Immersion lithography machine

Abstract

The present application relates to a kind of immersion photolithography machine, comprising: laser, emit laser beam;Multiple sets of lenses, be arranged between laser and immersion chamber, for focusing and collimating laser emitted by laser beam;Immersion chamber, be arranged between lens and mask, or be arranged between mask and wafer, fill high refractive index medium in it;Mask, be arranged below immersion chamber, laser beam is irradiated on mask after passing through immersion chamber and forms patterned beam;Control system is configured to adjust the flow speed and / or temperature of high refractive index medium;Wafer, be arranged below mask, patterned beam is irradiated on wafer after passing through mask, make photoresist on the surface of wafer chemical reaction or physical change, form corresponding pattern.The present application solves the technical problems that effective wavelength of photolithography light source is limited, focal depth is short, photolithography resolution and precision are low in existing photolithography process.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor technology, and in particular relates to an immersion lithography machine. Background Technology

[0002] In modern semiconductor manufacturing, photolithography is one of the core processes in integrated circuit manufacturing. The development of photolithography has evolved from dry lithography to immersion lithography to adapt to ever-shrinking feature sizes and improve chip manufacturing precision. Existing dry lithography machines, due to the low refractive index of air and limited light wavelength, struggle to further improve resolution. Immersion lithography, by introducing a high-refractive-index medium between the lens and the wafer, significantly improves resolution and the numerical aperture (NA) of the optical system, enabling the processing of finer patterns.

[0003] In addition, most existing immersion lithography systems are independent immersion modules, separate from the reticle (mask) system. This results in a complex system structure, high manufacturing cost, and certain difficulties in media flow and temperature control, affecting overall performance and stability. Summary of the Invention

[0004] To address the shortcomings of related technologies, this invention provides an immersion lithography machine that solves the technical problems of low lithography resolution and precision caused by the limited effective wavelength and depth of focus of the lithography light source in existing lithography processes.

[0005] In one possible implementation, an immersion lithography machine is provided, comprising: a laser for emitting a laser beam; multiple lenses disposed between the laser and an immersion chamber for focusing and collimating the laser beam emitted by the laser; an immersion chamber disposed between the lenses and a mask, or between the mask and a wafer, and filled with a high-refractive-index medium; a mask disposed below the immersion chamber, onto which the laser beam irradiates after passing through the immersion chamber and forms a patterned beam; a control system configured to adjust the flow rate and / or temperature of the high-refractive-index medium; and a wafer disposed below the mask, onto which the patterned beam irradiates after passing through the mask, causing a chemical reaction or physical change in the photoresist on the wafer surface to form a corresponding pattern.

[0006] In one possible implementation, the system further includes a temperature sensor and a temperature regulator, wherein the temperature sensor is used to detect the temperature of the high refractive index medium; the control system is configured to control the temperature regulator to heat or cool based on the temperature of the high refractive index medium; and the temperature regulator is used to heat or cool the high refractive index medium.

[0007] In one possible implementation, it also includes a flow rate regulator having a valve that is controlled by instructions from the control system to open to a corresponding degree.

[0008] In one possible implementation, the immersion chamber is a sealed space with a variable volume for containing a high refractive index medium.

[0009] In one possible implementation, the laser is an argon fluoride (ArF) laser.

[0010] In one possible implementation, the laser emits a laser beam with a wavelength of 193 nanometers.

[0011] In one possible implementation, the high refractive index medium is deionized water or highly purified oil.

[0012] In one possible implementation, the temperature range of the high refractive index medium is 15°C to 25°C.

[0013] In one possible implementation, a flow rate sensor is also included for detecting the flow rate of the high-refractive-index medium in the immersion chamber; the control system is further configured to control the opening of the valve of the flow rate regulator based on the flow rate of the high-refractive-index medium.

