Focusing and leveling device and photolithography machine

Abstract

The present invention provides a focusing and leveling device and a photolithography machine. J projection micromirror groups of a projection micromirror array assembly convert incident detection light beams into j projection light spots and project the light spots onto the surface of a substrate. J detection micromirror groups of a detection micromirror array assembly split the j detection light spots to form j first marking light spots and j second marking light spots. The projection micromirror array assembly and the detection micromirror array assembly are spatially synchronously modulated. The size of j and the positions of the j projection micromirror groups and the j detection micromirror groups are changed as needed to change the number and position of the projection light spots, the first marking light spots, and the second marking light spots. This can reduce process adaptability errors caused by different process patterns and process film systems used on the surface of the substrate during measurement by the focusing and leveling device.

Description

Technical Field

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

[0002] During the exposure process in a photolithography machine, factors such as wafer thickness deviation, surface undulations, and inaccuracies and non-repeatability in the focal plane position of the projection objective (which projects a bright, clear, real image of the illuminated object on the screen) can cause the wafer to defocus or tilt relative to the focal plane of the objective lens. If this defocus or tilt causes certain areas within the exposure field of view to fall outside the effective depth of focus, it can severely impact the quality and yield of the integrated circuits. Therefore, a focusing and leveling device is required to measure the height and tilt of the wafer surface relative to the focal plane of the projection objective lens. Throughout the exposure process, if the wafer's position deviates from the optimal focal plane, the workpiece stage is used to adjust the wafer's position to ensure it remains in the optimal focal plane of the projection objective lens, ensuring a clear image on the wafer.

[0003] In a focusing and leveling device based on spatial spectroscopic modulation, the projection slit assembly cannot be changed once it is installed and fixed. However, during the photolithography process on the silicon wafer surface, different process patterns are used or process film layers of different combinations and thicknesses are coated. When the size or shape of the slit of the projection slit assembly does not match the process well, the measured process adaptability error will increase. Summary of the Invention

[0004] The object of the present invention is to provide a focusing and leveling device and a photolithography machine to solve the problem of large process adaptability error of the existing focusing and leveling device of spatial light splitting modulation.

[0005] In order to achieve the above-mentioned object, the present invention provides a focusing and leveling device, comprising:

[0006] an illumination assembly for emitting a detection light beam;

[0007] A projection micromirror array assembly includes i projection micromirror groups, wherein j projection micromirror groups convert the detection light beam incident thereon into j projection light spots and project the images onto the surface of the substrate, wherein the j projection light spots are reflected by the surface of the substrate to form j detection light spots, wherein 0<j≤i;

[0008] A detection micromirror array assembly includes i detection micromirror groups, wherein j detection micromirror groups corresponding to j projection micromirror groups respectively split j detection light spots to form j first marking light spots and j second marking light spots; and

[0009] The detector assembly comprises a first detector unit and a second detector unit, wherein the first detector unit and the second detector unit are respectively used to detect energy of j first marking light spots and energy of j second marking light spots.

[0010] Optionally, the i projection micromirror groups and the i detection micromirror groups are distributed in the same manner, and the positions of the corresponding projection micromirror groups and the detection micromirror groups correspond to each other.

[0011] Optionally, each of the projection micromirror groups includes m projection micromirrors, each of the detection micromirror groups includes m detection micromirror sets, and each of the detection micromirror sets includes n detection micromirrors distributed along the measurement direction, where m≥1, n≥2 and n is an even number.

[0012] Optionally, the position distribution of the m projection micromirrors in the projection micromirror group is the same as the distribution of the m detection micromirror sets in the detection micromirror group, and the positions of the corresponding projection micromirrors correspond to those of the detection micromirror sets.

[0013] Optionally, a width L1 of the projection micromirror along the measurement direction and a width L2 of the detection micromirror along the measurement direction satisfy the following relationship:

[0014] L1=n·L2.

[0015] Optionally, the projection micromirror array assembly further includes a projection stray light trap, and each of the ij projection micromirror groups reflects the detection light beam incident thereon into the projection stray light trap; and / or,

[0016] The detection micromirror array assembly further includes a detection stray light trap, and the detection light spots incident on the ij detection micromirror groups are reflected into the detection stray light trap.

[0017] Optionally, the projection micromirror has a first posture and a second posture, the m projection micromirrors in the same projection micromirror group are all in the first posture or are all in the second posture, and the inclination angles of the projection micromirror in the first posture and the second posture are different; and

[0018] All the projection micromirrors in the j projection micromirror groups are in the first posture to convert the detection light beam incident thereon into the j projection light spots, and all the projection micromirrors in the ij projection micromirror groups are in the second posture to reflect the detection light beam incident thereon into the projection stray light trap.

