Longitudinally driven thin film resonant high viscosity photoresist droplet ejection device and method

Abstract

The application provides a longitudinal driving thin film resonance high-viscosity photoresist microdroplet spraying device and method, and relates to the technical field of photoresist microdroplet spraying devices.The device comprises a high-viscosity photoresist microdroplet spraying module, a high-viscosity photoresist spraying experiment platform and an upper computer;high-viscosity photoresist liquid is injected into a storage cavity through a glue supply module, a glue spraying driving module is adjusted, the resonance frequency of the microdroplet spraying device is determined, the on-demand microdroplet spraying technology is used to spray the high-viscosity photoresist liquid to the surface of a wafer;the resonance frequency, driving voltage, movement speed and distance between the microdroplet spraying device and the wafer substrate of the microdroplet spraying device are adjusted, and then the optimization and accurate control of the photoresist film thickness and uniformity and the patterned spraying are realized, so that the stable spraying of the high-viscosity photoresist to the specified position on the surface of the wafer is ensured, and the photoresist film is formed.

Description

Technical Field

[0001] This invention relates to the field of photoresist microdroplet ejection devices, and more particularly to a high-viscosity photoresist microdroplet ejection device and method with longitudinally driven thin film resonance. Background Technology

[0002] Integrated circuits, as the core driving force of modern electronic technology advancement, are a crucial factor in promoting global technological development, economic growth, and social progress. Among these processes, photolithography is a key step in patterning integrated circuit devices, and its precision has a decisive impact on the chip's functional integrity, performance indicators, and manufacturing costs. As a critical link in the photolithography process, the uniformity of the photoresist film thickness and the quality of the film formed by photoresist spraying directly affect the resolution and precision of the pattern after subsequent photolithography and development. The level of this process directly determines the minimum feature size, structural complexity, and the performance and yield of the final product achievable by the integrated circuit, making it one of the key links driving the continuous miniaturization of semiconductor manufacturing technology nodes.

[0003] For the two mainstream photoresist spraying processes, spin coating utilizes the centrifugal force generated by the high-speed rotation of the wafer substrate to spread the photoresist droplets and throw off excess resist, thereby achieving thin film formation. Although it can form photoresist films with extremely high uniformity, it has low material utilization and is generally only suitable for low-viscosity resists, while also having poor adaptability to complex morphologies. Atomization spraying, on the other hand, uses ultrasound or pressure to atomize the photoresist into micron-sized droplets, which are then deposited on the wafer surface and fused into a film. While it can improve photoresist utilization, the concentration of atomized droplets cannot be guaranteed, and as the viscosity of the photoresist increases, the droplet concentration and uniformity deteriorate, resulting in a film with lower uniformity. Furthermore, with the continuous improvement of the integration of high-end chips, methods such as nanoimprint lithography, as next-generation lithography technologies with higher precision (<10 nm), are widely used in advanced semiconductor processes. High-precision, on-demand patterned spraying of photoresist on crystalline silicon substrates is a key step in this process, which current photoresist spraying technologies cannot achieve.

[0004] Microdroplet inkjet technology, due to its non-contact nature, high precision, and excellent controllability, is widely used in high-end manufacturing fields such as solar cells. However, as a key component of microdroplet inkjet technology, current microdroplet inkjet devices primarily target the jetting of low-viscosity inks (<20 mPa·s), limiting their ability to jettison high-viscosity inks (>50 mPa·s). Microdroplet inkjet devices that can only jet low-viscosity inks can no longer meet market demands, posing new requirements for the efficient jetting of high-viscosity solutions. Therefore, how to introduce microdroplet inkjet technology into the photoresist coating process to achieve stable, uniform, efficient, and on-demand coating of high-viscosity photoresists is a pressing technical challenge that needs to be addressed. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a high-viscosity photoresist microdroplet spraying device and method with longitudinally driven thin-film resonance. This solves the problem of low particle size concentration in traditional photoresist spraying methods, effectively improving the uniformity of photoresist droplet size, increasing photoresist utilization, and reducing spraying costs. The photoresist film sprayed using microdroplet spraying technology exhibits higher uniformity and is also suitable for patterned spraying scenarios such as nanoimprint lithography, thus broadening its application scope.

