Focusing and leveling system and photoetching machine

Abstract

According to the focusing and leveling system and the photoetching machine provided by the invention, at least one of the projection module and the detection module is configured as the integrated cavity, so that external pollution is prevented, and chromatic aberration caused by arrangement of transmission-type optical window elements in the projection module and the detection module is avoided; therefore, the problem that the measurement precision is influenced by the residual chromatic aberration carried by a transmission-type optical window element in the focusing and leveling system can be solved, and the measurement precision of the focusing and leveling system is improved. In other words, the use of transmissive elements can be reduced to suppress chromatic aberration while preventing external contamination from intruding into the system without a diaphragm.

Description

Technical Field

[0001] The present invention relates to the technical field of photolithography, and in particular to a focusing and leveling system and a photolithography machine. Background Art

[0002] A projection lithography machine is a device that uses a projection lens to image a mask pattern onto a substrate surface, a glass substrate, or an LED. In order to ensure that the mask pattern can be accurately exposed, the focusing and leveling system must accurately control the substrate surface to be located at a specified position. The height and tilt information of the substrate surface in the exposure field is detected to determine whether the substrate surface is correctly focused and leveled. The position of the workpiece stage is further adjusted based on the measurement results so that the substrate surface on the workpiece stage is located at the optimal focal plane of the projection lens. As the core subsystem of the lithography machine, the focusing and leveling system is the key to achieving high-quality exposure in the lithography machine.

[0003] At present, transmissive optical window elements are used in multiple positions in the focusing and leveling system, causing the light beam to carry residual chromatic aberration that cannot be eliminated during the transmission of the optical system. After irradiating the process layer composed of the multi-layer film on the silicon wafer surface, the measurement height will produce an offset due to the difference in the material of the film system and the thickness of the photoresist; and because the thickness of the photoresist coating also fluctuates slightly, the measurement height will fluctuate randomly, affecting the measurement accuracy of the focusing and leveling system. Summary of the invention

[0004] The purpose of the present invention is to provide a focusing and leveling system and a photolithography machine, so as to improve the measurement accuracy of the focusing and leveling system.

[0005] In order to solve the above technical problems, the present invention provides a focusing and leveling system, comprising a projection module and a detection module; at least one of the projection module and the detection module has an integrated cavity.

[0006] Optionally, the integrated cavity is provided with a first ventilation unit, and a positive pressure is formed in the integrated cavity.

[0007] Optionally, a gas circulation direction in the integrated cavity of the projection module is opposite to a gas circulation direction in the integrated cavity of the detection module.

[0008] Optionally, the gas circulation direction in the integrated cavity of the projection module is along the direction of the main light of the optical path, and the gas circulation direction in the integrated cavity of the detection module is in the opposite direction of the main light of the optical path.

[0009] Optionally, the projection module includes an illumination unit, a first grating unit, a first imaging unit and a projection module shell, the projection module shell has an integrated cavity of the projection module, the illumination unit, the first grating unit and the first imaging unit are located in the integrated cavity of the projection module, and the first ventilation unit is located at the input end of the illumination unit and is located on the outside of the projection module shell; the detection module includes a second imaging unit, a second grating, a relay unit, a detection unit and a detection module shell, the detection module shell has an integrated cavity of the detection module, the second imaging unit, the second grating, the relay unit and the detection unit are located in the integrated cavity of the detection module, and the second ventilation unit is located on a side of the detection unit away from the relay unit and is located on the outside of the detection module shell.

[0010] Optionally, the integrated cavity is provided with a third ventilation unit, and the ventilation unit ventilates in a direction perpendicular to the optical axis to generate an air curtain.

[0011] Optionally, a third ventilation unit is provided at the output end of the first imaging unit, and a fourth ventilation unit is provided at the input end of the second imaging unit.

[0012] Optionally, the lighting unit, the first grating unit and the first imaging unit are connected via a flange, and the second imaging unit, the second grating, the relay unit and the detection unit are connected via a flange.

[0013] Optionally, gas is input into the integrated cavity of the projection module through the first ventilation unit, and the gas flows through the lighting unit, the first grating unit and the first imaging unit in sequence and then is output to the target to be measured, and gas is input into the integrated cavity of the detection module through the second ventilation unit, and the gas flows through the detection unit, the relay unit, the second grating and the second imaging unit in sequence and then is output to the target to be measured.

