Extreme ultraviolet lithography mask protective film detection device

Abstract

An EUV photolithography mask protective film detection device comprises: a detection light source module, which is used to generate an EUV light source used for detection, the wavelength of which is in the EUV band, and is equipped with an EUV irradiation time control electronic shutter to control the irradiation time, and a light source transmission system; a sample stage module, which is placed in a vacuum chamber and is used to fix, move and rotate the sample to be tested, so as to realize the switching of different performance detections of the protective film, and to realize the irradiation of the EUV light source at different positions and different incident angles on the protective film; a detection module for the influence of pollutants on the protective film on mask imaging, which is used to study the influence of pollutants of different types and sizes below 50µm, and the distance between the protective film and the mask on the mask imaging, and determine the optimal distance; a protective film transmittance, transmission uniformity and reflectance measurement module, which is used to measure the optical properties of the protective film at different incident angles, and to study the influence of chemical changes of the protective film on its optical properties.

Description

Technical Field

[0001] The present invention belongs to the technical field of extreme ultraviolet lithography, and specifically relates to an extreme ultraviolet lithography mask protective film detection device, which can be used for studying the influence of pollutants on the protective film on mask imaging, chemical changes of the protective film under extreme ultraviolet light irradiation, including chemical reaction research between the protective film and hydrogen, protective film transmittance, transmission uniformity and reflectivity measurement, and for research and development of new protective film materials. Background Art

[0002] Extreme ultraviolet lithography (EUVL) is a key technology for achieving large-scale mass production of chips at 7nm and below technology nodes. Compared with traditional transmissive deep ultraviolet (DUV) mask technology, EUVL uses a reflective mask design, which puts more stringent requirements on process control, material development and mask measurement.

[0003] During the EUV lithography process, any tiny contamination on the mask surface may cause serious pattern defects, thus affecting the final quality of the chip. To solve this problem, a protective film technology is introduced. The protective film is an ultra-thin film (tens of nanometers thick, suspended in the range of tens of centimeters) that is kept at a certain distance from the mask. On the one hand, this design can prevent particles in the environment from falling onto the mask pattern. On the other hand, it can keep the contaminants out of the focal plane, reducing the impact of the contaminants on the imaging, thereby minimizing printing defects. However, for larger contaminants, such as large particles, even in a defocused state, they will still have an important impact on pattern formation. Therefore, a device is needed that can be used to study the effects of different types and sizes of contaminants on EUV lithography imaging, and to give the optimal distance between the protective film and the mask.

[0004] Extreme ultraviolet lithography technology places comprehensive and high standards on the performance of protective films, including but not limited to excellent optical properties (high transmittance, uniform transmittance distribution and low reflectivity), outstanding thermal and chemical stability, and hydrogen radical durability life.

[0005] Since extreme ultraviolet light is strongly absorbed by almost all materials, the protective film used in deep ultraviolet lithography masks cannot meet the requirements of extreme ultraviolet lithography, forcing the industry to urgently develop a new protective film material system and measure its optical properties (transmittance, transmission uniformity and reflectivity). Among the candidate materials, silicon, zirconium disilicide and carbon materials (such as carbon nanotubes and nanoscale graphite films) have shown application potential. Graphite films, in particular, have excellent performance in terms of light transmittance and mechanical strength, but their reactivity with hydrogen has become a major challenge. Therefore, it is particularly important to deeply analyze the chemical reaction mechanism of graphite film-based protective films with hydrogen in the extreme ultraviolet lithography environment.

[0006] In addition, EUV masks usually adopt oblique incidence (e.g., the main ray angle of the object plane is usually 6°), and with the development of high numerical aperture (e.g., 0.55NA) EUV lithography, the incident angle on the mask is also increasing. Therefore, it is necessary to quickly and efficiently detect the changes in the optical properties (transmittance, transmission uniformity, and reflectivity) of the protective film at different incident angles, especially at large incident angles, and at the same time, the chemical changes that may occur in the protective film under EUV irradiation and their specific impact on the optical properties. Summary of the invention

[0007] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides an extreme ultraviolet lithography mask protective film detection device, which solves the problem mentioned in the above-mentioned background technology of the influence of different types and sizes of pollutants on the protective film and the distance between the protective film and the mask on the mask imaging. The present invention is suitable for different types of pollutants, i.e. particles and stains, pollutants of different sizes, i.e. sizes below 50 µm, and the distance between the protective film and the mask, with an adjustable distance range of 1-10 mm. Through the research of the device of the present invention, the relationship between the type and size of pollutants and the distance between the protective film and the mask on the mask imaging can be given, and then the optimal distance between the protective film and the mask can be obtained.

[0008] The optical properties of the protective film (i.e., transmittance, transmission uniformity, and reflectivity) are measured at different incident angles, with an adjustable angle range of 5-25°. While testing the optical properties of the protective film (i.e., transmittance, transmission uniformity, and reflectivity), the effects of the chemical changes in the protective film on its optical properties (i.e., transmittance, transmission uniformity, or reflectivity) are studied. The device includes a hydrogen generation module that can control the hydrogen partial pressure in the vacuum chamber of the device, with an adjustable range of 0-10 Pa. The chemical reaction between the protective film and hydrogen under extreme ultraviolet irradiation can be studied, especially the chemical changes of protective films based on carbon materials, to meet the development of new protective film materials.

[0009] The technical solution adopted by the present invention to achieve the above-mentioned purpose is as follows:

[0010] An extreme ultraviolet lithography mask protective film detection device, characterized by comprising:

[0011] A detection light source module, which is used to generate an extreme ultraviolet light source used for detection, with a wavelength in the extreme ultraviolet band, and is equipped with an extreme ultraviolet irradiation time control electronic shutter to control the irradiation time, and a light source transmission system;

[0012] The sample stage module is placed in the vacuum chamber and is used to fix, move and rotate the protective film and mask samples to be tested to ensure that the extreme ultraviolet light source can achieve irradiation at different positions and different incident angles, wherein the distance between the protective film and the mask can be adjusted in the range of 1-10 mm;

[0013] The module for detecting the impact of contaminants on the protective film on mask imaging is used to study the impact of different types and sizes of contaminants below 50 µm, as well as the distance between the protective film and the mask on mask imaging, and determine the optimal distance;

[0014] The protective film transmittance, transmittance uniformity and reflectance measurement module is used to measure the optical properties of the protective film at different incident angles and study the influence of chemical changes of the protective film on its optical properties; wherein the adjustable range of the incident angle is 5-25°; the protective film is fixed on the protective film fixing frame, and the position of the protective film is adjusted by the first electric three-axis translation stage; the mask is fixed on the mask fixing frame, and the position of the mask is adjusted by the second electric three-axis translation stage; the first electric three-axis translation stage and the second electric three-axis translation stage are both fixed on the electric rotation translation stage, and are placed in sequence along the propagation direction of the detection light.

[0015] For the detection of the influence of contaminants on the protective film on the mask imaging, the samples are the protective film and the mask, and the sample stage module is used to place the protective film and the mask at the same time, so as to realize the synchronous fixation, movement and rotation of the protective film and the mask. After the mask is placed on the protective film along the propagation direction of the detection light, the protective film and the mask are synchronously rotated to a preset incident angle by controlling the rotation of the electric rotary translation stage, so as to ensure that the mask imaging is optimal under this preset incident angle; the distance between the protective film and the mask is changed by adjusting the first electric three-axis translation stage, and the adjustable distance range is 1-10 mm, and the influence of contaminants on the mask imaging at different distances between the protective film and the mask is studied, and the relationship between the distance between the protective film and the mask and the influence of contaminants on the protective film on the mask imaging is obtained, and the optimal distance between the protective film and the mask is given; or;

[0016] For the measurement of transmittance, transmittance uniformity and reflectance of the protective film, the sample is a protective film, the sample stage module is used to fix, move and rotate the protective film, the irradiation position of the extreme ultraviolet light on the protective film is always located on the rotation axis of the electric rotary translation stage, and the measurement of different incident angles of the protective film is achieved by rotating the electric rotary translation stage, with an adjustable angle range of 5-25°. The measurement of different positions of the protective film is achieved by adjusting the first electric three-axis translation stage.