[0006] The technical solution adopted in this invention is as follows:

[0007] On one hand, the present invention provides a high-viscosity photoresist microdroplet jetting device for longitudinally driven thin film resonance, including a high-viscosity photoresist microdroplet jetting module, a high-viscosity photoresist spraying experimental platform, and a host computer;

[0008] The high-viscosity photoresist microdroplet jetting module includes a longitudinal driving device, a photoresist storage chamber, and a vibrating film, which are coaxially connected.

[0009] The longitudinal drive device includes a piezoelectric ceramic stack, a rear end cover, an amplitude transformer, and pre-tightening bolts; the length of the longitudinal drive device satisfies 1 / 4 wavelength or an integer multiple of 1 / 4 wavelength; the piezoelectric ceramic stack is composed of several piezoelectric ceramic rings; all piezoelectric ceramic rings have the same polarization direction and the same electric field direction; adjacent piezoelectric ceramic rings are connected by alternating polarity using electrode plates; the rear end cover, the piezoelectric ceramic stack, and the beginning of the amplitude transformer are sequentially fixed and connected by pre-tightening bolts.

[0010] The glue storage chamber is fixed to the end of the amplitude transformer via a threaded connection; the glue storage chamber has a glue inlet and a glue outlet; the glue storage chamber is made of metal.

[0011] The vibrating thin film has a micropore at its center, which serves as the nozzle of the ejector to spray high-viscosity photoresist liquid; the diameter of the micropore is smaller than the wavelength λ of capillary waves on the free surface. ,in, , , These are the liquid surface tension, density, and ultrasonic driving frequency, respectively.

[0012] The vibrating diaphragm is made of stainless steel.

[0013] The high-viscosity photoresist spraying experimental platform includes a microdroplet observation system, a spraying drive module, a precision motion control module, and a photoresist supply module.

[0014] The adhesive supply module includes an adhesive storage box and a negative pressure pump; the adhesive storage box stores high-viscosity photoresist liquid, the adhesive storage box is connected to the adhesive inlet through a first adhesive delivery pipe, and the adhesive outlet is connected to the adhesive storage box through a second adhesive delivery pipe, forming a closed loop; the negative pressure pump provides power for the flow of high-viscosity photoresist liquid;

[0015] The microdroplet observation system consists of a CCD camera and a strobe LED. It observes and measures the ejection characteristics of the ejected photoresist droplets in real time, and then adjusts and optimizes the driving parameters based on the measured data. The ejection characteristics of the photoresist droplets include the ejection size and velocity. The microdroplet observation system observes and measures the ejection characteristics of the ejected photoresist droplets in real time, and then optimizes the driving parameters in real time.

[0016] The glue spraying drive module includes a signal generator and a power amplifier, which generate high-voltage and high-frequency signals to drive the spraying device to achieve micro-droplet spraying.

[0017] The precision motion control module includes a precision motion control board, an X-axis motion module, a Y-axis motion module, a Z-axis rotary motor, and a rotating substrate. The X-axis motion module and the Y-axis motion module drive the spraying device to move according to the path planned by the precision motion control board. The rotating substrate is fixedly connected to the wafer, and the Z-axis rotary motor drives the rotating substrate to move, realizing the scanning motion of the entire wafer.

[0018] The X-axis motion module includes an X-axis servo motor and an X-axis lead screw slide, and the Y-axis motion module includes a Y-axis servo motor and a Y-axis lead screw slide. The X-axis servo motor and the Y-axis servo motor respectively drive the X-axis lead screw slide and the Y-axis lead screw slide to move, converting rotational motion into linear motion. The X-axis motion module is fixed on the Y-axis lead screw slide and moves with the Y-axis motion module.