[0014] Optionally, a light source module is further included, wherein the light source module is used to provide a light beam, and the light beam is projected by the projection module to form an image onto the target to be measured, and is received by the detection module after being reflected by the target to be measured.

[0015] Based on the same inventive concept, the present invention also provides a photolithography machine, comprising any of the focusing and leveling systems described above.

[0016] In the focusing and leveling system and the lithography machine provided by the present invention, at least one of the projection module and the detection module is configured as an integrated cavity, which can prevent external pollution and avoid chromatic aberration caused by the transmissive optical window elements provided in the projection module and the detection module, thereby solving the problem that the transmissive optical window elements in the focusing and leveling system carry residual chromatic aberration that affects the measurement accuracy, and improving the measurement accuracy of the focusing and leveling system, that is, it is possible to reduce the use of transmissive elements to suppress chromatic aberration, and at the same time prevent external pollution from invading the system in the absence of a window sheet.

[0017] Furthermore, a first ventilation unit is set at the input end of the projection module, and a second ventilation unit is set on the side of the detection module away from the projection module. By ventilating the first ventilation unit and the second ventilation unit, positive pressure is formed in the integrated cavity of the projection module and the integrated cavity of the detection module, thereby further reducing external pollution.

[0018] Furthermore, a third ventilation unit is provided at the output end of the projection module, and a fourth ventilation unit is provided at the input end of the detection module. The third ventilation unit and the fourth ventilation unit ventilate in a direction perpendicular to the optical axis to generate an air curtain, thereby achieving air isolation inside and outside the cavity, which is beneficial to prevent external pollution from invading the cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0020] Figure 1 It is a structural schematic diagram of a focusing and leveling system.

[0021] Figure 2 It is a structural schematic diagram of a focusing and leveling system according to an embodiment of the present invention.

[0022] Figure 3 It is a schematic diagram of the ventilation direction of the optical path in the focusing and leveling system of an embodiment of the present invention.

[0023] Figure 4 It is a schematic diagram of the structure of the target to be measured according to an embodiment of the present invention.

[0024] Figure 5 It is a graph of height deviation values ​​of different materials of the target to be measured measured by the focusing and leveling system in the prior art.

[0025] Figure 6 It is a curve diagram of height deviation values ​​of different materials of a target to be measured measured by the focusing and leveling system of an embodiment of the present invention.

[0026] In the attached figure:

[0027] 101-light source module; 102-optical fiber unit; 103-illumination optical path unit; 103a-illumination optical path unit housing; 103b-transmissive illumination optical path; 103c-illumination optical path unit reflector; 104-projection grating unit; 104a-projection grating unit housing; 104b-transmissive projection grating; 104c-projection grating unit window; 105-projection imaging unit; 105a-projection imaging unit housing; 105b-first reflector; 105c-second reflector; 105d-third reflector; 105e-fourth reflector; 105f-projection imaging unit window; 10 6-target to be measured; 107-detection imaging unit; 107a-detection imaging unit housing; 107b-fifth reflector; 107c-sixth reflector; 107d-seventh reflector; 107e-eighth reflector; 107f-detection imaging unit window; 108-detection grating unit; 108a-detection grating unit housing; 108b-transmissive detection grating; 108c-detection grating unit window; 109-relay unit; 109a-relay unit housing; 109b-relay unit reflector; 110-detection unit; 110a-detection unit housing; 110b-detector photosensitive surface;

[0028] 20-light source module;

[0029] 30-optical fiber unit;

[0030] 40-projection module; 401-first ventilation unit; 402-illumination unit; 403-first grating unit; 404-first imaging unit; 404a-projection imaging unit housing; 404b-first reflector; 404c-second reflector; 404d-third reflector; 404e-fourth reflector; 405-third ventilation unit;

[0031] 50 - target to be measured; 51 - substrate; 52 - first dielectric layer; 53 - second dielectric layer; 54 - anti-reflection layer; 55 - photoresist layer;

[0032] 60-detection module; 601-fourth ventilation unit; 602-second imaging unit; 602a-second imaging unit housing; 602b-fifth reflector; 602c-sixth reflector; 602d-seventh reflector; 602e-eighth reflector; 603-second grating unit; 604-relay unit; 605-detection unit; 606-second ventilation unit. DETAILED DESCRIPTION