[0017] Preferably, the sample stage module comprises: a protective film fixing frame for placing the protective film, and a mask fixing frame for placing the mask, the protective film fixing frame is controlled by the first electric three-axis translation stage, and the mask fixing frame is controlled by the second electric three-axis translation stage, the first electric three-axis translation stage and the second electric three-axis translation stage are both fixed on the electric rotation translation stage, and are placed in sequence along the propagation direction of the detection light.

[0018] Preferably, the light source transmission system includes a tire mirror or two cylindrical mirrors.

[0019] According to the difference between the two functions of detecting the impact of contaminants on the protective film on mask imaging and measuring the transmittance, transmittance uniformity and reflectance of the protective film, the sample placement is divided into two methods.

[0020] For the detection of the influence of contaminants on the protective film on the mask imaging, the above-mentioned samples are the protective film and the mask, and the above-mentioned sample stage module simultaneously places the protective film and the mask. The above-mentioned sample stage module is used to fix, move and rotate the protective film and the mask. After the above-mentioned mask is placed on the above-mentioned protective film along the propagation direction of the above-mentioned detection light, the protective film and the mask are synchronously rotated to a given incident angle by controlling the rotation of the above-mentioned electric rotary translation stage. Under the given incident angle, the mask imaging is optimal. By adjusting the above-mentioned first electric three-axis translation stage to change the distance between the protective film and the mask, the adjustable distance range is 1-10 mm, and the influence of contaminants on the mask imaging under different distances between the protective film and the mask is studied, and the relationship between the distance between the protective film and the mask and the influence of contaminants on the protective film on the mask imaging is obtained, and the optimal distance between the protective film and the mask is given.

[0021] For the measurement of transmittance, transmittance uniformity and reflectance of the protective film, the above-mentioned sample is a protective film, the above-mentioned sample stage module is used to fix, move and rotate the protective film, the irradiation position of the above-mentioned extreme ultraviolet light on the protective film is always located on the rotation axis of the above-mentioned electric rotary translation stage, and by rotating the above-mentioned electric rotary translation stage, different incident angles of the protective film are measured, and the adjustable angle range is 5-25°. By adjusting the above-mentioned first electric three-axis translation stage, different positions of the protective film are measured.

[0022] The module for detecting the effect of contaminants on the protective film on the mask imaging is used to study the effect of contaminants of different types and sizes, with a size below 50 µm, and the distance between the protective film and the mask, with an adjustable distance range of 1-10 mm, on the mask imaging. It is divided into two modes according to the purpose of detection.

[0023] The first mode is used to obtain the mask pattern and its defect diffraction signal, including: projection optical system and extreme ultraviolet camera.

[0024] In the second mode, the above-mentioned detection light source module develops after exposure of the photoresist, characterizes the developed pattern through a scanning electron microscope or an atomic force microscope, and analyzes the influence of contaminants on the mask exposure pattern, including the type of defects, the number of defects, line width, line width roughness, and line edge roughness. It includes: a projection optical system and a wafer coated with photoresist.

[0025] The protective film transmittance, transmittance uniformity and reflectance measurement modules are divided into two modes depending on whether the transmittance and reflectance are measured simultaneously.

[0026] In the first mode, the energy detection of the transmitted light beam and the reflected light beam is measured separately using two detectors, which can realize the synchronous measurement of the transmittance, transmission uniformity and reflectivity of the protective film. It includes: a first detector, a second detector, a first arc guide rail and a first electric slider; the axis of the first arc guide rail coincides with the axis of the above-mentioned electric rotary displacement stage, the central angle of the first arc guide rail is 60°, the first detector is fixed on the first electric slider, the first electric slider is fixed on the first arc guide rail, and is fixed in the direction of the reflected light beam. The energy of the reflected light beam is detected by rotating the sample by an angle of α and the first detector by an angle of 2α. The second detector is fixed in the direction of the transmitted light beam. When the sample is not placed, the incident light beam energy of the detection light source can be detected. After placing the sample, the sample transmission light beam energy at different incident angles can be obtained by rotating the above-mentioned electric rotary displacement stage. The reflectivity of the protective film is obtained by the ratio of the reflected light beam energy to the incident light beam energy, and the transmittance of the protective film is obtained by the ratio of the transmitted light beam energy to the incident light beam energy. The sample measurement position is changed by adjusting the above-mentioned first electric three-axis displacement stage to realize the multi-point transmittance measurement of the protective film and obtain the transmission uniformity of the protective film.

[0027] The second mode includes: a third detector, a second arc guide rail, and a second electric slider; based on the first mode, one detector is used less, the axis of the second arc guide rail coincides with the axis of the electric rotary translation stage, the center angle of the second arc guide rail is 180°, and the measurement principle is consistent with the first mode. The energy detection of the transmitted light beam and the reflected light beam is performed using the same detector, that is, the third detector. By rotating the third detector on the second arc guide rail to the position of the reflected light beam and the transmitted light beam, the transmittance, transmission uniformity, and reflectance of the protective film are measured respectively.

[0028] The electric rotary stage is used to control the rotation of the sample, thereby realizing the switching of the detection module of the influence of pollutants on the protective film on the mask imaging and the protective film transmittance, transmission uniformity and reflectance measurement module.

[0029] The hydrogen generation module is used to generate hydrogen and can control the hydrogen partial pressure in the vacuum chamber of the device, with an adjustable range of 0-10 Pa.

[0030] A chemical detection and analysis module is used to study the detection and analysis of chemical changes of the protective film under extreme ultraviolet light irradiation, including the chemical reaction between the protective film and the above-mentioned hydrogen, especially the chemical changes of the protective film based on carbon materials. The chemical detection and analysis module uses mass spectrometry and / or Raman spectroscopy to detect and analyze the chemical changes of the protective film under extreme ultraviolet light irradiation. The chemical detection and analysis module can be used simultaneously with the above-mentioned protective film transmittance, transmission uniformity and reflectivity measurement module, and can be used to study the influence of the chemical changes of the protective film under extreme ultraviolet irradiation on the optical properties of the protective film, namely transmittance, transmission uniformity or reflectivity.

[0031] The device is placed on a vibration isolation platform to ensure device stability and high-quality imaging.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention uses a detection module for the effect of pollutants on the protective film on mask imaging, which can be used to study the effect of different types of pollutants, i.e. particles and stains, and pollutants of different sizes, with a size below 50 µm, on mask imaging. The present invention can adjust the distance between the protective film and the mask, with an adjustable distance range of 1-10 mm, give the relationship between the distance between the protective film and the mask and the mask imaging, and give the optimal distance between the protective film and the mask.

[0034] The present invention can measure the transmittance, transmission uniformity and reflectivity of the protective film under different incident angles. The adjustable incident angle range is 5-25°. It can also be combined with chemical detection and analysis to study the relationship between the chemical changes of the protective film under extreme ultraviolet radiation and the transmittance, transmission uniformity and reflectivity of the protective film.