[0019] The rotating substrate includes a photoresist recovery tank and a vacuum adsorption heating chuck; the vacuum adsorption heating chuck uses vacuum negative pressure to fix the wafer and meets the temperature process requirements of the wafer processing; the photoresist recovery tank recovers unused photoresist dripping from the wafer and then transfers it to a photoresist storage box.

[0020] The host computer outputs driving parameters to the glue spraying driving module and the precision motion control module. The driving parameters specifically include driving voltage, driving frequency, and motion speed. The host computer and the precision motion control module are directly connected via gigabit Ethernet, and the host computer and the signal generator of the glue spraying driving module are connected via fiber optic interface.

[0021] On the other hand, a high-viscosity photoresist microdroplet ejection method based on longitudinally driven thin-film resonance, implemented using the aforementioned high-viscosity photoresist microdroplet ejection device, includes the following steps:

[0022] Step 1: Inject high-viscosity photoresist liquid into the storage cavity through the glue supply module, adjust the glue spraying drive module, and determine the resonant frequency of the micro-droplet spraying device;

[0023] Step 2: Using microdroplet on-demand spraying technology, high-viscosity photoresist liquid is sprayed onto the wafer surface;

[0024] Step 3: Adjust the resonant frequency, driving voltage, movement speed, and distance between the microdroplet ejection device and the wafer substrate to optimize and precisely control the thickness and uniformity of the photoresist film and patterned spraying, ensuring that high-viscosity photoresist is stably ejected and deposited on the designated position on the wafer surface to form a photoresist film.

[0025] The beneficial effects of adopting the above technical solution are as follows:

[0026] This invention provides a device and method for ejecting high-viscosity photoresist microdroplets with longitudinally driven thin-film resonance, which has the following beneficial effects:

[0027] 1. This invention proposes a microdroplet ejection device based on longitudinally driven thin-film resonance. By driving a stack of piezoelectric ceramics to generate vibration displacement, and through a matched displacement amplification structure, the displacement is amplified at the end, thereby driving a vibrating thin film with micropores to achieve microdroplet ejection. Compared with traditional microdroplet ejection devices, the microdroplet ejection device proposed in this invention can achieve high-frequency, on-demand, and stable ejection of high-viscosity solutions, with a solution viscosity of >100 mPa·s, thus broadening the ejection range of traditional microdroplet ejection devices.

[0028] 2. This invention introduces microdroplet spraying technology into the photoresist spraying process, achieving high-frequency, on-demand, and stable spraying of high-viscosity photoresist. Compared to traditional photoresist spraying methods, the microdroplet spraying technology used in this invention produces photoresist droplets with more uniform size, which is more conducive to forming high-quality photoresist films. At the same time, the photoresist utilization rate is high, and the spraying viscosity is greater, thereby effectively reducing manufacturing costs. In addition, the device proposed in this invention can realize on-demand spraying of photoresist droplets, which is suitable for patterned spraying scenarios such as nanoimprint lithography, providing a new alternative solution for photoresist spraying processes in semiconductor manufacturing. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the thin-film resonant photoresist droplet ejection principle according to an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of a high-viscosity photoresist microdroplet jetting module according to an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of a high-viscosity photoresist spraying system according to an embodiment of the present invention;

[0032] Figure 4 This is a schematic diagram of a high-viscosity photoresist spraying experimental platform according to an embodiment of the present invention;

[0033] Figure 5 This invention relates to the characteristics and observation results of high-viscosity photoresist droplet ejection in an embodiment of the invention.

[0034] Figure 6 This is a diagram showing the morphology of a single-nozzle sprayed "line" according to an embodiment of the present invention.