[0019] Optionally, the detection micromirror has a third posture, a fourth posture and a fifth posture, and the tilt angles of the detection micromirror in the third posture, the fourth posture and the fifth posture are all different; and

[0020] Half of the detection micromirrors in each of the j detection micromirror groups are in the third posture, and the other half are in the fourth posture, so as to respectively split the j projection light spots to form j first marking light spots and j second marking light spots, and all the detection micromirrors in the ij detection micromirror groups are in the fifth state, so as to reflect the detection light spots incident thereon into the detection stray light trap.

[0021] Optionally, the detection micromirrors in each detection micromirror set appear in pairs, one detection micromirror in each pair of detection micromirrors is in the third posture, and the other is in the fourth posture, and the positions of the detection micromirrors in the third posture in each pair of detection micromirrors correspond to each other, and the positions of the detection micromirrors in the fourth posture in each pair of detection micromirrors correspond to each other.

[0022] Optionally, surfaces of the two detection micromirrors in each pair of the detection micromirrors are opposite to or facing away from each other.

[0023] Optionally, the projection micromirror and the detection micromirror are both circular or rectangular in shape.

[0024] Optionally, the projection micromirror and the detection micromirror are refractive, reflective or catadioptric micromirrors.

[0025] Optionally, also include:

[0026] A projection imaging component is located between the projection micromirror array component and the detection micromirror array component, and is used to relay and amplify the j projection light spots and then project them into the substrate;

[0027] a detection imaging component, located between the projection imaging component and the detection micromirror array component, for relaying and amplifying the j detection light spots and then incident on the detection micromirror array component; and

[0028] The relay imaging component includes a first relay imaging unit and a second relay imaging unit. The first relay imaging unit is located between the detection micromirror array component and the first detector unit, and is used to relay and amplify j first marking light spots and then input them into the first detector unit. The second relay imaging unit is located between the detection micromirror array component and the second detector unit, and is used to relay and amplify j second marking light spots and then input them into the second detector unit.

[0029] Optionally, also include:

[0030] A first reflecting mirror is located between the projection imaging assembly and the detection imaging assembly, and is used to reflect the j projection light spots onto the substrate; and

[0031] The second reflector is located between the first reflector and the detection imaging assembly, and is used to reflect the j detection light spots into the detection imaging assembly.

[0032] Optionally, the first detector unit outputs j first electrical signals representing the energy of j first marking spots, and the second detector unit outputs j second electrical signals representing the energy of j second marking spots, and the defocus amount ΔZ of the position on the substrate incident by the Kth projection spot is calculated using the following formula: K :

[0033]

[0034] ΔZ K =α K ·S K ;

[0035] Among them, 1≤K≤j; A K is the amplitude of the Kth first electrical signal; B K is the amplitude of the Kth second electrical signal; S K is a demodulated signal of the Kth first electrical signal and the Kth second electrical signal; α K is the defocus value ΔZ calculated in advance and calibrated offline K With the demodulated signal S K The correlation coefficient of .

[0036] The present invention also provides a photolithography machine, comprising the focusing and leveling device.

[0037] In the focusing and leveling device and photolithography machine provided by the present invention, the j projection micromirror groups of the projection micromirror array assembly convert the detection light beam incident thereon into j projection light spots and project them onto the surface of the substrate. The j detection micromirror groups of the detection micromirror array assembly respectively split the j detection light spots to form j first marking light spots and j second marking light spots. The projection micromirror array assembly and the detection micromirror array assembly are spatially synchronously modulated. By changing the size of j and the positions of the j projection micromirror groups and the j detection micromirror groups as needed, the number and position of the projection light spots, the first marking light spots, and the second marking light spots can be changed. This can reduce the process adaptability error caused by the use of different process patterns and process film systems on the surface of the substrate during the measurement process of the focusing and leveling device. Furthermore, when the zero position deviation of the focusing and leveling device is well adjusted, a projection light spot with a smaller spot width can be selected to improve the measurement sensitivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic structural diagram of a focusing and leveling device provided in an embodiment of the present invention;

[0039] Figure 2 A schematic structural diagram of a projection micromirror array assembly and a detection micromirror array assembly provided in an embodiment of the present invention;

[0040] Figure 3a A schematic diagram of a distribution method of m projection micromirrors and m detection micromirror sets when m=3 provided in an embodiment of the present invention;

[0041] Figure 3b A schematic diagram of another distribution method of m projection micromirrors and m detection micromirror sets when m=3 provided in an embodiment of the present invention;

[0042] Figure 4a A diagram showing a deflection mode of the first detection micromirror and the second detection micromirror provided in an embodiment of the present invention;

[0043] Figure 4b A diagram illustrating another deflection mode of the first detection micromirror and the second detection micromirror provided in an embodiment of the present invention;

[0044] Figure 5 Another structural schematic diagram of a projection micromirror array assembly and a detection micromirror array assembly provided in an embodiment of the present invention;

[0045] Figure 6 The embodiment of the present invention provides Figure 2 and Figure 5 Schematic diagram of the demodulated signal in;

[0046] Wherein, the accompanying drawings are marked as follows:

