embodiments, the plasma module 170A is configured to operate in a variety of RPS / RF processes, including but not limited to RPS, RF plasma, RF-assisted RPS, RPS-assisted RF plasma, or pulsed RPS / RF processing. This versatility enables the implementation of tailored cleaning or activation processes depending on the specific substrate material and bonding applications in use.

[0025] The plasma module 170A is further adapted to utilize a range of RPS / RF cleaning or activation gas chemistries, including but not limited to H2, N2, Ar, He, NH3, NF3, and CDA. Such compatibility with various gas chemistries allows the plasma module 170A to adapt to a number of substrate materials and surface conditions, thereby optimizing surface preparation for the hybrid bonding process.

[0026] The surface preparation module 106 may include similar or alternative submodules as needed to address specific substrate cleaning and activation requirements. Collectively, the surface preparation modules 104 and 106 ensure that the source substrate 110A and target substrate 110B are thoroughly cleaned and activated, thereby preparing the substrates for the subsequent bonding process within the integrated hybrid bonding platform 100.

[0027] The bonding module 108 is responsible for bonding the die from the source substrate 110A to the target substrate 110B, following surface preparation. This module plays a key role in ensuring the high precision and reliability required for semiconductor device assembly. The bonding module 108 includes an automated module mainframe (AMM) 130C, a UV module 180, and one or more bonders 190. The automated module mainframe 130C acts as a central control unit, managing and coordinating the operation of the UV module 180 and bonders 190 to ensure efficient and accurate die bonding. The UV module 180 is responsible for weakening the adhesion of the die to the source substrate 110A. Exposure of the tape frame to ultraviolet light alters the molecular structure of the adhesive, reducing its strength and allowing for easy release of the die without damage. Finally, the bonders 190 perform the tasks of picking up, flipping, positioning, and bonding the die. By using a highly precise robotic system, the bonder 190 ensures precise alignment and positioning of the die throughout the hybrid bonding process. The bonder picks up the die from the source substrate 110A, flips the die over to the correct orientation, precisely places the die on the target substrate 110B, and initiates the bonding process. The bonding process may include pressure, heat, or both. Throughout the disclosures provided herein, the terms substrate and wafer are used interchangeably to describe a workpiece containing a number of dies on which one or more of the methods described herein are performed.

[0028] To control one or more components within the integrated hybrid bonding platform 100, the integrated hybrid bonding platform 100 is coupled to a system controller 112, such as a programmable computer. In one embodiment, the system controller 112 may control wafer handling and transfer between different processing modules to execute a process sequence. In another embodiment, the system controller 112 may control the operation of a brush box cleaning module 140, which will be described further later. When in operation, the system controller 112 allows data acquisition and feedback from each component to coordinate processing within the integrated hybrid bonding platform 100. The system controller 112 includes a programmable central processing unit (CPU) 114, which operates together with memory 116 (e.g., non-volatile memory) and support circuits 118. The support circuits 118 (e.g., cache, clock circuit, input / output subsystem, power supply, etc., and combinations thereof) are conventionally coupled to the CPU 114 and also coupled to various components within the integrated hybrid bonding platform 100.

[0029] During operation, the hybrid bonding process flow begins with one or more factory interface robots 113 loading the source substrate 110A and target substrate 110B onto the equipment front-end module 102. The substrates 110A and 110B, which contain multiple dies, are then transported within the integrated hybrid bonding platform 100 by automated module mainframes 130A and 130B.

[0030] Next, to ensure accurate die placement during the bonding process, substrates 110A and 110B are aligned using wafer aligners 132A and 132B. The aligned substrates 110A and 110B are then transported to brush box cleaning modules 140A and 140B, where residues and particles induced by the back-grinding tape or dicing tape are removed from the substrate surface. The brush box cleaning modules 140A and 140B may include a housing configured to surround the substrates 110A and 110B, a plurality of brushes configured to engage with the substrate surface, and a cleaning agent supply system configured to supply cleaning agent to the plurality of brushes.