[0014] Based on the above technical solution, the immersion lithography machine of the present invention sets up a lens and an immersion chamber filled with a high refractive index medium between the laser and the mask, which solves the problem of being limited by the wavelength of the light source in the high-resolution patterning process of traditional lithography machines; using water or oil as immersion material increases the refractive index of the system, reduces the light wavelength, and increases the depth of focus to achieve higher resolution and more precise chip manufacturing; improves lithography accuracy and pattern clarity, and enhances the reliability and efficiency of semiconductor manufacturing processes. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0016] Figure 1 This is a schematic diagram of an immersion lithography machine according to one embodiment of the present invention;

[0017] Figure 2 This is a schematic diagram of the refraction principle of an immersion lithography machine according to one embodiment of the present invention;

[0018] Figure 3 This is a schematic diagram of an immersion lithography machine according to another embodiment of the present invention;

[0019] Figure 4 This is a schematic diagram of an immersion lithography machine according to another embodiment of the present invention.

[0020] In the picture:

[0021] 1. Laser; 2. Lens; 3. Immersion chamber; 4. Mask; 5. Wafer; 6. Control system; 7. Temperature sensor; 8. Temperature regulating device; 9. Flow rate regulator; 10. Flow rate sensor; 111. Optical sensor; 112. Immersion material storage tank I; 113. Immersion material storage tank II; 114. Immersion material storage tank III; 115. Valve I; 116. Valve II; 117. Valve III. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0023] In the description of this invention, it should be understood that the terms "center", "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0024] The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] To address the technical problems of low lithography resolution and precision caused by the limited effective wavelength and depth of focus of the lithography light source in existing photolithography processes, this application provides an immersion lithography machine.

[0027] See Figure 1In one possible implementation, the system includes: a laser 1 that emits a laser beam; multiple lenses 2 disposed between the laser 1 and an immersion chamber 3 for focusing and collimating the laser beam emitted by the laser 1; an immersion chamber 3 disposed between the lenses 2 and a mask 4, or between the mask 4 and a wafer 5, and filled with a high-refractive-index medium; a mask 4 disposed below the immersion chamber 3, onto which the laser beam, after passing through the immersion chamber 3, illuminates and forms a patterned beam; a control system 6 configured to adjust the flow rate and / or temperature of the high-refractive-index medium; and a wafer 5 disposed below the mask 4, onto which the patterned beam, after passing through the mask 4, illuminates and causes a chemical reaction or physical change in the photoresist on the surface of the wafer 5, forming a corresponding pattern.

[0028] In the above scheme, laser 1 is used to emit a laser beam, and multiple lenses 2 are arranged between laser 1 and immersion chamber 3 to focus and collimate the laser beam emitted by laser 1; immersion chamber 3 is arranged between lenses 2 and mask 4, see [reference]. Figure 3 Alternatively, it can be positioned between mask 4 and wafer 5, see [reference needed]. Figure 1 The laser beam is filled with a high refractive index medium. After being focused and collimated by lens 2, the laser beam enters immersion chamber 3. Due to the high refractive index medium in immersion chamber 3, the propagation path and focal length of the laser beam are changed, thereby improving the lithography resolution. After passing through immersion chamber 3, the laser beam irradiates mask 4 to form a patterned beam. The patterned beam then passes through mask 4 and irradiates wafer 5, causing the photoresist on the surface of wafer 5 to undergo a chemical reaction or physical change to form the corresponding pattern. Control system 6 is used to adjust the flow rate and / or temperature of the high refractive index medium to ensure the stability and accuracy of the lithography process.

[0029] See Figure 2 By introducing a high-refractive-index medium and immersion lithography, the wavelength of the laser is reduced and the depth of focus is increased, which enables more efficient beam focusing and collimation, thereby improving the resolution and precision of lithography.

[0030] In one possible implementation, it also includes a temperature sensor 7 and a temperature regulating device 8.

[0031] Temperature sensor 7 is used to detect the temperature of the high refractive index medium; control system 6 controls temperature regulating device 8 to heat or cool according to the temperature of the high refractive index medium, thereby keeping the medium within the optimal operating temperature range and ensuring the stability and accuracy of the photolithography process.