[0035] Figure 7 This is a diagram showing the results of multi-nozzle collaborative spraying according to an embodiment of the present invention;

[0036] Among them, 110-photoresist, 120-vibrating film, 120A-initial position of vibrating film, 120B-maximum amplitude point of vibrating film, 130-rear end cover, 140-pre-tightening bolt, 150-piezoelectric ceramic, 160-electrode sheet, 170-amplifier rod, 180-resin storage chamber, 190A-resin inlet, 190B-resin outlet, 210-high viscosity photoresist microdroplet jetting module, 220-X-axis motion module, 230-Y-axis motion module, 240-Z-axis rotary motor, 250-nozzle mounting plate, 260-wafer, 270-vacuum adsorption heating chuck, 280-resin recovery tank, 290-resin storage box, 310-initial state of droplets at nozzle, 320-droplet compression state, 330-droplet necking state, 340-stable droplet state. Detailed Implementation

[0037] The specific implementation methods of this application will be further described in detail below with reference to the accompanying drawings and embodiments.

[0038] On one hand, the present invention provides a high-viscosity photoresist microdroplet ejection device for longitudinally driven thin-film resonance, such as... Figure 3 As shown, it includes a high-viscosity photoresist microdroplet jetting module, a high-viscosity photoresist spraying experimental platform, and a host computer;

[0039] The high-viscosity photoresist microdroplet jetting module includes a longitudinal driving device, a photoresist storage chamber, and a vibrating film, which are coaxially connected.

[0040] The longitudinal drive device includes a piezoelectric ceramic stack, a rear end cover, an amplitude transformer, and preload bolts. The length of the longitudinal drive device is 1 / 4 wavelength or an integer multiple of 1 / 4 wavelength, thereby effectively increasing the end displacement under resonance and reducing the impedance of the connection surface. The piezoelectric ceramic stack is composed of several piezoelectric ceramic rings connected in series mechanically and in parallel electrically. That is, all piezoelectric ceramic rings have the same polarization direction and the same electric field direction. Adjacent piezoelectric ceramic rings are connected by alternating polarity using electrode plates, which are usually made of brass. The rear end cover, the piezoelectric ceramic stack, and the beginning of the amplitude transformer are sequentially fixed together by preload bolts.

[0041] The glue storage chamber is fixed to the end of the amplitude transformer via a threaded connection; the glue storage chamber has a glue inlet and a glue outlet; the glue storage chamber is made of metal.

[0042] The vibrating diaphragm has a microhole at its center, which serves as the nozzle of the ejector; specifically, laser processing technology is used to fabricate a microhole as the nozzle, and the diameter of the microhole is smaller than the wavelength of capillary waves on the free surface. ,in, , , These are the liquid surface tension, density, and ultrasonic driving frequency, respectively. The nozzle diameter is typically 10-100 μm.

[0043] Because stainless steel films are isotropic and perfectly elastic, they can transmit vibrations better; therefore, the vibration film is made of stainless steel.

[0044] The high-viscosity photoresist spraying experimental platform includes a microdroplet observation system, a spraying drive module, a precision motion control module, and a photoresist supply module.

[0045] The adhesive supply module includes an adhesive storage box and a negative pressure pump; the adhesive storage box stores high-viscosity photoresist liquid, the adhesive storage box is connected to the adhesive inlet through a first adhesive delivery pipe, and the adhesive outlet is connected to the adhesive storage box through a second adhesive delivery pipe, forming a closed loop; the negative pressure pump provides power for the flow of high-viscosity photoresist liquid;

[0046] The microdroplet observation system consists of a CCD camera and a strobe LED. It observes and measures the ejection characteristics of the ejected photoresist droplets in real time, and then adjusts and optimizes the driving parameters based on the measured data. The ejection characteristics of the photoresist droplets include the ejection size and velocity. The microdroplet observation system observes and measures the ejection characteristics of the ejected photoresist droplets in real time, and thus optimizes the driving parameters in real time.

[0047] The glue spraying drive module includes a signal generator and a power amplifier, which generate high-voltage and high-frequency signals to drive the spraying device to achieve micro-droplet spraying.

[0048] The precision motion control module includes a precision motion control board, an X-axis motion module, a Y-axis motion module, a Z-axis rotary motor, and a rotating substrate. The X-axis motion module and the Y-axis motion module drive the spraying device to move according to the path planned by the precision motion control board. The rotating substrate is fixedly connected to the wafer, and the Z-axis rotary motor drives the rotating substrate to move, realizing the scanning motion of the entire wafer.