[0031] Following the initial brush box cleaning, the substrates 110A and 110B are subjected to a wet cleaning step in wet cleaning modules 150A and 150B. The wet cleaning step may include supplying cleaning fluids and rinsing fluids, along with the use of megasonic or atomizer cleaning methods, to remove contaminants from the substrate surface.

[0032] Following wet cleaning, substrates 110A and 110B are transported to degassing modules 160A and 160B, where unwanted gases, moisture, or contaminants are removed from the substrate surface or the surface of the workpiece containing the die. The degassing process typically involves heating the substrate or workpiece to a specific temperature, thereby evaporating or desorbing contaminants, captured gases, or moisture from the surface. In some cases, this process may also involve applying a vacuum or inert gas to facilitate the removal of contaminants. Proper degassing can improve adhesion, reduce defects, and enhance the overall performance of semiconductor devices, particularly in the context of die-stack hybrid bonding applications.

[0033] The degassed substrates 110A and 110B are then processed in plasma modules 170A and 170B for surface activation and further cleaning. During the plasma activation process, the surface of the die or wafer is exposed to a plasma containing charged particles such as ions and electrons. These high-energy ions impact the surface, and this impact activates the surface by creating reactive sites that remove contaminants and increase surface energy and wettability. This activation process makes the surface more hydrophilic and chemically reactive, promoting better adhesion and bonding quality in the hybrid bonding process.

[0034] Subsequently, substrates 110A and 110B are transferred into the chamber of the automated module mainframe 130C and then processed in a UV module 180 coupled to the automated module mainframe 130C to facilitate the release of the die from the adhesive tape frame prior to bonding. The UV module functions by exposing the tape frame holding the die to ultraviolet light. High-energy UV photons interact with the adhesive material, thereby altering the molecular structure of the adhesive. As a result of this change, the adhesive strength decreases, which allows the die to be easily released from the tape frame.

[0035] Finally, the dies on substrates 110A and 110B are bonded using a hybrid bonding process performed by bonder 190A or bonder 190B. In bonder 190, the process of bonding source substrate 110A to target substrate 110B begins with precise alignment of the die on source substrate 110A and the corresponding bonding area on target substrate 110B. This alignment is achieved using advanced alignment systems, such as high-resolution cameras and pattern recognition algorithms, to precisely align the copper interconnects and surrounding dielectric materials on the die or substrate.

[0036] After alignment is achieved, the bonder module 190 picks up individual dies from the source substrate 110A using a pick-and-place mechanism. This mechanism may include a vacuum-based gripping system or other suitable mechanism for handling semiconductor dies. The picked-up dies are then turned over and placed in close proximity to the target substrate 110B.

[0037] To ensure close contact between the surface of the source substrate and the surface of the target substrate, the bonder module 190 may apply a pre-bonding force before the actual bonding step. This pre-bonding force ensures that the copper interconnects and dielectric materials are in close proximity, which is essential for establishing reliable electrical connections and minimizing defects in the bonded structure.

[0038] To initiate the bonding process, the bonder module 190 then applies controlled force and temperature to the source and target substrates. The force and temperature applied during the bonding process depend on the specific bonding technique being used, such as thermocompression bonding or direct bonding. The bonding process may include the formation of molecular bonds between dielectric layers and the fusion of copper pads to establish electrical connections.

[0039] Throughout the bonding process, the bonder module 190 is equipped with sensors and feedback systems to monitor critical parameters such as force, temperature, and alignment accuracy. This real-time monitoring allows for fine-tuning and control of the bonding process to ensure optimal bonding performance and yield.

[0040] After the bonding process is complete, the bonded dies form a stacked semiconductor structure in which the source substrate 110A is bonded to the target substrate 110B. The bonder module 190 then repeats this process for the remaining dies on the source substrate 110A, iteratively creating vertically integrated stacks of dies or substrates.

[0041] The bonding process performed by the Bonder Module 190 ensures optimal electrical connections and minimal defects, resulting in high-performance, compact, and multifunctional semiconductor devices.

