Wafer adsorption method, vacuum adsorption equipment and computer program product

Abstract

The embodiment of the invention provides a wafer adsorption method, vacuum adsorption equipment and a computer program product, and the method is applied to the vacuum adsorption equipment, and comprises the steps: obtaining a to-be-adsorbed wafer with an adsorption surface and a functional surface which are opposite to each other; the adsorption surface is subjected to vacuum adsorption; target pressure control gas with preset flow is applied to the functional surface in the vacuum adsorption state, and the pressure value of the adsorption surface and the pressure value of the functional surface are changed; judging whether the current pressure value of the adsorption surface and the pressure value of the functional surface meet a preset pressure value condition or not; the condition is determined based on a pressure value for supporting the wafer to be attached and adsorbed; if yes, prompting that the wafer is successfully adsorbed, and completing the adsorption; and if not, iteratively executing the step of applying the target pressure control gas with the preset flow to the functional surface in the vacuum adsorption state until the condition is met. According to the technical scheme provided by the embodiment of the invention, the fitting degree of the wafer and the vacuum adsorption equipment can be improved when the wafer is adsorbed, and the adsorption effect is improved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of semiconductor technology, and in particular to a wafer adsorption method, a vacuum adsorption device and a computer program product. BACKGROUND

[0002] The wafer vacuum adsorption device is a special device for realizing non-damage fixing, precise positioning and auxiliary transfer of a wafer (silicon wafer, etc.) by using the principle of vacuum negative pressure to generate uniform adsorption force in the field of semiconductor manufacturing. For example, the wafer vacuum adsorption device adsorbs the wafer by negative pressure adsorption in an atomic layer deposition process.

[0003] However, due to the reasons such as stress accumulation caused by complex process in wafer manufacturing, stress caused by increasing number of material layers, increasing size of the wafer and decreasing thickness of the wafer, and weakening of deformation resistance, the wafer warpage increases. The wafer warpage increase affects the fitting degree of the wafer and the wafer vacuum adsorption device in the adsorption process, resulting in an unsatisfactory deposition effect of the atomic layer deposition process.

[0004] Therefore, how to improve the fitting degree of the wafer and the vacuum adsorption device when the wafer is adsorbed and improve the adsorption effect has become a technical problem to be solved by those skilled in the art. SUMMARY

[0005] To solve the above problems, embodiments of the present application provide a wafer adsorption method, a vacuum adsorption device and a computer program product to improve the fitting degree of the wafer and the vacuum adsorption device when the wafer is adsorbed and improve the adsorption effect.

[0006] In a first aspect, embodiments of the present application provide a wafer adsorption method applied to a vacuum adsorption device, the wafer adsorption method comprising: obtaining a wafer to be adsorbed, the wafer to be adsorbed having an adsorption surface and a functional surface opposite to each other; vacuum-adsorbing the adsorption surface of the wafer to be adsorbed; applying a target pressure control gas with a preset flow rate to the functional surface of the wafer to be adsorbed in a vacuum adsorption state to change the pressure value of the adsorption surface and the pressure value of the functional surface; judging whether the pressure value of the adsorption surface in the current iteration and the pressure value of the functional surface in the current iteration satisfy a preset pressure value condition, the preset pressure value condition being determined based on a pressure value supporting wafer adhesion; if yes, prompting that the wafer adsorption is successful, and completing the adsorption of the wafer to be adsorbed; if no, iteratively performing the step of applying the target pressure control gas with the preset flow rate to the functional surface of the wafer to be adsorbed in the vacuum adsorption state until the preset pressure value condition is satisfied.

[0007] In a second aspect, the embodiments of the present application provide a vacuum adsorption device, comprising: a wafer adsorption control unit configured to perform the wafer adsorption method according to the first aspect.

[0008] In a third aspect, the embodiments of the present application provide a computer program product comprising a computer program which, when executed by a processor, implements the wafer adsorption method according to the first aspect.

[0009] The wafer adsorption method provided by the embodiments of the present application is applied to a vacuum adsorption device, and comprises: obtaining a wafer to be adsorbed, the wafer to be adsorbed having opposite adsorption surfaces and functional surfaces; vacuum-adsorbing the adsorption surfaces of the wafer to be adsorbed; applying a target pressure control gas with a preset flow rate to the functional surfaces of the wafer to be adsorbed in a vacuum-adsorbed state, so as to change the pressure values of the adsorption surfaces and the functional surfaces; judging whether the pressure value of the adsorption surface in the current iteration and the pressure value of the functional surface in the current iteration satisfy a preset pressure value condition; the preset pressure value condition is determined based on a pressure value supporting wafer adhesion; if yes, it is prompted that wafer adsorption is successful, and the adsorption of the wafer to be adsorbed is completed; if no, the step of applying the target pressure control gas with the preset flow rate to the functional surfaces of the wafer to be adsorbed in the vacuum-adsorbed state is iteratively executed until the preset pressure value condition is satisfied.

