Lithography equipment detection system and detection method thereof

Abstract

The present invention discloses a photolithography equipment detection system and a detection method thereof, comprising a simulated end projection objective lens, a gas supply system and a sampling detection system, wherein the simulated end projection objective lens has a mirror side surface facing an immersion control unit and a mirror bottom surface facing a substrate, and a plurality of side openings distributed in an annular shape and facing the immersion control unit are provided in the mirror side surface; an injection flow channel and a sampling flow channel are provided in the simulated end projection objective lens, one end of the injection flow channel is connected to the gas supply system, the gas supply system supplies gas that is poorly soluble in immersion liquid to the injection flow channel, and the other end of the injection flow channel is connected to the side opening; one end of the sampling flow channel is connected to the sampling detection system, and the other end of the sampling flow channel passes through the mirror bottom surface. The poorly soluble gas is used to separate the free interface of the immersion flow field from the ambient gas to avoid interference from environmental factors, thereby accurately detecting the cleanliness of the immersion liquid to evaluate the cleanliness quality of the immersion control unit and its affiliated flow paths.

Description

Technical Field

[0001] The present invention relates to a photolithography machine technology, and in particular to a photolithography equipment detection system and a detection method thereof used for detecting cleanliness in a photolithography machine. Background Art

[0002] The photolithography machine is one of the core equipment for manufacturing VLSI. It uses an optical system to accurately project the circuit pattern on the mask onto a substrate coated with photoresist and expose and modify the photoresist, thereby leaving the circuit pattern information on the substrate. It includes a laser light source, a projection lens system, a projection mask containing the circuit pattern, and a substrate coated with photosensitive photoresist.

[0003] Compared with dry lithography machines with gas as the intermediate medium, immersion lithography equipment fills a certain high-refractive-index liquid (called immersion liquid or immersion liquid) between the last projection objective and the substrate, and increases the numerical aperture (NA) of the projection objective by increasing the refractive index (n) of the gap liquid medium, thereby improving the resolution and depth of focus of the lithography equipment. In the current mainstream lithography technology, immersion lithography is widely used because it has good inheritance compared to early dry lithography. As for the filling of immersion liquid, the currently widely used solution is the local immersion method, that is, the immersion control unit is used to limit the liquid to the local area between the lower surface of the last projection objective and the upper surface of the substrate. The space occupied by the immersion liquid flowing between the immersion control unit, the projection objective and the substrate is called the immersion flow field. Maintaining the optical consistency and transparency of the immersion liquid in the exposure area is the key to ensuring the exposure quality of immersion lithography. To this end, existing technical solutions often achieve real-time updating of the immersion flow field through liquid injection and recovery, and promptly remove photochemical pollutants, local heat, micro-nano bubbles, etc. from the core exposure area to ensure the high purity and uniformity of the immersion liquid.

[0004] The immersion lithography process has very high requirements for the cleanliness of the immersion liquid, and therefore also has high requirements for the cleanliness of the immersion lithography equipment. During the integration and assembly of the immersion lithography equipment, it is necessary to inspect the cleanliness quality of its immersion liquid flow path to ensure that the immersion liquid delivered to the projection lens and the substrate has qualified cleanliness. Specifically, after the immersion control unit and its affiliated flow paths are assembled, it is necessary to conduct a trial run to provide immersion liquid, and use the detection system to detect the cleanliness of the immersion liquid it provides. If the cleanliness of the immersion control unit and its affiliated flow paths is not good, pollutants will be released during the trial run, causing the cleanliness index of the immersion liquid to deteriorate; if the immersion liquid prepared by the immersion liquid supply source is unqualified, the cleanliness index of the immersion liquid will also deteriorate. If the test finds that the quality of the immersion liquid produced by the trial run is unqualified, it is necessary to check the source of contamination and correct it. Summary of the invention

[0005] The present invention provides a lithography equipment detection system and a detection method thereof for performing cleanliness detection of an immersion liquid flow path of an assembled immersion control unit and its affiliated flow paths during the integrated assembly of the lithography equipment to evaluate the cleanliness quality of the immersion control unit and its affiliated flow paths.

