Adsorption method for improving warping degree of wafer and semiconductor equipment

Abstract

According to the adsorption method for improving the warping degree of the wafer and the semiconductor equipment, a process chamber is pumped to the bottom pressure before a base starts to move, the density of gas in the process chamber can be reduced, and therefore when the base moves subsequently, the disturbance effect of gas flow on the wafer can be effectively reduced, and the warping degree of the wafer can be improved. Therefore, the base can stably operate at a higher speed, and the wafer is ensured to be stably arranged on the base. And secondly, the wafer adsorption operation and the process of moving the base from the bearing position to the process position are executed in parallel, so that the time of the whole wafer handover and adsorption process is shortened, and the total time from bearing the wafer by the base to completing the adsorption is remarkably shortened; therefore, the baking time of the wafer exposed to the high-temperature base before the wafer is completely adsorbed is correspondingly and directly reduced, thermally induced buckling deformation of the wafer caused by long-time heating can be inhibited or slowed down, uniform and reliable sealing can be formed between the wafer and the base, and the adsorption effect of the wafer is improved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the field of semiconductor, in particular to an adsorption method for improving wafer warpage and a semiconductor device. BACKGROUND

[0002] In the field of semiconductor device manufacturing, atomic layer deposition (ALD) technology has become one of the key processes for preparing high-quality and high-uniformity functional thin films due to its accuracy in thin film thickness and component control, excellent step coverage, and low-temperature process compatibility. Atomic layer deposition technology grows thin films layer by layer on an atomic scale through self-limiting surface chemical reactions, and is applied throughout multiple core manufacturing links such as logic devices, memories, and optoelectronic devices, playing a crucial role in improving device performance and integration.

[0003] In the atomic layer deposition process, the adsorption quality of a wafer in a process chamber is a decisive factor to ensure the uniformity of thin film deposition, electrical performance, and the yield of the final product. To achieve stable adsorption of the wafer, existing devices usually rely on adjusting the temperature of the pedestal heating plate that supports the wafer and the pressure in the reaction chamber to fix the wafer on the surface of the pedestal by electrostatic force. This process involves a series of physical operation steps such as wafer import, placement on the pedestal, execution of adsorption, and subsequent lifting.

[0004] However, fixing the wafer on the surface of the pedestal by electrostatic force alone has significant limitations in dealing with certain process challenges. SUMMARY

[0005] The problem solved by embodiments of the present application is to provide an adsorption method for improving wafer warpage and a semiconductor device to form a uniform and reliable seal between the wafer and the pedestal, and to improve the adsorption effect of the wafer.

[0006] To solve the above problems, embodiments of the present application provide an adsorption method for improving wafer warpage, applied in a semiconductor device, comprising: providing a pedestal in a tab position and a plurality of temporary support structures penetrating the pedestal in a process chamber, the pedestal being capable of moving in a vertical direction relative to the temporary support structures, and when in the tab position, the temporary support structures protrude from the top of the pedestal for supporting the wafer; placing the wafer on the plurality of temporary support structures; after placing the wafer on the temporary support structures, pumping the pressure of the process chamber to a bottom pressure; driving the pedestal to move from the tab position to a receiving position in the vertical direction, and in the receiving position, the pedestal receives the wafer; driving the pedestal to move the wafer from the receiving position to a process position, and in the process of moving the pedestal from the receiving position to the process position, starting the wafer adsorption operation.

[0007] Optionally, the adsorbing method further comprises: after the wafer adsorbing operation is started, increasing the pressure of the process chamber to a first pressure value for exerting pressure on the top surface of the wafer to press the wafer against the susceptor, and the first pressure value is greater than a process pressure required during the process; during the process of receiving the wafer by the susceptor, the susceptor and the wafer form a space to be pumped; and during the step of starting the wafer adsorbing operation, when it is monitored that the pressure in the space to be pumped is lower than a preset threshold value, decreasing the pressure of the process chamber from the first pressure value to the process pressure.

[0008] Optionally, the process chamber is provided with a positive pressure reservoir and a jet port in communication with the positive pressure reservoir, and the positive pressure reservoir stores a pre-charged gas; the step of increasing the pressure of the process chamber to the first pressure value comprises: opening the jet port in communication with the positive pressure reservoir to release the pre-charged gas into the process chamber.

[0009] Optionally, the pre-charged gas comprises an inert gas.

[0010] Optionally, the semiconductor device comprises: a plurality of adsorbing units, each of which comprises an adsorbing pipeline, an adsorbing end of the adsorbing pipeline being in communication with a space to be pumped between the susceptor and the wafer; a negative pressure reservoir provided on the adsorbing pipeline, the negative pressure reservoir being in a negative pressure state; and a first valve provided on the adsorbing pipeline and located between the negative pressure reservoir and the wafer; the wafer adsorbing operation comprises the steps of: opening the first valve to make the space to be pumped between the back surface of the wafer and the susceptor in communication with the negative pressure reservoir in the negative pressure state, and pumping the gas in the space to be pumped between the back surface of the wafer and the susceptor to thereby adsorb the wafer.

[0011] Optionally, each of the adsorbing units comprises: a first pressure sensor in communication with the adsorbing pipeline, the first pressure sensor being used to monitor the pressure of the space to be pumped between the susceptor and the wafer; and during the step of monitoring the pressure in the space to be pumped, the first pressure sensor is used to detect the pressure on the adsorbing pipeline.

[0012] Optionally, the preset threshold value is less than 1 Torr.

[0013] Optionally, the first pressure value is 1 to 5 times the process pressure.

[0014] Optionally, the process chamber includes: a second valve disposed in the process chamber for controlling the connection or disconnection between the process chamber and the outside; a second pressure sensor disposed in the process chamber for sensing the pressure in the process chamber; and a controller connected to the second valve and the second pressure sensor. The step of reducing the pressure in the process chamber from the first pressure value to the process pressure includes: the controller receiving real-time pressure feedback in the process chamber sensed by the second pressure sensor and adjusting the second valve.

