TWI244716B - Method and device for measuring variation of focal length of projection lens of stepper - Google Patents

Abstract

Disclosed is a device for measuring variation of focal length of a projection lens of a stepper, comprising a light source, a filter, a lens set, a transmittance-modulatable mask set, a projection lens, an analysis system, and a platform. The following steps are taken to proceed with the measurement: (a) using the transmittance-modulatable mask set to provide the same transmittance as the mask for mass production; (b) setting the transmittance-modulatable mask set in the stepper and performing a predetermined number of exposure operation; and (c) using the analysis system to measure the position of focal point of the projection lens in the predetermined number of exposure operations.

Description

1244716 V. Description of the invention (3) ~~-Device for changing the focal length of a mirror, which includes: a light source, a filter, a lens group, a modifiable transmittance mask group, a projection lens, _: analysis system And a platform. One of the features of the present invention is that the masks having the same transmittance are formed when the mask group is formed with a modifiable transmittance, so that the measurement of the projection lens's distance,%, and the amount of heat absorbed by the projection lens can be measured. The amount of exposure heat absorbed during production is the same as measuring the focal length of the projection lens and the transmittance of the projection lens during production. The second feature is that it uses a liquid crystal device as a modifiable and simple illustration: Figure 1 shows A step of projection exposure. The second picture is an overview showing the projection scene and the individualization; the lens ~ the focal length changes after the lens is irradiated by light. The third diagram is an outline showing a focal distance change pattern; Figure 4 of the projection lens in the aircraft is a schematic display of a quantified device. Figure 5 shows the focal length of the projection lens in a stepper. Figure 5 is a schematic analysis of the change in focal length after exposure and exposure. Figures 6A and 6B are spectroscopic masks constituting the adjustable report of the present invention. * The liquid crystal device and the high transmittance are used to schematically show the tenth volume =, photomask group, and another device. The focal length of the projection lens changes in the V-feeder

1244716 V. Description of the invention (4) Symbol description: 2 ~ light source reflector; 4 ~ lens group; 6 ~ projection lens; 8 ~ platform; 15 ~ light source reflector; 30 ~ lens group; 4 2 ~ modifiable Transmittance filter 42b ~ two polarizers; 50 ~ projection lens; 70 ~ platform; 150 ~ light source reflector; 300 ~ lens group; 41 0 ~ modulable transmission filter 44 0 ~ High penetration filter; 600 ~ analysis system;

1 ~ light source; 3 ~ filter; 5 ~ photomask; 7 ~ wafer; 10 ~ light source; 20 ~ filter; 40 ~ adjustable transmittance mask group 42a ~ liquid crystal device; 44 ~ high penetration Transmittance mask; 6 0 ~ analysis system; 100 ~ light source; 2000 ~ filter; 400 ~ adjustable transmittance mask group 420 ~ aperture; 500 ~ projection lens; 700 ~ platform . Explanation of the embodiment: In the embodiment of the present invention, FIG. 4 schematically shows a device for measuring a change in a focal length of a projection lens in a stepper. As shown in FIG. 4, regarding the present invention, a device for measuring the focal length change of a projection lens in a stepper includes: a light source 10, a filter 20, a lens group 30, and a modifiable lens. Transmittance light

1244716 Source reflection 10 Light Modulation transmittance and quantity Exposure wave Light wavelength and exposure time, through projection value. When the lens 50 stepper cover 15 is anti-line, the transmittance of the long light beam through the light beam, the wavelength of light passes through the above lens 50, the analysis system is on the hot projection cover 15, 20. The exposure wave can be adjusted at the same rate, and can be modulated to adjust the photometric mask at the time of penetration. Platform 70 Sequential measurement Focus value At this time, it changes. V. Description of the invention (5) It may further include a light source reflecting the cover group 40 of a predetermined wavelength of the filter, so that the penetration of the light cover is guided to the above-mentioned adjustable beam, and the mass-transmittable transmission shadow can be set in the setting. The system 60 can read the equilibrium state according to the system 60. The focal length of the lens allows another part of the light to pass through the light filter 20 to filter the long beam from the light source. The transmission of the above-mentioned transmittance mask group 40 is modulated, and then the transmittance mask group 40 is put on the lens group 30. The light intensity after removing the photomask group 40 is the same as the light intensity after the mask. The mask pattern of the connector 40 is passed through the analysis system 60 described above. Each time the focal length of the above-mentioned projection lens 50 does not change, it means that the projection can stop exposure or stop measuring. In the measurement method of the present invention, the modulation transmittance of the transmittance mask and the group 40 is first modulated so that The adjustable transmittance mask group forms the same transmittance as that of the mask during mass production. Furthermore, the exposure intensity of the projection lens 50 after passing through the tunable transmittance mask group 40 is the same as that of the mask during mass production. Next, the above-mentioned modifiable transmittance mask group 40 is set to perform 1¾ exposures n times in a stepper. The analysis system 60 sequentially measures the change in focal length of the projection lens 50 after n exposures and displays it in the fifth figure. As shown in Figure 5, the i-th focal length of the projection lens during the i-th exposure