[0006] The specific technical solution adopted by the present invention to solve the above technical problems is: a photolithography equipment detection system, including a simulated end projection objective lens, a gas supply system and a sampling detection system, the simulated end projection objective lens has a mirror side surface facing the immersion control unit and a mirror bottom surface facing the substrate, and the mirror side surface is provided with a plurality of side openings distributed in an annular manner and facing the immersion control unit; an injection flow channel and a sampling flow channel are provided in the simulated end projection objective lens, one end of the injection flow channel is connected to the gas supply system, the gas supply system supplies gas that is difficult to dissolve in the immersion liquid to the injection flow channel, and the other end of the injection flow channel is connected to the side opening; one end of the sampling flow channel is connected to the sampling detection system, and the other end of the sampling flow channel passes through the mirror bottom surface. The free interface of the immersion flow field is separated from the ambient gas by using the insoluble gas, so as to avoid the situation that part of the ambient gas or the particles in the ambient gas are dissolved in or mixed into the immersion flow field due to contact with the free interface of the immersion flow field, and reduce or avoid the situation that the gas supplied by the gas supply system is dissolved in the immersion flow field, thereby ensuring the reliability of the cleanliness quality detection.

[0007] Preferably, the sampling and detection system includes an impurity detector, which is used to detect detection indicators related to impurities in the immersion liquid and accurately measure the impurity content.

[0008] Preferably, the mirror side is provided with multiple layers of side openings, and the aperture of each side opening is between 0.05 mm and 0.2 mm, so that the gas flowing out through the above-mentioned side openings is almost isobaric everywhere, and the airflow is uniform, so that an airtight structure shaped like an air curtain with more uniform gas and larger width can be formed in the space area between the mirror side and the immersion control unit to effectively separate the free interface of the immersion flow field from the ambient gas.

[0009] Preferably, the angle α between the central axis of the side opening and the tangent line of the inner wall of the immersion control unit is less than 90°, so as to prevent the sparingly soluble gas flowing out through the side opening from directly rushing to the free interface of the immersion flow field, causing bubbles to be drawn into the immersion liquid and interfering with the detection.

[0010] Preferably, there are multiple sampling channels, each of which has a unique corresponding switch valve, and different sampling channels are evenly spaced and distributed at different positions. It is possible to achieve multi-point detection in the immersion flow field, determine the cleanliness at each point, and then determine the cleanliness of the immersion control unit and its affiliated flow paths.

[0011] Preferably, the simulated end projection objective lens is coaxially arranged with the central through hole of the immersion control unit, so that the operating state of the immersion control unit and its affiliated flow path being tested can be closer to its actual exposure operating state, and the test result can be closer to the actual situation of the immersion control unit and its affiliated flow path in the actual exposure operating state.

[0012] Preferably, the gas supplied by the gas supply system is nitrogen which is insoluble in the immersion liquid. By using the insoluble gas to separate the free interface of the immersion flow field from the ambient gas, it is possible to reduce or avoid the dissolution of the gas supplied by the gas supply system in the immersion flow field while avoiding the contact between the ambient gas and the immersion flow field, thereby ensuring the reliability of the cleanliness quality inspection.

[0013] Another invention object of the present invention application is to provide a method for detecting a lithography device, comprising the following detection steps:

[0014] A1. The simulated end projection objective lens connected to the gas supply system and the sampling and detection system is arranged inside the immersion control unit and above the substrate, so that the mutual position relationship formed between the simulated end projection objective lens, the substrate and the immersion control unit is the same as the mutual position relationship formed between the end projection objective lens, the substrate and the immersion control unit in the immersion lithography machine;