[0015] Optionally, during the process of reducing the pressure in the process chamber to a low pressure, the base is driven to move upward a predetermined distance, and the predetermined distance is less than the distance between the contact point and the receiving point; or, after reducing the pressure in the process chamber to a low pressure, the base is driven to move upward to the receiving point.

[0016] Optionally, the process chamber is connected to the transfer chamber; the wafer adsorption method further includes: before placing the wafer on the plurality of temporary support structures, further including: reducing the pressure in the process chamber so that the pressure in the process chamber is lower than the pressure in the transfer chamber.

[0017] This application embodiment also provides a semiconductor device, including: a process chamber, wherein a base and a plurality of temporary support structures penetrating the base are disposed in the process chamber, the base being movable in a vertical direction relative to the temporary support structures, the temporary support structures being used to support the wafer; a plurality of adsorption units, each adsorption unit including an adsorption pipeline, the adsorption end of the adsorption pipeline being connected to a space to be evacuated formed by the base and the wafer; a negative pressure reservoir disposed on the adsorption pipeline, the negative pressure reservoir being in a negative pressure state; a first valve disposed on the adsorption pipeline, located between the negative pressure reservoir and the adsorption end; a negative pressure generating device, connected to the process chamber, used to evacuate the pressure of the process chamber to a low pressure; and a lifting mechanism located at the bottom of the base, the lifting mechanism including an output end, the output end of the lifting mechanism being connected to the base, used to drive the base to move.

[0018] Optionally, the semiconductor device further includes: a positive pressure reservoir located in the process chamber, the positive pressure reservoir being connected to a jet end, the positive pressure reservoir storing pre-charge gas for releasing the pre-charge gas into the process chamber.

[0019] Optionally, the process chamber includes: a second valve disposed in the process chamber for controlling the passage or disconnection between the process chamber and the outside; a second pressure sensor disposed in the process chamber for sensing the pressure in the process chamber; and a controller connected to the second valve and the second pressure sensor, wherein the controller is used to receive real-time pressure feedback in the process chamber sensed by the second pressure sensor and to adjust the second valve.

[0020] Optionally, the adsorption unit further includes a first pressure sensor disposed on the adsorption pipeline, the first pressure sensor being used to monitor the pressure in the space to be evacuated between the base and the wafer.

[0021] Compared with the prior art, the technical solution of this application has the following advantages:

[0022] The adsorption method for improving wafer warpage provided in this application involves first reducing the pressure in the process chamber to a low level after the wafer is placed on the temporary support structure, and then simultaneously initiating wafer adsorption during the subsequent movement of the drive base from the receiving position to the process position. Firstly, reducing the pressure in the process chamber to a low level before the base begins to move lowers the gas density within the chamber. This effectively reduces the disturbance effect of gas flow on the wafer during subsequent base movement, allowing the base to operate smoothly at a higher speed and ensuring the wafer is stably positioned on the base. Secondly, the wafer adsorption operation and the process of moving the substrate from the receiving position to the process position are executed in parallel. Through the overlap of the timing, the adsorption process, which originally had to start after the substrate reached the process position, is integrated into the movement of the substrate. This reduces the time of the entire wafer handover and adsorption process. Because the total time from the substrate receiving the wafer to the completion of adsorption is significantly shortened, the baking time of the wafer exposed to the high temperature substrate before it is fully adsorbed is directly reduced. This helps to suppress or slow down the thermal warpage deformation of the wafer caused by prolonged heating, allowing the wafer to be adsorbed in a better flat state. As a result, the wafer can form a uniform and reliable seal with the substrate, improving the wafer adsorption effect. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0024] Figure 1 This is a flowchart of an adsorption method for improving wafer warpage according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the substrate being positioned at the wafer bonding location during the adsorption method for improving wafer warpage according to an embodiment of the present invention.

[0026] Figure 3 This is a schematic diagram of the structure of the substrate in the receiving position during the adsorption method for improving wafer warpage according to an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the substrate in the process position during the adsorption method for improving wafer warpage according to an embodiment of the present invention;

[0028] Figure 5 This is a schematic diagram of the adsorption unit in an embodiment of the present invention;

[0029] Figure 6 This is a schematic diagram of the structure of the adsorption unit and the base in an embodiment of the present invention;

[0030] Figure 7 This is a schematic diagram showing the change of pressure over time in the process chamber during the adsorption method for improving wafer warpage according to an embodiment of the present invention. Detailed Implementation

[0031] As the background technology shows, simply fixing wafers to the substrate surface using electrostatic force or vacuum suction has significant limitations in addressing specific process challenges. Specifically, existing methods generally neglect the dynamic impact of the time the wafer is baked by the high-temperature substrate during transport and placement on wafer warpage. Especially in high-temperature processes above 500°C, the warpage of the wafer increases dramatically within a very short time after contact with the high-temperature substrate, followed by a relatively long, slow recovery period (e.g., 10 to 20 minutes). This rapid and drastic deformation prevents the wafer from effectively adhering to the substrate surface, resulting in adsorption failure or incomplete adsorption, which severely affects film quality and production yield. Therefore, how to improve the adsorption success rate of high-warpage wafers by optimizing the process flow without changing the core hardware has become a pressing technical challenge for improving the production efficiency and stability of atomic layer deposition equipment.