[0042] In the die-to-wafer bonding embodiment, individual dies are bonded to a receiving wafer, and the receiving wafer may include pre-patterned bond pads or other structures to facilitate the bonding process. The dies and receiving wafer are first subjected to the previously described cleaning, degassing, plasma treatment, and UV curing steps. The bonder 190 is configured to pick up the individual dies, align them with the receiving wafer, and bond them using a hybrid bonding process. This process may include aligning the bond pads on the dies with the corresponding bond pads on the receiving wafer and applying pressure and heat to form a strong bond between the dies and the receiving wafer.

[0043] One or more embodiments described herein involve bonding a number of dies from a donor wafer to a host wafer simultaneously. In this method, the entire array of dies is aligned and bonded to the host wafer in a single step. In other embodiments, individual dies from the donor wafer are bonded to the host wafer one at a time. In this method, each die is picked up, aligned, and bonded to the host wafer independently.

[0044] In a wafer-to-wafer bonding embodiment, two wafers having aligned patterns are bonded together to form a stacked wafer structure. The wafers are first subjected to the previously described cleaning, degassing, plasma treatment, and UV curing steps. The bonder 190 is configured to align the wafers, which ensures the precise alignment of bond pads or other structures on each wafer. The aligned wafers are then bonded together using a hybrid bonding process, which may include applying pressure and heat to form a strong bond between the two wafers.

[0045] By incorporating a brushbox cleaning module into an integrated hybrid bonding platform, embodiments of the present disclosure provide an effective and efficient method for removing residues and particles from die surfaces in die-stack bonding applications, leading to improved bonding yield and reliability in semiconductor device manufacturing. Embodiments of the present disclosure are adaptable for use in various bonding embodiments, including die-to-wafer and wafer-to-wafer bonding, which provides flexibility in advanced packaging applications.

[0046] Figure 2A is an isometric view of a brush washer 200 that may be used within the integrated hybrid bonding platform 100 described above. For simplicity of discussion, the lid portion of the brush washer 200, including the door, has been removed from Figures 2A and 2B. The brush washer 200 shown in Figure 2A can be a scrubber-type brush box type vertical washer. The exemplary brush washer 200 includes a tank 205 supported by a first support 225 and a second support 230. The brush washer 200 includes actuators 235, each actuator 235 coupled to a cylindrical roller 228 (shown in Figure 2B) placed inside the tank 205. Each actuator 235 may include a drive motor, such as a direct-drive servo motor, adapted to rotate its respective cylindrical roller around axes A' and A'' (shown in Figure 2B). Each actuator 235 is coupled to a controller 112 adapted to control the rotational speed of the cylindrical roller.

[0047] The linkage 210 and actuator 245 are configured to allow cylindrical rollers 228, placed inside the tank 205, to move relative to the main surface of the substrate 201 (shown in Figure 2B). The actuator 245 is coupled to the controller 112 to control the movement of the linkage 210 relative to the substrate positioned between the cylindrical rollers 228. During operation, the first support 225 and the second support 230 may be moved simultaneously relative to the base 240. To allow insertion and / or removal of the substrate 201 from the brush cleaner 200, such movement may bring the first and second cylindrical rollers 228 closer to the substrate 201 as shown in Figure 2C, or separate the first and second cylindrical rollers 228 as shown in Figure 2D.

[0048] Figure 2B is a top view of the brush cleaner 200 of Figure 2A, showing a cylindrical roller 228 in the processing position, where the cylindrical roller 228 is closed to or pressed against the main surface of the substrate 201. The brush cleaner 200 also includes one or more drive motors 244 and rotating devices 247. Each drive motor 244 and rotating device 247 includes a roller 249 located at the end of the output shaft of each drive motor 244 and rotating device 247, the roller 249 being configured to support and / or engage with the substrate 201 and to facilitate the rotation of the substrate 201 around an axis parallel to the horizontal plane (i.e., the XY plane).