[0015] A2. The gas supply system supplies the gas that is insoluble in the immersion liquid to the gas injection channel, and the gas that is insoluble in the immersion liquid is supplied to the space area between the side of the mirror and the immersion control unit through the gas injection channel and the side opening in sequence, and the ambient gas in the space area is exhausted to the outside; and an atmosphere filled with the insoluble gas is formed in the space area, that is, the space of the first gap;

[0016] A3. An immersion flow field in which the immersion liquid continuously flows is formed in the space between the simulated end projection objective lens and the substrate through the flow channel system in the immersion control unit, so that the bottom surface of the simulated end projection objective lens is immersed in the immersion flow field;

[0017] A4. Keep the immersion liquid flowing for a while;

[0018] A5. The immersion liquid in the immersion flow field is pumped from the lower side of the mirror bottom surface through the sampling flow channel to the sampling detection system. The impurity detector in the sampling detection system is used to detect detection indicators related to impurities in the immersion liquid.

[0019] By providing a plurality of side openings distributed in an annular shape and facing the immersion control unit in the mirror side surface of the simulated terminal projection objective lens, the plurality of side openings are all connected to the first gap, and are equipped with a gas supply system, and a sparingly soluble gas is used to separate the free interface of the immersion flow field from the ambient gas, so as to avoid a situation in which part of the ambient gas is dissolved in the immersion flow field due to contact with the free interface of the immersion flow field, and to avoid a situation in which particulate matter in the ambient gas is mixed into the immersion flow field.

[0020] Preferably, the number of sampling channels is multiple, and by sequentially opening and closing the switch valve corresponding to each sampling channel, the immersion liquid at different positions in the immersion flow field is sequentially pumped through different sampling channels to the sampling detection system for impurity detection. The cleanliness at each point can be determined, and then the cleanliness of the immersion control unit and its affiliated flow paths can be determined.

[0021] Preferably, when the gas that is poorly soluble in the immersion liquid flows out of the opening, the flow rate of the gas is higher than 0.1 m / s, so that the ambient gas in the first gap is fully discharged, thereby ensuring the reliability of the cleanliness quality detection.

[0022] The beneficial effects of the present invention are as follows: during the integrated assembly of a lithography device, the cleanliness of the immersion liquid flow path of the assembled immersion control unit and its affiliated flow path is detected; during the detection process, a sparingly soluble gas is used to separate the free interface of the immersion flow field from the ambient gas, thereby preventing part of the ambient gas from dissolving in the immersion flow field due to contact with the free interface of the immersion flow field, and preventing particulate matter in the ambient gas from mixing into the immersion flow field, thereby accurately detecting the cleanliness of the immersion liquid and evaluating the cleanliness quality of the immersion control unit and its affiliated flow path. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the photolithography equipment detection system of the present invention.

[0024] Figure 2 for Figure 1 Enlarged schematic diagram at point A in the middle.

[0025] Figure 3 It is a schematic front view of an implementation scheme of simulating the end projection objective lens in the photolithography equipment detection system of the present invention.

[0026] Figure 4 It is a schematic top view of an implementation scheme of simulating an end projection objective lens in the photolithography equipment detection system of the present invention.

[0027] Figure 5 It is a schematic diagram of another implementation scheme of the photolithography equipment detection system of the present invention.

[0028] Figure 6 A schematic diagram of an existing photolithography device. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0030] Figure 6 The figure shows a schematic diagram of an existing lithography device, which includes an end projection objective lens 4, an immersion control unit 5, and a main immersion liquid supply system MLS, a main pumping system VM, an auxiliary immersion liquid supply system ALS and a sealed pumping system VC used in conjunction with the immersion control unit 5.