[0010] It can be seen that the wafer adsorption method applied to the vacuum adsorption equipment provided by the embodiment of the present application first completes the preliminary adsorption of the wafer to be adsorbed by vacuum adsorption, and then applies the target pressure control gas with the preset flow to the functional surface of the wafer to be adsorbed in the vacuum adsorption state, so that the pressure value of the adsorption surface and the pressure value of the functional surface of the wafer to be adsorbed can be changed in the process of applying the target pressure control gas, thereby realizing the effect of further adsorption pressure flattening of the wafer to be adsorbed. On this basis, the technical scheme provided by the embodiment of the present application judges whether the wafer to be adsorbed can be attached and adsorbed after the target pressure control gas is applied in combination with the preset pressure value condition; since the preset pressure value condition is determined based on the pressure value at which the wafer to be adsorbed can be attached and adsorbed, if it is judged that the pressure value of the functional surface of the current time and the pressure value of the adsorption surface of the current time satisfy the preset pressure value condition, it means that the attachment degree of the wafer to be adsorbed is in line with the expectation (the wafer to be adsorbed can be attached and adsorbed), and at the same time, the stability and reliability of wafer adsorption can be ensured; the problem of unsatisfactory deposition effect of the wafer to be adsorbed in subsequent processes (such as atomic layer deposition process) is avoided. Therefore, when it is judged that the preset pressure value condition is met, it is prompted that the wafer adsorption is successful, and the wafer to be adsorbed which is successfully adsorbed can be processed in subsequent processes. If it is not met, the step of applying the target pressure control gas with the preset flow to the functional surface is continued to be executed multiple times, that is, the technical scheme provided by the embodiment of the present application can apply the target pressure control gas with the preset flow to the functional surface multiple times, so that the pressure value of the adsorption surface and the pressure value of the functional surface can be continuously changed to finally satisfy the preset pressure value condition, so that the wafer to be adsorbed can be better attached to the vacuum adsorption equipment, and the attachment effect of the wafer to be adsorbed entering the next process is fully ensured. It can be seen that, through the judgment of the preset pressure value condition and the cyclic iteration of the step of applying the target pressure control gas with the preset flow to the functional surface of the wafer to be adsorbed in the vacuum adsorption state, the technical scheme provided by the embodiment of the present application ultimately achieves the purpose of improving the attachment degree of the wafer to the vacuum adsorption equipment when the wafer is adsorbed, and improving the adsorption effect. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0012] Figure 1 is a flowchart of the wafer adsorption method provided by the embodiment of the present application; Figure 2 is another flowchart of the wafer adsorption method provided by the embodiment of the present application; Figure 3This is another schematic diagram of the wafer adsorption method provided in the embodiments of the present invention; Figure 4 This is another schematic diagram of the wafer adsorption method provided in the embodiments of the present invention; Figure 5 This is a schematic diagram of the structure of the vacuum adsorption device provided in an embodiment of the present invention. Detailed Implementation

[0013] As the foundational substrate supporting all chip structures, the wafer undergoes complex manufacturing processes, such as "increasing the trench aspect ratio" and "increasing the number of stacked memory layers," as chip performance requirements (such as higher storage density and computing efficiency) continue to increase. These processes disrupt the original stress balance of the wafer. The differences in thermal expansion coefficients of different stacked materials and the impact of high aspect ratio etching on the substrate structure cause stress to accumulate continuously inside the wafer and become difficult to release. Ultimately, this leads to the wafer bending from its original flat state, resulting in a significant increase in wafer warpage.

[0014] In the wafer manufacturing process, a thin film is grown on the functional side (front side) of the wafer using atomic layer deposition in a vacuum chamber. Because the wafer is tilted, the adsorption side (back side) also deposits a thin film, resulting in suboptimal deposition – an undesirable outcome in production. Therefore, related technologies employ a method where the wafer is placed on a tray in a vacuum adsorption device, the adsorption valve is opened to hold the wafer in place, and then the pressure from the chamber's gas flow (controlled pressure gas applied) is used to flatten the wafer before it enters the process, ensuring the stability and reliability of subsequent wafer production.

[0015] However, as wafer warpage increases (>1mm at room temperature), the high-temperature environment required for atomic layer deposition exacerbates wafer warpage. The method of directly adsorbing wafers by applying a single pressurized gas on the tray of the vacuum adsorption equipment makes it difficult to ensure that the adsorption surface of the wafer has an ideal fit with the vacuum adsorption equipment. In other words, the adsorption surface of the wafer does not fit well with the vacuum adsorption equipment. If the subsequent atomic layer deposition process is directly carried out under these conditions, the deposition effect of the atomic layer deposition process will be unsatisfactory.

[0016] To address the aforementioned technical problems, this invention provides a wafer adsorption method to improve the adhesion between the wafer and the vacuum adsorption equipment during wafer adsorption, thereby enhancing the adsorption effect.

[0017] Please refer to Figure 1 , Figure 1 This is a schematic diagram of a wafer adsorption method provided in an embodiment of the present invention, which is applied to a vacuum adsorption device.

[0018] like Figure 1As shown, the wafer adsorption method includes the following steps: Step S101: Obtain the wafer to be adsorbed, wherein the wafer to be adsorbed has a relative adsorption surface and a functional surface.

[0019] The functional surface of the wafer to be adsorbed is the area that carries the structure and function of the device (such as the circuit formed by photolithography, the deposited thin film, the doped PN junction, etc.), and is the key area for the device to realize its electrical performance.

[0020] The adsorption surface of the wafer to be adsorbed is a non-functional area specifically designed for adsorption and process compatibility. Its characteristics (such as flatness and cleanliness requirements) are entirely geared towards the stability of vacuum adsorption. It has no functional structure and serves only as a support surface for mechanical fixation (vacuum adsorption, clamping), and can be designed around adsorption stability.

[0021] Subsequent processes are mainly carried out on the functional surfaces of the wafer to be adsorbed.

[0022] Step S102: Vacuum adsorption of the adsorption surface of the wafer to be adsorbed.

[0023] Since the adsorption surface of the wafer to be adsorbed is mainly for vacuum adsorption, when using vacuum adsorption equipment to adsorb the wafer, the main adsorption location is the adsorption surface, so as to avoid damaging the function-related structures on the functional surface and affecting the function of the wafer itself.

[0024] Step S103: Apply a target pressure control gas with a preset flow rate to the functional surface of the wafer to be adsorbed, which is kept in a vacuum adsorption state, so as to change the pressure value of the adsorption surface and the pressure value of the functional surface.

[0025] After the wafer to be adsorbed is initially vacuum adsorbed, a target control gas with a preset flow rate is applied to the functional surface. This allows for precise and dynamic control of the pressure difference between the functional surface and the adsorption surface through the input target control gas with a preset flow rate.

[0026] For example, for warped areas of the wafer to be adsorbed (such as upturned edges or localized protrusions), local airflow adjustments can be made (e.g., increasing the negative pressure suction of the tray in the vacuum adsorption device corresponding to the warped area, or fine-tuning the pressure value of the functional surface of the wafer to be adsorbed) to increase the local pressure difference in that area, counteracting the internal stress of the wafer and forcing the warped portion to conform to the tray. Alternatively, for stepped / protruding areas of wafers with multiple structural types to be adsorbed, zoned airflow control can be used to ensure that the pressure difference acts evenly on the surface of the wafer to be adsorbed (avoiding pressure concentration at protrusions and insufficient pressure at depressions), reducing the bonding gap caused by structural unevenness. This improves the bonding effect of the wafer to be adsorbed.