[0049] The X-axis motion module includes an X-axis servo motor and an X-axis lead screw slide, and the Y-axis motion module includes a Y-axis servo motor and a Y-axis lead screw slide. The X-axis servo motor and the Y-axis servo motor respectively drive the X-axis lead screw slide and the Y-axis lead screw slide to move, converting rotational motion into linear motion. The X-axis motion module is fixed on the Y-axis lead screw slide and moves with the Y-axis motion module.

[0050] The rotating substrate includes a photoresist recovery tank and a vacuum adsorption heating chuck; the vacuum adsorption heating chuck uses vacuum negative pressure to fix the wafer and meets the temperature process requirements of the wafer processing; the photoresist recovery tank recovers unused photoresist dripping from the wafer and transfers it to the photoresist storage box after recovery, reducing photoresist waste;

[0051] The host computer outputs driving parameters to the glue spraying driving module and the precision motion control module. The driving parameters specifically include driving voltage, driving frequency, and motion speed. The host computer and the precision motion control module are directly connected via gigabit Ethernet, and the host computer and the signal generator of the glue spraying driving module are connected via fiber optic interface.

[0052] On the other hand, a high-viscosity photoresist microdroplet ejection method based on longitudinally driven thin-film resonance, implemented using the aforementioned high-viscosity photoresist microdroplet ejection device, includes the following steps:

[0053] Step 1: Inject high-viscosity photoresist liquid into the storage cavity through the glue supply module, adjust the glue spraying drive module, and determine the resonant frequency of the micro-droplet spraying device;

[0054] Step 2: Using microdroplet on-demand spraying technology, high-viscosity photoresist liquid is sprayed onto the wafer surface;

[0055] Step 3: Adjust the resonant frequency, driving voltage, movement speed, and distance between the microdroplet ejection device and the wafer substrate to optimize and precisely control the thickness and uniformity of the photoresist film and patterned spraying, ensuring that high-viscosity photoresist is stably ejected and deposited on the designated position on the wafer surface to form a photoresist film.

[0056] Example 1:

[0057] The high-viscosity photoresist microdroplet ejection system described in this embodiment is as follows: Figure 2 As shown, the device includes photoresist 110, a vibrating thin film 120, a rear end cover 130, a preload bolt 140, a piezoelectric ceramic 150, an electrode sheet 160, an amplitude transformer 170, a photoresist storage chamber 180, a photoresist inlet 190A, and a photoresist outlet 190B. The stainless steel vibrating thin film is approximately 0.2 mm thick. A micro-hole with a diameter of approximately 44 μm is laser-processed at the center of the vibrating thin film 120, serving as the nozzle of the ejector.

[0058] The rear end cover 130, preload bolt 140, piezoelectric ceramic 150, and electrode plate 160 constitute a piezoelectric transducer. The piezoelectric transducer is small in size and capable of high-frequency vibration. Utilizing the piezoelectric effect of the piezoelectric ceramic, when an electrical signal is applied to drive it, the piezoelectric ceramic deforms. Simultaneously, through transducer design matching, the end displacement is amplified. The output displacement of the piezoelectric transducer is relatively small, and it is amplified in conjunction with the amplitude transformer 170. The high-viscosity photoresist microdroplet ejection device with longitudinally driven thin-film resonance contains multiple piezoelectric ceramics 150 and multiple electrode plates 160, enabling the central nozzle of the thin film to have a larger vibration displacement and eject higher viscosity droplets. The reservoir cavity 180 is hollow inside and has an inlet 190A and an outlet 190B.

[0059] The photoresist supply module consists of a photoresist storage box 290 and a negative pressure pump, which provides power quickly and efficiently. High-viscosity photoresist is delivered via a delivery tube to a high-viscosity photoresist micro-droplet ejection device that drives the longitudinally driven thin-film resonant circuit. After leaving the supply / storage box, the delivery tube connects to the inlet 190A and outlet 190B, eventually returning to the supply / storage box to form a closed loop, saving space. All delivery tubes are on a single line, ensuring that there is always sufficient photoresist available inside the storage chamber 180.