[0031] The immersion control unit 5 surrounds the radial outer side of the end projection lens 4 and is located above the substrate 8. A substrate table 9 for supporting the substrate 8 is provided below the substrate 8. A flow channel system is provided in the immersion control unit 5, and the flow channel system includes a main liquid supply channel 10, a main recovery channel 12, an auxiliary liquid supply channel 14 and a sealed extraction channel 16. The main immersion liquid supply system MLS provides immersion liquid to the space between the end projection lens 4 and the substrate 8 through the main liquid supply channel 10, and the main extraction system VM extracts immersion liquid from the space between the end projection lens 4 and the substrate 8 through the main recovery channel 12. The side of the immersion control unit 5 facing the substrate 8 is the bottom surface of the immersion control unit 5, and one side opening of the auxiliary liquid supply channel 14 is arranged on the bottom surface of the immersion control unit 5. The auxiliary immersion liquid supply system ALS supplies immersion liquid to the space between the end projection lens 4 and the substrate 8 through the auxiliary supply channel 12. The liquid flow channel 14 supplies immersion liquid to the gap between the bottom surface of the immersion control unit 5 and the top surface of the substrate 8 to form a liquid seal. In order to limit the immersion liquid from flowing out of the gap between the bottom surface of the immersion control unit 5 and the top surface of the substrate 8, a sealing gas GAS is provided in the gap between the bottom surface of the immersion control unit 5 and the top surface of the substrate 8, and the sealing gas GAS can be selected as air; one side opening of the sealed pumping and exhausting channel 16 is arranged on the bottom surface of the immersion control unit 5, and the opening of the sealed pumping and exhausting channel 16 is located radially outside the opening of the auxiliary liquid supply channel 14. The sealed pumping and exhausting system VC simultaneously pumps the immersion liquid and the sealing gas GAS between the bottom surface of the immersion control unit 5 and the top surface of the substrate 8 through the sealed pumping and exhausting channel 16; the immersion liquid continues to flow in the space between the end projection objective 4 and the substrate 8 to form an immersion flow field 7.

[0032] like Figure 6As shown, after the immersion flow field 7 is formed, the upper interface of the immersion flow field 7 partially exists in the gap between the immersion control unit 5 and the terminal projection objective lens 4. The gap between the immersion control unit 5 and the terminal projection objective lens 4 can be called the first gap 19. Since the upper interface of the immersion flow field 7 located in the first gap 19 is completely exposed to the outer area, the upper interface of the immersion flow field 7 located in the first gap 19 is a free interface. The ambient gas in the outer area will contact the free interface of the immersion flow field 7. When the ambient gas is air and the immersion medium is ultrapure water, CO2, Impurities such as NH3 and particulate matter will dissolve in or enter the immersion liquid supplied by the main liquid supply channel 10 through the upper interface of the immersion flow field 7 in the first gap 19, and flow together with the immersion liquid to the bottom of the terminal projection objective lens 4, which will cause the impurity content in the immersion liquid to change. Subsequently, when the cleanliness of the immersion control unit and its affiliated flow paths is tested, impurities such as CO2, NH3, particulate matter in the outside air will interfere with the cleanliness test of the immersion control unit and its affiliated flow paths, making it impossible to use the test results to evaluate the cleanliness quality of the immersion control unit and its affiliated flow paths.

[0033] Embodiment 1:

[0034] Figure 1 and 2The invention illustrates a photolithography equipment detection system according to an embodiment of the present invention. During the process of integrated assembly of the photolithography equipment, the cleanliness of the immersion liquid flow path of the assembled immersion control unit and its affiliated flow path is detected. During the detection process, the detection influence caused by the ambient gas is avoided, so as to accurately detect the cleanliness of the immersion liquid and evaluate the cleanliness quality of the immersion control unit and its affiliated flow path. The photolithography equipment detection system includes a simulated end projection objective lens 6, a gas supply system GS and a sampling detection system SD. The simulated end projection objective lens 6 has a similar shape and size to the end projection objective lens in the immersion photolithography machine, and in particular, has a mirror side surface 61 and a mirror bottom surface 62 of the same shape and size as the end projection objective lens, the mirror side surface 61 is in the shape of an inclined annular cylinder, and the mirror bottom surface 62 is in the shape of a plane. The position setting method of the simulated end projection objective lens 6 simulates the position of the end projection objective lens in the immersion photolithography machine. The simulated end projection objective lens 6 is arranged on the inner side of the immersion control unit 5, the mirror side surface 61 in the simulated end projection objective lens 6 faces the immersion control unit 5, and the simulated end projection objective lens 6 is coaxially arranged with the central through hole of the immersion control unit 5; a substrate 8 is arranged at a position below the simulated end projection objective lens 6 and the immersion control unit 5, the mirror bottom surface 62 in the simulated end projection objective lens 6 faces the substrate 8, and a substrate table 9 for supporting the substrate 8 is arranged below the substrate 8; the simulated end projection objective lens 6 serves as a sampling end component for collecting immersion liquid, and the sampling end component has a similar shape and size to the end projection objective lens in the immersion lithography machine, and has the same position installation situation, which can make the operating state of the immersion control unit and its affiliated flow path being tested closer to its actual exposure operating state, and the detection result is closer to the actual situation of the immersion control unit and its affiliated flow path in the actual exposure operating state.