[0047] 101-illumination assembly; 102-projection micromirror array assembly; 102a-projection micromirror group; 1021a-projection micromirror; 102b-projection stray light trap; 103-projection imaging assembly; 104-first reflector; 105-substrate; 106-second reflector; 107-detection imaging assembly; 108-detection micromirror array assembly; 108a-detection micromirror group; 118a-detection micromirror set; 1181a-first detection micromirror; 1182a-second detection micromirror; 108b-detection stray light trap; 109-relay imaging assembly; 109a-first relay imaging unit; 109b-second relay imaging unit; 110-detector assembly; 110a-first detector unit; 110b-second detector unit; 200-projection objective lens;

[0048] L1-the width of the projection micromirror along the measurement direction;

[0049] L2-detects the width of the micromirror along the measurement direction. DETAILED DESCRIPTION

[0050] The following is a more detailed description of the specific embodiments of the present invention with reference to schematic diagrams. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are greatly simplified and not to exact scale, and are only used for the purpose of conveniently and clearly illustrating the embodiments of the present invention.

[0051] Figure 1 This is a schematic diagram of the structure of the focusing and leveling device provided in this embodiment. Figure 1 As shown, the focusing and leveling device provided in this embodiment includes an illumination component 101, a projection micromirror array component 102, a projection imaging component 103, a first reflector 104, a second reflector 106, a detection imaging component 107, a detection micromirror array component 108, a relay imaging component 109 and a detector component 110, which are arranged in sequence along the optical path.

[0052] Please continue reading Figure 1 The lighting assembly 101 can be a broadband gas-phase, liquid-phase, or solid-phase lamp, a gas-phase, liquid-phase, or solid-phase laser, or a semiconductor-excited light source. The lighting assembly 101 is configured to emit a detection beam, which can be an ultraviolet beam, a visible beam, an infrared beam, or a broadband beam that is a mixture of the above three bands. The detection beam can be a preliminarily collimated parallel beam.

[0053] Figure 2 A schematic diagram of the structure of the projection micromirror array assembly 102 and the detection micromirror array assembly 108 provided in this embodiment. Figure 1 and Figure 2 As shown, the projection micromirror array assembly 102 includes i projection micromirror groups 102a and a projection stray light trap 102b.

[0054] Specifically, the detection beam is irradiated across the entire surface of i projection micromirror assemblies 102a, and each projection micromirror assembly 102a is capable of receiving the detection beam. Based on design requirements, j of the i projection micromirror assemblies 102a convert the incident detection beam into j projection spots, which are then projected onto the surface of the substrate 105. Each of the j projection micromirror assemblies 102a projects a corresponding projection spot onto the surface of the substrate 105. The j projection spots are then reflected from the surface of the substrate 105 to form j detection spots. The remaining ij of the i projection micromirror assemblies 102a reflect the incident detection beam into the projection stray light trap 102b, eliminating the stray light.

[0055] Furthermore, 0<j≤i, that is, a portion of the i projection micromirror groups 102a can be selected to convert the incident detection beam thereon into the projection light spot, or all of the i projection micromirror groups 102a can be selected to convert the incident detection beam thereon into the projection light spot. The number and position of the projection light spots can be changed by changing the value of j and the positions of the j projection micromirror groups 102a.

[0056] Each projection micromirror group 102a includes m projection micromirrors 1021a, which collectively convert the incident detection beam into a projection light spot, where m ≥ 1. The projection micromirrors 1021a can be circular or rectangular, and their optical operation can be refractive, reflective, or reflective, without limitation in the present invention.

[0057] Furthermore, each projection micromirror 1021a has a first posture and a second posture. The m projection micromirrors 1021a in the same projection micromirror group 102a are all in the first posture or the second posture. In other words, the m projection micromirrors 1021a in the same projection micromirror group 102a are in the same posture. The projection micromirrors 1021a have different tilt angles in the first and second postures. For example, the tilt angle of the projection micromirror 1021a in the first posture is 10°, while the tilt angle in the second posture is 0°. The projection micromirrors 1021a can be switched between different postures by deflecting them using a circuit. The drive method can be mechanical conduction, electromagnetic force, pneumatics, pressure sensitivity, thermal transmission, or other methods.

[0058] All of the projection micromirrors 1021a in j of the projection micromirror groups 102a in the i projection micromirror groups 102a are in the first posture to convert the detection light beam incident thereon into j of the projection light spots; and all of the projection micromirrors 1021a in the remaining ij of the projection micromirror groups 102a in the i projection micromirror groups 102a are in the second posture to reflect the detection light beam incident thereon into the projection stray light trap 102b for elimination.

[0059] In this embodiment, i=25, that is, the projection micromirror array assembly 102 includes 25 projection micromirror groups 102a, and the 25 projection micromirror groups 102a are arranged in an array of 5 rows and 5 columns; m=1, that is, each projection micromirror group 102a includes one projection micromirror 1021a, and a certain gap exists between the projection micromirrors 1021a of two adjacent projection micromirror groups 102a.