[0032] To address the technical problem, the method for improving wafer adsorption capacity provided in this application involves first reducing the pressure in the process chamber to a low level after the wafer is placed on the temporary support structure, and then simultaneously initiating wafer adsorption during the subsequent movement of the drive base from the receiving position to the process position. Firstly, reducing the pressure in the process chamber before the base begins to move lowers the gas density within the chamber. This effectively reduces the disturbance effect of gas flow on the wafer during subsequent base movement, allowing the base to operate smoothly at a higher speed and ensuring the wafer is stably positioned on the base. Secondly, the wafer adsorption operation and the process of moving the substrate from the receiving position to the process position are executed in parallel. Through the overlap of the timing, the adsorption process, which originally had to start after the substrate reached the process position, is integrated into the movement of the substrate. This reduces the time of the entire wafer handover and adsorption process. Because the total time from the substrate receiving the wafer to the completion of adsorption is significantly shortened, the baking time of the wafer exposed to the high temperature substrate before it is fully adsorbed is directly reduced. This helps to suppress or slow down the thermal warpage deformation of the wafer caused by prolonged heating, allowing the wafer to be adsorbed in a better flat state. As a result, the wafer can form a uniform and reliable seal with the substrate, improving the wafer adsorption effect.

[0033] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] Figure 1 This is a flowchart of an adsorption method for improving wafer warpage according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the substrate being positioned at the wafer bonding location during the adsorption method for improving wafer warpage according to an embodiment of the present invention.

[0035] Figure 3 This is a schematic diagram of the structure of the substrate in the receiving position during the adsorption method for improving wafer warpage according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the substrate in the process position during the adsorption method for improving wafer warpage according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the adsorption unit in an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the adsorption unit and the base in an embodiment of the present invention; Figure 7 This is a schematic diagram showing the change of pressure over time in the process chamber during the adsorption method for improving wafer warpage according to an embodiment of the present invention.

[0036] The adsorption method for improving wafer warpage provided in this invention is applied in semiconductor equipment. (Reference) Figure 1 and Figure 2 A base 101 is provided in the process chamber 100 at the wafer bonding position L1 and a plurality of temporary support structures 102 passing through the base 101. The base 101 is movable in the vertical direction relative to the temporary support structures 102, and at the wafer bonding position L1, the temporary support structures 102 protrude from the top of the base 101 to support the wafer.

[0037] By setting a vertically movable base 101 and multiple temporary support structures 102 penetrating the base 101, a structure for receiving and transferring wafers is formed. Then, by utilizing the state where the temporary support structure 102 protrudes from the top of the base 101 at the wafer connection position L1, an initial support platform isolated from the surface of the high-temperature base 101 is provided for the incoming wafer. This avoids the wafer from directly contacting the high-temperature base 101 at the moment of placement, thus preventing severe thermal shock. This makes the wafer transfer process smoother and more controllable, which is beneficial for the base 101 to smoothly receive the wafer from the temporary support structure 102.

[0038] It should be noted that the process chamber 100 is a chamber used for atomic layer deposition processes.

[0039] Atomic layer deposition (ALD) processes have stringent requirements for film thickness, uniformity, and conformal coverage. A high-temperature environment is typically required in ALD processes, so the substrate 101 is usually in a high-temperature state, which can easily lead to thermal warping of the wafer.

[0040] In some embodiments, a lifting mechanism (not shown in the figure) is provided at the bottom of the base 101, and the output end of the lifting mechanism is connected to the bottom of the base 101 to raise or lower the base 101.

[0041] As an example, the lifting mechanism includes: a motor, the motor including an output shaft; a lead screw fixedly connected to the output shaft of the motor; and a rotating component located on the lead screw for rotatable engagement with the lead screw, wherein the rotating component moves vertically when the lead screw rotates. In other embodiments, the lifting mechanism may also employ a telescopic rod, or a pneumatic cylinder, or a hydraulic cylinder for linear extension and retraction to achieve the lifting effect.

[0042] In some embodiments, the temporary support structure 102 has an extending direction, and the extending direction is vertical. As an example, the temporary support structure 102 includes a lifting pin.

[0043] It should be noted that the temporary support structure 102 is fixedly installed at the bottom of the process chamber, meaning that the position of the temporary support structure 102 does not change during the process of the base 101 rising.

[0044] refer to Figure 2 The wafer is placed on the plurality of temporary support structures 102.

[0045] By placing the wafer on multiple temporary support structures 102, the initial positioning of the wafer from the transfer chamber 200 to the process chamber 100 is completed. The temporary support structures 102 serve as temporary carriers, so that the wafer is in a known position before the base 101 rises, preparing for the subsequent acceptance of the wafer by the base 101.

[0046] In some embodiments, the process chamber 100 is in communication with the transfer chamber 200; the wafer adsorption method further includes: before placing the wafer on the plurality of temporary support structures 102, further including: reducing the pressure in the process chamber 100 such that the pressure in the process chamber 100 is lower than the pressure in the transfer chamber 200.

[0047] Before the wafer is transferred, the pressure in the process chamber 100 is reduced to be lower than that in the transfer chamber 200, thereby establishing a directional pressure gradient between the two connected chambers. This generates a weak airflow from the transfer chamber 200 to the process chamber 100, preventing particulate contamination of the transfer chamber from the process chamber 100.

[0048] As an example, in the step of reducing the pressure in the process chamber 100 so that the pressure in the process chamber 100 is lower than the pressure in the transfer chamber 200, the pressure in the process chamber 100 is 0.2 Torr to 0.3 Torr lower than the pressure in the transfer chamber 200.

[0049] By controlling the pressure difference between the process chamber 100 and the transfer chamber 200 within the range of 0.2 Torr to 0.3 Torr, an airflow that can stabilize the wafer without interfering with the wafer transfer is formed. This avoids the turbulence that may be caused by an excessively large pressure difference or the loss of stability due to an excessively small pressure difference. Therefore, it can ensure the stability of wafer transfer without placing an additional burden on the motion control of the transfer robot.

[0050] refer to Figure 2 and Figure 7 After the wafer is placed on the temporary support structure 102, the pressure in the process chamber 100 is reduced to a low pressure.