[0035] A plurality of side openings 21 distributed in an annular shape and facing the immersion control unit 5 are provided in the mirror side surface 61 of the simulated terminal projection objective lens 6, and the plurality of side openings 21 are all connected to the first gap 19. A gas injection channel 20 and a sampling channel 22 are provided in the simulated terminal projection objective lens 6, one end of the gas injection channel 20 is connected to the gas supply system GS, and the other end of the gas injection channel 20 is connected to the side opening 21; one end of the sampling channel 22 is connected to the sampling detection system SD, and the other end of the sampling channel 22 passes through the mirror bottom surface 62; the sampling detection system SD includes an impurity detector, which is used to detect detection indicators related to impurities in the immersion liquid; more specifically, the impurity detector can be, for example, a pH meter, an ion detector, a particle detector and other detection instruments, or a combination of two or more of the above detection instruments, which can detect detection indicators such as pH, ion content, and particulate matter content in the immersion liquid.

[0036] In the process of testing the immersion control unit and its affiliated flow path by the photolithography equipment testing system according to one embodiment of the present invention, the gas that is insoluble in the immersion liquid is first supplied to the gas injection channel 20 by the gas supply system GS. The gas has a solubility volume of less than 0.2 in 1 volume of the immersion liquid at a temperature of 283K and a standard atmospheric pressure. The gas that is insoluble in the immersion liquid is continuously supplied to the first gap 19 through the gas injection channel and the side opening in sequence, and the ambient gas in the space area of ​​the first gap 19 is exhausted to the outside, so that an atmosphere filled with insoluble gas is formed in the space of the first gap 19. Then, the main immersion liquid supply system MLS, the main pumping system VM, the auxiliary immersion liquid supply system ALS and the sealed pumping system VC used in conjunction with the immersion control unit 5 are used to continuously flow in the space between the simulated end projection objective lens 6 and the substrate 8 to form an immersion flow field 7. The immersion liquid in the immersion flow field 7 is ultrapure water, and the gas that is insoluble in the immersion liquid supplied by the gas supply system GS is nitrogen. The solubility volume of nitrogen in 1 volume of ultrapure water at a temperature of 283K and a standard atmospheric pressure is about 0.02. During the formation of the immersion flow field 7, the gas supply system GS continues to supply nitrogen to the first gap 19, and the space of the first gap 19 is kept filled with nitrogen. After the immersion flow field 7 is formed, the mirror bottom surface 62 of the simulated terminal projection objective lens 6 is immersed in the immersion flow field 7, and the side opening 21 is still located higher than the top of the immersion flow field 7. The nitrogen supplied by the gas supply system GS continues to flow outward from the side opening 21 through the gas injection channel 20, and separates the free interface of the immersion flow field 7 from the ambient gas, thereby avoiding the detection influence caused by the ambient gas, and while avoiding the contact between the ambient gas and the immersion flow field, reducing or avoiding the situation where the gas supplied by the gas supply system is dissolved in the immersion flow field; the angle α between the central axis of the side opening 21 and the tangent of the inner wall of the immersion control unit 5 is not greater than 90°, thereby avoiding the insoluble gas flowing out through the side opening 21 from directly rushing to the free interface of the immersion flow field 7, causing bubbles to be drawn into the immersion liquid and interfering with the detection.