[0035] The present invention has a high degree of integration. The protective film transmittance, transmission uniformity and reflectance measurement module and the protective film contaminant on the mask imaging impact detection module are integrated together. By rotating the sample, the protective film transmittance, transmission uniformity and reflectance measurement module and the protective film contaminant on the mask imaging impact detection module can be quickly and efficiently switched, and the device has high stability. The chemical changes of the protective film under extreme ultraviolet light irradiation are detected and analyzed using mass spectrometry and / or Raman spectroscopy. The present invention includes a hydrogen generation module, which can study the chemical reaction of the protective film and hydrogen under extreme ultraviolet irradiation, such as the chemical changes of the protective film based on carbon materials and hydrogen. Further, the relationship between the chemical changes of the protective film and the transmittance, transmission uniformity and reflectivity of the protective film is studied. It is conducive to the research and development of new extreme ultraviolet lithography mask protective film materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a structural schematic diagram of an embodiment of an EUV lithography mask protective film detection device of the present invention;

[0037] Figure 2 It is a schematic diagram of the first mode embodiment of the protective film transmittance, transmittance uniformity and reflectance measurement module of the EUV lithography mask protective film detection device of the present invention (the light source transmission is a tire mirror, and the contaminants on the protective film affect the mask imaging detection module in the first mode);

[0038] Figure 3It is a schematic diagram of the first mode embodiment of the protective film transmittance, transmittance uniformity and reflectance measurement module of the EUV lithography mask protective film detection device of the present invention (the light source transmission is a tire mirror, and the contaminants on the protective film affect the mask imaging detection module in the second mode);

[0039] Figure 4 It is a schematic diagram of the first mode embodiment of the protective film transmittance, transmittance uniformity and reflectance measurement module of the EUV lithography mask protective film detection device of the present invention (the light source transmission is two cylindrical mirrors, and the contaminants on the protective film affect the mask imaging detection module in the first mode);

[0040] Figure 5 It is a schematic diagram of the first mode embodiment of the protective film transmittance, transmittance uniformity and reflectance measurement module of the EUV lithography mask protective film detection device of the present invention (the light source transmission is two cylindrical mirrors, and the contaminants on the protective film affect the mask imaging detection module in the second mode);

[0041] Figure 6 It is a schematic diagram of the second mode embodiment of the protective film transmittance, transmittance uniformity and reflectance measurement module of the extreme ultraviolet lithography mask protective film detection device of the present invention (the light source transmission is a tire mirror, and the contaminants on the protective film affect the mask imaging in the first mode of the detection module);

[0042] Figure 7 It is a schematic diagram of the second mode embodiment of the protective film transmittance, transmittance uniformity and reflectance measurement module of the extreme ultraviolet lithography mask protective film detection device of the present invention (the light source transmission is a tire mirror, and the contaminants on the protective film affect the mask imaging in the second mode of the detection module);

[0043] Figure 8 It is a schematic diagram of the second mode embodiment of the protective film transmittance, transmittance uniformity and reflectance measurement module of the EUV lithography mask protective film detection device of the present invention (the light source transmission is two cylindrical mirrors, and the contaminants on the protective film affect the mask imaging detection module in the first mode);

[0044] Fig. 9 It is a schematic diagram of the second mode embodiment of the protective film transmittance, transmittance uniformity and reflectance measurement module of the EUV lithography mask protective film detection device of the present invention (the light source transmission is two cylindrical mirrors, and the contaminants on the protective film affect the mask imaging detection module in the second mode);

[0045] Fig.10 It is a schematic diagram of the first mode embodiment of the detection module of the effect of contaminants on the protective film of the EUV lithography mask protective film detection device on the mask imaging of the present invention (the light source transmission is a tire mirror, and the first mode of the protective film transmittance, transmission uniformity and reflectance measurement module);

[0046] Fig.11 It is a schematic diagram of the first mode embodiment of the detection module of the effect of contaminants on the protective film of the EUV lithography mask protective film detection device on the mask imaging of the present invention (the light source transmission is two cylindrical mirrors, and the first mode of the protective film transmittance, transmission uniformity and reflectance measurement module);

[0047] Fig.12 It is a schematic diagram of the first mode embodiment of the detection module of the effect of contaminants on the protective film of the EUV lithography mask protective film detection device on the mask imaging of the present invention (the light source transmission is a tire mirror, and the second mode of the protective film transmittance, transmission uniformity and reflectivity measurement module);

[0048] Fig.13 It is a schematic diagram of the first mode embodiment of the detection module of the effect of contaminants on the protective film of the EUV lithography mask protective film detection device on the mask imaging (the light source transmission is two cylindrical mirrors, and the second mode of the protective film transmittance, transmission uniformity and reflectance measurement module);

[0049] Fig.14 It is a schematic diagram of the second mode embodiment of the detection module of the effect of contaminants on the protective film of the EUV lithography mask protective film detection device on the mask imaging of the present invention (the light source transmission is a tire mirror, and the protective film transmittance, transmission uniformity and reflectance measurement module is the first mode);

[0050] Fig.15 It is a schematic diagram of the second mode embodiment of the detection module of the effect of contaminants on the protective film of the EUV lithography mask protective film detection device on the mask imaging of the present invention (the light source transmission is two cylindrical mirrors, and the first mode of the protective film transmittance, transmission uniformity and reflectance measurement module);

[0051] Fig.16 It is a schematic diagram of the second mode embodiment of the detection module of the effect of contaminants on the protective film of the EUV lithography mask protective film detection device on the mask imaging of the present invention (the light source transmission is a tire mirror, and the second mode of the protective film transmittance, transmission uniformity and reflectance measurement module);

[0052] Fig.17 It is a schematic diagram of the second mode embodiment of the detection module of the effect of contaminants on the protective film of the EUV lithography mask protective film detection device on the mask imaging of the present invention (the light source transmission is two cylindrical mirrors, and the second mode of the protective film transmittance, transmission uniformity and reflectance measurement module);

[0053] In the figure:

[0054] 201-EUV light source; 202-EUV irradiation time-controlled electronic shutter; 203-tire mirror; 204-protective film; 205-protective film fixing frame; 206-first electric three-axis translation stage; 207-mask fixing frame; 208-second electric three-axis translation stage; 209-electric rotation translation stage; 210-first detector; 211-first electric slider; 212-first circular arc guide rail; 213-second detector; 214-hydrogen generation module; 215-chemical detection and analysis module; 216-projection optical system; 217-EUV camera.

[0055] 301- extreme ultraviolet light source; 302- extreme ultraviolet irradiation time-controlled electronic shutter; 303- tire mirror; 304- protective film; 305- protective film fixing frame; 306- first electric three-axis translation stage; 307- mask fixing frame; 308- second electric three-axis translation stage; 309- electric rotation translation stage; 310- first detector; 311- first electric slider; 312- first arc guide rail; 313- second detector; 314- hydrogen generation module; 315- chemical detection and analysis module; 316- projection optical system; 317- wafer coated with photoresist.

[0056] 401- extreme ultraviolet light source; 402- extreme ultraviolet irradiation time-controlled electronic shutter; 403- first cylindrical mirror; 404- second cylindrical mirror; 405- protective film; 406- protective film fixing frame; 407- first electric three-axis translation stage; 408- mask fixing frame; 409- second electric three-axis translation stage; 410- electric rotation translation stage; 411- first detector; 412- first electric slider; 413- first arc guide rail; 414- second detector; 415- hydrogen generation module; 416- chemical detection and analysis module; 417- projection optical system; 418- extreme ultraviolet camera.

[0057] 501- extreme ultraviolet light source; 502- extreme ultraviolet irradiation time-controlled electronic shutter; 503- first cylindrical mirror; 504- second cylindrical mirror; 505- protective film; 506- protective film fixing frame; 507- first electric three-axis translation stage; 508- mask fixing frame; 509- second electric three-axis translation stage; 510- electric rotation translation stage; 511- first detector; 512- first electric slider; 513- first circular arc guide rail; 514- second detector; 515- hydrogen generation module; 516- chemical detection and analysis module; 517- projection optical system; 518- wafer coated with photoresist.

[0058] 601-EUV light source; 602-EUV irradiation time-controlled electronic shutter; 603-tire mirror; 604-protective film; 605-protective film fixing frame; 606-first electric three-axis translation stage; 607-mask fixing frame; 608-second electric three-axis translation stage; 609-electric rotation translation stage; 610-third detector; 611-second electric slider; 612-second circular arc guide rail; 613-hydrogen generation module; 614-chemical detection and analysis module; 615-projection optical system; 616-EUV camera.