[0060] It should be understood that the projection micromirror array assembly 102 is not limited to having 25 projection micromirror groups 102a, but may also have 1, 2, 3, 5, or 10 projection micromirror groups 102a; the projection micromirror groups 102a are not limited to being distributed in an array, but may also be distributed in a circular, honeycomb, triangular, or single row / column pattern; each projection micromirror group 102a is not limited to having one projection micromirror 1021a, but may also have 2, 5, or 6 projection micromirrors; when each projection micromirror group 102a has multiple projection micromirrors 1021a, a certain gap exists between two adjacent projection micromirrors 1021a, and the multiple projection micromirrors 1021a in each projection micromirror group 102a may be distributed in an array, circular, honeycomb, triangular, or single row / column pattern; the present invention is not limited to the above solutions.

[0061] Please continue reading Figure 1 The projection imaging assembly 103 may include one or more refractive or reflective lenses for relaying and amplifying the j projection light spots. Of course, the projection imaging assembly 103 may also include optical lenses with special adjustment functions, such as wedges, parallel plates, aspherical mirrors, or free-form mirrors, for adjusting the imaging quality of the projection imaging assembly 103. Optionally, the projection imaging assembly 103 may also include an aperture for adjusting the field of view of the j projection light spots.

[0062] The first reflector 104 is used to project the j projection light spots amplified by the projection imaging component 103 onto the surface of the substrate 105 . The j projection light spots are reflected by the surface of the substrate 105 to form j detection light spots.

[0063] The substrate 105 is located below the projection objective lens 200 . The substrate 105 may be a silicon wafer or a surface that requires surface measurement in other precision machining processes.

[0064] Furthermore, the second reflector 106 and the first reflector 104 can be symmetrically distributed on both sides of the projection objective 200 to reflect j detection light spots. The second reflector 106 can bend the light path to reduce the space occupied by the focusing and leveling device.

[0065] The detection imaging assembly 107 may include one or more refractive or reflective lenses for relaying and amplifying the j detection light spots. Of course, the detection imaging assembly 107 may also include optical lenses with special adjustment functions, such as wedges, parallel plates, aspherical mirrors, or free-form mirrors, to adjust the imaging quality of the detection imaging assembly 107. Optionally, the detection imaging assembly 107 may also include an aperture to adjust the field of view of the j detection light spots.

[0066] It should be understood that since the second reflector 106 and the first reflector 104 are symmetrically distributed on both sides of the projection objective lens 200 , the detection imaging component 107 and the projection imaging component 103 are also symmetrically distributed on both sides of the projection objective lens 200 .

[0067] It should be understood that, as an optional embodiment, the second reflector 106 and / or the first reflector 104 may be omitted; and additional optical elements may be added to the optical path to deflect the optical path, which will not be illustrated one by one here.

[0068] Please continue reading Figure 1 and Figure 2 The detection micromirror array assembly 108 includes i detection micromirror groups 108a and a detection stray light trap 108b.

[0069] Specifically, j detection light spots are incident on i detection micromirror groups 108a. The j detection micromirror groups 108a corresponding to the j projection micromirror groups 102a in the i detection micromirror groups 108a respectively split the j detection light spots to form j first marking light spots and j second marking light spots. Each detection micromirror group 108a in the j detection micromirror groups 108a splits the corresponding detection light spot to form one first marking light spot and one second marking light spot. The remaining ij detection micromirror groups 108a in the i detection micromirror groups 108a reflect the incident detection light spots onto them into the detection stray light trap 108b for elimination.

[0070] It can be seen that the detection micromirror array assembly 108 and the projection micromirror array assembly 102 are spatially synchronously modulated. By changing the size of j and the positions of the j detection micromirror groups 108a as needed, the projection light spots with a predetermined number and position can be adaptively split, which can reduce the process adaptability error caused by the use of different process patterns and process film systems on the surface of the substrate 105 during the measurement process of the focusing and leveling device.

[0071] from Figure 2As can be seen in FIG, the i projection micromirror groups 102a and the i detection micromirror groups 108a are distributed in the same manner, both in an array. Moreover, the i detection micromirror groups 108a correspond one-to-one with the i projection micromirror groups 102a, and the positions of the corresponding projection micromirror groups 102a and the detection micromirror groups 108a correspond to each other. For example, Figure 2 The first projection micromirror group 102a in the first row corresponds to the first detection micromirror group 108a in the first row, the second projection micromirror group 102a in the first row corresponds to the second detection micromirror group 108a in the first row, ... the fourth projection micromirror group 102a in the fifth row corresponds to the fourth detection micromirror group 108a in the fifth row, and the fifth projection micromirror group 102a in the fifth row corresponds to the fifth detection micromirror group 108a in the fifth row.