[0033] In order to make the purpose, advantages and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0034] As used in the present invention, the singular forms "one", "an" and "the" include plural objects, the term "or" is usually used to include the meaning of "and / or", the term "several" is usually used to include the meaning of "at least one", and the term "at least two" is usually used to include the meaning of "two or more". In addition, the terms "first", "second" and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first", "second" and "third" can explicitly or implicitly include one or at least two of the features. In addition, as used in the present invention, an element is arranged on another element, which usually only indicates that there is a connection, coupling, matching or transmission relationship between the two elements, and the connection, coupling, matching or transmission between the two elements can be direct or indirect through an intermediate element, and cannot be understood as indicating or implying the spatial position relationship between the two elements, that is, an element can be in any orientation such as inside, outside, above, below or on one side of another element, unless the content clearly indicates otherwise. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] Figure 1 This is a schematic diagram of the structure of a focusing and leveling system. Figure 1 As shown, the current conventional focusing and leveling system includes: a light source module 101, an optical fiber unit 102, an illumination optical path unit 103, a projection grating unit 104, a projection imaging unit 105, a detection imaging unit 107, a detection grating unit 108, a relay unit 109, and a detection unit 110.

[0036] The light source module 101 is used to provide light beam energy in a required wavelength band.

[0037] The optical fiber unit 102 is used to transmit the light beam energy generated by the light source module 101 .

[0038] The illumination optical path unit 103 is used to amplify the light beam output by the optical fiber unit 102 and provide uniform telecentric illumination for the projection grating unit 104. The illumination optical path unit 103 includes an illumination optical path unit housing 103a (i.e., the mechanical structure and cover of the illumination optical path unit), a transmissive illumination optical path 103b, and an illumination optical path unit reflector 103c.

[0039] The projection grating unit 104 includes a projection grating unit housing 104a (ie, the mechanical structure and cover of the projection grating unit), a transmissive projection grating 104b, and a projection grating unit window sheet 104c.

[0040] The projection imaging unit 105 is used to project the image of the projection grating unit 104 onto the target surface 106 to be measured with extremely high imaging quality. The projection imaging unit 105 includes a projection imaging unit housing 105a (i.e., the mechanical structure and cover of the projection imaging unit), a first reflector 105b, a second reflector 105c, a third reflector 105d, a fourth reflector 105e and a projection imaging unit window 105f, wherein the second reflector 105c is a primary reflector and the third reflector 105d is a secondary reflector.

[0041] The target to be measured 106 is, for example, a silicon wafer. The structure and function of the detection imaging unit 107 are similar to those of the projection imaging unit 105, and the detection imaging unit 107 and the projection imaging unit 105 are placed symmetrically about the axis of the target to be measured 106. The detection imaging unit 107 includes a detection imaging unit housing 107a, a fifth reflector 107b, a sixth reflector 107c, a seventh reflector 107d, an eighth reflector 107e and a detection imaging unit window 107f, wherein the sixth reflector 107c is a primary reflector and the seventh reflector 107d is a secondary reflector.

[0042] The detection grating unit 108 is used to split the light beam reflected by the target 106 to be measured into two differential signals. The detection grating unit 108 includes a detection grating unit housing 108a (i.e., the mechanical structure and cover of the detection grating unit), a transmission-type detection grating 108b and a detection grating unit window piece 108c, wherein the transmission-type detection grating 108b is, for example, a triangular grating.

[0043] The relay unit 109 is used to transmit the two differential signals to the detection unit 110. The relay unit 109 includes a relay unit housing 109a and a relay unit reflector (group) 109b.

[0044] The detection unit 110 is used to receive light signals, and includes a detection unit housing 110a and a detector photosensitive surface 110b.