[0059] 701- extreme ultraviolet light source; 702- extreme ultraviolet irradiation time-controlled electronic shutter; 703- tire mirror; 704- protective film; 705- protective film fixing frame; 706- first electric three-axis translation stage; 707- mask fixing frame; 708- second electric three-axis translation stage; 709- electric rotation translation stage; 710- third detector; 711- second electric slider; 712- second circular arc guide rail; 713- hydrogen generation module; 714- chemical detection and analysis module; 715- projection optical system; 716- wafer coated with photoresist.

[0060] 801- extreme ultraviolet light source; 802- extreme ultraviolet irradiation time-controlled electronic shutter; 803- first cylindrical mirror; 804- second cylindrical mirror; 805- protective film; 806- protective film fixing frame; 807- first electric three-axis translation stage; 808- mask fixing frame; 809- second electric three-axis translation stage; 810- electric rotation translation stage; 811- third detector; 812- second electric slider; 813- second arc guide rail; 814- hydrogen generation module; 815- chemical detection and analysis module; 816- projection optical system; 817- extreme ultraviolet camera.

[0061] 901- extreme ultraviolet light source; 902- extreme ultraviolet irradiation time-controlled electronic shutter; 903- first cylindrical mirror; 904- second cylindrical mirror; 905- protective film; 906- protective film fixing frame; 907- first electric three-axis translation stage; 908- mask fixing frame; 909- second electric three-axis translation stage; 910- electric rotation translation stage; 911- third detector; 912- second electric slider; 913- second circular arc guide rail; 914- hydrogen generation module; 915- chemical detection and analysis module; 916- projection optical system; 917- wafer coated with photoresist.

[0062] 1001-EUV light source; 1002-EUV irradiation time-controlled electronic shutter; 1003-tire mirror; 1004-protective film; 1005-protective film fixing bracket; 1006-first electric three-axis translation stage; 1007-mask; 1008-mask fixing bracket; 1009-second electric three-axis translation stage; 1010-electric rotation translation stage; 1011-projection optical system; 1012-EUV camera; 1013-hydrogen generation module; 1014-chemical detection and analysis module; 1015-first detector; 1016-first electric slider; 1017-first arc guide rail; 1018-second detector.

[0063] 1101-EUV light source; 1102-EUV irradiation time-controlled electronic shutter; 1103-first cylindrical mirror; 1104-second cylindrical mirror; 1105-protective film; 1106-protective film fixing bracket; 1107-first electric three-axis translation stage; 1108-mask; 1109-mask fixing bracket; 1110-second electric three-axis translation stage; 1111-electric rotary translation stage; 1112-projection optical system; 1113-EUV camera; 1114-hydrogen generation module; 1115-chemical detection and analysis module; 1116-first detector; 1117-first electric slider; 1118-first circular arc guide rail; 1119-second detector.

[0064] 1201-EUV light source; 1202-EUV irradiation time-controlled electronic shutter; 1203-tire mirror; 1204-protective film; 1205-protective film fixing bracket; 1206-first electric three-axis translation stage; 1207-mask; 1208-mask fixing bracket; 1209-second electric three-axis translation stage; 1210-electric rotary translation stage; 1211-projection optical system; 1212-EUV camera; 1213-hydrogen generation module; 1214-chemical detection and analysis module; 1215-third detector; 1216-second electric slider; 1217-second circular arc guide rail.

[0065] 1301- extreme ultraviolet light source; 1302- extreme ultraviolet irradiation time-controlled electronic shutter; 1303- first cylindrical mirror; 1304- second cylindrical mirror; 1305- protective film; 1306- protective film fixing bracket; 1307- first electric three-axis translation stage; 1308- mask; 1309- mask fixing bracket; 1310- second electric three-axis translation stage; 1311- electric rotation translation stage; 1312- projection optical system; 1313- extreme ultraviolet camera; 1314- hydrogen generation module; 1315- chemical detection and analysis module; 1316- third detector; 1317- second electric slider; 1318- second arc guide rail.

[0066] 1401- extreme ultraviolet light source; 1402- extreme ultraviolet irradiation time-controlled electronic shutter; 1403- tire mirror; 1404- protective film; 1405- protective film fixing frame; 1406- first electric three-axis translation stage; 1407- mask; 1408- mask fixing frame; 1409- second electric three-axis translation stage; 1410- electric rotation translation stage; 1411- projection optical system; 1412- wafer coated with photoresist; 1413- hydrogen generation module; 1414- chemical detection and analysis module; 1415- first detector; 1416- first electric slider; 1417- first arc guide rail; 1418- second detector.

[0067] 1501- extreme ultraviolet light source; 1502- extreme ultraviolet irradiation time-controlled electronic shutter; 1503- first cylindrical mirror; 1504- second cylindrical mirror; 1505- protective film; 1506- protective film fixing frame; 1507- first electric three-axis translation stage; 1508- mask; 1509- mask fixing frame; 1510- second electric three-axis translation stage; 1511- electric rotation translation stage; 1512- projection optical system; 1513- wafer coated with photoresist; 1514- hydrogen generation module; 1515- chemical detection and analysis module; 1516- first detector; 1517- first electric slider; 1518- first arc guide rail; 1519- second detector.

[0068] 1601- extreme ultraviolet light source; 1602- extreme ultraviolet irradiation time-controlled electronic shutter; 1603- tire mirror; 1604- protective film; 1605- protective film fixing frame; 1606- first electric three-axis translation stage; 1607- mask; 1608- mask fixing frame; 1609- second electric three-axis translation stage; 1610- electric rotation translation stage; 1611- projection optical system; 1612- wafer coated with photoresist; 1613- hydrogen generation module; 1614- chemical detection and analysis module; 1615- third detector; 1616- second electric slider; 1617- second circular arc guide rail.

[0069] 1701- extreme ultraviolet light source; 1702- extreme ultraviolet irradiation time-controlled electronic shutter; 1703- first cylindrical mirror; 1704- second cylindrical mirror; 1705- protective film; 1706- protective film fixing frame; 1707- first electric three-axis translation stage; 1708- mask; 1709- mask fixing frame; 1710- second electric three-axis translation stage; 1711- electric rotation translation stage; 1712- projection optical system; 1713- wafer coated with photoresist; 1714- hydrogen generation module; 1715- chemical detection and analysis module; 1716- third detector; 1717- second electric slider; 1718- second circular arc guide rail. DETAILED DESCRIPTION

[0070] The present invention is further described below in conjunction with the embodiments and drawings. The present application can be implemented in different forms, which should not limit the scope of protection of the present invention. The terms used in the present application specification are for describing specific embodiments and are not intended to limit the present application.

[0071] Figure 1 This is a flow chart of an embodiment of the EUV lithography mask protective film detection device of the present invention. It includes: a detection light source module, a sample stage module, a detection module for the effect of contaminants on the protective film on mask imaging, a protective film transmittance, transmission uniformity and reflectivity measurement module, a hydrogen generation module and a chemical detection and analysis module. By rotating the sample, the switch between the detection module for the effect of contaminants on the protective film on mask imaging and the protective film transmittance, transmission uniformity and reflectivity measurement module is realized.