[0051] After the wafer is placed on the temporary support structure 102, the pressure in the process chamber 100 is reduced to a low level, thereby reducing the number of residual gas molecules in the chamber and eliminating gas resistance and disturbance sources for the subsequent faster movement of the pedestal 101. This allows the pedestal 101 to rise at a speed much higher than in conventional processes without triggering airflow that could cause wafer displacement, enabling high-speed movement of the pedestal 101 and helping to shorten wafer transport time.

[0052] In some embodiments, after the pressure in the process chamber 100 is reduced to a low pressure, the base 101 is driven to move upward to the receiving position L2.

[0053] After the process chamber 100 reaches a low pressure state, the drive base 101 moves to the receiving position L2, thereby ensuring that when the base 101 approaches and contacts the wafer, the environment of the process chamber 100 is in a stable state with no gas disturbance or minimal disturbance, thus enabling rapid and stable wafer receiving.

[0054] As an example, the floor pressure is less than or equal to 0.1 Torr. For example, 0.02 Torr, 0.06 Torr, 0.08 Torr.

[0055] refer to Figure 1 and Figure 3 The base 101 is driven to move vertically from the bonding position L1 to the receiving position L2, where the base 101 receives the wafer.

[0056] By driving the base 101 to move upward from the bonding position L1 to the receiving position L2, the surface of the base 101 supports the wafer located on the lifting pin, thereby completing the transfer of the wafer from the temporary support structure 102 (i.e., the lifting pin) to the base 101. This marks the beginning of the wafer directly receiving heat from the base 101, which is the starting point for subsequent adsorption and process flow.

[0057] In some embodiments, during the process of drawing the pressure of the process chamber 100 to a low pressure, the base 101 is driven to move from the contact position L1 to the receiving position L2 by a predetermined distance, and the predetermined distance is less than the distance between the contact position L1 and the receiving position L2.

[0058] By simultaneously evacuating the pressure in the process chamber 100 to a low pressure and driving the base 101 upward a predetermined distance, the process of driving the wafer upward with the evacuation of the process chamber 100 is processed in parallel. The time window for evacuating to a low pressure is utilized to shorten the physical distance between the base 101 and the wafer. Therefore, this embodiment completes the lifting action of the base 101 without increasing the additional process time, improving time utilization and further reducing the total time from wafer transfer into the process chamber 100 to the final wafer adsorption. Moreover, after the process chamber 100 reaches a low pressure state, the base 101 completes the remaining stroke and moves to the receiving position L2. Thus, when the base 101 approaches and contacts the wafer, the environment of the process chamber 100 is already in a stable state with little or no gas disturbance, enabling rapid and smooth wafer reception.

[0059] As an example, the base 101 moves from the bonding position L1 to the receiving position L2 at a speed greater than or equal to 6 mm / s. This shortens the time required for the base 101 to move from the bonding position L1 to the receiving position L2, improving time utilization and helping to reduce wafer warpage. For example, the base 101 can move from the bonding position L1 to the receiving position L2 at a speed of 10 mm / s.

[0060] As an example, the distance between the splice position L1 and the receiving position L2 can be 25mm, and the corresponding preset distance can be 10mm, 15mm, etc.

[0061] Continue to refer to Figure 1 and Figure 4 The base 101 is driven to move the wafer from the receiving position L2 to the process position L3, and during the process of the base 101 moving from the receiving position L2 to the process position L3, the wafer adsorption operation is initiated.

[0062] The method for improving wafer adsorption capacity provided in this application embodiment involves first reducing the pressure in the process chamber 100 to a low pressure after the wafer is placed on the temporary support structure, and then simultaneously initiating wafer adsorption while the drive base 101 moves from the receiving position L2 to the process position L3. Firstly, reducing the pressure in the process chamber 100 before the base 101 begins to move lowers the gas density within the process chamber. This effectively reduces the disturbance effect of gas flow on the wafer when the base 101 subsequently moves, allowing the base 101 to operate smoothly and ensuring the wafer is stably positioned on the base 101. Secondly, the wafer adsorption operation is performed in parallel with the process of the substrate 101 moving from the receiving position L2 to the process position L3. Through the overlap in timing, the adsorption process, which originally had to start after the substrate 101 reached the process position L3, is integrated into the movement of the substrate 101, thus compressing the time. Because the total time from the substrate 101 receiving the wafer to the completion of adsorption is significantly shortened, the baking time of the wafer exposed to the high temperature of the substrate 101 before it is fully adsorbed is directly reduced. This helps to suppress or slow down the thermal warpage deformation of the wafer caused by prolonged heating, allowing the wafer to be adsorbed in a better flat state. As a result, the wafer can form a uniform and reliable seal with the substrate 101, improving the wafer adsorption effect.

[0063] It should be noted that the wafer adsorption operation begins immediately after the base 101 receives the wafer from the receiving position L2.

[0064] The wafer adsorption operation begins immediately after the substrate 101 receives the wafer, making full use of the entire movement time of the substrate 101 from the receiving position L2 to the process position L3 to perform adsorption. This compresses the "window period" during which the wafer is in an unadsorbed state on the high-temperature substrate 101, which helps to suppress wafer thermal warping.

[0065] refer to Figure 5 The semiconductor device includes: a plurality of adsorption units 300, each adsorption unit 300 including an adsorption pipe 301, the adsorption end 301a of the adsorption pipe 301 being connected to the space to be evacuated between the base 101 and the wafer; a negative pressure reservoir 302 disposed on the adsorption pipe 301, the negative pressure reservoir 302 being in a negative pressure state; and a first valve 303 disposed on the adsorption pipe 301 and located between the negative pressure reservoir 302 and the wafer; the adsorption operation on the wafer includes the steps of: opening the first valve 303, so that the space to be evacuated between the back of the wafer and the base 101 is connected to the negative pressure reservoir 302 in a negative pressure state, evacuating the gas in the space to be evacuated between the back of the wafer and the base 101, and adsorbing the wafer.