[0045] Research has found that the window elements that currently cause chromatic aberration mainly include the projection grating unit window 104c, the projection imaging unit window 105f, the detection imaging unit window 107f, and the detection grating unit window 108c. When measuring the target to be measured, the chromatic aberration of the light beam will cause the process adaptability measurement error. The projection grating unit window 104c and the detection grating unit window 108c are mainly used to isolate the illumination optical path unit 103 and the projection grating unit 104, isolate the detection grating unit 108 and the relay unit 109, and prevent the projection grating or the detection grating from being contaminated. The projection imaging unit window 105f and the detection imaging unit window 107f are mainly used to isolate the projection imaging unit 105, the detection imaging unit 107 and the target to be measured 106, and prevent the photoresist and other organic matter, dust and other pollutants on the target to be measured 106 from entering the light path and contaminating the optical lens.

[0046] Based on the above research, the embodiment of the present invention provides a focusing and leveling system and a photolithography machine, in which at least one of the projection module and the detection module is configured as an integrated cavity, which can prevent external pollution and avoid the chromatic aberration caused by the transmissive optical window element in the projection module and the detection module, thereby solving the problem that the transmissive optical window element in the focusing and leveling system carries residual chromatic aberration to affect the measurement accuracy, and improving the measurement accuracy of the focusing and leveling system, that is, it can reduce the use of transmissive elements to suppress chromatic aberration, and at the same time, it can prevent external pollution from invading the system without a window sheet. In addition, the embodiment of the present invention sets a first ventilation unit at the input end of the projection module, and sets a second ventilation unit on the side of the detection module away from the projection module, and ventilates the first ventilation unit and the second ventilation unit to form a positive pressure in the integrated cavity of the projection module and the integrated cavity of the detection module. And a third ventilation unit is set at the output end of the projection module, and a fourth ventilation unit is set at the input end of the detection module. The third ventilation unit and the fourth ventilation unit are ventilated in a direction perpendicular to the optical axis to generate an air curtain, so as to achieve air isolation inside and outside the cavity, which is conducive to preventing external pollution from invading the cavity.

[0047] Figure 2 FIG. 1 is a schematic diagram of the structure of the focusing and leveling system according to an embodiment of the present invention. Figure 2 As shown, this embodiment provides a focusing and leveling system, including a light source module 20, a projection module 40 and a detection module 60. At least one of the projection module 40 and the detection module 60 has an integrated cavity. While avoiding external contamination, the number of transmissive optical elements is reduced, and the use of transmissive elements that cause chromatic aberration in existing focusing and leveling systems can be avoided, thereby effectively suppressing process adaptability error problems such as compensation (offset) deviation when the focusing and leveling device measures the surface of a 50-layer film to be measured and measurement random errors caused by film system fluctuations.

[0048] Preferably, the projection module 40 has an integrated first cavity, and a first ventilation unit 401 is provided at the input end of the projection module 40. The detection module 60 has an integrated second cavity, and a second ventilation unit 606 is provided on the side of the detection module 60 away from the projection module 40. Positive pressure is formed in the first cavity and the second cavity, that is, the air pressure in the first cavity and the second cavity is slightly higher than the air pressure outside, which can prevent external pollutants from entering the cavity. The light source module 20 is used to provide a light beam, which is projected and imaged to the target 50 to be measured by the projection module 40, and is received by the detection module 60 after being reflected by the target 50 to be measured. The projection module 40 and the detection module 60 are set in an integrated cavity and form a positive pressure, which reduces the number of transmission optical elements while avoiding external pollution, and can avoid the use of transmission elements that cause chromatic aberration in the existing focusing and leveling system, thereby effectively suppressing the compensation (offset) deviation when the focusing and leveling device measures the surface of the multi-layer film of the target 50 to be measured and the measurement random error caused by the fluctuation of the film system and other process adaptability error problems.

[0049] Figure 3 It is a schematic diagram of the ventilation direction of the optical path in the focusing and leveling system of an embodiment of the present invention. Clean gas is introduced into the first cavity through the first ventilation unit 401, and clean gas is passed into the second cavity through the second ventilation unit 606, so that positive pressure is formed in the first cavity and the second cavity. In this embodiment, the clean gas is, for example, compressed air or nitrogen, or other gases, which is not limited in this embodiment. The gas circulation direction in the first cavity is opposite to the gas circulation direction in the second cavity. Specifically, the gas circulation direction in the first cavity may be along the direction of the main light of the optical path, and the gas circulation direction in the second cavity may be the opposite direction of the main light of the optical path.