[0072] Please continue reading Figure 2 Each detection micromirror group 108a includes m detection micromirror sets 118a, and each detection micromirror set 118a includes n detection micromirrors distributed along the measurement direction, where n ≥ 2 and is an even number. The detection micromirrors can be circular or rectangular, and their optical operating modes can be refractive, reflective, or reflective, which are not limited in the present invention.

[0073] Furthermore, the n detection micromirrors collectively split the incident detection light spot to form a first marking light spot and a second marking light spot. In the corresponding detection micromirror group 108a and the projection micromirror group 102a, the m detection micromirror sets 118a correspond one-to-one with the m projection micromirrors 1021a. The detection light spot projected by the projection micromirror 1021a is collectively split by the n detection micromirrors in the corresponding detection micromirror set 118a to form a first marking light spot and a second marking light spot.

[0074] In this embodiment, since m=1, each detection micromirror group 108a includes one detection micromirror set 118a. However, this should not be limiting. When m>1, each detection micromirror group 108a includes multiple detection micromirror sets 118a. Furthermore, the positional distribution of the m projection micromirrors 1021a in the projection micromirror group 102a is similar to the distribution of the m detection micromirror sets 118a in the detection micromirror group 108a, such as an array distribution, a circular distribution, a honeycomb distribution, a triangular distribution, or a single row / column distribution.

[0075] Figure 3a Schematic diagram of a distribution mode of m projection micromirrors 1021a and m detection micromirror sets 118a when m=3 provided in this embodiment. Figure 3aAs shown, when m=3, each projection micromirror group 102a has three projection micromirrors 1021a, and each detection micromirror group 108a has three detection micromirror sets 118a. The three projection micromirrors 1021a and the three detection micromirror sets 118a are distributed in an isosceles triangle, wherein the first projection micromirror 1021a in the first row corresponds to the first detection micromirror set 118a in the first row, the second projection micromirror 1021a in the first row corresponds to the second detection micromirror set 118a in the first row, and the first projection micromirror 1021a in the second row corresponds to the first detection micromirror set 118a in the second row.

[0076] Figure 3b Schematic diagram of another distribution mode of m projection micromirrors 1021a and m detection micromirror sets 118a when m=3 provided in this embodiment. Figure 3b As shown, the three projection micromirrors 1021a and the three detection micromirror sets 118a are all distributed in a single row, wherein the first, second, and third projection micromirrors 1021a in a row correspond to the first, second, and third detection micromirror sets 118a in the first row, respectively.

[0077] Please continue reading Figure 1 and Figure 2 In this embodiment, n=2, that is, each of the detection micromirrors 118a has two detection micromirrors distributed along the measurement direction. For the convenience of description, the two detection micromirrors in each of the detection micromirrors 118a are referred to as a first detection micromirror 1181a and a second detection micromirror 1182a. The first detection micromirror 1181a and the second detection micromirror 1182a are a pair of detection micromirrors.

[0078] It should be understood that each detection micromirror set 118a is not limited to having two detection micromirrors, but may also have 4, 8 or 10 detection micromirrors, etc., with a gap between two adjacent detection micromirrors.

[0079] The width L1 of the projection micromirror 1021a along the measurement direction corresponds to the width L2 of the detection micromirror along the measurement direction. Specifically, the width L1 of the projection micromirror 1021a along the measurement direction and the width L2 of the detection micromirror along the measurement direction satisfy the following relationship:

[0080] L1=n·L2.

[0081] Furthermore, each of the detection micromirrors has a third posture, a fourth posture, and a fifth posture. The detection micromirror has different tilt angles in the third posture, the fourth posture, and the fifth posture. For example, the tilt angle of the detection micromirror in the third posture is 10°, the tilt angle in the fourth posture is -10°, and the tilt angle in the fifth posture is 0°. The detection micromirror can be switched to its posture by deflecting the detection micromirror through a circuit. The driving method can be mechanical conduction, electromagnetic force, pneumatic, pressure-sensitive, thermal transmission, etc.

[0082] Half of the detection micromirrors in each detection micromirror set 118a of the j detection micromirror groups 108a corresponding to the j projection micromirror groups 102a are in the third posture, and the other half of the detection micromirrors are in the fourth posture, so as to respectively split the j projection light spots to form j first marking light spots and j second marking light spots; all of the detection micromirrors in the remaining ij detection micromirror groups 108a in the i detection micromirror group 108a are in the fifth posture, so as to reflect the detection light spots incident thereon into the detection stray light trap 108b for elimination.