[0049] Each of the cylindrical rollers 228 includes a tubular cover (tubular covers 213a, 213b shown in Figures 2C and 2D; not shown in Figure 2B) positioned over it. The tubular covers 213a, 213b may be removable sleeves made of a pad material used for polishing the substrate 201 or for polishing a brush body adapted for cleaning the substrate 201. In this specification, the tubular covers 213a, 213b are also referred to as scrubber brushes. During processing in the brush cleaner 200, the tubular covers 213a, 213b of the cylindrical rollers 228 are rotated by actuators 235, and the substrate 201 is rotated using support rollers 249 coupled to the output shafts of the drive motor 244 and the rotating device 247, while the tubular covers 213a, 213b are brought into contact with the substrate. While the substrate 201 and cylindrical roller 228 are being rotated by various actuators and motors, a second processing fluid, such as deionized (DI) water and / or one or more second substrate cleaning fluids (e.g., aqueous solutions containing acids or bases), is applied to the surface of the substrate 201 from a second fluid source.

[0050] According to one embodiment, a dedicated adjustment device 260 may be provided for each of the cylindrical rollers 228. The adjustment device 260 is sometimes referred to as a “beater bar”. The adjustment device 260 is mounted adjacent to the side wall of the tank 205 by one or more support members 270. The adjustment device 260 is positioned away from the center of the tank 205 so as not to interfere with the substrate transfer and / or substrate polishing or cleaning process. However, the adjustment device 260 is positioned to contact each of the cylindrical rollers 228 when the first and second supports 225, 230 are actuated downward and outward so as to move away from each other. In one embodiment, this movement of the first and second supports 225, 230 causes the cylindrical rollers 228 to contact their respective adjustment devices 260. In this position, the processing surfaces of the tubular covers 213a, 213b on each of the cylindrical rollers 228 may be adjusted during the relative movement between the cylindrical rollers 228 and the adjustment devices 260. In one or more embodiments, a dedicated adjustment device 260 ("beater bar") is used to enhance brush cleaning during the brush cleaning operation.

[0051] Figure 2C is an isometric view of one or more embodiments of a scrubbing device 211 located within a brush cleaning unit 200. The scrubbing device 211 shown in Figure 2C is depicted with the substrate 201 loaded inside, as the scrubbing device 211 is in a loaded state. The scrubbing device 211 comprises a pair of cylindrical rollers 228, including a pair of tubular covers 213a, 213b. In one or more embodiments, the pair of tubular covers 213a, 213b are polyvinyl acetate (PVA) brushes. Each brush includes a set of numerous small knots 215 that are raised across the entire surface of the brush, and a set of numerous valleys 217 that are placed between the knots 215. A pair of cylindrical rollers 228 are supported by a pivot mounting, which is adapted to move a pair of tubular covers 213a, 213b of the cylindrical rollers 228 to contact a substrate 201 (e.g., a semiconductor wafer) supported by a substrate support (sometimes called a wafer support), and to stop contacting the substrate 201 (e.g., a semiconductor wafer). Thus, the pivot mounting allows the cylindrical rollers 228 to move between a closed position and an open position, enabling the substrate 201 to be removed from between the cylindrical rollers 228 and inserted between the cylindrical rollers 228, as described below.

[0052] The scrubbing device 211 also includes a substrate support adapted to support the substrate 201 and to rotate the substrate 201. In one embodiment, the substrate support may include a plurality of rollers 249a-c (Figures 2C-2D), each having a groove adapted to vertically support the substrate 201. A cylindrical roller 228 is coupled to a first motor (or a first plurality of motors) of an actuator 235, which is adapted to rotate the tubular covers 213a and 213b of the cylindrical roller 228 in a clockwise or counterclockwise direction, respectively. A second motor 244 is coupled to rollers 249a and 249c, respectively, which is adapted to rotate rollers 249a and 249c, while a third motor 247 is coupled to roller 249b, which is adapted to rotate roller 249b.

[0053] The scrubbing apparatus 211 may further comprise a plurality of sprayers 221 (including at least 221a, 221b, 221c, and 221d) connected to a source 223 of cleaning fluid via a supply pipe 226. The sprayers 221 are configured to distribute a high-pressure liquid spray onto the substrate surface, which helps remove particles, contaminants, and residues. The sprayers 221 can include a variety of configurations, such as a fluid jet, a spray bar with nozzles, a shower-type spray manifold, or a cryogenic aerosol jet.