[0050] Please continue to refer to Figure 2 and Figure 3 , a third ventilation unit 405 is provided at the output end of the projection module 40, and a fourth ventilation unit 601 is provided at a side of the detection module 60 close to the projection module 40. The third ventilation unit 405 and the fourth ventilation unit 601 ventilate in a direction perpendicular to the optical axis to generate an air curtain. Preferably, the third ventilation unit 405 and the fourth ventilation unit 601 are high-speed ventilation devices, which are placed at the position of the window sheet in the prior art, and high-speed ventilation is performed in a direction perpendicular to the optical axis to generate an air curtain effect, further isolating the pollution outside the first cavity or the second cavity, such as the photoresist and other organic matter, dust and other pollutants on the target 50 to be measured.

[0051] Specifically, the projection module 40 includes an illumination unit 402, a first grating unit 403, a first imaging unit 404 and a projection module housing, the projection module housing has a first cavity, and the illumination unit 402, the first grating unit 403 and the first imaging unit 404 are located in the first cavity. The first ventilation unit 401 is located at the input end of the illumination unit 402 and at the outside of the projection module housing, the output end of the first imaging unit 404 is provided with a third ventilation unit 405, and the third ventilation unit 405 is also located at the outside of the projection module housing. The projection module housing includes an illumination unit housing, a first grating unit housing and a first imaging unit housing. The illumination unit 402, the first grating unit 403 and the first imaging unit 404 are connected by a flange, specifically, the illumination unit housing, the first grating unit housing and the first imaging unit housing are connected by a flange, that is, the mechanical structure of each unit is connected to the cover shell by the flange. Gas is input into the first cavity through the first ventilation unit 401 , and the gas flows through the lighting unit 402 , the first grating unit 403 , and the first imaging unit 404 in sequence before being output toward the target 50 to be measured.

[0052] In this embodiment, the light source module 20 and the projection module 40 can be connected through the optical fiber unit 30, and the optical fiber unit 30 is used to transmit the light beam energy generated by the light source module 20. The lighting unit 402 is used to amplify the output light beam of the optical fiber unit 30 and provide uniform telecentric illumination for the first grating unit 403. The first grating unit 403 is, for example, a projection grating, which is used to disperse the light beam into different directions. The first imaging unit 404 is, for example, a projection imaging unit, which is used to project the image of the projection grating onto the target 50 to be measured with extremely high imaging quality. The first imaging unit 404 includes a projection imaging unit housing 404a, a first reflector 404b, a second reflector 404c, a third reflector 404d and a fourth reflector 404e, and the first reflector 404b and the fourth reflector 404e are used to change the light path and reasonably set the position of the optical element. The second reflector 404c is a primary reflector, and the third reflector 404d is a secondary reflector. The second reflector 404c is a concave reflector, and the third reflector 404d is a convex reflector. The second reflector 404c is used to converge the light beam passing through the projection grating, and the third reflector 404d is used to reflect the light beam reflected by the second reflector 404c to the third reflector 404d again to improve the imaging quality of the light beam.

[0053] Specifically, the detection module 60 includes a second imaging unit 602, a second grating 603, a relay unit 604, a detection unit 605 and a detection module housing, and the detection module housing has a second cavity. The second imaging unit 602, the second grating 603, the relay unit 604 and the detection unit 605 are located in the second cavity, the second ventilation unit 606 is located on the side of the detection unit 605 away from the relay unit 604 and is located on the outside of the detection module housing, and the input end of the second imaging unit 602 is provided with a fourth ventilation unit 601, and the fourth ventilation unit 601 is also located on the outside of the detection module housing. The detection module housing includes a second imaging unit housing, a second grating housing, a relay unit housing and a detection unit housing. The second imaging unit 602, the second grating 603, the relay unit 604 and the detection unit 605 are connected by a flange, and specifically, the second imaging unit housing, the second grating housing, the relay unit housing and the detection unit housing are connected by a flange, that is, the mechanical structure of each unit is connected to the cover by a flange. Gas is input into the second cavity through the second ventilation unit 606 , and the gas flows through the detection unit 605 , the relay unit 604 , the second grating 603 , and the second imaging unit 602 in sequence before being output to the target 50 to be measured.