[0066] By setting an adsorption unit 300 with a negative pressure storage device 302 and a first valve 303 on the base 101, a vacuum pumping system for the back side of the wafer is formed. When the first valve 303 is opened, the low pressure state pre-stored in the negative pressure storage device 302 can be used to instantly and massively pump the gas in the space to be pumped between the wafer and the base 101. Thus, a rapid vacuum is achieved on the back side of the wafer, forming the negative pressure required for adsorption. This allows the wafer to be firmly fixed on the base 101, which is beneficial for synergistic effect with the high pressure on the front side of the process chamber to generate a strong adsorption force.

[0067] In some embodiments, the base 101 moves from the receiving position L2 to the process position L3 at a speed greater than or equal to 6 mm / s. This shortens the time required for the base 101 to move from the receiving position L2 to the process position L3, improving time utilization and helping to reduce wafer warpage. For example, the speed at which the base 101 moves from the receiving position L2 to the process position L3 can be 10 mm / s.

[0068] The wafer adsorption method further includes: after initiating the wafer adsorption operation, increasing the pressure in the process chamber 100 to a first pressure value P1 (e.g., ...). Figure 7 As shown), it is used to apply pressure to the top surface of the wafer, pressing the wafer onto the base 101, and the first pressure value P1 is greater than the process pressure P2 required for subsequent processes (e.g., ...). Figure 7 (As shown).

[0069] By increasing the pressure in the process chamber 100 to a first pressure value P1 greater than the process pressure P2, a larger pressure is applied to the top surface of the wafer, thus generating a mechanical force sufficient to overcome the thermally induced warping deformation of the wafer. This allows even warped wafers to be forcibly flattened and tightly adhered to the surface of the base 101, which helps to provide initial sealing conditions for wafer adsorption and creates a huge pressure difference with the vacuum environment being established on the back side of the wafer, which is beneficial for flattening the wafer.

[0070] It should be noted that the evacuation space is not a completely enclosed space. The upper interface of the evacuation space is the back side of the wafer to be processed, and the lower interface is the top bearing surface of the base 101. There is a gap between the back side of the wafer to be processed and the top bearing surface of the base 101. This gap decreases as the warpage of the wafer to be processed decreases.

[0071] As an example, such as Figure 6As shown, the base 101 has a support surface 101a, on which an annular structure 103 is disposed. The annular structure 103 serves as the portion of the base 101 that abuts against the wafer. The abutment of the wafer against the annular structure 103 creates a vacuum space (not shown in the figure) consisting of the wafer, the annular structure 103, and the support surface 101a. It should be noted that the adsorption end 301a penetrates the base 101 and is exposed on the support surface 101a, enabling the adsorption unit 300 to extract gas from the vacuum space. There are multiple adsorption units 300, each with multiple adsorption ends 301a, distributed across multiple locations penetrating the base 101.

[0072] In some embodiments, the process chamber 100 is provided with a positive pressure reservoir (not shown in the figure) and a jet end (not shown in the figure) communicating with the positive pressure reservoir, wherein the positive pressure reservoir stores pre-charged gas; the step of raising the pressure of the process chamber 100 to a first pressure value P1 includes: opening the jet end communicating with the positive pressure reservoir and releasing the pre-charged gas into the process chamber 100.

[0073] By setting a positive pressure reservoir containing pre-charged gas in the process chamber 100 and opening its jet end when needed, the pre-charged gas is released by utilizing the pressure difference between the positive pressure reservoir and the process chamber 100, thereby allowing the gas to be rushed into the process chamber 100. This increases the chamber pressure to the first pressure value P1, achieving a forced downward pressure on the wafer, which is beneficial for cooperating with the moving base 101 and reducing wafer warpage.

[0074] In some embodiments, the first valve 303 includes a diaphragm valve.

[0075] Specifically, the jet end includes a spray head.

[0076] In some embodiments, the first pressure value P1 is 1 to 5 times the process pressure P2. This allows for the suppression of wafer warpage while simultaneously reducing the potential risks associated with excessively high pressures in the process chamber 100. Therefore, while the wafer is being held in place, damage to the wafer is avoided. This allows for the selection of an appropriate pressure boosting factor based on the actual degree of wafer warpage and material properties, thereby improving the applicability and robustness of the process. For example, the first pressure value P1 is 1.5 times the process pressure P2.

[0077] In some embodiments, the pre-charge gas includes an inert gas. By using an inert gas as the pre-charge gas, it is ensured that the gas introduced during rapid pressing will not chemically react with the wafer surface or components within the cavity, thereby avoiding contamination or interference with the upcoming thin film deposition process. Therefore, while achieving physical adhesion, the purity of the process environment is guaranteed, and the quality of the subsequent atomic layer deposition film is not affected. For example, the inert gas includes one or more of argon, helium, and nitrogen.

[0078] As an example, in the step of increasing the pressure in the process chamber 100 to the first pressure value P1, the pressure in the process chamber 100 is linearly related to time. By making the pressure in the process chamber 100 linearly related to time during the pressure increase phase, that is, by achieving a linearly controlled pressure increase process within the process chamber 100, compared to instantaneous pressure surges in the process chamber 100, the gradual pressure increase in the process chamber 100 can smoothly apply force to the wafer, avoiding the risk of wafer vibration or damage caused by excessively rapid pressure increases in the process chamber 100. This results in a stable pressure increase in the process chamber 100, which is beneficial for improving process safety while ensuring adsorption effectiveness. In other embodiments, during the pressure increase process of the process chamber, the pressure in the process chamber can also exhibit a curvilinear growth relationship with time.

[0079] In some embodiments, during the process of the base 101 moving from the receiving position L2 to the process position L3, the base 101 and the wafer form a space to be evacuated. When the pressure in the space to be evacuated is detected to be lower than a preset threshold, the pressure in the process chamber 100 is reduced from the first pressure value P1 to the process pressure P2.