[0027] Meanwhile, the airflow parameters can be flexibly adjusted according to the specific parameters of the wafer to be adsorbed (such as thickness, warpage, and structural complexity) to further ensure the bonding effect.

[0028] The preset flow rate can be determined according to the specific adsorption state of the wafer to be adsorbed. This ensures that the applied target control gas can improve the adsorption and bonding effect, while also preventing the applied target control gas flow rate from being too large, which could cause the wafer to fall off the vacuum adsorption equipment and disrupt the overall process.

[0029] In other words, the flow rate of the preset flow rate can be flexibly adjusted each time the target pressure control gas is applied, so that it can both change the pressure value of the functional surface and the pressure value of the adsorption surface, such as adjusting the pressure difference between the two so that the pressure difference falls within the range that can improve the bonding effect, and ensure the stability of the overall process.

[0030] Step S104: Determine whether the pressure value of the current adsorption surface and the pressure value of the current functional surface meet the preset pressure value condition. If yes, proceed to step S105; otherwise, continue to step S103.

[0031] The preset pressure value condition can be determined based on the pressure value that supports wafer adhesion and adsorption.

[0032] For example, the pressure value that supports wafer bonding and adsorption can be determined based on empirical pressure values, thereby significantly reducing debugging costs and improving production efficiency.

[0033] Step S105 indicates that the wafer adsorption is successful, completing the adsorption of the wafer to be adsorbed.

[0034] The pressure value of the functional surface obtained after applying the target controlled pressure gas is the pressure value of the current functional surface, and the pressure value of the adsorption surface obtained is the pressure value of the current adsorption surface.

[0035] In related technologies, after performing step S103 once, the process directly proceeds to the subsequent atomic layer deposition process. However, the wafer warpage of the wafer to be adsorbed varies. For wafers with small warpage, the pressure values ​​of the current adsorption surface and the current functional surface obtained after performing step S103 once may meet the preset pressure value conditions. However, for wafers with large warpage, if the preset pressure value conditions are not checked and the atomic layer deposition process is performed directly after applying the target control gas once, the adsorption surface of the wafer to be adsorbed will not have good adhesion to the vacuum adsorption equipment. This will result in the thin film being deposited on the adsorption surface during the atomic layer deposition process, affecting the final deposition effect.

[0036] Based on this, in this embodiment of the invention, after performing the application of the target controlled pressure gas (step S103), the subsequent atomic layer deposition process is not directly executed. Instead, a preset pressure value condition is introduced for monitoring and judgment. This avoids directly entering the atomic layer deposition process when the wafer warpage is increasing and the wafer to be adsorbed has not yet achieved a good adhesion with the vacuum adsorption equipment. Furthermore, if it is determined that the pressure value of the current adsorption surface and the pressure value of the current functional surface obtained after applying the target controlled pressure gas do not meet the preset pressure value condition, step S103 is continued, i.e., the step of applying the target controlled pressure gas is iteratively executed. This allows the target controlled pressure gas to further improve the adhesion between the adsorption surface of the wafer to be adsorbed and the vacuum adsorption equipment, deepening the adhesion until the preset pressure value condition is met. This indicates that the adhesion between the adsorption surface of the wafer to be adsorbed and the vacuum adsorption equipment is as expected, meaning that the adsorption surface better adheres to the vacuum adsorption equipment, which can reduce the impact on the effect of the subsequent atomic layer deposition process and improve the adsorption effect of the vacuum adsorption equipment on the wafer to be adsorbed.

[0037] As can be seen, in the wafer adsorption method applied to a vacuum adsorption device provided by the embodiments of the present invention, the wafer to be adsorbed is first initially adsorbed using vacuum adsorption. Then, a target pressure control gas with a preset flow rate is applied to the functional surface of the wafer to be adsorbed while maintaining a vacuum adsorption state. This allows the pressure values ​​of the adsorption surface and the functional surface of the wafer to be adsorbed to be changed during the application of the target pressure control gas, thereby achieving a further adsorption and flattening effect on the wafer to be adsorbed. Based on this, the technical solution provided by the embodiments of the present invention combines a preset pressure value condition to determine whether the wafer to be adsorbed can be adhered and adsorbed after the application of the target pressure control gas. Since the preset pressure value condition is determined based on the pressure value that supports wafer adhesion and adsorption, if it is determined that the pressure value of the current functional surface and the pressure value of the current adsorption surface meet the preset pressure value condition, it indicates that the adhesion degree of the wafer to be adsorbed is as expected (supporting wafer adhesion and adsorption), and at the same time, it can also ensure the stability and reliability of wafer adsorption; avoiding the problem of unsatisfactory deposition effect of the wafer to be adsorbed in subsequent processes (such as atomic layer deposition process). Therefore, when the preset pressure value condition is met, it indicates successful wafer adsorption, and the successfully adsorbed wafer can proceed to subsequent processing. If the condition is not met, the step of applying the target controlled pressure gas to the functional surface is repeated multiple times. That is, the technical solution provided in this embodiment of the invention can repeatedly apply a preset flow rate of target controlled pressure gas to the functional surface, thereby continuously changing the pressure value of the adsorption surface and the pressure value of the functional surface until the preset pressure value condition is finally met. This allows the wafer to be adsorbed to better adhere to the vacuum adsorption equipment, fully ensuring the adhesion effect of the wafer to be adsorbed before entering the next process. It can be seen that the technical solution provided in this embodiment of the invention, by judging the preset pressure value condition and iteratively executing the step of applying a preset flow rate of target controlled pressure gas to the functional surface of the wafer to be adsorbed in a vacuum adsorption state, can ultimately improve the adhesion between the wafer and the vacuum adsorption equipment during wafer adsorption and improve the adsorption effect.