[0072] The detection light source module is an extreme ultraviolet light source with a wavelength of 10-20 nm, and the light source is used to generate extreme ultraviolet light for detection;

[0073] The sample stage module is used to fix, move and rotate the sample, so that the extreme ultraviolet light can be irradiated at different positions and angles of the sample. In the protective film transmittance, transmission uniformity and reflectivity measurement module, the sample is a protective film, and the sample stage module is used to fix, move and rotate the protective film, so that the extreme ultraviolet light can be irradiated at different positions of the protective film at different incident angles within an adjustable angle range of 5-25°; each time the transmittance, transmission uniformity and reflectivity of the protective film are measured, the irradiation position of the extreme ultraviolet light on the protective film is located on the rotation axis of the electric rotary translation stage. In the detection module of the influence of contaminants on the protective film on the mask imaging, the samples are a protective film and a mask, and the sample stage module is used to fix, move and rotate the protective film and the mask, so that the extreme ultraviolet light can be irradiated on the protective film and the mask at a given incident angle, and the mask imaging is optimal at this incident angle.

[0074] The module for detecting the impact of contaminants on the protective film on mask imaging introduces different types of contaminants, i.e. particles and stains, and contaminants of different sizes, with a size below 50 µm, to detect the impact of contaminants of different types and sizes on mask imaging. The distance between the protective film and the mask is adjusted, with an adjustable distance range of 1-10 mm, to study the impact of the distance between the protective film and the mask on mask imaging, and to provide the relationship between the distance between the protective film and the mask and the mask imaging, and to provide the optimal distance between the protective film and the mask. The module for detecting the impact of contaminants on the protective film on mask imaging uses two modes. The first mode includes: a projection optical system and an extreme ultraviolet camera, which are used to obtain the mask pattern and its defect diffraction signal. Considering that the transfer of mask pattern to photoresist is also related to the type of photoresist and subsequent processes such as development, post-baking temperature and time, the second mode includes: projection optical system and wafer coated with photoresist; photoresist is developed after extreme ultraviolet exposure, and the developed pattern is characterized by scanning electron microscope or atomic force microscope to analyze the influence of contaminants on the photolithography pattern, including the type of defects, number of defects, line width, line width roughness and line edge roughness. It can be used to study the influence of development conditions, post-baking temperature and time on photolithography patterns.

[0075] The protective film transmittance, transmission uniformity and reflectance measurement module is used to measure the extreme ultraviolet transmittance, transmission uniformity and reflectance of the protective film at different incident angles. The incident angle can be adjusted from 5 to 25 degrees. The protective film transmittance, transmission uniformity and reflectance measurement module and the chemical detection and analysis module are used together to study the chemical changes of the protective film under extreme ultraviolet irradiation and the optical properties of the protective film, that is, the relationship between transmittance, transmission uniformity and reflectance.

[0076] The hydrogen generation module is used to generate hydrogen and can control the hydrogen partial pressure in the vacuum chamber of the device, i.e. 0-10 Pa.

[0077] The chemical detection and analysis module is used to study the chemical changes of the protective film under extreme ultraviolet light irradiation, including the chemical reaction between the protective film and the above-mentioned hydrogen. Specifically, mass spectrometry and / or Raman spectroscopy are used for detection and analysis. This device can simultaneously perform chemical detection and analysis and research on the optical properties of the protective film.

[0078] Figure 2 It is a schematic diagram of the first mode embodiment of the protective film transmittance, transmission uniformity and reflectance measurement module of the extreme ultraviolet lithography mask protective film detection device of the present invention (the light source transmission is a tire mirror, and the contaminants on the protective film affect the mask imaging in the first mode of the detection module).

[0079] The working process of the device is as follows: the extreme ultraviolet light source 201 reaches the light source transmission of the detection light through the extreme ultraviolet irradiation time controlled electronic shutter 202, i.e., the tire mirror 203, and then is transmitted to the protective film 204. The protective film 204 is fixed on the protective film fixing frame 205, and the protective film fixing frame 205 is fixed on the first electric three-axis displacement stage 206, and the first electric three-axis displacement stage 206 is fixed on the electric rotation displacement stage 209. The irradiation position of the extreme ultraviolet light on the protective film is always located on the rotation axis of the electric rotation displacement stage 209. By rotating the electric rotation displacement stage 209, the protective film 204 is measured at different incident angles θ, and the adjustable angle range of θ is 5-25°. By adjusting the first electric three-axis displacement stage 206, different positions of the protective film 204 are measured. The mask fixing frame 207 is fixed on the second electric three-axis displacement stage 208, and the second electric three-axis displacement stage 208 is fixed on the electric rotation displacement stage 209. In the protective film transmittance, transmittance uniformity and reflectance measurement modules, it is not necessary to place a mask. The mask fixing frame 207 will not block the transmitted light after passing through the protective film 204 .

[0080] The transmittance, transmittance uniformity and reflectance of the protective film are measured through the first mode of the protective film transmittance, transmittance uniformity and reflectance measurement module. Two detectors are used for the energy detection of the transmitted light beam and the reflected light beam, so that the transmittance and reflectance of the protective film can be measured simultaneously. It includes: a first detector 210, a first electric slider 211, a first circular arc guide 212 and a second detector 213; the axis of the first circular arc guide 212 coincides with the axis of the sample electric rotation translation stage 209, and the center angle of the first circular arc guide 212 is 60°. The first detector 210 is fixed on the first electric slider 211, and the first electric slider 211 is fixed on the first circular arc guide 212 in the direction of the reflected light beam; the reflected light beam energy is detected by the relationship between the sample rotating by an angle of α and the first detector 210 rotating by an angle of 2α. The second detector 213 is fixed in the direction of the transmitted light beam, and can detect the incident light intensity of the detection light source when no sample is placed. After placing the protective film 204, the sample transmitted light beam energy at different incident angles is obtained by rotating the above-mentioned electric rotary translation stage 209, and the reflectivity of the protective film is obtained by the ratio of the reflected light beam energy to the incident light beam energy. The transmittance of the protective film is obtained by the ratio of the transmitted light beam energy to the incident light beam energy. The sample measurement position is changed by adjusting the first electric three-axis translation stage 206 to realize multi-point transmittance measurement of the protective film and obtain the transmission uniformity of the protective film.

[0081] The specific measurement of the transmittance and reflectance of the protective film is as follows: first, without placing the protective film, the light intensity is measured by the second detector 213 to be Then the protective film 204 is fixed on the protective film fixing frame 205. The protective film fixing frame 205 is fixed on the first electric three-axis translation stage 206. The position of the protective film 204 is adjusted by the first electric three-axis translation stage 206 so that the detection light is irradiated on the position of the protective film to be detected. Each time the position of the protective film is adjusted, it is necessary to ensure that the irradiation position of the extreme ultraviolet light on the protective film is located on the rotation axis of the electric rotation translation stage 209. The protective film 204 is rotated by the electric rotation translation stage 209 to obtain the required incident angle ( ), the light intensity measured by the first detector 210 is , the light intensity measured by the second detector 213 is , at the above incident angle ( ), the reflectivity of the protective film is calculated as ; The transmittance of the protective film is calculated as .

[0082] By adjusting the first electric three-axis translation stage 206, different positions of the protective film 204 are measured. Each time the position of the protective film is adjusted, it is necessary to ensure that the irradiation position of the extreme ultraviolet light on the protective film is located on the rotation axis of the above-mentioned electric rotation translation stage 209, and the second detector 213 is used to measure the transmitted light intensity ( , where n is the number of the measurement position), calculate the transmittance at each position (i.e. ) to obtain the uniformity of transmission of the protective film 204. The protective film 204 is rotated by the electric rotation stage 209 to obtain different incident angles ( , where m is the number of different measured incident angles, the incident angle can be adjusted in the range of 5-25°, and the corresponding reflected light intensity is measured by the first detector 210 ( , where m is the number of different measured incident angles, the incident angle can be adjusted in the range of 5-25°, and the reflectivity of the protective film 204 at different incident angles (i.e. ); The corresponding transmitted light intensity is measured by the second detector 213 ( , where m is the number of different measured incident angles), and calculate the transmittance at different incident angles (i.e. );

[0083] The device includes a hydrogen generation module 214, which can control the hydrogen partial pressure in the vacuum chamber of the device, with an adjustable range of 0-10 Pa, and is used to study the chemical reaction between the protective film 204 and hydrogen under extreme ultraviolet irradiation, especially the chemical changes of protective films based on carbon materials. The chemical changes of the protective film under extreme ultraviolet irradiation are detected and analyzed using a chemical detection and analysis module 215, specifically using mass spectrometry and / or Raman spectroscopy for detection and analysis. The device can simultaneously perform chemical detection and analysis and protective film transmittance or reflectivity measurement. The protective film 204 is rotated by an electric rotary displacement stage 209, and the protective film transmittance, transmission uniformity and reflectivity measurement modules and the contaminant imaging module can be quickly switched. The contaminant imaging module is the first mode, which is used to obtain the mask pattern and its defect diffraction signal, including a projection optical system 216 and an extreme ultraviolet camera 217. The entire device is placed in a vibration isolation.