[0080] By monitoring the pressure of the space to be evacuated between the substrate 101 and the wafer in real time, and taking the pressure below a preset threshold as the switching node, a closed-loop feedback control mechanism based on the actual adsorption state is established. This allows for accurate determination that a stable and effective airtight seal has been formed between the wafer and the substrate 101. Based on this specific signal, rather than a fixed time delay, the action of switching from high pressure to process pressure P2 is triggered. This facilitates the immediate restoration of process conditions after ensuring successful adsorption, avoiding unnecessary waiting.

[0081] In some embodiments, each adsorption unit 300 includes: a first pressure sensor 304 connected to the adsorption pipeline 301, wherein the first pressure sensor 304 is used to monitor the pressure of the space to be evacuated between the base 101 and the wafer; in the step of monitoring the pressure in the space to be evacuated, the first pressure sensor 304 is used to detect the pressure on the adsorption pipeline 301.

[0082] Because the space to be evacuated between the substrate 101 and the wafer is connected to the adsorption pipeline 301, the pressure in the adsorption pipeline 301 detected by the first pressure sensor 304 is the pressure in the sealed space between the substrate 101 and the wafer. By installing the first pressure sensor 304 on the adsorption pipeline 301, the pressure in the space to be evacuated between the wafer and the substrate 101 can be measured, thereby enabling real-time acquisition of information reflecting the adsorption and sealing status of the wafer.

[0083] As an example, the preset threshold is less than 1 Torr. When the reading of the first pressure sensor 304 drops below 1 Torr and no longer increases, it indicates that the vacuum space between the wafer and the substrate 101 has reached a sufficient level, forming a reliable seal, providing an execution command to reduce the pressure in the process chamber 100 back to the process pressure P2. For example, 0.2 Torr, 0.6 Torr, 0.8 Torr.

[0084] In some embodiments, the process chamber 100 includes: a second valve (not shown) disposed in the process chamber 100 for controlling the passage or disconnection between the process chamber 100 and the outside; a second pressure sensor (not shown) disposed in the process chamber 100 for sensing the pressure in the process chamber 100; and a controller connected to the second valve and the second pressure sensor. The step of reducing the pressure in the process chamber 100 from the first pressure value P1 to the process pressure P2 includes: the controller receiving real-time pressure feedback in the process chamber 100 sensed by the second pressure sensor and adjusting the second valve.

[0085] By configuring a controller, a second pressure sensor, and a second valve, a real-time feedback control system for the pressure in the process chamber 100 is constructed. The controller can dynamically adjust the opening of the second valve based on the difference between the real-time pressure sensed by the second pressure sensor and the process pressure P2. This achieves precise and stable control of the chamber pressure, allowing the pressure to be stably reduced from the higher first pressure value P1 to the process pressure P2. This is beneficial for creating a stable and precise pressure environment for the subsequent atomic layer deposition process.

[0086] In some embodiments, in the step of reducing the pressure of the process chamber 100 from the first pressure value P1 to the process pressure P2, the pressure of the process chamber 100 is linearly related to time.

[0087] By making the pressure in the process chamber 100 decrease linearly with time from the first pressure value P1 to the process pressure P2, a linear and uniform pressure reduction process is achieved. This controlled linear decrease provides a smooth transition for the process environment in the process chamber 100, gently reaching the process state. In other embodiments, during the pressure reduction process in the process chamber, the pressure in the process chamber may also decrease in a curve-like relationship with time.

[0088] In some embodiments, the controller is a PID controller; the step of adjusting the second valve includes: the PID controller taking the process pressure P2 as a setpoint, taking the real-time pressure value sensed by the second pressure sensor as a process variable, and calculating and outputting a control signal to adjust the opening degree of the second valve based on the error between the setpoint and the process variable.

[0089] By employing a PID controller to regulate the second valve, a mature and robust control algorithm is introduced. The PID control algorithm performs proportional, integral, and derivative calculations on the error between the setpoint and the process variable, thus generating a precise control signal to dynamically adjust the opening of the second valve. This enables rapid response to pressure changes, elimination of steady-state errors, and suppression of process oscillations, allowing the chamber pressure to converge quickly, smoothly, and accurately to the process pressure P2, which is beneficial for improving the accuracy and stability of pressure control.

[0090] As an example, the PID controller can adjust the opening of the second valve using the following control terms: a proportional control term to provide a rapid response to the error; an integral control term to eliminate steady-state error to ensure that the pressure in the process chamber 100 accurately reaches the process pressure P2; and a derivative control term to suppress overshoot and oscillation during the pressure drop process, thereby achieving a smooth pressure transition.

[0091] By combining proportional, integral, and derivative control terms in a PID controller, a fully functional control logic is formed. The proportional term ensures response speed, the integral term ensures final accuracy, and the derivative term ensures process smoothness. Therefore, it can effectively suppress overshoot and oscillation phenomena throughout the entire dynamic process of the pressure decreasing from the first pressure value P1 to the process pressure P2, making the pressure transition curve smooth and controllable, which is conducive to creating a highly stable chamber environment before the process starts.

[0092] As an example, the second valve includes a butterfly valve. Butterfly valves are simple, compact, lightweight, and easy to operate.

[0093] As an example, the distance between the receiving position L2 and the process position L3 is 60mm.

[0094] This invention also provides a semiconductor device, comprising: a process chamber 100, wherein a base 101 and a plurality of temporary support structures 102 penetrating the base 101 are disposed in the process chamber 100, the base 101 being movable in a vertical direction relative to the temporary support structures 102, the temporary support structures 102 being used to support the wafer; and a plurality of adsorption units 300, each adsorption unit 300 including an adsorption conduit 301, wherein the adsorption end 301a of the adsorption conduit 301 is in a vacuum to be evacuated between the base 101 and the wafer. Interconnected; negative pressure storage 302, disposed on the adsorption pipeline 301, the negative pressure storage 302 being in a negative pressure state; first valve 303, disposed on the adsorption pipeline 301, and located between the negative pressure storage 302 and the adsorption end 301a; negative pressure generating device, connected to the process chamber 100, used to draw the pressure of the process chamber 100 to a low pressure; lifting mechanism, located at the bottom of the base 101, the lifting mechanism including an output end, the output end of the lifting mechanism being connected to the base 101, used to drive the base 101 to move.