[0038] In one embodiment, the target pressure control gas is selected from argon, nitrogen, hydrogen, oxygen, and helium; the preset flow rate ranges from [1 slm to 40 slm]; and the preset functional surface pressure value ranges from [1 Torr to 60 Torr]. When the step of applying a target pressure control gas with a preset flow rate to the functional surface of the wafer to be adsorbed, which is in a vacuum adsorption state, is performed for the first time, the corresponding execution time is less than or equal to 300 seconds. When the step of applying a target pressure control gas with a preset flow rate to the functional surface of the wafer to be adsorbed, which is in a vacuum adsorption state, is performed in subsequent iterations other than the initial execution, the corresponding execution time is less than or equal to 120 seconds.

[0039] Argon, nitrogen, hydrogen, oxygen, and helium are all used as target pressure control gases, which can achieve high purity and avoid introducing impurities to contaminate the wafer to be adsorbed. Moreover, the gas state is easy to adjust (flow rate and pressure are controllable), which is suitable for the precise control requirements of flow-pressure control technology. At the same time, there is no conflict with mainstream wafer materials (silicon, silicon carbide, sapphire) and no surface damage will be caused.

[0040] For example, argon, nitrogen, and helium are suitable for interference-free scenarios; hydrogen and oxygen are suitable for surface treatment / auxiliary reaction scenarios.

[0041] The preset flow rate range can be determined by comprehensively considering process objectives (pressure control accuracy, flow field uniformity), equipment parameters (chamber volume, pumping speed), and wafer characteristics (size, surface condition). Determining the preset flow rate range maintains constant chamber pressure, avoiding problems such as adsorption shift and uneven film deposition caused by pressure fluctuations between the adsorption surface and the functional surface. Furthermore, it allows for flexible flow rate adjustment for wafers of different sizes and materials, ensuring uniform flow field coverage while preventing physical damage or chemical interference, thus adapting to diverse process requirements.

[0042] Determining the pressure range of the preset functional surface pressure value can adapt to fluctuations in process variables, such as gas flow rate (affected by flow meter accuracy), chamber pumping speed (affected by vacuum pump status), and wafer surface flatness (which has micron-level differences). Determining the pressure range of the preset functional surface pressure value can avoid pressure control failure caused by the migration of a single value due to variable migration.

[0043] At the same time, the pressure range of the preset functional surface pressure value can also balance functional requirements and safety thresholds, that is, the pressure range of the preset functional surface pressure value is a defined safe and effective range.

[0044] In this embodiment of the invention, the step of applying a preset flow rate of target controlled pressure gas can be repeated multiple times during the successful adsorption of the wafer to be adsorbed. Therefore, when applying the preset flow rate of target controlled pressure gas in subsequent iterations, adjustments can be made based on the results obtained from the previous step, thereby reducing the time spent on trial and error and unstable processes. Thus, the execution time for the first iteration of applying the preset flow rate of target controlled pressure gas is longer than the execution time for subsequent iterations.

[0045] Of course, the execution time is set to meet the time requirements of that execution process.

[0046] To ensure the proper execution of the atomic layer deposition (ALD) process, in one embodiment, the adsorption process of the wafer to be adsorbed can be adjusted and designed to meet the requirements of the ALD process. Please refer to [reference needed]. Figure 2 ,Figure 2 This is another schematic diagram of the wafer adsorption method provided in the embodiments of the present invention.

[0047] like Figure 2 The method includes the following steps: Step S200: Obtain the wafer to be adsorbed, wherein the wafer to be adsorbed has a relative adsorption surface and a functional surface.

[0048] Step S201: Place the wafer to be adsorbed on the tray of the vacuum adsorption device and heat the tray to maintain the temperature within a preset temperature range.

[0049] The tray can be a vacuum suction cup. Vacuum suction cups can solve the problems of easy damage and difficulty in positioning of traditional mechanical clamping in the processing of precision workpieces (such as wafers and glass substrates) through non-contact / flexible fixation, precise adaptation and stable control, and are especially suitable for high-precision manufacturing scenarios such as semiconductors and display panels.

[0050] To ensure the reaction temperature required for the atomic layer deposition process, the vacuum chuck is kept at a constant temperature within a preset temperature range to achieve heat transfer to the wafer to be adsorbed. This preset temperature range is determined based on the requirements of the atomic layer deposition process.

[0051] It should be noted that the wafer adsorption method provided in this embodiment of the invention is also implemented under temperature conditions within a preset temperature range. Therefore, in addition to improving the adhesion effect of the wafer to be adsorbed, the aforementioned step S103 can also achieve a uniform heating effect on the wafer to be adsorbed through changes in airflow and pressure, making the expansion and deformation of the wafer to be adsorbed after heating more uniform, thereby reducing the degree of wafer warpage and further increasing the adsorption effect on the adsorption surface.

[0052] In the atomic layer deposition process, heating and maintaining the temperature of the vacuum chuck can ensure that the "adsorption-reaction-desorption" process of the precursor on the functional surface of the wafer to be adsorbed is precisely controllable, ensuring the self-limitation of the atomic layer deposition process and the quality of the film (such as the uniformity, purity, and density of the film) from the thermodynamic and kinetic perspectives.

[0053] Step S202: Vacuum adsorption of the adsorption surface of the wafer to be adsorbed.

[0054] In one embodiment, the execution time range corresponding to step S201 is [0.5s, 120s]; the preset temperature range is [100℃, 700℃]; and the execution time range corresponding to step S202 is less than or equal to 120s.

[0055] The execution time range corresponding to step S201 can avoid insufficient heating and unstable temperature control due to insufficient time, and can also prevent waste of efficiency or damage to the workpiece / process due to excessive time, thereby balancing the achievement of the target effect and cost efficiency.

[0056] The preset temperature range is the temperature range that ensures the normal execution of the atomic layer deposition process. For example, the temperature of the tray can be heated and maintained at 680°C.

[0057] The execution time range corresponding to step S202 helps to eliminate the gap between the wafer to be adsorbed and the tray, ensuring that the wafer to be adsorbed is in contact and aligned, avoiding misalignment; it can also reduce the initial temperature difference between the wafer to be adsorbed and the tray by using contact heat conduction, reducing uneven heating when the target control gas is applied subsequently; at the same time, it can stabilize the vacuum environment and detect the current adsorption state of the wafer to be adsorbed, avoiding the initial pressure fluctuation of the target control gas from damaging the adsorption stability of the wafer to be adsorbed.