[0037] Since the mirror bottom surface 62 of the simulated end projection objective lens 6 is immersed in the immersion flow field 7, the immersion liquid in the immersion flow field 7 can be pumped from the lower side of the mirror bottom surface 62 to the sampling detection system SD through the sampling flow channel 22, and the collected immersion liquid is tested for impurities through the sampling detection system SD to check the cleanliness quality of the immersion control unit and its affiliated flow paths. In the detection process, a sparingly soluble gas is used to prevent part of the ambient gas or particulate matter in the ambient gas in the space area from the mirror side 61 to the immersion control unit 5 from being dissolved or mixed into the immersion flow field 7 due to contact with the free interface of the immersion flow field 7, and to reduce or avoid the gas supplied by the gas supply system from being dissolved in the immersion flow field, thereby ensuring the reliability of the cleanliness quality detection.

[0038] Embodiment 2:

[0039] In the process of supplying insoluble gas to the space area between the mirror side 61 and the immersion control unit 5, when the side openings 21 in the mirror side 61 are all in the form of single through holes, the air curtain-shaped structure formed in the space area from the mirror side 61 to the immersion control unit 5 will have the problem of uneven gas distribution.

[0040] Therefore, according to a lithography apparatus detection system of an embodiment of the present invention, Figures 1 to 3 As shown, the mirror side 61 is provided with multiple layers of side openings 21, and the aperture of each side opening 21 is between 0.05 mm and 0.2 mm. When the sparingly soluble gas flows out of the side opening 21, the sparingly soluble gas flowing out from different side openings 21 is approximately at equal pressure everywhere, and the airflow is uniform, so that an airtight structure shaped like an air curtain with more uniform gas and larger width can be formed in the space area between the mirror side 61 and the immersion control unit 5, so as to effectively separate the free interface of the immersion flow field 7 from the ambient gas.

[0041] Embodiment three:

[0042] like Figure 4 and 5 As shown, there are multiple sampling channels 22, each sampling channel 22 has a unique corresponding switch valve 23, and different sampling channels 22 are evenly spaced and distributed at different positions. By switching the switch valve 23 corresponding to each sampling channel 22 in turn, the immersion liquid at different positions in the immersion flow field is sequentially pumped through different sampling channels 22 to the sampling detection system SD for impurity detection, which can realize multi-point detection in the immersion flow field 7, and determine the cleanliness at each point based on the detection results, and then determine the cleanliness of the immersion control unit and its affiliated flow paths.

[0043] Embodiment 4:

[0044] A method for detecting a lithography device comprises the following detection steps:

[0045] A1. The simulated end projection objective lens 6 connected to the gas supply system GS and the sampling detection system SD is arranged inside the immersion control unit 5 and above the substrate 8, so that the mutual position relationship formed between the simulated end projection objective lens 6, the substrate 8 and the immersion control unit 5 is kept the same as the mutual position relationship formed between the end projection objective lens, the substrate 8 and the immersion control unit 5 in the immersion lithography machine; by arranging the simulated end projection objective lens 6 inside the immersion control unit 5 and above the substrate 8 as a substitute for the end projection objective lens, the operating state of the immersion control unit and its affiliated flow path to be detected can be closer to its actual exposure operating state, and the detection result can be closer to the actual situation of the immersion control unit and its affiliated flow path in the actual exposure operating state;