[0095] The semiconductor device provided in this embodiment of the invention includes a process chamber 100, a base 101 that can move vertically within it, a lifting mechanism for driving the base 101 to move, and a negative pressure generating device for drawing the process chamber 100 to a low pressure. The base 101 integrates an adsorption unit 300 including a negative pressure reservoir 302 pre-positioned in a negative pressure state and a first valve 303. By providing a negative pressure generating device communicating with the process chamber 100, the pressure inside the process chamber 100 can be drawn to a low pressure before the base 101 moves. This significantly reduces the gas molecule density inside the process chamber 100, thereby effectively reducing the flow field disturbance caused by the gas on the wafer placed on the temporary support structure 102 when the lifting mechanism drives the base 101 to move at high speed. This creates conditions for high-speed and stable movement of the base 101, thereby shortening the transfer time from being received to being fully adsorbed, and helping to suppress wafer warping caused by prolonged heating. Furthermore, the negative pressure storage device 302 provided in the adsorption unit 300 of the base 101 can, at the start of the adsorption process, instantaneously apply a pre-stored high vacuum to the space between the base 101 and the wafer to be evacuated by opening the first valve 303. This generates a rapid and strong initial adsorption force, which can effectively pull the wafer, which has a certain degree of warping, toward and adhere to the surface of the base 101, significantly improving the success rate and reliability of adsorption. Therefore, this semiconductor device shortens the wafer heating time while enhancing the wafer adsorption capacity.

[0096] In some embodiments, the adsorption unit 300 further includes a first pressure sensor 304 disposed on the adsorption pipeline 301, the first pressure sensor 304 being used to monitor the pressure of the space to be evacuated between the base 101 and the wafer.

[0097] The first pressure sensor 304 installed on the adsorption pipeline 301 is used to monitor the pressure status of the space to be evacuated between the substrate 101 and the wafer in real time, thereby enabling real-time monitoring of the vacuum adsorption effect on the back side of the wafer and providing a basis for determining whether a stable airtightness has been formed between the wafer and the substrate 101. Therefore, when the pressure value of the space between the back side of the wafer and the substrate 101 reaches the preset stable low pressure threshold, the pressure of the process chamber 100 is restored to the process pressure P2 to prepare for subsequent atomic layer deposition.

[0098] In some embodiments, the semiconductor device further includes: a positive pressure reservoir located in the process chamber 100, the positive pressure reservoir being connected to a jet end, the positive pressure reservoir storing pre-charge gas for releasing the pre-charge gas into the process chamber 100.

[0099] The positive pressure reservoir is used to release pre-charged gas into the process chamber 100 when the adsorption unit 300 adsorbs the wafer, thereby raising the pressure in the process chamber 100 to a first pressure value P1 that is higher than the normal process pressure P2 in a short time. Together with the negative pressure suction on the back of the wafer, a large pressure difference is formed between the front and back of the wafer. Therefore, a downward pressure sufficient to overcome the warping stress of the wafer itself can be generated, so that the warped wafer can be forced to flatten and tightly adhere to the surface of the base 101, which is beneficial to achieve effective adsorption and sealing of wafers with high warping.

[0100] In some embodiments, the process chamber 100 includes: a second valve disposed in the process chamber 100 for controlling the passage or disconnection between the process chamber 100 and the outside; a second pressure sensor disposed in the process chamber 100 for sensing the pressure in the process chamber 100; and a controller connected to the second valve and the second pressure sensor, the controller being used to receive real-time pressure feedback in the process chamber 100 sensed by the second pressure sensor and to adjust the second valve.

[0101] The second pressure sensor is used to sense the pressure in the process chamber 100 in real time and provide pressure feedback to the controller, so that the controller can dynamically adjust the opening of the second valve according to the preset process pressure P2 curve. After the positive pressure storage is completed, the pressure in the process chamber 100 can be smoothly reduced from the first pressure value P1 and stabilized at the process pressure P2. Therefore, closed-loop control of the pressure in the process chamber 100 can be achieved, making the entire adsorption and pressure conversion process stable and controllable, avoiding pressure fluctuations from disturbing the adsorbed wafers, and also helping to provide the pressure environment required for subsequent thin film deposition steps after high-pressure adsorption is completed.

[0102] In some embodiments, the first valve 303 includes a diaphragm valve and a clamp valve.

[0103] In some embodiments, the negative pressure generating device includes a negative pressure pump, such as a dry pump or a high vacuum pump.

[0104] In some embodiments, the lifting mechanism includes: a motor, the motor including an output shaft; a lead screw fixedly connected to the output shaft of the motor; and a rotating member located on the lead screw for rotatably engaging with the lead screw, wherein the rotating member moves vertically when the lead screw rotates. In other embodiments, the lifting mechanism may also employ a telescopic rod, or a pneumatic cylinder, or a hydraulic cylinder for linear extension and retraction to achieve the lifting effect.

[0105] The foregoing describes multiple embodiment schemes provided by the embodiments of this application. The optional methods described in each embodiment scheme can be combined and cross-referenced with each other without conflict, thereby extending to a variety of possible embodiment schemes. These can all be considered as the embodiment schemes disclosed and published by the embodiments of this application.

[0106] While the embodiments disclosed above are described in this application, this application 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 should be determined by the scope defined in the claims.