[0054] In various embodiments of the present disclosure, the cleaning fluid used in the brush cleaner may include, but is not limited to, deionized (DI) water, diluted citric acid, diluted quaternary ammonium compounds (a mixture of organic solvents such as glycol ether, tetramethylammonium hydroxide and other additives), diluted ammonium hydroxide (NH4OH), diluted hydrogen peroxide (H2O2), a mixture of NH4OH and H2O2 (SC1), diluted hydrofluoric acid, a mixture of sulfuric acid (H2SO4) and hydrogen peroxide (H2O2) (SPM), Electra Clean, or other solutions used for cleaning substrates.

[0055] In one or more embodiments, a sprayer 221 may be positioned to spray cleaning fluid onto the surface of the substrate 201 or one or more scrubber brushes (including, for example, tubular covers 213a, 213b) during the scrubbing process. In one or more embodiments, the substrate cleaning fluid and / or brush cleaning fluid, which will be discussed later, may be supplied from the internal region of the scrubber brushes themselves (e.g., cylindrical roller 228 and tubular covers 213a, 213b). The fluid supplied to the inside of the scrubber brushes passes through the holes in the tubular cover 213 to clean the surface of the substrate or remove debris found on the surface of the scrubber brushes.

[0056] Figure 2D is an isometric view of one or more embodiments of the scrubbing device 211 of the brush cleaner 200, drawn when the scrubbing device 211 is idle and no substrate is loaded. In the idle state, the scrubbing device 211 may perform a brush cleaning operation. In one or more embodiments, when a brush cleaning operation is performed, the scrubbing device 211 cannot be used to perform a substrate cleaning operation. A plurality of sprayers 221 are connected to a source 223 of brush cleaning fluid via a supply pipe 226. The sprayers 221 may be arranged to spray the brush cleaning fluid onto one or more scrubber brushes (including, for example, tubular covers 213a, 213b). In one or more embodiments, the brush cleaning fluid may be supplied by the scrubber brushes themselves.

[0057] In one or more embodiments, the brush cleaning fluid is the same as the substrate cleaning fluid. In one or more embodiments, the brush cleaning fluid is different from the substrate cleaning fluid. For example, the brush cleaning fluid is hydrofluoric acid (e.g., diluted hydrofluoric acid), SPM, or SC1 (e.g., hydrogen peroxide), and the substrate cleaning fluid is a solution different from hydrofluoric acid, SPM, or SC1. In this case, it is desirable to use a brush cleaning fluid configured to efficiently clean the surface of the scrubber brush and remove debris from the surface of the scrubber brush in order to improve the subsequent substrate cleaning step. However, these brush cleaning chemistrys may attack and damage one or more materials placed on the surface of the substrate being cleaned in the brush cleaner 200. Therefore, the brush cleaning process needs to be performed separately from the substrate cleaning process.

[0058] In one or more embodiments, the sprayer 221 includes a first set of sprayers 221a, 221b for substrate cleaning fluid and a second set of sprayers 221c, 221d for brush cleaning fluid. In these embodiments, the supply pipe 226 is divided into separate supplies (not shown) for sources 223 of substrate cleaning fluid and brush cleaning fluid.

[0059] Overall, the brush cleaner 200 ensures efficient cleaning of substrates in a variety of applications. The modular design and adjustable supports allow the brush box to adapt to substrates of different sizes and shapes. Actuators, cylindrical rollers, and adjustment devices work in harmony to provide an optimized cleaning process that minimizes the risk of substrate damage while maximizing cleaning efficiency.

[0060] During operation, the substrate handling system transports the substrate 201 to the brush cleaner 200. To ensure the substrate's position and orientation are accurate when it enters the module, the system employs precise handling techniques and controlled transport. The entire cleaning process is carried out within a housing surrounding the substrate, which provides a controlled environment for the cleaning process. Within this environment, a cleaning agent supply system applies a uniform layer of cleaning agent to the substrate surface, ensuring effective cleaning across the entire surface.

[0061] Once the cleaning agent covers the substrate, a pair of brushes gently scrub the surface, chemically and mechanically removing residues and particles. The brushes work in conjunction with the cleaning agent, optimizing cleaning performance while minimizing the risk of substrate damage. Simultaneously, rollers support and rotate the substrate to ensure that the brushes and cleaning agent effectively clean all areas of the surface. The controller 112 manages various components and adjusts parameters such as brush rotation speed, cleaning agent flow rate, and roller rotation speed to maximize efficiency.