[0058] Step S203: Apply a target pressure control gas with a preset flow rate to the functional surface of the wafer to be adsorbed, which is kept in a vacuum adsorption state, so as to control the pressure value of the functional surface of the wafer to be adsorbed to the preset pressure value of the functional surface.

[0059] The preset flow rate corresponds to the current adsorption state of the wafer to be adsorbed.

[0060] The pressure value of the preset functional surface can be calculated in advance. Since the pressure environment of the functional surface of the wafer to be adsorbed is controllable, has few interfering factors, and is strongly tied to process requirements, the pressure value of the preset functional surface can be calculated in advance.

[0061] The pressure value of the preset functional surface is: the pressure value of the functional surface in the pressure value that supports the adhesion and adsorption of the wafer, that is, the pressure value of the preset functional surface is a value that forms one of the conditions for the preset pressure value.

[0062] Since gases are compressible, once the pressure value of a preset functional surface is determined, a target pressure control gas with a preset flow rate can be applied to make the pressure value of the current functional surface reach and remain at the determined pressure value of the preset functional surface.

[0063] Step S204: Determine whether the pressure value of the current functional surface meets the preset pressure value of the functional surface, and whether the pressure value of the current adsorption surface is less than the preset pressure value of the adsorption surface. If yes, proceed to step S205; otherwise, continue to step S203.

[0064] The pressure value of the preset adsorption surface is a first value; the pressure value of the preset functional surface is a second value; the second value is greater than the first value.

[0065] The pressure value of the preset adsorption surface serves as another value for forming the preset pressure value condition.

[0066] If the pressure value of the current adsorption surface is less than the preset pressure value of the adsorption surface, and the pressure value of the current functional surface meets the preset pressure value of the functional surface, then the preset pressure value condition is met, indicating that there is a good bonding effect between the wafer to be adsorbed and the vacuum adsorption equipment, and the wafer adsorption is successful.

[0067] For example, the first value can be 20 Torr, and the second value can be 3 Torr. Step S204 can be: determining whether the pressure value of the functional surface in the current iteration meets the requirement of 20 Torr, and whether the pressure value of the adsorption surface in the current iteration is less than 3 Torr.

[0068] In one embodiment, the number of iterations for performing the step of applying a target pressure control gas with a preset flow rate to the functional surface of the wafer to be adsorbed, which is kept in a vacuum adsorption state, is less than or equal to 3.

[0069] In other words, after applying a preset flow rate of controlled-pressure gas for a maximum of 3 cycles, the adsorption of the wafer to be adsorbed can be ensured to be successful.

[0070] Step S205 indicates that wafer adsorption was successful, completing the adsorption of the wafer to be adsorbed.

[0071] When it is determined that the pressure value of the current adsorption surface and the pressure value of the current functional surface both meet the preset pressure value conditions, the wafer adsorption is considered successful, meaning that the adhesion between the adsorption surface and the tray meets expectations.

[0072] If either of these conditions is not met, wafer adsorption is determined to have failed. Step S203 is then executed, and a target pressure gas with a preset flow rate is applied again to the wafer to be adsorbed, which is in a vacuum adsorption state, until the preset pressure value condition is met and the adsorption surface and the tray have a good adhesion effect. Then, the next atomic layer deposition process is performed.

[0073] In order to ensure the stability of the vacuum adsorption state of the wafer to be adsorbed during the iterative application of the target controlled pressure gas, in one embodiment, the vacuum adsorption state of the wafer to be adsorbed can also be adjusted and optimized.

[0074] Please refer to Figure 3 , Figure 3 This is another schematic diagram of the wafer adsorption method provided in the embodiments of the present invention.

[0075] like Figure 3 As shown, the method includes the following steps: Step S300: Obtain the wafer to be adsorbed, wherein the wafer to be adsorbed has a relative adsorption surface and a functional surface.

[0076] Step S301: Place the wafer to be adsorbed on the tray of the vacuum adsorption device and heat the tray to maintain the temperature within a preset temperature range.

[0077] Step S302: Vacuum adsorption of the adsorption surface of the wafer to be adsorbed.

[0078] Step S303: Apply a target pressure control gas with a preset flow rate to the functional surface of the wafer to be adsorbed, which is kept in a vacuum adsorption state, so as to control the pressure value of the functional surface of the wafer to be adsorbed to the preset pressure value of the functional surface.

[0079] Step S304: Determine whether the pressure value of the current functional surface meets the preset pressure value of the functional surface, and whether the pressure value of the current adsorption surface is less than the preset pressure value of the adsorption surface. If not, proceed to step S305; if yes, proceed to step S307.

[0080] Step S305: Reduce the pressure value of the functional surface obtained after applying the target pressure control gas; and continue to maintain the vacuum adsorption state of the wafer to be adsorbed.

[0081] If the target controlled pressure gas is applied for the first time and the result is that the wafer to be adsorbed fails to adsorb (i.e., the preset pressure value condition is not met), the pressure value of the functional surface obtained after applying the target controlled pressure gas can be reduced before proceeding to the step of applying the target controlled pressure gas again. This can adjust the vacuum adsorption state of the wafer to be adsorbed, making the pressure conditions more consistent with the characteristics of the wafer to be adsorbed and the vacuum adsorption equipment, thereby improving the adsorption success rate and reliability after the target controlled pressure gas is applied subsequently.

[0082] For example, if the pressure value of the functional surface obtained after applying the target control gas is too high, this pressure value may counteract the vacuum adsorption force, thus weakening the vacuum adsorption effect. Furthermore, when the pressure value of the functional surface is too high, the gas between the wafer to be adsorbed and the adsorption surface of the tray may not be completely expelled, forming an air cushion that hinders the action of the vacuum adsorption force. In this case, reducing the pressure value of the functional surface can reduce this counteracting force, allowing the vacuum adsorption force to function better, thereby achieving successful adsorption.

[0083] To maintain the vacuum adsorption state, the adsorption stability of the wafer to be adsorbed is ensured when the target control gas is applied subsequently, so as not to affect the operation of applying the target control gas.