[0054] The second imaging unit 602 is, for example, a detection imaging unit, which can converge the light beam reflected by the target 50 to improve the imaging quality of the light beam. The second imaging unit 602 includes a second imaging unit housing 602a, a fifth reflector 602b, a sixth reflector 602c, a seventh reflector 602d and an eighth reflector 602e. Among them, the fifth reflector 602b and the eighth reflector 602e are used to change the path of the light path to reasonably set the position of the optical element, for example, to save space. The sixth reflector 602c is a main reflector, and the sixth reflector 602c is, for example, a concave reflector, which is used to converge the light beam, and the seventh reflector 602d is a secondary reflector, and the seventh reflector 602d is a convex reflector, which reflects the light beam reflected by the sixth reflector 602c to the sixth reflector 602c again, changes the direction of the light beam, and cooperates with the sixth reflector 602c to improve the imaging quality of the light beam. The second grating unit 603 is a detection grating, such as a triangular grating, which is used to split the light beam reflected by the target 50 into two differential signals. The relay unit 604 includes a reflector or a reflector group, which is used to transmit the two differential signals to the detection unit 605. The detection unit 605 is, for example, a detector, which is used to receive light signals.

[0055] The focusing and leveling system in this embodiment removes the window pieces separating the modules and reduces the number of transmissive optical elements. In order to prevent external pollution from invading the cavity along the window piece position, an airtight design is adopted for the module, positive pressure is maintained through an internal ventilation system, and an air curtain design is adopted at the original window piece position to isolate the air inside and outside the module; thereby avoiding the use of transmissive optical elements that cause chromatic aberration in the existing focusing and leveling systems, thereby effectively suppressing process adaptability error problems such as compensation (offset) deviation when the focusing and leveling device measures the surface of more than 50 layers of the target film to be measured and measurement random errors caused by film system fluctuations.

[0056] This embodiment also provides a photolithography machine, comprising any of the above-mentioned focusing and leveling systems.

[0057] The inventors conducted an experimental verification of the above research. The inventors used the focusing and leveling system in the prior art to test the target 50. The test structure is as follows: Figure 5 The inventor uses the focusing and leveling system of this embodiment to test the target 50. The test structure is as shown in FIG. Figure 6 shown. Figure 4 : is a schematic diagram of the structure of the target to be measured according to an embodiment of the present invention. The target to be measured 50 includes a substrate 51, on which a first dielectric layer 52, a second dielectric layer 53, an anti-reflection layer 54 and a photoresist layer 55 are sequentially arranged from bottom to top. The substrate 51 is, for example, a silicon substrate. The first dielectric layer 51 is, for example, an oxide layer, and the thickness is, for example, 40nm to 60nm. The second dielectric layer 53 is, for example, one or more of silicon, copper, aluminum, silicon nitride, and titanium nitride, and the thickness is, for example, 60nm to 80nm. The thickness of the anti-reflection layer 54 is, for example, 30nm to 50nm. The thickness of the photoresist layer 55 is, for example, 80nm to 1000nm. The inventor tested the measured height deviation values ​​of different materials. Figure 5 and Figure 6 The horizontal axis is the thickness of the photoresist layer, in nanometers (nm), and the vertical axis is the measured height deviation value, in nanometers (nm). The focusing and leveling system in the prior art is used for testing, that is, under the condition that the original focusing and leveling system is not achromatic (color difference = 0.7μm), the measured height deviation values ​​generated by different types of semiconductor and metal layers are as follows Figure 5 As shown, Figure 5 The range of the vertical axis in the figure is -40nm to 10nm. The height deviation values ​​of different types of semiconductor and metal layers produced by the focusing and leveling system of this embodiment, that is, the focusing and leveling system with achromatic difference (color difference = 0.1μm), are shown in FIG. Figure 6 As shown, Figure 6The range of the vertical axis in is -5nm to 1nm. It can be seen that in this embodiment, the window pieces separating the modules are removed, the transmission optical elements are reduced, the chromatic aberration is suppressed, and the achromatic focusing and leveling device can effectively reduce the measurement height error caused by the process adaptability of the system.