[0062] After scrubbing is complete, the substrate is rinsed with deionized water or another suitable rinse agent. This step removes any remaining detergent and removed particles from the surface. A drying mechanism such as an air knife or spin drying is then used to remove any remaining moisture from the substrate, ensuring a clean and dry surface for subsequent processes.

[0063] After the cleaning process is complete, the substrate handling system transports the cleaned substrates to the next process module. This transport ensures that the substrates maintain their cleanliness and are properly aligned and oriented for subsequent processes.

[0064] Throughout the operation, the controller 112 manages various components within the brush cleaner. This controller 112 ensures accurate and efficient cleaning by adjusting parameters such as brush rotation speed, detergent flow rate, and roller rotation speed. The controller 112 may also provide feedback on cleaning performance, which allows the operator to optimize the process to improve substrate cleanliness and process efficiency.

[0065] In addition to the features described above, one embodiment of the brush box may include optional components and accessories to improve the cleaning performance of the brush box. For example, a temperature control system can be incorporated into the brush box to regulate the temperature of the cleaning fluid, ensuring optimal cleaning conditions for specific substrates and cleaning agents. The brush box can also be configured to support multiple cleaning stages using different cleaning fluids such as cryogenic aerosols, brushes, or other cleaning mechanisms, enabling a more thorough and customized cleaning process tailored to specific substrate requirements. This flexibility makes the brush box suitable for a wide range of industries and applications, including semiconductor manufacturing, solar panel production, glass processing, and various other industries requiring precise and efficient cleaning of substrates.

[0066] In one or more embodiments, to enhance the effectiveness of substrate cleaning in a hybrid bonding process, the brush box module includes an integrated cryogenic aerosol system as a form of cleaning agent supply system. In one embodiment, the integrated cryogenic aerosol system may be a spray bar configured to have a number of cryogenic aerosol jets. The cryogenic aerosol cleaning system consists of a cryogenic aerosol particle source and a nozzle, the nozzle being designed to guide a high-speed jet of cryogenic aerosol particles toward the substrate. The cryogenic aerosol particles are generated from a cryogenic fluid such as liquid nitrogen, liquid carbon dioxide, or liquid argon, which vaporizes and rapidly expands to produce a jet of particles. The aerosol jet can be adjusted to control the angle, direction, and velocity of the cryogenic aerosol particles, thereby ensuring the desired efficient cleaning.

[0067] The brush box module of this embodiment includes a cryogenic aerosol supply system configured to generate cryogenic aerosol particles and guide them toward the substrate surface. The module may also include brushes, which can be used in conjunction with the cryogenic aerosol particles to enhance the cleaning process. The brushes can be designed to engage with the substrate surface, which allows for the mechanical removal of stubborn residues and particles. The cryogenic aerosol particles act as a cleaning agent by impacting surface contaminants, thereby freezing and brittle the contaminants, which then crumble away from the substrate surface. As a result of this combined action of cryogenic aerosol particles and brushes, the cleaning process becomes highly effective and damage-free.

[0068] The controller 112 within the brush box module coordinates the operation of the brush assembly and the cryogenic aerosol cleaning system to optimize cleaning efficiency and substrate compatibility. The cryogenic aerosol cleaning system can operate in pulsed mode or continuous mode depending on specific cleaning requirements and substrate characteristics.

[0069] This brushbox module, with its integrated cryogenic aerosol jet, offers several advantages over conventional cleaning methods. The use of cryogenic aerosol particles eliminates the need for liquid chemicals that can cause watermarks, scratches, corrosion, or surface roughness. In addition, the cryogenic aerosol cleaning process provides a versatile and effective cleaning solution for various types of contaminants and substrate materials, resulting in cleaner and more passivated surfaces suitable for high-yield hybrid bonding applications.