[0083] Specifically, the detection micromirrors in each detection micromirror set appear in pairs, and two adjacent detection micromirrors in each detection micromirror set in the measurement direction constitute a pair of detection micromirrors. When half of the detection micromirrors in each detection micromirror set 118a of the j detection micromirror groups 108a are in the third posture, and the other half are in the fourth posture, one detection micromirror in each pair of detection micromirrors in the corresponding detection micromirror set 118a is in the third posture, and the other is in the fourth posture. The positions of the detection micromirrors in the third posture in each pair of detection micromirrors correspond, and the positions of the detection micromirrors in the fourth posture in each pair of detection micromirrors correspond. For example, the positions of all the first detection micromirrors 1181a in the detection micromirror set 118a correspond, and the positions of all the second detection micromirrors 1182a correspond. All the first detection micromirrors 1181a in the detection micromirror set 118a are in the third posture, and all the second detection micromirrors 1182a in the detection micromirror set 118a are in the fourth posture.

[0084] Figure 4a A deflection diagram of the first detection micromirror 1181a and the second detection micromirror 1182a provided in this embodiment. Figure 4aAs shown in FIG. 1 , when the first detection micromirror 1181a is in the third posture and the second detection micromirror 1182a is in the fourth posture, the surfaces of the first detection micromirror 1181a and the second detection micromirror 1182a are opposite to each other. In this way, the optical paths of the first marking light spot and the second marking light spot do not cross and do not affect each other.

[0085] Figure 4b FIG. 1 is another deflection diagram of the first detection micromirror 1181a and the second detection micromirror 1182a provided in this embodiment. Figure 4b As shown, when the first detection micromirror 1181a is in the third posture and the second detection micromirror 1182a is in the fourth posture, the surfaces of the first detection micromirror 1181a and the second detection micromirror 1182a are opposite to each other. In this way, the optical paths of the first marking light spot and the second marking light spot intersect, which does not affect the implementation of the present invention.

[0086] Please continue reading Figure 1 The relay imaging assembly 109 includes a first relay imaging unit and a second relay imaging unit. The first relay imaging unit 109a and the second relay imaging unit 109b may include one or more refractive lenses or reflective lenses for relaying and amplifying the j first marker light spots and the j second marker light spots, respectively. Of course, the first relay imaging unit 109a and the second relay imaging unit 109b may also include optical lenses with special adjustment functions, such as wedges, parallel plates, aspherical mirrors, or free-form mirrors, for adjusting the imaging quality of the first relay imaging unit 109a and the second relay imaging unit 109b. Optionally, the first relay imaging unit 109a and the second relay imaging unit 109b may also include apertures for adjusting the field of view of the j first marker light spots and the j second marker light spots.

[0087] The detector assembly 110 includes a first detector unit 110a and a second detector unit 110b. The first detector unit 110a is configured to detect the energy of j first marking light spots and output j first electrical signals representing the energy of the j first marking light spots; the second detector unit 110b is configured to detect the energy of j second marking light spots and output j second electrical signals representing the energy of the j second marking light spots. It should be understood that in order to detect the energy of the j first marking light spots and the j second marking light spots and output the corresponding electrical signals, the first detector unit 110a and the second detector unit 110b may be array or planar array detectors, such as photodiode arrays, CCD arrays, or CMOS arrays.

[0088] It is understood that if the surface of the substrate 105 is uneven, the projection spot projected at a certain location on the surface of the substrate 105 will not be reflected at the optimal focal plane of the projection objective 200, resulting in distortion of the corresponding detection spot and defocusing the substrate 105 at this location. When the detection spot is distorted, the n detection micromirrors that split the detection spot cannot fully receive the detection spot (part of the detection spot is reflected by other detection micromirrors into the detection stray light trap 108b), resulting in different energies of the first and second marking spots generated by the splitting.

[0089] Please continue reading Figure 1 , for the defocus amount ΔZ of the position on the substrate 105 where the Kth (1≤K≤j) projection spot is incident K , which is reflected by the substrate 105 to form the Kth detection spot, the Kth detection spot is split into the Kth first marking spot and the Kth second marking spot, the first detector unit 110a and the second detector unit 110b respectively detect the energy of the Kth first marking spot and the Kth second marking spot and output the Kth first electrical signal and the Kth second electrical signal. According to the amplitude A of the Kth first electrical signal K and the amplitude B of the Kth second electrical signal K The corresponding demodulated signal S can be calculated K :

[0090]

[0091] The defocus amount ΔZ of the position on the substrate 105 incident by the Kth projection spot can be calculated using the following formula: K ::

[0092]

[0093] Among them, α K is the defocus value ΔZ calculated in advance and calibrated offline K With S K The correlation coefficient of .

[0094] Furthermore, α K It can be considered as the reciprocal of the sensitivity coefficient ε, that is:

[0095]

[0096]

[0097] Wherein, d is the spot width of the projection light spot, and θ is the incident angle of the projection light spot onto the substrate 105 .

[0098] Formula (2) can be rewritten as:

[0099]

[0100] As can be seen from formula (5), when the zero deviation of the focusing and leveling device is well adjusted, a smaller projection spot width can be selected, and the projection micromirror array assembly 102 and the detection micromirror array assembly 108 can also be adaptively made into a denser array. The sizes of the projection micromirrors 1021a and the detection micromirrors can be made smaller, or fewer projection micromirrors 1021a and detection micromirrors can be used for projection and light splitting, respectively, thereby improving the measurement sensitivity.