[0046] A2. The gas supply system GS supplies a gas that is poorly soluble in the immersion liquid to the gas injection channel 20. The gas has a solubility volume of less than 0.2 in 1 volume of the immersion liquid at a temperature of 283K and a standard atmospheric pressure. The gas that is poorly soluble in the immersion liquid is supplied to the space region between the mirror side 61 and the immersion control unit 5 through the gas injection channel 20, and the ambient gas in the space region is exhausted to the outside; and an atmosphere filled with the poorly soluble gas is formed in the space region, i.e., the space of the first gap;

[0047] A3. Immersion liquid is provided to the space between the simulated terminal projection objective lens 6 and the substrate 8 through the main liquid supply channel 10, and the immersion liquid is pumped out from the space between the simulated terminal projection objective lens 6 and the substrate 8 through the main recovery channel 12; one side opening of the auxiliary liquid supply channel 14 is arranged on the bottom surface of the immersion control unit 5, and the immersion liquid is supplied to the gap between the bottom surface of the immersion control unit 5 and the top surface of the substrate 8 through the auxiliary liquid supply channel 14 to form a liquid seal; one side opening of the sealed pumping and draining channel 16 is arranged on the bottom surface of the immersion control unit 5, and the opening of the sealed pumping and draining channel 16 is located radially outward of the opening of the auxiliary liquid supply channel 14, and the immersion liquid and the sealing gas GAS between the bottom surface of the immersion control unit 5 and the top surface of the substrate 8 are simultaneously pumped out through the sealed pumping and draining channel 16; the immersion liquid continuously flows in the space between the simulated terminal projection objective lens 6 and the substrate 8 to form an immersion flow field 7, and the mirror bottom surface 62 of the simulated terminal projection objective lens 6 is immersed in the immersion flow field 7;

[0048] A4. Keep the immersion liquid flowing for a period of time so that bubbles that may be formed during the establishment of the immersion flow field 7 are discharged from the immersion flow field 7 to avoid interference of bubbles on the immersion liquid sampling and detection;

[0049] A5. The immersion liquid in the immersion flow field 7 is pumped from the lower side of the mirror bottom surface 62 through the sampling flow channel 22 to the sampling detection system SD. The impurity detector in the sampling detection system SD is used to detect detection indicators related to impurities in the immersion liquid.

[0050] Preferably, in steps A1 to 5 of the above-mentioned lithography equipment detection method, ultrapure water is used as the immersion liquid, and the gas that is hardly soluble in the immersion liquid supplied by the gas supply system GS is nitrogen. The soluble volume of nitrogen in 1 volume of ultrapure water at a temperature of 283K and a standard atmospheric pressure is approximately 0.02, so that when the immersion liquid in the space area between the mirror side 61 and the immersion control unit 5 is blocked from the ambient gas by nitrogen, a part of the ambient gas in the space area from the mirror side 61 to the immersion control unit 5 is prevented from dissolving in the immersion flow field 7 due to contact with the upper interface of the immersion flow field 7, and particulate matter in the ambient gas is prevented from mixing into the immersion flow field 7.

[0051] Preferably, in step A5 of the above-mentioned lithography equipment detection method, there are multiple sampling channels 22, each sampling channel 22 has a switch valve 23 uniquely corresponding to it, and different sampling channels 22 are evenly spaced and distributed at different positions. By switching on and off the switch valve 23 corresponding to each sampling channel 22 in turn, the immersion liquid at different positions in the immersion flow field 7 is sequentially pumped through different sampling channels 22 to the sampling detection system SD for impurity detection, which can realize multi-point detection in the immersion flow field 7, and determine the cleanliness at each point based on the detection results, and then determine the cleanliness of the immersion control unit and its affiliated flow paths.

[0052] Preferably, in step A2 of the above-mentioned lithography equipment detection method, by controlling the speed of the gas that is sparingly soluble in the immersion liquid, when the gas that is sparingly soluble in the immersion liquid flows out of the side opening 21, the flow rate of the gas is higher than 0.1 m / s, so that the ambient gas in the first gap 19 can be fully discharged, thereby ensuring the reliability of the cleanliness quality detection.