[0032] The temperature sensor 7 and the temperature regulation device 8 can monitor and regulate the temperature of the high refractive index medium in real time to ensure that it is in the best working condition and improve the lithography accuracy and stability.

[0033] In one possible implementation, a flow rate regulator 9 is also included.

[0034] The flow rate regulator 9 has a valve that is controlled by the control system 6 to open to the corresponding degree to regulate the flow rate of the high refractive index medium and ensure the stability and accuracy of the photolithography process.

[0035] By introducing the flow rate regulator 9, precise control of the flow rate of the high refractive index medium can be achieved, further improving the stability and accuracy of the photolithography process.

[0036] The flow rate regulator 9 can use different types of valves, such as electric valves and pneumatic valves, to meet different control requirements.

[0037] In one possible implementation, the immersion chamber 3 is a sealed space with a variable volume.

[0038] The immersion chamber 3 is designed as a variable-volume sealed space to contain a high-refractive-index medium. By adjusting the volume of the immersion chamber 3, the amount and flow state of the medium can be controlled, further optimizing the photolithography effect.

[0039] The variable volume immersion chamber 3 design increases the flexibility of control over high refractive index media, which can better adapt to different lithography requirements and improve the efficiency and accuracy of lithography.

[0040] In one possible implementation, laser 1 is an argon fluoride (ArF) laser.

[0041] An argon fluoride (ArF) laser emits a 193-nanometer wavelength laser beam, which is focused and collimated by lens 2 before entering immersion chamber 3. After being refracted by a high-refractive-index medium, the beam finally illuminates mask 4, forming a high-resolution patterned beam.

[0042] Using an argon fluoride (ArF) laser to emit a 193-nanometer wavelength can effectively improve the resolution and precision of lithography, making it suitable for the lithography requirements of advanced processes.

[0043] In one possible implementation, laser 1 emits a laser beam with a wavelength of 193 nanometers.

[0044] Laser 1 emits a laser beam with a wavelength of 193 nanometers. After being focused and collimated by lens 2, the beam enters immersion chamber 3. After being refracted by a high refractive index medium, the beam finally illuminates mask 4, forming a high-resolution patterned beam.

[0045] Using a 193-nanometer wavelength laser can effectively improve the resolution and precision of lithography, making it suitable for the lithography requirements of advanced processes.

[0046] In one possible implementation, the high refractive index medium is deionized water or highly purified oil.

[0047] The immersion chamber 3 is filled with a high refractive index medium, such as deionized water or highly purified oil. The high refractive index medium changes the propagation path and focal length of the laser beam, thereby improving the lithography resolution and accuracy.

[0048] Deionized water or highly purified oil can be used as a high refractive index medium. The type of medium can be adjusted according to different process requirements to optimize the photolithography effect.

[0049] In one possible implementation, the temperature range of the high refractive index medium is 15°C to 25°C.

[0050] The temperature of the high refractive index medium is controlled within the range of 15°C to 25°C, which helps to maintain the stability of the medium and the accuracy of the photolithography process. The control system 6 heats or cools the high refractive index medium through the temperature adjustment device 8 based on the detection results of the temperature sensor 7 to ensure that it is within the optimal temperature range.

[0051] By controlling the temperature of the high refractive index medium within the range of 15℃ to 25℃, the impact of temperature changes on photolithography accuracy can be effectively reduced, and the stability and effectiveness of the photolithography process can be improved.

[0052] The temperature control device 8 can employ different heating or cooling technologies, such as resistance heating or heat pump refrigeration, to improve the accuracy and efficiency of temperature control.

[0053] In one possible implementation, a flow rate sensor 10 is also included.