[0084] In one implementation, step S305 may include: The pressure value of the functional surface obtained after applying the target control gas is gradually reduced at a preset rate until it reaches the range that can support the pressure reduction. The supported pressure reduction range is [1 Torr, 10 Torr]; The execution time for the step of gradually reducing the pressure value of the functional surface obtained after applying the target pressure control gas at a preset speed to a range that can support pressure reduction is less than or equal to 120 seconds. The holding time corresponding to maintaining the vacuum adsorption state of the wafer to be adsorbed is less than or equal to 300s.

[0085] Applying the target controlled-pressure gas gradually at a preset rate—that is, slowly—allows for gradual changes in pressure values ​​on both the functional and adsorption surfaces. This facilitates precise control of the pressure magnitude and rate of change, enabling better observation of the adsorption process on the wafer and timely adjustment of the target controlled-pressure gas flow rate and pressure to achieve optimal adsorption results. Applying the target controlled-pressure gas too quickly can cause sudden and significant pressure changes, making precise control difficult and increasing the risk of adsorption failure.

[0086] Furthermore, gradually applying the target controlled pressure gas can avoid airflow impacts and prevent adverse effects on the wafer to be adsorbed. For example, airflow impacts may cause the wafer to shift or shake, disrupting the initial contact between the wafer and the adsorption surface of the vacuum adsorption equipment, leading to adsorption failure. Slowly applying the target controlled pressure gas can reduce airflow impacts, protect the positional stability of the wafer to be adsorbed, and create favorable conditions for adsorption.

[0087] Setting a range for pressure reduction allows the process of lowering the pressure value of the functional surface to adapt to different process requirements and the characteristics of the wafer to be adsorbed. Different wafer processing techniques may have different requirements for the pressure value of the functional surface, and different types of wafers also have different physical properties. Setting a range allows for flexible adjustments based on the specific process and the wafer to be adsorbed, while ensuring adsorption effectiveness. Furthermore, setting a range can prevent adsorption failure due to excessively low pressure, ensuring that the basic requirements for wafer adsorption are still met while reducing pressure.

[0088] Setting the execution time corresponding to the step of gradually reducing the pressure value of the functional surface obtained after applying the target control gas at a preset speed to a range that can support pressure reduction can avoid sudden changes in pressure value that could cause process fluctuations, damage to equipment, or stress on the wafer to be adsorbed, thus ensuring process stability, equipment performance, and the safety of the wafer to be adsorbed.

[0089] To enhance the adsorption and adhesion effect of the applied target pressure-controlled gas, in some embodiments, the type of target pressure-controlled gas applied in subsequent iterations can be adjusted. Please refer to [link / reference needed]. Figure 3 .

[0090] like Figure 3As shown, the method further includes: Step S306: Adjust the type of control gas; wherein, the target control gas applied in subsequent iterations is the control gas with the adjusted type.

[0091] By changing the type of control gas and using the adjusted control gas as the target control gas, key issues in the current process can be addressed specifically. For example, the adsorption and bonding of the wafer to be adsorbed can be optimized, its surface treatment requirements can be adapted, or the conditions for its participation in specific chemical reactions can be met, ultimately ensuring the process stability and effectiveness of the wafer to be adsorbed.

[0092] For example, the target pressure control gas applied for the first time is argon, and the target pressure control gas applied for the second time can be nitrogen, so that the nitrogen gas after type adjustment is more suitable for the current working environment and achieves a better bonding effect.

[0093] After step S306 is executed, step S303 is executed again to apply the target pressure control gas (the type of pressure control gas is adjusted).

[0094] Step S307 indicates that wafer adsorption was successful, completing the adsorption of the wafer to be adsorbed.

[0095] To improve the accuracy and reliability of the applied pressure-controlled gas, in some implementations, the gas can be selected and adjusted according to the specific type of wafer to be adsorbed and the process conditions. Please refer to [reference needed]. Figure 4 , Figure 4 This is another schematic diagram of the wafer adsorption method provided in the embodiments of the present invention.

[0096] like Figure 4 As shown, the method includes the following steps: Step S400: Obtain the wafer to be adsorbed, wherein the wafer to be adsorbed has a relative adsorption surface and a functional surface.

[0097] Step S401: Place the wafer to be adsorbed on the tray of the vacuum adsorption device and heat the tray to maintain the temperature within a preset temperature range.

[0098] Step S402: Vacuum adsorption of the adsorption surface of the wafer to be adsorbed.

[0099] Step S403: Determine the wafer type of the wafer to be adsorbed. The wafer type is used to determine the type of the control gas applied for the first time, which is used as the target control gas for the first application.

[0100] The type of pressure-controlled gas applied initially can be adapted to the wafer type and the overall process. This is based on the comprehensive requirements of the entire process flow of the wafer to be adsorbed (such as subsequent deposition and etching), prioritizing the stability of the overall process.

[0101] The matching relationship between the type of control gas and the wafer type can be preset and configured. This allows for the selection of a suitable control gas as the initial target control gas based on the real-time detected wafer type during adsorption and atomic layer deposition on a specific wafer. This improves the selectivity and convenience of the target control gas.

[0102] Step S404: Apply a target pressure control gas with a preset flow rate to the functional surface of the wafer to be adsorbed, which is kept in a vacuum adsorption state, so as to control the pressure value of the functional surface of the wafer to be adsorbed to the preset pressure value of the functional surface.

[0103] Step S405: Determine whether the pressure value of the current functional surface meets the preset pressure value of the functional surface, and whether the pressure value of the current adsorption surface is less than the preset pressure value of the adsorption surface. If not, proceed to step S406; if yes, proceed to step S409.

[0104] Step S406: Reduce the pressure value of the current functional surface; and continue to maintain the vacuum adsorption state of the wafer to be adsorbed.

[0105] Step S407: Determine the wafer warpage measurement value of the wafer to be adsorbed.

[0106] Before the wafer to be adsorbed is adsorbed, the wafer warpage of the wafer to be adsorbed can be measured to obtain the actual wafer warpage measurement value of the wafer to be adsorbed.

[0107] Step S408: Based on the comparison result between the wafer warpage measurement value and the wafer warpage threshold, adjust the type of control gas so as to use the control gas with the adjusted type as the target control gas.