[0070] Figure 3 is a flowchart showing an exemplary process 300 for manufacturing a stacked semiconductor structure according to one embodiment of the present disclosure. Process 300 begins with operation 310, in which a wafer 110 containing multiple dies is first loaded into the equipment front-end module 120 of an integrated hybrid bonding system. The system controller 112 is configured to execute a pre-programmed process sequence that guides the automated module mainframe 130 to transfer the wafer to different modules for processing.

[0071] To remove contaminants from the wafer surface, an optional wet cleaning and drying process may be used in operation 320. A brush box cleaning process (e.g., operation 330) is then performed. The substrate undergoes the brush cleaning process within a brush box cleaning module (e.g., 140A or 140B), which uses a combination of brush rollers, cleaning solution, and a high-pressure sprayer to effectively remove particles and contaminants from the substrate surface.

[0072] Operation 340 represents an optional additional wet cleaning and drying process similar to Operation 320, which may be performed to further enhance the cleanliness of the wafer surface. After these cleaning steps are complete, the wafer is moved to a degassing module, where it is subjected to a thermal process (e.g., Operation 350) that evaporates moisture and other adsorbed contaminants from the wafer surface and reduces the release of plastic gases from the tape frame during subsequent vacuum processing.

[0073] In operation 360, the wafer surface is activated using a plasma module that makes the surface hydrophilic by using ion bombardment, thereby facilitating better bonding. Plasma activation ensures that the bonding process results in a high-quality stacked semiconductor structure.

[0074] Operation 370 includes hydration and drying of the substrate surface. This step ensures optimal bonding conditions by hydrating the surface and then drying it to remove excess moisture.

[0075] In operation 380, the UV release process is performed. Using a UV module (e.g., 180), the adhesive tape frame holding the die is exposed to ultraviolet light, thereby altering the molecular structure of the adhesive. As a result, the adhesive strength is reduced, which allows the die to be easily released from the tape frame.

[0076] Finally, in operation 390, bonder 190 removes, picks up, flips over, and bonds the die to the substrate. The die is bonded to the substrate wafer to form the desired stacked semiconductor structure. Throughout the entire process, an in-line measurement system may be used to inspect and verify the alignment and positioning of the die and substrate, which ensures a high-quality stacked semiconductor structure.

[0077] This exemplary process for manufacturing stacked semiconductor structures using an integrated hybrid bonding platform demonstrates the advantages of a state-of-the-art automated system that effectively combines various modules and technologies to achieve high-performance die-stack bonding. By incorporating a brush-box cleaning module into the hybrid bonding platform, this disclosure provides an effective and efficient method for removing residues and particles from die surfaces in die-stack bonding applications, leading to enhanced bonding yield. The brush-box cleaning module is advantageous over conventional wet cleaning methods because it can remove stubborn residues and particles strongly adhered to the substrate surface without causing watermarks, scratches, corrosion, or surface roughness.

[0078] In alternative embodiments, the hybrid bonding platform and brush box assembly may be adapted to accommodate different substrate sizes, shapes, and materials. For example, the brush box assembly may be configured to clean substrates made of silicon, glass, or quartz materials. Similarly, the brush box assembly may be adapted to clean substrates of various dimensions, such as 200mm, 300mm, or 450mm wafers.

[0079] In some embodiments, the brush box cleaning module may include a number of brush box assemblies configured in parallel or in series to enhance cleaning efficiency and effectiveness. For example, the brush box cleaning module may include a first brush box assembly configured to remove coarse particles and residues, followed by a second brush box assembly configured to remove fine particles and residues.

[0080] In yet another embodiment, the brush box cleaning module may be configured to use different types of brushes or cleaning agents depending on specific cleaning requirements and substrate materials. For example, the brushes may be made of various materials such as polyvinyl alcohol / polyvinyl acetate (PVA), nylon, polypropylene, or other suitable materials, and may include different porous structures or bristle-containing structures having the desired rigidity and structural configuration. The cleaning agents may include deionized (DI) water, diluted citric acid, diluted quaternary ammonium compounds (a mixture of organic solvents such as glycol ether, tetramethylammonium hydroxide, and other additives), diluted ammonium hydroxide (NH4OH), diluted hydrogen peroxide (H2O2), a mixture of NH4OH and H2O2 (SC1), diluted hydrofluoric acid, a mixture of sulfuric acid (H2SO4) and hydrogen peroxide (H2O2) (SPM), Electraclean, or other suitable chemicals for effectively removing residues and particles.