[0060] Example 2:

[0061] High-viscosity photoresist spraying experimental platform, such as Figure 4 As shown, it consists of a high-viscosity photoresist microdroplet jetting module 210, an X-axis motion module 220, a Y-axis motion module 230, a Z-axis rotary motor 240, a nozzle mounting plate 250, a wafer 260, a vacuum adsorption heating chuck 270, a photoresist recovery tank 280, and a photoresist storage box 290.

[0062] In this embodiment, the precision motion control module includes an X-axis motion module 220, a Y-axis motion module 230, and a Z-axis rotary motor 240. The servo motors on the X and Y axes drive the lead screws, converting rotational motion into linear motion. The X-axis motion module 220 is fixed to the lead screw slide of the Y-axis motion module 230 and moves with it. The rotating substrate consists of an adhesive recovery tank 280 and a vacuum adsorption heating chuck 270. The Z-axis rotary motor 240 controls the movement of the rotating substrate, which is connected to the wafer 260. The precision motion control module uses three servo motors to achieve three degrees of freedom control: the movement of the nozzle on the X and Y axes and the rotation of the wafer 260 on the Z axis. The X and Y axis motion platforms enable the nozzle to scan the entire wafer 260, while the high-speed rotation on the Z axis is essential for wafer pretreatment and cleaning. During adhesive spraying, if the wafer has no complex surface structure, low-speed rotation can improve uniformity; however, if the surface is complex, rotation is not possible.

[0063] The rotating substrate consists of a photoresist recovery tank 280 and a vacuum adsorption heated chuck 270. The vacuum adsorption heated chuck 270 uses vacuum negative pressure to fix the wafer and meets the temperature process requirements of the wafer processing. The photoresist recovery tank 280 is used to recover unused photoresist dripping from the wafer, and after recovery, it can be transferred to the supply / storage box to reduce photoresist waste.

[0064] Example 3:

[0065] The principle of thin-film resonant photoresist droplet ejection is as follows: Figure 1 As shown, a sinusoidal waveform is used to drive the jetting device to achieve stable droplet jetting. The figure also shows the initial position 120A of the vibrating film and the point of maximum amplitude 120B of the vibrating film.

[0066] The entire droplet ejection process is divided into four stages: A, B, C, and D. Stage A represents the initial droplet state at the nozzle (310). At this stage, no driving voltage has been applied to the high-viscosity photoresist microdroplet ejection device with longitudinally driven thin-film resonance, and the liquid storage cavity is in equilibrium. Simultaneously, under the influence of surface tension and capillary force, the liquid at the nozzle exhibits a slightly convex surface shape. Stage B represents the droplet compression state (320). At this stage, the driving signal is within the time interval 0 to T / 2. The vibrating thin film is excited upward by a positive voltage, increasing the pressure within the cavity and causing the liquid to be squeezed out of the nozzle, forming the initial droplet. Stage C represents the droplet necking state (330). At this stage, the driving waveform is between T / 2 and T. The thin film is excited downward by a reverse voltage, and the squeezed droplet forms a liquid filament. After forming a liquid filament, the droplet gradually elongates and breaks, reaching stage D (340), the stable droplet state. At this point, a stable droplet is formed, completing one ejection cycle. The next cycle then begins, achieving continuous and stable droplet ejection.

[0067] The high-viscosity photoresist microdroplet ejection module 210 consists of five longitudinally driven thin-film resonant high-viscosity photoresist microdroplet ejection devices and a nozzle mounting plate 250. The five longitudinally driven thin-film resonant high-viscosity photoresist microdroplet ejection devices are arranged alternately along the X and Y axes, and can achieve full coverage of the wafer through a precision motion control module. Each longitudinally driven thin-film resonant high-viscosity photoresist microdroplet ejection device can be controlled independently to achieve high-precision on-demand spraying.