[0108] The wafer warpage threshold can be preset to determine whether the measured wafer warpage value indicates excessive warpage of the wafer to be adsorbed. If the wafer warpage is too large, it indicates that the initially applied target pressure control gas may not be well-suited to the adsorption and adhesion effect of the wafer. In this case, the type of pressure control gas can be changed, and the adjusted pressure control gas can be used as the target pressure control gas in subsequent iterations to meet the current actual process conditions of the wafer to be adsorbed. Adjusting the type of pressure control gas at this time is a locally optimal solution selected based on the specific needs of this stage (such as reducing surface tension and optimizing flow field uniformity) without violating the basic compatibility of the wafer to be adsorbed (such as not damaging the surface or compromising material compatibility), thereby improving the adsorption efficiency and accuracy.

[0109] After step S408 is executed, step S404 is executed to apply the target control pressure gas again.

[0110] Step S409 indicates that wafer adsorption was successful, completing the adsorption of the wafer to be adsorbed.

[0111] To demonstrate the application of the wafer adsorption method provided in the embodiments of the present invention, the following description is provided in conjunction with specific implementation methods.

[0112] To ensure the reaction temperature required for atomic layer deposition (ALD), we will use the example of maintaining a constant temperature of 680°C with a vacuum chuck to achieve heat transfer on the wafer to be adsorbed. Of course, the subsequent wafer adsorption process will also be carried out under this temperature condition.

[0113] Step 1: Place the wafer to be adsorbed on the vacuum chuck and open the adsorption valve to allow the adsorption surface of the wafer to enter the adsorption state as soon as possible. The execution time for step 1 is 1 second.

[0114] Step 2: Apply the target pressure control gas (argon) for the first time at 8 slm, and control the pressure value of the functional surface at the preset pressure value of 20 Torr. Step 2 will be demonstrated using the example of a preset flow rate of 8 slm applied first.

[0115] At this point, the changes in airflow, pressure values ​​on the functional surface, and pressure values ​​on the adsorption surface can achieve a uniform heating effect on the wafer to be adsorbed, making the expansion and deformation of the heated wafer more uniform, thereby reducing the wafer warpage and increasing the adsorption effect on the back side.

[0116] The execution time for step 2 is 30 seconds.

[0117] Step 3: After reducing the pressure value of the functional surface to 1 Torr, maintain the chamber state for 60 seconds; At this point, it has been determined that the preset pressure value condition is not met after the first application of the target control gas. Therefore, step 4 is executed.

[0118] Step 4: The wafer to be adsorbed continues to be kept in a vacuum adsorption state, and the pressure value of the functional surface of the wafer to be adsorbed slowly decreases to 1 Torr.

[0119] The execution time for step 4 is 60 seconds.

[0120] Step 5: The wafer to be adsorbed continues to be in a vacuum adsorption state, and the functional surface of the wafer to be adsorbed remains stable without any action. The execution time for step 5 is 60 seconds to ensure that the adsorption state of the wafer to be adsorbed will not be affected when the target controlled pressure gas is applied again.

[0121] Step 6: Apply 10 slm of target pressure control gas for the second time: argon (taking the type of target pressure control gas applied in both cases as an example without changing the type of gas).

[0122] The preset flow rate in the steps is 10slm, and the execution time is 20s.

[0123] Then, continue to confirm whether the adsorption of the wafer to be adsorbed is successful, that is, whether the pressure value of the current adsorption surface and the pressure value of the current functional surface meet the preset pressure value conditions: the pressure value of the current functional surface is 20 Torr of the preset functional surface pressure value, and the pressure value of the current adsorption surface is < 3 Torr of the preset adsorption surface pressure value.

[0124] If it fails, continue applying the preset flow rate target control gas a third time, and repeat up to three times to ensure successful wafer adsorption.

[0125] This invention also provides a vacuum adsorption device for implementing the wafer adsorption method described in any of the foregoing embodiments.

[0126] Please refer to Figure 5 , Figure 5 This is a schematic diagram of the structure of the vacuum adsorption device provided in an embodiment of the present invention.

[0127] like Figure 5 As shown, the vacuum adsorption device includes: The wafer adsorption control unit 51 is configured to perform the wafer adsorption method as described in any of the foregoing embodiments.

[0128] As can be seen, the vacuum adsorption equipment provided in this embodiment of the invention, being configured to execute the wafer adsorption method described in the foregoing embodiments, allows for the repeated application of a target controlled pressure gas with a preset flow rate to the functional surface of the wafer to be adsorbed based on a preset pressure value. This continuously changes the pressure values ​​of the adsorption surface and the functional surface until the preset pressure value is met, enabling the wafer to be adsorbed to better adhere to the vacuum adsorption equipment and fully ensuring the adhesion effect of the wafer entering the next process. Therefore, the technical solution provided in this embodiment of the invention can achieve the goal of improving the adhesion between the wafer and the vacuum adsorption equipment during wafer adsorption and improving the adsorption effect.

[0129] Please continue to refer to this. Figure 5 In one embodiment, the vacuum adsorption device may further include: a wafer adsorption execution unit 52, which, under the control of the wafer adsorption control unit 51, performs an adsorption operation on the wafer to be adsorbed; and provides the wafer adsorption control unit 51 with the current adsorption state of the wafer to be adsorbed.

[0130] This invention also provides a computer program product, including a computer program that, when executed by a processor, implements the wafer adsorption method as described in any of the foregoing embodiments.

[0131] The foregoing describes multiple embodiments of the present invention. The optional methods described in each embodiment can be combined and cross-referenced without conflict, thereby extending to a variety of possible embodiments. These can all be considered as embodiments disclosed or made public by the present invention.

[0132] While this application discloses the above information, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of this application; therefore, the scope of protection of this application shall be determined by the scope defined in the claims.