[0081] In addition to die-stack bonding applications, hybrid bonding platforms and brushbox assemblies may also be used in other semiconductor manufacturing processes that require a clean substrate surface, such as wafer bonding, 3D integration, or advanced packaging processes.

[0082] It should be noted that this disclosure is not limited to the specific embodiments and uses described herein, and that modifications, variations, and alternative embodiments may be implemented without departing from the spirit and scope of this disclosure as defined by the appended claims.

Claims

1. It is a hybrid bonding platform, A substrate handling system configured to transport substrates within the aforementioned platform, A brush box cleaning module coupled to the platform, configured to clean the surface of the substrate by removing residues and particles, A bonding module coupled to the platform, configured to bond a die to the surface of the substrate, A controller configured to control the substrate handling system, the brush box cleaning module, and the bonding module. A hybrid bonding platform equipped with [specific features / features].

2. The hybrid bonding platform according to claim 1, wherein the substrate handling system is further configured to transport the substrate between different process modules.

3. The hybrid bonding platform according to claim 1, wherein the brush box cleaning module is configured to remove residues and particles induced by the back-grinding tape or dicing tape.

4. The hybrid bonding platform according to claim 1, wherein the brush box cleaning module comprises a plurality of brushes configured to chemically and mechanically remove stubborn residues and particles from the substrate surface.

5. The hybrid bonding platform according to claim 1, wherein the bonding module is configured to perform a hybrid bonding process on the cleaned surface of the substrate.

6. The hybrid bonding platform according to claim 1, further comprising a system controller for managing and controlling the operation of each process module.

7. A brush box assembly for cleaning a substrate within a hybrid bonding platform, wherein the brush box assembly is A housing configured to surround the aforementioned substrate, Multiple brushes configured to gently scrub the wafer surface, A plurality of rollers configured to support and rotate the wafer during the cleaning process, A cleaning agent supply system configured to apply a cleaning agent to the wafer surface during the scrubbing process, A brush box assembly comprising:

8. The brush box assembly according to claim 6, further comprising a controller configured to control the operation of the brush, roller and detergent supply system.

9. The brush box assembly according to claim 6, wherein the plurality of brushes are configured to chemically and mechanically remove stubborn residues and particles induced by the back-grinding tape or dicing tape from the substrate surface.

10. The brush box assembly according to claim 6, wherein the cleaning agent supply system is configured to supply the cleaning agent to the plurality of brushes in order to facilitate the removal of residues and particles from the substrate surface.

11. The brush box assembly according to claim 6, wherein the cleaning agent supply system comprises a cryogenic aerosol jet configured to dispense the cryogenic cleaning agent onto the substrate surface during the scrubbing process.

12. A method for manufacturing a stacked semiconductor structure, wherein the method is To provide a substrate including multiple dies, To remove residues and particles, the surface of the substrate is cleaned using a brush box cleaning module, The die on the substrate is bonded using a hybrid bonding process. Methods that include...

13. The method according to claim 11, wherein cleaning the surface of the substrate includes removing residues and particles induced by the back-grinding tape or dicing tape.

14. The method according to claim 11, wherein cleaning the surface of the substrate includes chemically and mechanically removing stubborn residues and particles using a plurality of brushes.

15. The method according to claim 11, wherein the cleaning step using at least one wet cleaning module is optional, and the cleaning step using at least one wet cleaning module can be performed before and / or after the brush box cleaning module step.

16. The method according to claim 11, wherein the at least one degassing module heats the wafer surface in order to evaporate moisture and to reduce the release of plastic gas from the tape frame.

17. The method according to claim 11, wherein the at least one plasma module uses ion bombardment to activate the wafer surface and make the wafer surface hydrophilic for bonding.

18. The method according to claim 11, wherein the at least one bonder module precisely aligns and bonds a die to a substrate to produce a stacked semiconductor structure.

19. The method according to claim 11, wherein the removal of residues and particles by the brush box cleaning module results in the stacked semiconductor structure having an enhanced bonding yield.

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