[0054] The flow rate sensor 10 is used to detect the flow rate of the high refractive index medium in the immersion chamber 3; the control system 6 controls the valve opening of the flow rate regulator 9 according to the detection result of the flow rate sensor 10, so as to adjust the flow rate of the high refractive index medium and ensure the stability and accuracy of the photolithography process.

[0055] By introducing the flow rate sensor 10, real-time monitoring and precise control of the flow rate of the high refractive index medium can be achieved, further improving the stability and accuracy of the photolithography process.

[0056] The flow sensor 10 can employ different types of sensors, such as ultrasonic flow sensors or electromagnetic flow sensors, to meet different requirements for detection accuracy and response speed.

[0057] In one possible implementation, it also includes: a material selection mechanism, see [link to relevant documentation]. Figure 4The system includes: optical sensor 111, immersion material storage tank I 112, immersion material storage tank II 113, immersion material storage tank III 114, valve I 115, valve II 116, and valve III 117. Two optical sensors 111 are respectively installed on the two surfaces of the wafer to measure the wafer thickness and transmit the thickness data to the control system. Immersion material storage tanks I 112, II 113, and III 114 are connected to the immersion chamber 3 via valves I 115, II 116, and III 117, respectively. 15. Valves II 116 and III 117 are controlled by the control system 6 to open or close. Immersion material storage tanks I 112, II 113, and III 114 store immersion liquids / high refractive index media of different materials. The control system 6 determines the use of different immersion liquids / high refractive index media according to the thickness of the wafer and controls the corresponding valves to open so as to fill the immersion chamber 3 with the corresponding immersion liquid / high refractive index media. Thus, the material selection mechanism automatically selects the immersion liquid / high refractive index media, improving the automation and intelligence level of the system.

[0058] The liquid filling the immersion hood can be deionized water, oil, or other mixed liquids, but currently it is mostly filled with deionized water.

[0059] Immersion lithography is an advanced form of photolithography technology. It uses water as a medium to improve lithographic resolution, enabling higher numerical apertures and smaller feature sizes. It is typically deployed using ArF lasers with a wavelength of 193 nanometers. During immersion lithography, water fills the space between the wafer and the lithography machine lens, utilizing the high refractive index of water to shorten the wavelength and increase the depth of focus.

[0060] Immersion lithography is a crucial technology in semiconductor manufacturing. By introducing water, a high-refractive-index medium, between the wafer and the lens during the lithography process, it achieves smaller light spots and higher resolution. This enables the production of chips with finer features and is a key technology driving the advancement of microelectronics towards the nanometer scale. Currently, light sources supporting wavelengths up to 193 nanometers are primarily used in the production of high-performance chips, such as memory and advanced processors. With continuous technological advancements, immersion lithography continues to challenge even smaller dimensions.

[0061] This invention proposes a scheme for integrating an immersion system onto a mask reticle, which can selectively use water or oil as the immersion material. This design aims to further reduce the light wavelength by increasing the system's refractive index, thereby achieving higher resolution and more precise chip manufacturing. The main technologies and steps include the following:

[0062] System components:

[0063] Immersion chamber: Located between the reticle and the lens, it can be filled with water or oil.

[0064] Material selection mechanism: Automatically selects whether to use water or oil as the immersion material based on photolithography requirements.

[0065] Control system: Regulates the flow and temperature of the immersion material to ensure the stability of the photolithography process.

[0066] Operating instructions:

[0067] The type and parameters of the immersion material are set according to manufacturing requirements.

[0068] Before photolithography, the selected immersion material is automatically filled into the immersion chamber.

[0069] During the photolithography process, the control system monitors and adjusts the state of the immersed material in real time to ensure the quality of the photolithography.

[0070] advantage:

[0071] This invention effectively improves photolithography resolution, reduces equipment costs, and enhances the flexibility and reliability of the manufacturing process. This technology is of great significance in driving the development of microelectronic devices towards higher performance and smaller sizes.

[0072] Scope of protection:

[0073] The scope of protection of this invention includes all the methods, steps, algorithms, and their software and hardware implementations, and is applicable to various occasions requiring photolithography fabrication.