[0101] Figure 5 Another structural diagram of the projection micromirror array assembly 102 and the detection micromirror array assembly 108 provided in this embodiment. When the zero position deviation of the focusing and leveling device is well adjusted, a projection light spot with a smaller light spot width can be selected. Figure 2 and Figure 5 As shown, Figure 2 The width of the projection spot is d, Figure 5 The width of the projection spot is 2d, and adaptively, Figure 5 Each of the projection micromirror groups 102a has four projection micromirrors 1021a, and each of the detection micromirror groups 108a has four detection micromirror groups 118a.

[0102] Figure 6 Provided for this embodiment Figure 2 and Figure 5 Schematic diagram of the demodulated signal in . Figure 6 As shown, assuming that the incident angle θ of the projection light spot on the substrate 105 is constant, for example, 86°, and the spot width of the projection light spot is d, the focus and leveling device has a smaller defocus and higher sensitivity. Therefore, when the zero deviation of the focus and leveling device is well adjusted, a projection light spot with a smaller spot width can be selected to improve measurement sensitivity.

[0103] Based on this, this embodiment also provides a photolithography machine, including the above-mentioned focusing and leveling device.

[0104] In summary, in the focusing and leveling device and lithography machine provided by the embodiments of the present invention, the j projection micromirror groups of the projection micromirror array assembly convert the detection light beam incident thereon into j projection light spots and project the images onto the surface of the substrate. The j detection micromirror groups of the detection micromirror array assembly respectively split the j detection light spots to form j first marking light spots and j second marking light spots. The projection micromirror array assembly and the detection micromirror array assembly are spatially synchronously modulated. By changing the size of j and the positions of the j projection micromirror groups and the j detection micromirror groups as needed, the number and position of the projection light spots, the first marking light spots, and the second marking light spots can be changed. This can reduce the process adaptability error caused by the use of different process patterns and process film systems on the surface of the substrate during the measurement process of the focusing and leveling device. Furthermore, when the zero position deviation of the focusing and leveling device is well adjusted, a projection light spot with a smaller spot width can be selected to improve the measurement sensitivity.

[0105] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. The systems disclosed in the embodiments are described briefly because they correspond to the methods disclosed in the embodiments. For relevant details, refer to the method description.

[0106] It should also be noted that although the present invention has been disclosed above with reference to preferred embodiments, the above embodiments are not intended to limit the present invention. For any person skilled in 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 to modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of protection of the technical solution of the present invention.

[0107] It should also be understood that, unless otherwise specified or indicated, the terms "first", "second", "third", etc. in the specification are only used to distinguish the various components, elements, steps, etc. in the specification, and are not used to indicate the logical relationship or sequential relationship between the various components, elements, steps, etc.

[0108] It should also be understood that the terms described herein are intended to describe particular embodiments only and are not intended to limit the scope of the invention. It should be noted that the singular forms "a" and "an" as used herein and in the appended claims include plural references unless the context clearly indicates otherwise. For example, a reference to "a step" or "a device" means a reference to one or more steps or devices, and may include secondary steps as well as secondary devices. All conjunctions used should be understood in their broadest sense. Also, the word "or" should be understood to have the definition of a logical "or" rather than a logical "exclusive or" unless the context clearly indicates otherwise. Furthermore, implementation of the methods and / or apparatus in embodiments of the present invention may include performing selected tasks manually, automatically, or in combination.

[0109] The above description is merely a preferred embodiment of the present invention and does not limit the present invention in any way. Any person skilled in the art who, without departing from the scope of the present invention, makes any equivalent substitution, modification, or other changes to the technical solution and technical content disclosed in the present invention shall be deemed to be within the scope of the present invention and still fall within the scope of protection of the present invention.

Claims

1. A focusing and leveling device, characterized in that: Including the following arranged in sequence along the light path: an illumination assembly for emitting a detection light beam; A projection micromirror array assembly includes i projection micromirror groups, wherein j projection micromirror groups convert the detection light beam incident thereon into j projection light spots and project the images onto the surface of the substrate, wherein the j projection light spots are reflected by the surface of the substrate to form j detection light spots, wherein 0<j≤i; A detection micromirror array assembly includes i detection micromirror groups, wherein j detection micromirror groups corresponding to j projection micromirror groups respectively split j detection light spots to form j first marking light spots and j second marking light spots; and The detector assembly comprises a first detector unit and a second detector unit, wherein the first detector unit and the second detector unit are respectively used to detect energy of j first marking light spots and energy of j second marking light spots.

2. The focusing and leveling device according to claim 1, wherein: The i projection micromirror groups and the i detection micromirror groups are distributed in the same manner, and the positions of the corresponding projection micromirror groups and the detection micromirror groups correspond to each other.