[0068] High-viscosity photoresist droplet ejection characteristics and observation results are as follows: Figure 5As shown in the figure, the ejection characteristics of high-viscosity photoresist droplets are illustrated: as the driving voltage increases from 60V to 180V, the diameter of the ejected droplets (left vertical axis, μm) continuously increases, while the droplet ejection velocity (right vertical axis, m / s) increases synchronously. The actual ejection observation image embedded in the figure visually demonstrates that the ejected droplets have a stable morphology and are not broken. This result clarifies the positive control relationship between the driving voltage and the diameter and velocity of the high-viscosity photoresist ejected droplets, providing quantitative support for the precise matching of droplet parameters in the ejection process.

[0069] To verify the feasibility of the device and process of the present invention, experiments were conducted on the morphology of a single nozzle spraying line and the pattern of multi-nozzle collaborative spraying.

[0070] The results of single-nozzle spraying of "line" morphology are as follows Figure 6 As shown, this experiment used a high-viscosity photoresist microdroplet ejection device with longitudinally driven thin film resonance through precise power supply. The ejected "line" morphology was observed under a microscope. It can be seen that the photoresist width of the "line" morphology is stable and the interior is uniform, which verifies the high precision and stability of single-nozzle spraying.

[0071] Multi-nozzle collaborative spraying graphic results are as follows Figure 7 As shown, this experiment used multiple longitudinally driven thin-film resonant high-viscosity photoresist microdroplet ejection devices. The host computer analyzed the data and sent signals to a precision motion control module, accurately controlling the direction of the high-viscosity photoresist droplet ejection module to spray the letter "NEU" onto the wafer surface completely. Microscopic observation of the spraying effect revealed uniform droplet distribution, consistent filling density, and no missing corners or breaks, verifying the high efficiency and reliability of multi-nozzle collaborative spraying.

[0072] Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a computer program product.

[0073] The various embodiments in this application are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0074] The scope of protection of this application is not limited to the embodiments described above. Obviously, those skilled in the art can make various modifications and variations to this disclosure without departing from the scope and spirit of this disclosure. If such modifications and variations fall within the scope of the methods disclosed herein and their equivalents, then the intent of this disclosure also includes such modifications and variations.

Claims

1. A high-viscosity photoresist microdroplet ejection device with longitudinally driven thin-film resonance, characterized in that, This includes a high-viscosity photoresist microdroplet jetting module, a high-viscosity photoresist spraying experimental platform, and a host computer; The high-viscosity photoresist microdroplet jetting module includes a longitudinal driving device, a photoresist storage chamber, and a vibrating film, which are coaxially connected. The longitudinal drive device includes a piezoelectric ceramic stack, a rear end cover, an amplitude transformer, and pre-tightening bolts. The length of the longitudinal drive device satisfies 1 / 4 wavelength or an integer multiple of 1 / 4 wavelength. The piezoelectric ceramic stack is composed of several piezoelectric ceramic rings. All piezoelectric ceramic rings have the same polarization direction and the same electric field direction. Adjacent piezoelectric ceramic rings are connected by alternating polarity using electrode plates. The rear end cover, the piezoelectric ceramic stack, and the beginning of the amplitude transformer are sequentially fixed and connected by pre-tightening bolts. The glue storage chamber is fixed to the end of the amplitude transformer via a threaded connection; the glue storage chamber has a glue inlet and a glue outlet; the glue storage chamber is made of metal. The high-viscosity photoresist spraying experimental platform includes a microdroplet observation system, a spraying drive module, a precision motion control module, and a photoresist supply module. The adhesive supply module includes an adhesive storage box and a negative pressure pump; the adhesive storage box stores high-viscosity photoresist liquid, the adhesive storage box is connected to the adhesive inlet through a first adhesive delivery pipe, and the adhesive outlet is connected to the adhesive storage box through a second adhesive delivery pipe, forming a closed loop; the negative pressure pump provides power for the flow of high-viscosity photoresist liquid; The microdroplet observation system consists of a CCD camera and a strobe LED. It observes and measures the ejection characteristics of the ejected photoresist droplets in real time, and then adjusts and optimizes the driving parameters based on the measured data. The ejection characteristics of the photoresist droplets include the ejection size and velocity. The microdroplet observation system observes and measures the ejection characteristics of the ejected photoresist droplets in real time, and thus optimizes the driving parameters in real time. The host computer outputs driving parameters to the glue spraying drive module and the precision motion control module; the host computer and the precision motion control module are directly connected via gigabit Ethernet, and the host computer and the signal generator of the glue spraying drive module are connected via a fiber optic interface.