[0053] The above specific implementation modes are used to explain the present invention rather than to limit the present invention. Any modification and change made to the present invention within the protection scope of the claims of the present invention shall fall within the protection scope of the present invention.

[0054] The above content and structure describe the basic principle, main features and advantages of the product of the present invention, which should be understood by those skilled in the art. The above examples and descriptions are only for explaining the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which are within the scope of the present invention. The scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A lithography equipment detection system, characterized in that: The method comprises a simulated end projection objective lens, a gas supply system and a sampling detection system. The simulated end projection objective lens has a mirror side surface facing the immersion control unit and a mirror bottom surface facing the substrate. The mirror side surface is provided with a plurality of side openings distributed in a ring shape and facing the immersion control unit. A gas injection channel and a sampling channel are provided in the simulated end projection objective lens. One end of the gas injection channel is connected with the gas supply system. The gas supply system supplies gas that is hardly soluble in the immersion liquid to the gas injection channel. The other end of the gas injection channel is connected with the side opening. One end of the sampling channel is connected with the sampling detection system. The other end of the sampling channel passes through the mirror bottom surface.

2. The lithography equipment detection system according to claim 1, characterized in that: The sampling and detection system comprises an impurity detector, which is used to detect detection indicators related to impurities in the immersion liquid.

3. The lithography equipment detection system according to claim 1, characterized in that: The side surface of the mirror is provided with a plurality of side openings, and the aperture of each side opening is between 0.05 mm and 0.2 mm.

4. The lithography equipment detection system according to claim 1 or 3, characterized in that: The angle α between the central axis of the side opening and the tangent line of the inner wall surface of the immersion control unit is less than 90°.

5. The lithography equipment detection system according to claim 1, characterized in that: There are multiple sampling flow channels, each of which has a unique corresponding switch valve, and different sampling flow channels are distributed at different positions with equal spacing.

6. The lithography equipment detection system according to claim 1, characterized in that: The simulated end projection objective lens is coaxially arranged with the central through hole of the immersion control unit.

7. The lithography equipment detection system according to claim 1, characterized in that: The gas supplied by the gas supply system is nitrogen which is hardly soluble in the immersion liquid.

8. A method for detecting a lithography device, characterized in that: The detection steps include the following: A1. The simulated end projection objective lens connected to the gas supply system and the sampling and detection system is arranged inside the immersion control unit and above the substrate, so that the mutual positional relationship formed between the simulated end projection objective lens, the substrate and the immersion control unit is the same as the mutual positional relationship formed between the end projection objective lens, the substrate and the immersion control unit in the immersion lithography machine; A2. The gas supply system supplies a gas that is insoluble in the immersion liquid to the gas injection channel, and the gas that is insoluble in the immersion liquid is sequentially supplied to the space region between the side of the mirror and the immersion control unit through the gas injection channel and the side opening, and the ambient gas in the space region is exhausted to the outside; and an atmosphere filled with the insoluble gas is formed in the space region, that is, the space of the first gap; A3. forming an immersion flow field in which the immersion liquid continuously flows in the space between the simulated end projection lens and the substrate through the flow channel system in the immersion control unit, so that the bottom surface of the simulated end projection lens is immersed in the immersion flow field; A4. Keep the immersion liquid flowing for a while; A5. The immersion liquid in the immersion flow field is pumped from the lower side of the mirror bottom surface through the sampling flow channel to the sampling detection system. The impurity detector in the sampling detection system is used to detect the detection indicators related to impurities in the immersion liquid.

9. The method for detecting a lithography device according to claim 8, characterized in that: The number of the sampling flow channels is multiple, and by switching the switch valve corresponding to each sampling flow channel in turn, the immersion liquid at different positions in the immersion flow field is sequentially pumped through different sampling flow channels to the sampling detection system for impurity detection.

10. The method for detecting a lithographic device according to claim 8, characterized in that: When the gas that is poorly soluble in the immersion liquid flows out through the opening on the side, the flow rate of the gas is higher than 0.1 m / s.

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