3. The focusing and leveling device according to claim 1 or 2, characterized in that: Each of the projection micromirror groups includes m projection micromirrors, each of the detection micromirror groups includes m detection micromirror sets, and each of the detection micromirror sets includes n detection micromirrors distributed along a measurement direction, wherein m≥1, n≥2, and n is an even number.

4. The focusing and leveling device according to claim 3, wherein: The position distribution of the m projection micromirrors in the projection micromirror group is the same as the distribution of the m detection micromirror sets in the detection micromirror group, and the positions of the corresponding projection micromirrors correspond to the positions of the detection micromirror sets.

5. The focusing and leveling device according to claim 3, wherein: The width L1 of the projection micromirror along the measurement direction and the width L2 of the detection micromirror along the measurement direction satisfy the following relationship: L1=n·L2.

6. The focusing and leveling device according to claim 3, wherein: The projection micromirror array assembly further includes a projection stray light trap, wherein each of the ij projection micromirror groups reflects the detection light beam incident thereon into the projection stray light trap; and / or, The detection micromirror array assembly further includes a detection stray light trap, and the detection light spots incident on the ij detection micromirror groups are reflected into the detection stray light trap.

7. The focusing and leveling device according to claim 6, wherein: The projection micromirror has a first posture and a second posture, the m projection micromirrors in the same projection micromirror group are all in the first posture or in the second posture, and the tilt angles of the projection micromirror in the first posture and the second posture are different; and All the projection micromirrors in the j projection micromirror groups are in the first posture to convert the detection light beam incident thereon into the j projection light spots, and all the projection micromirrors in the ij projection micromirror groups are in the second posture to reflect the detection light beam incident thereon into the projection stray light trap.

8. The focusing and leveling device according to claim 6, wherein: The detection micromirror has a third posture, a fourth posture, and a fifth posture, and the tilt angles of the detection micromirror in the third posture, the fourth posture, and the fifth posture are all different; and Half of the detection micromirrors in each of the j detection micromirror groups are in the third posture, and the other half are in the fourth posture, so as to respectively split the j projection light spots to form j first marking light spots and j second marking light spots, and all the detection micromirrors in the ij detection micromirror groups are in the fifth state, so as to reflect the detection light spots incident thereon into the detection stray light trap.

9. The focusing and leveling device according to claim 8, wherein: The detection micromirrors in each detection micromirror set appear in pairs, one detection micromirror in each pair of detection micromirrors is in the third posture, and the other is in the fourth posture, and the positions of the detection micromirrors in the third posture in each pair of detection micromirrors correspond to each other, and the positions of the detection micromirrors in the fourth posture in each pair of detection micromirrors correspond to each other.

10. The focusing and leveling device according to claim 9, wherein: The surfaces of the two detection micromirrors in each pair of the detection micromirrors are opposite to or facing away from each other.

11. The focusing and leveling device according to claim 3, wherein: The projection micromirror and the detection micromirror are both circular or rectangular in shape.

12. The focusing and leveling device according to claim 3, wherein: The projection micromirror and the detection micromirror are refractive, reflective or catadioptric micromirrors.

13. The focusing and leveling device according to claim 1, wherein: Also includes: A projection imaging component is located between the projection micromirror array component and the detection micromirror array component, and is used to relay and amplify the j projection light spots and then project them into the substrate; A detection imaging component is located between the projection imaging component and the detection micromirror array component, and is used to relay and amplify the j detection light spots and then inject them into the detection micromirror array component; as well as, The relay imaging component includes a first relay imaging unit and a second relay imaging unit. The first relay imaging unit is located between the detection micromirror array component and the first detector unit, and is used to relay and amplify j first marking light spots and then input them into the first detector unit. The second relay imaging unit is located between the detection micromirror array component and the second detector unit, and is used to relay and amplify j second marking light spots and then input them into the second detector unit.

14. The focusing and leveling device according to claim 13, wherein: Also includes: a first reflecting mirror, located between the projection imaging assembly and the detection imaging assembly, for reflecting the j projection light spots onto the substrate; as well as, The second reflector is located between the first reflector and the detection imaging assembly, and is used to reflect the j detection light spots into the detection imaging assembly.

15. The focusing and leveling device according to claim 1, wherein: The first detector unit outputs j first electrical signals representing the energy of j first marking spots, and the second detector unit outputs j second electrical signals representing the energy of j second marking spots, and the defocus amount ΔZ of the position on the substrate incident by the Kth projection spot is calculated using the following formula: K : ΔZ K =a K ·S K ; Among them, 1≤K≤j; A K is the amplitude of the Kth first electrical signal; B K is the amplitude of the Kth second electrical signal; S K is a demodulated signal of the Kth first electrical signal and the Kth second electrical signal; α K The defocus value ΔZ is pre-calculated and calibrated offline K With the demodulated signal S K The correlation coefficient of .

16. A photolithography machine, characterized in that: The device comprises the focusing and leveling device according to any one of claims 1 to 15.

Images