[0058] In summary, in the focusing and leveling system and the lithography machine provided by the embodiment of the present invention, at least one of the projection module and the detection module is configured as an integrated cavity, which can prevent external pollution and avoid the chromatic aberration caused by the transmissive optical window element in the projection module and the detection module, thereby solving the problem that the transmissive optical window element in the focusing and leveling system carries residual chromatic aberration to affect the measurement accuracy, and improving the measurement accuracy of the focusing and leveling system, that is, it can reduce the use of transmissive elements to suppress chromatic aberration, and at the same time, it can prevent external pollution from invading the system without a window sheet. Further, a first ventilation unit is provided at the input end of the projection module, and a second ventilation unit is provided on the side of the detection module away from the projection module. By ventilating the first ventilation unit and the second ventilation unit, a positive pressure is formed in the first cavity and the second cavity, further preventing external pollution. Further, a third ventilation unit is provided at the output end of the projection module, and a fourth ventilation unit is provided at the input end of the detection module. The third ventilation unit and the fourth ventilation unit are ventilated in a direction perpendicular to the optical axis to generate an air curtain, so as to achieve air isolation inside and outside the cavity, which is conducive to preventing external pollution from invading the cavity.

[0059] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other. In addition, the different parts between the various embodiments can also be used in combination with each other, and the present invention is not limited to this.

[0060] In addition, it should be recognized that although the present invention has been disclosed as a preferred embodiment, the above embodiment is not intended to limit the present invention. For any technician familiar with the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or modified into equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still belongs to the scope of protection of the technical solution of the present invention.

Claims

1. A focusing and leveling system, comprising a projection module and a detection module, characterized in that: At least one of the projection module and the detection module has an integrated cavity.

2. The focusing and leveling system according to claim 1, characterized in that: The integrated cavity is provided with a first ventilation unit, and a positive pressure is formed in the integrated cavity.

3. The focusing and leveling system according to claim 2, characterized in that: The gas circulation direction in the integrated cavity of the projection module is opposite to the gas circulation direction in the integrated cavity of the detection module.

4. The focusing and leveling system according to claim 3, characterized in that: The gas circulation direction in the integrated cavity of the projection module is along the direction of the main light of the optical path, and the gas circulation direction in the integrated cavity of the detection module is in the opposite direction of the main light of the optical path.

5. The focusing and leveling system according to claim 4, characterized in that: The projection module includes an illumination unit, a first grating unit, a first imaging unit and a projection module housing, the projection module housing has an integrated cavity of the projection module, the illumination unit, the first grating unit and the first imaging unit are located in the integrated cavity of the projection module, and the first ventilation unit is located at the input end of the illumination unit and is located on the outside of the projection module housing; the detection module includes a second imaging unit, a second grating, a relay unit, a detection unit and a detection module housing, the detection module housing has an integrated cavity of the detection module, the second imaging unit, the second grating, the relay unit and the detection unit are located in the integrated cavity of the detection module, and the second ventilation unit is located on a side of the detection unit away from the relay unit and is located on the outside of the detection module housing.

6. The focusing and leveling system according to claim 1, characterized in that: The integrated cavity is provided with a third ventilation unit, and the ventilation unit ventilates in a direction perpendicular to the optical axis to generate an air curtain.

7. The focusing and leveling system according to claim 5, characterized in that: The output end of the first imaging unit is provided with a third ventilation unit, and the input end of the second imaging unit is provided with a fourth ventilation unit.

8. The focusing and leveling system according to claim 5, characterized in that: The illumination unit, the first grating unit and the first imaging unit are connected via a flange, and the second imaging unit, the second grating, the relay unit and the detection unit are connected via a flange.

9. The focusing and leveling system according to claim 5, characterized in that: Gas is input into the integrated cavity of the projection module through the first ventilation unit, and the gas flows through the lighting unit, the first grating unit and the first imaging unit in sequence, and then is output to the target to be measured; gas is input into the integrated cavity of the detection module through the second ventilation unit, and the gas flows through the detection unit, the relay unit, the second grating and the second imaging unit in sequence, and then is output to the target to be measured.

10. The focusing and leveling system according to claim 1, characterized in that: It also includes a light source module, which is used to provide a light beam. The light beam is projected by the projection module to form an image onto the target to be measured, and is received by the detection module after being reflected by the target to be measured.

11. A photolithography machine, characterized in that: It comprises the focusing and leveling system as described in any one of claims 1 to 10.

Images