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0503-6234TW; TSMC2001-0032; J a s pe r. P t d p. 8

Claims (1)

! 244716 Scope of patent application 1. A measuring stepper includes: a device for changing a focal length of a middle projection lens, a light source, a filter for exposure wavelength light, a lens, an adjustable and a photomask, a modulation transmittance to modulate the modifiable beam; an analysis A projection system, in which the pattern beam of the mask 2. The focal length of the Rushen mirror changes the modulation transmittance 3. The focal length of the Rushen mirror changes the cover, so that the focal length of the 4 Rushen mirror is changed to provide a beam; Pass; set; transmittance light, wherein the translucent cover group, through the transmittance mask transmittance element system; lens, receive 'the analysis system to measure the projection of the patented device, filter, The light asks for a patented device, and the portion of the light is borrowed from the patented device. The light beam from the light source makes a wavelength of a predetermined wavelength, including a modifiable transmittance element. Guide to the transmittance which can modulate one of the modifiable transmittance tuples, and then warm the t Λ + light wavelength beam through the mask, and form a mask pattern light and the mask pattern beam projection To this analysis system, the mask pattern beam is received, and a focal length position from the main lens is obtained. In the measurement stepping machine according to the first item, the projection transmittance is a mask capable of being a high transmittance mask. The measurement stepper according to item 1, wherein the light source further includes a light source reflection, and the light source reflection cover reflects the light to the filter. Projection through in the measurement stepper described in item 2 0503-6234TWFl.ptc Page 11 1244716 Amendment _Case No. 901174Π Only 6. The scope of patent application includes an aperture. The projection transmittance mask set in the measurement stepper described in the mirror ^, ^ ^ ^ ^ ^ 2 = = the transmittance makes the above-mentioned modifiable penetration = 'by changing two polarizers;] = = 々 The mirror system's two first cover groups have a modifiable transmittance. The angle can be modulated by the above-mentioned modulation. A method of measuring the projection through a stepper is described in the following steps. The method of changing the focal length of the lens, the package (a) uses a modulating penetration cover with the same penetration. The Yangxian mask group is formed with a light called mass production — (^ i will expose the above-mentioned modifiable transmittance mask 4a, M, A to a large number of exposures; and, and σ is also placed on a stepper machine. Perform (C) use an analysis of the focal length position of the shadow lens. ',,,, to measure the change in the focal length of this predetermined number of exposures, such as the method described in the patent application, and the measuring step described in the item In the machine, you can adjust 9: r transmittance mirror and -transmittance mask 9. If the patent application Fanyuan No. 8 transmittance first mask. The square of the focal length of the mirror changes. = Place the cover first by changing the liquid crystal device: pass through transparent; make ^^ The transmittance of the first cover group is formed to have the same rate as =, so that the above-mentioned cover can have the same transmittance. 牙 0503-6234TWF1. Ρί0 Page 12 1244716 ·. _Case No. 90117408, Year / Month > -Day__ VI. Patent Application Range 1 〇 As described in item 8 of the patent application range Method for measuring a focal length change of a projection lens in a stepper, wherein the above-mentioned tunable transmittance filter is two polarizers, and the above-mentioned tunable transmittance light is changed by changing an included angle between the two polarizers The mask group is formed to have the same transmittance as a mass production mask. 0503-6234TWFl.ptc Page 13 < 12447 ϊ6〇117408 Schematic correction page Revision date: 94.2.22 η Figure 5 1244716 Corrected sample 1 Figure 6A Figure 6B Figure 1244716-Case No. 90117408 〇, the Chinese invention invented the stepping machine to measure the focal length of the projection lens f * a filter, a lens group, a modifiable package, and a projection lens , An analysis system, and a flat A σ, tooth, and reticle steps to measure the change in focal length ... (a) using a corrugated ray and having the same penetration rate as a mass-produced photomask; The b ° dental permeability mask set is set in a stepper for a predetermined number of times: the above-mentioned modifiable penetration uses an analysis system to measure this predetermined number of times = exposure separately; and (c) the focal length position. " (1) of the projection lens at light time, the representative picture of this case is ... Figure 4 (b), the component symbols of the representative picture of the case are briefly explained _ 10 ~ light source; 15 ~ light is the English abstract of the invention (name of the invention :) " " " ', page 2-1 0503-6234TWF2.ptc 2005.07.01.002