Claims

1. An adsorption method for improving wafer warpage, applied in semiconductor equipment, characterized in that, include: A base is provided in a process chamber at a wafer bonding position and a plurality of temporary support structures passing through the base. The base is movable in a vertical direction relative to the temporary support structures, and when in the wafer bonding position, the temporary support structures protrude from the top of the base to support the wafer. The wafer is placed on the plurality of temporary support structures; After the wafer is placed on the temporary support structure, the pressure in the process chamber is reduced to a low level. The base is driven to move vertically from the bonding position to the receiving position, where the base receives the wafer; The base is driven to move the wafer from the receiving position to the process position, and the wafer adsorption operation is initiated during the process of the base moving from the receiving position to the process position.

2. The adsorption method for improving wafer warpage as described in claim 1, characterized in that, The wafer adsorption method further includes: after starting the wafer adsorption operation, increasing the pressure of the process chamber to a first pressure value to apply pressure to the top surface of the wafer, pressing the wafer onto the base, and the first pressure value is greater than the process pressure required during the process; During the process of the base receiving the wafer, the base and the wafer form a space to be evacuated; in the step of starting the wafer adsorption operation, when the pressure in the space to be evacuated is detected to be lower than a preset threshold, the pressure in the process chamber is reduced from the first pressure value to the process pressure.

3. The adsorption method for improving wafer warpage as described in claim 2, characterized in that, The process chamber is equipped with a positive pressure reservoir and a jet end connected to the positive pressure reservoir, and the positive pressure reservoir stores pre-charge gas. The step of increasing the pressure in the process chamber to the first pressure value includes: opening the jet end connected to the positive pressure reservoir and releasing the pre-charge gas into the process chamber.

4. The adsorption method for improving wafer warpage as described in claim 3, characterized in that, The pre-charged gas includes an inert gas.

5. The adsorption method for improving wafer warpage as described in claim 2, characterized in that, The semiconductor device includes: multiple adsorption units, each adsorption unit including an adsorption pipeline, the adsorption end of the adsorption pipeline being connected to the space to be evacuated between the base and the wafer; a negative pressure reservoir disposed on the adsorption pipeline, the negative pressure reservoir being in a negative pressure state; and a first valve disposed on the adsorption pipeline and located between the negative pressure reservoir and the wafer. The wafer adsorption operation includes the following steps: opening the first valve to connect the space to be evacuated between the back of the wafer and the base with the negative pressure storage device which is under negative pressure, and evacuating the gas in the space to be evacuated between the back of the wafer and the base to adsorb the wafer.

6. The adsorption method for improving wafer warpage as described in claim 5, characterized in that, Each adsorption unit includes: a first pressure sensor connected to the adsorption pipeline, the first pressure sensor being used to monitor the pressure of the space to be evacuated between the base and the wafer; In the step of monitoring the pressure in the space to be evacuated, the first pressure sensor is used to detect the pressure on the adsorption pipeline.

7. The adsorption method for improving wafer warpage as described in claim 2, characterized in that, The preset threshold is less than 1 Torr.

8. The adsorption method for improving wafer warpage as described in claim 2, characterized in that, The first pressure value is 1 to 5 times the process pressure.

9. The adsorption method for improving wafer warpage as described in claim 2, characterized in that, The process chamber includes: a second valve disposed in the process chamber for controlling the connection or disconnection between the process chamber and the outside; a second pressure sensor disposed in the process chamber for sensing the pressure in the process chamber; and a controller connected to the second valve and the second pressure sensor. The step of reducing the pressure in the process chamber from the first pressure value to the process pressure includes: the controller receiving real-time pressure feedback in the process chamber sensed by the second pressure sensor, and adjusting the second valve.

10. The adsorption method for improving wafer warpage as described in claim 1, characterized in that, During the process of drawing the pressure in the process chamber to a low pressure, the base is driven to move upward a predetermined distance, and the predetermined distance is less than the distance between the contact point and the receiving point; Alternatively, after the pressure in the process chamber is reduced to a minimum, the base is driven to move upward to the receiving position.

11. The adsorption method for improving wafer warpage as described in claim 1, characterized in that, The process chamber is connected to the transmission chamber; The wafer adsorption method further includes: before placing the wafer on the plurality of temporary support structures, reducing the pressure in the process chamber to a level lower than the pressure in the transfer chamber.

12. A semiconductor device, characterized in that, include: A process chamber is provided with a base and a plurality of temporary support structures penetrating the base. The base is movable in the vertical direction relative to the temporary support structures, and the temporary support structures are used to support the wafer. Multiple adsorption units, each including an adsorption pipeline, the adsorption end of the adsorption pipeline being connected to the space to be evacuated formed by the base and the wafer; a negative pressure reservoir disposed on the adsorption pipeline, the negative pressure reservoir being in a negative pressure state; a first valve disposed on the adsorption pipeline, located between the negative pressure reservoir and the adsorption end; A negative pressure generating device, connected to the process chamber, is used to draw the pressure in the process chamber down to a low pressure. A lifting mechanism is located at the bottom of the base. The lifting mechanism includes an output end, which is connected to the base and is used to drive the base to move.

13. The semiconductor device as claimed in claim 12, characterized in that, The semiconductor device further includes: a positive pressure reservoir located in the process chamber, the positive pressure reservoir being connected to a jet end, the positive pressure reservoir storing pre-charge gas for releasing the pre-charge gas into the process chamber.

14. The semiconductor device as claimed in claim 12, characterized in that, The process chamber includes: The second valve is installed in the process chamber and is used to control the passage or disconnection between the process chamber and the outside. A second pressure sensor is installed in the process chamber to sense the pressure in the process chamber; a controller is connected to the second valve and the second pressure sensor, and the controller is used to receive real-time pressure feedback in the process chamber sensed by the second pressure sensor and adjust the second valve accordingly.

15. The semiconductor device as claimed in claim 12, characterized in that, The adsorption unit further includes: A first pressure sensor is installed on the adsorption pipeline. The first pressure sensor is used to monitor the pressure in the space to be evacuated between the base and the wafer.

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