2. The high-viscosity photoresist microdroplet ejection device with longitudinally driven thin-film resonance according to claim 1, characterized in that, The precision motion control module includes a precision motion control board, an X-axis motion module, a Y-axis motion module, a Z-axis rotary motor, and a rotating substrate. The X-axis motion module and the Y-axis motion module drive the spraying device to move according to the path planned by the precision motion control board. The rotating substrate is fixedly connected to the wafer, and the Z-axis rotary motor drives the rotating substrate to move, thereby realizing the scanning motion of the entire wafer.

3. The high-viscosity photoresist microdroplet ejection device for longitudinally driven thin-film resonance according to claim 2, characterized in that, The driving parameters specifically include driving voltage, driving frequency, and motion speed.

4. The high-viscosity photoresist microdroplet ejection device for longitudinally driven thin-film resonance according to claim 3, characterized in that, The vibrating diaphragm has a micropore at its center, which serves as the nozzle of the ejector; the diameter of the micropore is smaller than the wavelength λ of the capillary wave on the free surface. ,in, , , These are the liquid surface tension, density, and ultrasonic driving frequency, respectively.

5. The high-viscosity photoresist microdroplet ejection device for longitudinally driven thin-film resonance according to claim 4, characterized in that, The vibrating diaphragm is made of stainless steel.

6. The high-viscosity photoresist microdroplet ejection device for longitudinally driven thin-film resonance according to claim 5, characterized in that, The glue spraying drive module includes a signal generator and a power amplifier, which generate high-voltage, high-frequency signals to drive the spraying device to achieve micro-droplet spraying.

7. The high-viscosity photoresist microdroplet ejection device for longitudinally driven thin-film resonance according to claim 6, characterized in that, The X-axis motion module includes an X-axis servo motor and an X-axis lead screw slide, and the Y-axis motion module includes a Y-axis servo motor and a Y-axis lead screw slide. The X-axis servo motor and the Y-axis servo motor drive the X-axis lead screw slide and the Y-axis lead screw slide to move respectively, converting rotational motion into linear motion. The X-axis motion module is fixed on the Y-axis lead screw slide and moves with the Y-axis motion module.

8. The high-viscosity photoresist microdroplet ejection device for longitudinally driven thin-film resonance according to claim 7, characterized in that, The rotating substrate includes a photoresist recovery tank and a vacuum adsorption heating chuck; the vacuum adsorption heating chuck uses vacuum negative pressure to fix the wafer and meets the temperature process requirements of the wafer processing; the photoresist recovery tank recovers unused photoresist dripping from the wafer and then transfers it to a photoresist storage box.

9. A method for ejecting high-viscosity photoresist microdroplets based on longitudinally driven thin-film resonance, implemented using the high-viscosity photoresist microdroplet ejection device described in claim 1, characterized in that... Includes the following steps: Step 1: Inject high-viscosity photoresist liquid into the storage cavity through the glue supply module, adjust the glue spraying drive module, and determine the resonant frequency of the micro-droplet spraying device; Step 2: Using microdroplet on-demand spraying technology, high-viscosity photoresist liquid is sprayed onto the wafer surface; Step 3: Adjust the resonant frequency, driving voltage, movement speed, and distance between the microdroplet ejection device and the wafer substrate to optimize and precisely control the thickness and uniformity of the photoresist film and patterned spraying, ensuring that high-viscosity photoresist is stably ejected and deposited on the designated position on the wafer surface to form a photoresist film.

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