Claims

1. A wafer adsorption method, characterized in that, The wafer adsorption method, applied in vacuum adsorption equipment, includes: Obtain a wafer to be adsorbed, wherein the wafer to be adsorbed has a relative adsorption surface and a functional surface; Vacuum adsorption is applied to the adsorption surface of the wafer to be adsorbed; A target pressure control gas with a preset flow rate is applied to the functional surface of the wafer to be adsorbed, which is kept in a vacuum adsorption state, so as to change the pressure value of the adsorption surface and the pressure value of the functional surface. Determine whether the pressure value of the current adsorption surface and the pressure value of the current functional surface meet the preset pressure value condition; the preset pressure value condition is determined based on the pressure value that supports wafer bonding and adsorption. If so, it indicates that the wafer adsorption was successful, and the adsorption of the wafer to be adsorbed is completed; If not, the step of applying a target pressure control gas with a preset flow rate to the functional surface of the wafer to be adsorbed, which is in a vacuum adsorption state, is performed iteratively until the preset pressure value condition is met.

2. The wafer adsorption method as described in claim 1, characterized in that, The process of applying a target pressure control gas with a preset flow rate to the functional surface of the wafer to be adsorbed, which is kept in a vacuum adsorption state, includes: A target pressure control gas with a preset flow rate is applied to the functional surface of the wafer to be adsorbed, which is kept in a vacuum adsorption state, so as to control the pressure value of the functional surface of the wafer to be adsorbed to the preset pressure value of the functional surface; the preset flow rate corresponds to the current adsorption state of the wafer to be adsorbed. The step of determining whether the pressure value of the current adsorption surface and the pressure value of the current functional surface meet the preset pressure value condition includes: Determine whether the pressure value of the current functional surface meets the preset pressure value of the functional surface, and whether the pressure value of the current adsorption surface is less than the preset pressure value of the adsorption surface; the preset pressure value of the adsorption surface is a first value; the preset pressure value of the functional surface is a second value; the second value is greater than the first value.

3. The wafer adsorption method as described in claim 2, characterized in that, When it is determined that the pressure value of the current adsorption surface and the pressure value of the current functional surface do not meet the preset pressure value condition, before iteratively executing the step of applying a preset flow rate of target pressure control gas to the functional surface of the wafer to be adsorbed in a vacuum adsorption state, the method further includes: adjusting the type of pressure control gas; wherein, the target pressure control gas applied in subsequent iterations is the pressure control gas after type adjustment.

4. The wafer adsorption method as described in claim 3, characterized in that, After the step of vacuum adsorption of the adsorption surface of the wafer to be adsorbed, and before the step of applying a target pressure control gas at a preset flow rate to the functional surface of the wafer to be adsorbed while maintaining a vacuum adsorption state, the method further includes: The wafer type of the wafer to be adsorbed is determined, and the wafer type is used to determine the type of the control gas applied for the first time, so as to serve as the target control gas for the first application; When it is determined that the pressure values ​​of the adsorption surface and the functional surface do not meet the preset pressure value conditions, before performing the step of adjusting the type of pressure control gas, the method further includes: determining the wafer warpage measurement value of the wafer to be adsorbed; The types of the pressure-regulating gas include: Based on the comparison between the measured wafer warpage value and the wafer warpage threshold, the type of control gas is adjusted so that the adjusted control gas is used as the target control gas.

5. The wafer adsorption method as described in claim 3, characterized in that, If it is determined that the pressure value of the current adsorption surface and the pressure value of the current functional surface do not meet the preset pressure value condition, before iteratively executing the step of applying a preset flow rate of target pressure-controlled gas to the functional surface of the wafer to be adsorbed, which is in a vacuum adsorption state, the method further includes: Reduce the pressure value of the functional surface obtained after applying the target control gas; In addition, the vacuum adsorption state of the wafer to be adsorbed is maintained.

6. The wafer adsorption method as described in claim 5, characterized in that, The reduction of the pressure value of the functional surface obtained after applying the target control gas includes: The pressure value of the functional surface obtained after applying the target control gas is gradually reduced at a preset rate until it reaches the range that can support the pressure reduction. The supported pressure reduction range is [1 Torr, 10 Torr]; The execution time for the step of gradually reducing the pressure value of the functional surface obtained after applying the target pressure control gas at a preset speed to a range that can support pressure reduction is less than or equal to 120 seconds. The holding time corresponding to maintaining the vacuum adsorption state of the wafer to be adsorbed is less than or equal to 300s.

7. The wafer adsorption method according to any one of claims 1-6, characterized in that, The number of iterations for performing the step of applying a target controlled pressure gas with a preset flow rate to the functional surface of the wafer to be adsorbed, which is kept in a vacuum adsorption state, is less than or equal to 3.

8. The wafer adsorption method according to any one of claims 1-6, characterized in that, Before the step of vacuum adsorption of the adsorption surface of the wafer to be adsorbed, the method further includes: The wafer to be adsorbed is placed on the tray of the vacuum adsorption device, and the tray is heated to maintain the temperature within a preset temperature range. The tray is a vacuum suction cup.

9. The wafer adsorption method as described in claim 8, characterized in that, The execution time range for the step of placing the wafer to be adsorbed on the tray of the vacuum adsorption device and heating the tray to maintain the temperature within a preset temperature range is [0.5s, 120s]; the preset temperature range is [100℃, 700℃]. The execution time for the step of vacuum adsorption of the adsorption surface of the wafer to be adsorbed is less than or equal to 120 seconds.

10. The wafer adsorption method according to any one of claims 1-6, characterized in that, The target pressure control gas is selected from argon, nitrogen, hydrogen, oxygen, and helium; the preset flow rate range is [1 slm, 40 slm]; the preset functional surface pressure value range is [1 Torr, 60 Torr]. When the step of applying a target pressure control gas with a preset flow rate to the functional surface of the wafer to be adsorbed, which is in a vacuum adsorption state, is performed for the first time, the corresponding execution time is less than or equal to 300 seconds. When the step of applying a target pressure control gas with a preset flow rate to the functional surface of the wafer to be adsorbed, which is in a vacuum adsorption state, is performed in subsequent iterations other than the initial execution, the corresponding execution time is less than or equal to 120 seconds.

11. A vacuum adsorption device, characterized in that, include: A wafer adsorption control unit is configured to perform the wafer adsorption method as described in any one of claims 1-10.

12. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the wafer adsorption method as described in any one of claims 1-10.

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