[0084] Figure 3 This is a schematic diagram of the first mode embodiment of the protective film transmittance, transmittance uniformity and reflectance measurement module of the EUV lithography mask protective film detection device of the present invention (the light source transmission is a tire mirror, and the contaminants on the protective film affect the mask imaging detection module in the second mode). Considering that the transfer of the mask pattern to the photoresist is also related to the photoresist type and subsequent processes, such as development, post-baking temperature and time, and Figure 2 compared to, Figure 3 The contaminant removal imaging module adopts the second mode. The detection light source module develops the photoresist after exposure, and characterizes the developed pattern through a scanning electron microscope or an atomic force microscope and analyzes the influence of contaminants on the mask exposure pattern, including the type of defects, the number of defects, line width, line width roughness and line edge roughness. It includes: a projection optical system 316 and a wafer coated with photoresist 317, other module workflows and Figure 2 same.

[0085] Figure 4 This is a schematic diagram of the first mode embodiment of the protective film transmittance, transmittance uniformity and reflectance measurement module of the EUV lithography mask protective film detection device of the present invention (the light source transmission is two cylindrical mirrors, and the contaminants on the protective film affect the mask imaging detection module in the first mode). Figure 2 The processing difficulty and cost of the tire mirror 203 in the light source transmission, and Figure 2 compared to, Figure 4 Except for the light source transmission using two cylindrical mirrors, namely the first cylindrical mirror 403 and the second cylindrical mirror 404, the workflow of other modules is the same as Figure 2 same.

[0086] Figure 5This is a schematic diagram of the first mode embodiment of the protective film transmittance, transmission uniformity and reflectance measurement module of the EUV lithography mask protective film detection device of the present invention (the light source transmission is two cylindrical mirrors, and the contaminants on the protective film affect the mask imaging detection module in the second mode). Figure 3 The processing difficulty and cost of the tire mirror 303 in the light source transmission, and Figure 3 compared to, Figure 5 Except for the light source transmission using two cylindrical mirrors, namely the first cylindrical mirror 503 and the second cylindrical mirror 504, the workflow of other modules is the same as Figure 3 same.

[0087] Figure 6 This is a schematic diagram of the second mode embodiment of the protective film transmittance, transmittance uniformity and reflectance measurement module of the EUV lithography mask protective film detection device of the present invention (the light source transmission is a tire mirror, and the contaminants on the protective film affect the mask imaging detection module in the first mode). Figure 2 A second detector was used, and Figure 2 compared to, Figure 6 The protective film transmittance, transmission uniformity and reflectivity measurement module adopts the second mode, which reduces the use of one detector on the basis of the first mode, including: a third detector 610, a second electric slider 611 and a second circular arc guide 612; the third detector 610 is fixed on the second electric slider 611, the second electric slider 611 is on the second circular arc guide 612, the axis of the second circular arc guide coincides with the axis of the electric rotary translation stage 609, the center angle of the second circular arc guide is 180°, and the measurement principle is consistent with the first mode. The energy detection of the transmitted light beam and the reflected light beam is performed using the same detector, that is, the third detector 610. By rotating the third detector 610 on the second circular arc guide 612 to the position of the reflected light beam and the transmitted light beam, the transmittance, transmission uniformity and reflectivity of the protective film are measured respectively.

[0088] Each time the transmittance, transmittance uniformity and reflectance of the protective film are measured, the irradiation position of the extreme ultraviolet light on the protective film is located on the rotation axis of the electric rotary stage 609 .

[0089] For the transmittance measurement of the protective film 604, at a certain incident angle, along the propagation direction of the detection light, the third detector 610 is placed behind the protective film 604. The second electric slider 611 allows the transmitted light to enter the effective detection position of the third detector 610. The electric rotary translation stage 609 is rotated to change the incident angle of the detection light on the protective film 604. For the transmittance test of the protective film, when the incident angle is changed, the position of the third detector 610 remains unchanged, and the transmission light intensity of the protective film 604 is measured at different incident angles, and the adjustable angle range is 5-25°. The specific measurement of the transmittance of the protective film is as follows. First, without placing the protective film, the light intensity is measured by the third detector 610. Then the protective film 604 is fixed on the protective film fixing frame 605. The protective film fixing frame 605 is fixed on the first electric three-axis translation stage 606. The position of the protective film 604 is adjusted by the first electric three-axis translation stage 606 so that the detection light is irradiated on the position of the protective film to be detected. Each time the position of the protective film is adjusted, it is necessary to ensure that the position on the protective film where the detection light is irradiated is on the rotation axis of the electric rotation translation stage 609. The protective film 604 is rotated by the electric rotation translation stage 609 to obtain the required incident angle ( ). The light intensity measured by the third detector 610 is At the above incident angle ( ), the transmittance of the protective film is calculated as The first electric three-axis translation stage 606 is used to irradiate different positions of the protective film 604. Each time the position of the protective film is adjusted, it is necessary to ensure that the position of the protective film irradiated by the detection light is on the rotation axis of the electric rotation translation stage 609. The third detector 610 is used to measure the transmitted light intensity at different positions of the protective film 604 ( , where n is the number of the measurement position), calculate the transmittance at each position (i.e. ) to obtain the uniformity of transmission of the protective film 604. The protective film 604 is rotated by the electric rotation stage 609 to obtain different incident angles ( , where m is the number of different measured incident angles), and the corresponding transmitted light intensity is measured by the third detector 610 ( , where m is the number of different measured incident angles), and calculate the transmittance of the protective film 604 at different incident angles (i.e. ). For the reflectivity measurement of the protective film 604, the position of the third detector 610 is controlled by the second electric slider 611, so that the reflected light after the protective film 604 enters the effective detection position of the third detector 610. The third detector 610 measures the reflected light intensity corresponding to the protective film 604 at different incident angles ( , where m is the number of different measured incident angles), and calculate the reflectivity at different incident angles (i.e. ).

[0090] Figure 7 This is a schematic diagram of the second mode embodiment of the protective film transmittance, transmittance uniformity and reflectance measurement module of the EUV lithography mask protective film detection device of the present invention (the light source transmission is a tire mirror, and the contaminants on the protective film affect the mask imaging detection module in the second mode). Considering that the transfer of the mask pattern to the photoresist is also related to the photoresist type and subsequent processes, such as development, post-baking temperature and time, and Figure 6 compared to, Figure 7 The contaminant removal imaging module includes a projection optical system 715 and a photoresist-coated wafer 716, and other module workflows and Figure 6 same.

[0091] Figure 8 This is a schematic diagram of the second mode embodiment of the protective film transmittance, transmittance uniformity and reflectance measurement module of the EUV lithography mask protective film detection device of the present invention (the light source transmission is two cylindrical mirrors, and the contaminants on the protective film affect the mask imaging detection module in the first mode). Figure 6 The processing difficulty and cost of the tire mirror 603 in the light source transmission, and Figure 6 compared to, Figure 8 Except for the light source transmission using two cylindrical mirrors, namely the first cylindrical mirror 803 and the second cylindrical mirror 804, the workflow of other modules is the same as Figure 6 same.