[0074] The immersion lithography machine of this invention employs a high-refractive-index medium and immersion lithography technology, effectively improving the resolution and precision of lithography. The high-refractive-index medium alters the propagation path and focal length of the laser beam, thereby significantly enhancing the fineness and accuracy of the pattern, meeting the lithography requirements of advanced processes.

[0075] The introduction of a control system allows for real-time adjustment of the temperature and flow rate of the high-refractive-index medium, ensuring the continuity and stability of the photolithography process. The configuration of multiple lenses improves the focusing and collimation efficiency of the laser beam, further shortening the photolithography time and increasing overall production efficiency.

[0076] By integrating temperature and flow rate sensors, this invention achieves automated control of high-refractive-index media, simplifying operation and reducing the need for human intervention. The intelligent design of the control system makes equipment debugging and maintenance more convenient, improving the user experience.

[0077] The control system of this invention can monitor and adjust the temperature and flow rate of the high refractive index medium in real time, avoiding equipment failures or safety hazards caused by excessive temperature or unstable flow rate. The sealed immersion chamber design reduces the risk of leakage of the high refractive index medium and improves the safety of the equipment.

[0078] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0079] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. An immersion lithography machine, characterized in that, include: Laser (1) emits a laser beam; Multiple lenses (2) are arranged between the laser (1) and the immersion chamber (3) to focus and collimate the laser beam emitted by the laser (1); An immersion chamber (3) is disposed between the lens (2) and the mask (4), and is filled with a high refractive index medium. The immersion chamber (3) is a sealed space with a variable volume. The material selection mechanism, which is connected to the immersion chamber (3), includes three immersion material storage tanks (112, 113, 114) and three valves (115, 116, 117). Each of the immersion material storage tanks (112, 113, 114) is connected to the immersion chamber (3) through one of the valves (115, 116, 117). The immersion material storage tanks store different types of immersion liquids. The mask (4) is set below the immersion chamber (3). After the laser beam passes through the immersion chamber (3), it irradiates the mask (4) and forms a patterned beam. The control system (6) is configured to regulate the flow rate and / or temperature of the high refractive index medium and control the opening and closing of the valves (115, 116, 117) according to the thickness of the wafer to selectively fill the immersion chamber (3) with different types of immersion liquids. The wafer (5) is placed below the mask (4). The patterned beam passes through the mask (4) and then shines on the wafer (5), causing the photoresist on the surface of the wafer (5) to undergo a chemical reaction or physical change, forming the corresponding pattern.

2. The immersion lithography machine according to claim 1, characterized in that, It also includes a temperature sensor (7) and a temperature control device (8), wherein, Temperature sensor (7) is used to detect the temperature of a high refractive index medium; The control system (6) is configured to control the temperature regulating device (8) to heat or cool according to the temperature of the high refractive index medium; Temperature control device (8) is used to heat or cool high refractive index media.

3. The immersion lithography machine according to claim 2, characterized in that, It also includes a flow rate regulator (9) with a valve, which is controlled by the instructions of the control system (6) to open to the corresponding degree.

4. The immersion lithography machine according to claim 3, characterized in that, The laser (1) is an argon fluoride (ArF) laser.

5. The immersion lithography machine according to claim 4, characterized in that, The laser (1) emits a laser with a wavelength of 193 nanometers.

6. The immersion lithography machine according to claim 5, characterized in that, The high refractive index medium is deionized water or highly purified oil.

7. The immersion lithography machine according to claim 6, characterized in that, The temperature range for high refractive index media is 15°C to 25°C.

8. The immersion lithography machine according to claim 7, characterized in that, It also includes a flow rate sensor (10) for detecting the flow rate of the high refractive index medium in the immersion chamber (3); The control system (6) is also configured to control the opening of the valve of the flow rate regulator (9) according to the flow rate of the high-refractive medium.

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