[0092] Fig. 9 This is a schematic diagram of the second mode embodiment of the protective film transmittance, transmittance uniformity and reflectance measurement module of the EUV lithography mask protective film detection device of the present invention (the light source is transmitted by two cylindrical mirrors, and the contaminants on the protective film affect the mask imaging in the second mode of the detection module). Figure 7 The processing difficulty and cost of the tire mirror 703 in the light source transmission, and Figure 7 compared to, Fig. 9 Except for the light source transmission using two cylindrical mirrors, namely the first cylindrical mirror 903 and the second cylindrical mirror 904, the workflow of other modules is the same as Figure 7 same.

[0093] Fig.10 It is a schematic diagram of the first mode embodiment of the detection module of the influence of contaminants on the protective film of the extreme ultraviolet lithography mask protective film detection device on the mask imaging (the light source transmission is a tire mirror, the first mode of the protective film transmittance, transmission uniformity and reflectivity measurement module).

[0094] The protective film 1004 is rotated by the electric rotating stage 1010 to switch from the protective film transmittance, transmittance uniformity and reflectance measurement module to the pollutant imaging module. The mask 1007 is fixed to the mask fixing frame 1008. Specifically, the protective film 1004 and the mask 1007 are rotated by the electric rotating stage 1010 to obtain the required incident angle (θ), at which the mask imaging is optimal, and the detection is performed at this incident angle.

[0095] The working process of the device is as follows: the extreme ultraviolet light source 1001 reaches the light source transmission of the detection light through the extreme ultraviolet irradiation time-controlled electronic shutter 1002, i.e., the tire mirror 1003, and then is transmitted to the protective film 1004 and the mask 1007. The protective film 1004 is fixed on the protective film fixing frame 1005, the protective film fixing frame 1005 is fixed on the first electric three-axis translation stage 1006, and the first electric three-axis translation stage 1006 is fixed on the electric rotation translation stage 1010. The mask 1007 is fixed on the mask fixing frame 1008, the mask fixing frame 1008 is fixed on the second electric three-axis translation stage 1009, and the second electric three-axis translation stage 1009 is fixed on the electric rotation translation stage 1010.

[0096] The detection module for the influence of contaminants on the protective film on the mask imaging includes a projection optical system 1011 and an extreme ultraviolet camera 1012, which are used to obtain the mask pattern and its defect diffraction signal. Contaminants of different types and sizes are introduced on the protective film 1004, with a size of less than 50 μm, to study the influence of contaminants of different types and sizes on the mask imaging. The position of the protective film fixing frame 1005 is changed by the first electric three-axis translation stage 1006, and then the position of the protective film 1004 is adjusted, and the distance (d) between the protective film 1004 and the mask 1007 is changed. The influence of contaminants on the mask imaging under different d is studied, and the optimal distance between the protective film and the mask is given.

[0097] Fig.11 This is a schematic diagram of the first mode of the detection module of the effect of contaminants on the protective film of the EUV lithography mask protective film detection device on the mask imaging (the light source is transmitted by two cylindrical mirrors, and the first mode of the protective film transmittance, transmission uniformity and reflectance measurement module). Considering Fig.10 The processing difficulty and cost of the tire mirror 1003 in the light source transmission, and Fig.10 compared to, Fig.11 Except for the light source transmission using two cylindrical mirrors, namely the first cylindrical mirror 1103 and the second cylindrical mirror 1104, the workflow of other modules is the same as Fig.10 same.

[0098] Fig.12 This is a schematic diagram of the first mode of the detection module of the effect of contaminants on the protective film of the EUV lithography mask protective film detection device on the mask imaging (the light source transmission is a tire mirror, and the second mode of the protective film transmittance, transmission uniformity and reflectivity measurement module). Considering Fig.10 Two detectors are used, namely a first detector 1015 and a second detector 1018, and Fig.10 compared to, Fig.12 The protective film transmittance, transmittance uniformity and reflectance measurement modules use a detector, namely the third detector 1215, to respectively measure the transmittance or reflectance of the protective film 1204. Fig.10 same.

[0099] Fig.13 This is a schematic diagram of the first mode of the detection module of the effect of contaminants on the protective film of the EUV lithography mask protective film detection device on the mask imaging (the light source transmission is two cylindrical mirrors, and the second mode of the protective film transmittance, transmission uniformity and reflectivity measurement module). Considering Fig.12 The processing difficulty and cost of the tire mirror 1203 in the light source transmission, and Fig.12 compared to, Fig.13 Except for the light source transmission using two cylindrical mirrors, namely the first cylindrical mirror 1303 and the second cylindrical mirror 1304, the workflow of other modules is the same as Fig.12 same.

[0100] Fig.14 This is a schematic diagram of the second mode embodiment of the detection module of the effect of contaminants on the protective film of the EUV lithography mask protective film detection device of the present invention (the light source transmission is a tire mirror, and the first mode of the protective film transmittance, transmission uniformity and reflectivity measurement module). Considering that the transfer of the mask pattern to the photoresist is also related to the type of photoresist and subsequent processes such as development, post-baking temperature and time, and Fig.10 compared to, Fig.14 The module for detecting the effect of contaminants on the protective film on the mask imaging includes a projection optical system 1411 and a wafer coated with photoresist 1412; the photoresist is developed after extreme ultraviolet exposure, and the developed pattern is characterized by a scanning electron microscope or an atomic force microscope to analyze the effect of contaminants on the mask exposure pattern, including the type of defects, the number of defects, line width, line width roughness and line edge roughness. Fig.10 Same as in.

[0101] Fig.15 This is a schematic diagram of the second mode embodiment of the detection module of the effect of contaminants on the protective film of the EUV lithography mask protective film detection device of the present invention (the light source transmission is two cylindrical mirrors, and the first mode of the protective film transmittance, transmission uniformity and reflectivity measurement module). Considering that the transfer of the mask pattern to the photoresist is also related to the photoresist type and subsequent processes, such as development, post-baking temperature and time, and Fig.11 compared to, Fig.15 The module for detecting the effect of contaminants on the protective film on the mask imaging includes a projection optical system 1512 and a wafer coated with photoresist 1513; the photoresist is developed after extreme ultraviolet exposure, and the developed pattern is characterized by a scanning electron microscope or an atomic force microscope to analyze the effect of contaminants on the mask exposure pattern, including the type of defects, the number of defects, line width, line width roughness and line edge roughness. Fig.11 Same as in.

[0102] Fig.16 This is a schematic diagram of the second mode embodiment of the detection module of the effect of contaminants on the protective film of the EUV lithography mask protective film detection device of the present invention (the light source transmission is a tire mirror, and the second mode of the protective film transmittance, transmission uniformity and reflectivity measurement module). Considering that the transfer of the mask pattern to the photoresist is also related to the type of photoresist and subsequent processes such as development, post-baking temperature and time, and Fig.12 compared to, Fig.16 The module for detecting the effect of contaminants on the protective film on the mask imaging includes a projection optical system 1611 and a wafer coated with photoresist 1612; the photoresist is developed after extreme ultraviolet exposure, and the developed pattern is characterized by a scanning electron microscope or an atomic force microscope to analyze the effect of contaminants on the mask exposure pattern, including the type of defects, the number of defects, line width, line width roughness and line edge roughness. Fig.12 Same as in.

[0103] Fig.17 This is a schematic diagram of the second mode embodiment of the detection module of the effect of contaminants on the protective film of the EUV lithography mask protective film detection device of the present invention (the light source transmission is two cylindrical mirrors, and the second mode of the protective film transmittance, transmission uniformity and reflectivity measurement module). Considering that the transfer of the mask pattern to the photoresist is also related to the type of photoresist and subsequent processes such as development, post-baking temperature and time, and Fig.13 compared to, Fig.17 The module for detecting the effect of contaminants on the protective film on the mask imaging includes a projection optical system 1712 and a wafer coated with photoresist 1713; the photoresist is developed after extreme ultraviolet exposure, and the developed pattern is characterized by a scanning electron microscope or an atomic force microscope to analyze the effect of contaminants on the mask exposure pattern, including the type of defects, the number of defects, line width, line width roughness and line edge roughness. Fig.13 Same as in.

[0104] The present invention provides an extreme ultraviolet lithography mask protective film detection device. It is used to study the influence of pollutants of different types and sizes on mask imaging and optimize the distance between the protective film and the mask. By rotating the sample, the detection module of the influence of pollutants on the protective film on mask imaging and the protective film transmittance, transmission uniformity and reflectance measurement module can be quickly and efficiently switched. The transmittance, transmission uniformity and reflectance of the protective film can be measured at different incident angles, and the incident angle can be adjusted in the angle range of 5-25°. The chemical changes of the protective film under extreme ultraviolet light irradiation are detected by mass spectrometry and / or Raman spectroscopy, including the study of the chemical reaction between the protective film and hydrogen. The optical properties of the protective film (i.e., transmittance, transmission uniformity and reflectivity) and the changes in the chemical reaction in the process can be detected at the same time, and then the influence of the chemical changes of the protective film under extreme ultraviolet irradiation on the optical properties of the protective film can be studied. In addition, the extreme ultraviolet lithography mask protective film detection device system in the present invention includes but is not limited to the above structure, which includes all combinations that can produce the same light path.

Claims

1. An extreme ultraviolet lithography mask protective film detection device, characterized in that: include: A detection light source module, which is used to generate an extreme ultraviolet light source used for detection, with a wavelength in the extreme ultraviolet band, and is equipped with an extreme ultraviolet irradiation time control electronic shutter to control the irradiation time, and a light source transmission system; The sample stage module is placed in the vacuum chamber and is used to fix, move and rotate the protective film and mask samples to be tested to ensure that the extreme ultraviolet light source can achieve irradiation at different positions and different incident angles, wherein the distance between the protective film and the mask can be adjusted in the range of 1-10 mm; The module for detecting the impact of contaminants on the protective film on mask imaging is used to study the impact of different types and sizes of contaminants below 50 µm, as well as the distance between the protective film and the mask on mask imaging, and determine the optimal distance; The protective film transmittance, transmittance uniformity and reflectance measurement module is used to measure the optical properties of the protective film at different incident angles and study the influence of chemical changes of the protective film on its optical properties; wherein the adjustable range of the incident angle is 5-25°; For the detection of the influence of contaminants on the protective film on the mask imaging, the samples are the protective film and the mask, and the sample stage module is used to place the protective film and the mask at the same time, so as to realize the synchronous fixation, movement and rotation of the protective film and the mask. After the mask is placed on the protective film along the propagation direction of the detection light, the protective film and the mask are synchronously rotated to a preset incident angle by controlling the rotation of the electric rotary translation stage, so as to ensure that the mask imaging is optimal under this preset incident angle; the distance between the protective film and the mask is changed by adjusting the first electric three-axis translation stage, and the adjustable distance range is 1-10 mm, and the influence of contaminants on the mask imaging at different distances between the protective film and the mask is studied, and the relationship between the distance between the protective film and the mask and the influence of contaminants on the protective film on the mask imaging is obtained, and the optimal distance between the protective film and the mask is given; or; For the measurement of the transmittance, transmittance uniformity and reflectance of the protective film, the sample is a protective film, the sample stage module is used to fix, move and rotate the protective film, the irradiation position of the extreme ultraviolet light on the protective film is always located on the rotation axis of the electric rotary displacement stage, and the measurement of different incident angles of the protective film is achieved by rotating the electric rotary displacement stage, with an adjustable angle range of 5-25°, and the measurement of different positions of the protective film is achieved by adjusting the first electric three-axis displacement stage; The sample stage module comprises: a protective film fixing frame for placing the protective film, and a mask fixing frame for placing the mask, the protective film fixing frame is controlled by the first electric three-axis translation stage, and the mask fixing frame is controlled by the second electric three-axis translation stage, the first electric three-axis translation stage and the second electric three-axis translation stage are both fixed on the electric rotation translation stage, and are placed in sequence along the propagation direction of the detection light; The protective film transmittance, transmittance uniformity and reflectance measurement module is divided into two modes according to whether the transmittance and reflectance can be measured simultaneously: In the first mode, the energy detection of the transmitted light beam and the reflected light beam is measured respectively using two detectors to realize the synchronous measurement of the transmittance, transmission uniformity and reflectance of the protective film, including: a first detector, a second detector, a first circular arc guide and a first electric slider; the axis of the first circular arc guide coincides with the axis of the electric rotary translation stage, the central angle of the first circular arc guide is 60°, the first detector is fixed on the first electric slider, the first electric slider is on the first circular arc guide, and is fixed in the direction of the reflected light beam. The energy of the reflected light beam is detected by the relationship that the sample rotates by an angle α and the first detector rotates by an angle 2α, and 0°<α≤20°. The second detector is fixed in the direction of the transmitted light beam, and the incident light beam energy of the detection light source can be detected when the sample is not placed. After the sample is placed, the transmitted light beam energy of the sample at different incident angles is obtained by rotating the above-mentioned electric rotary translation stage, the reflectance of the protective film is obtained by the ratio of the reflected light beam energy to the incident light beam energy, and the transmittance of the protective film is obtained by the ratio of the transmitted light beam energy to the incident light beam energy. The measurement position of the sample is changed by adjusting the first electric three-axis translation stage to realize multi-point transmittance measurement of the protective film and obtain the transmission uniformity of the protective film. The second mode includes: a third detector, a second circular arc guide and a second electric slider; based on the first mode, one detector is used less, the axis of the second circular arc guide coincides with the axis of the above-mentioned electric rotary translation stage, the center angle of the second circular arc guide is 180°, and the measurement principle is consistent with the first mode; the energy detection of the transmitted light beam and the reflected light beam both use the same detector, that is, the third detector, and the third detector is rotated on the second circular arc guide to the position of the transmitted light beam and the reflected light beam to measure the transmittance, transmission uniformity and reflectance of the protective film respectively.

2. The EUV lithography mask protective film detection device according to claim 1, characterized in that: The light source transmission system includes a tire mirror or two cylindrical mirrors.

3. The EUV lithography mask protective film detection device according to claim 1, characterized in that: The detection module for the effect of contaminants on the protective film on mask imaging is divided into two modes according to the purpose of detection: The first mode is used to obtain the mask pattern and its defect diffraction signal, including: a projection optical system and an extreme ultraviolet camera; In the second mode, the above-mentioned detection light source module develops the photoresist after exposure, and characterizes the developed pattern through a scanning electron microscope or an atomic force microscope and analyzes the influence of contaminants on the mask exposure pattern, including the type of defects, the number of defects, line width, line width roughness and line edge roughness, including: a projection optical system and a wafer coated with photoresist.

4. The EUV lithography mask protective film detection device according to claim 1, characterized in that: The electric rotary stage is used to control the rotation of the sample, thereby realizing the switching of the detection module of the influence of pollutants on the protective film on the mask imaging and the protective film transmittance, transmission uniformity and reflectance measurement module.

5. The EUV lithography mask protective film detection device according to any one of claims 1 to 4, characterized in that: Also includes: A hydrogen generation module, used to generate hydrogen and control the hydrogen partial pressure in the vacuum chamber, with an adjustable range of 0-10 Pa, and The chemical detection and analysis module uses mass spectrometry and / or Raman spectroscopy detection technology to study the changes in the chemical reaction of the protective film with hydrogen under extreme ultraviolet light irradiation.

Images