KR100621623B1 - Blind unit of projection exposure system - Google Patents

Abstract

The present invention relates to a blind unit of a projection exposure system for preventing exposure misses during exposure in a projection exposure system. The blind unit of the present invention includes moving blades for blocking or opening the opening through which the illumination light passes; Drive members respectively supporting said moving blades and moving said moving blades respectively; A blind control member controlling the driving of the driving members so that the moving blades move by a predetermined moving distance; And a detecting member for automatically detecting a moving position of the moving blade, wherein the detecting member includes a sensor for detecting a moving distance of the moving blade, a measured value input from the sensor, and a predetermined value in the blind control member. Comparing unit for comparing the moving distance, the comparison unit characterized in that it comprises an alarm generating unit for generating an alarm when the predetermined moving distance is different.

Description

Blind unit of projection exposure system {BLIND UNIT OF PROJECTION EXPOSURE SYSTEM}

1 is a block diagram of a projection exposure system to which the blind unit of the present invention is applied;

2 shows a blind unit of a projection exposure system according to a preferred embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

112: light source

120: illumination optical system

140: blind unit

142A, 142B: Moving Blade

143: opening

170: reticle stage

180: projection optical system

190: wafer stage

The present invention relates to a blind unit of a projection exposure system, and more particularly to the blind unit of a projection exposure system for preventing exposure misses during exposure in a projection exposure system.

In general, a photoresist in a semiconductor manufacturing process is a photoresist applied on a wafer by irradiating light onto a photo mask on which a circuit pattern to be designed is designed by using a photoresist for a circuit actually required on the wafer. By photosensitive, a desired pattern can be formed on the wafer. And a projection exposure system (stepper) used in such a photo process is a kind of photographic exposure equipment, and is an equipment which reduces and projects the pattern of a photo mask on a wafer using an optical lens, and transfers it. When light from a light source passes through the reticle in the exposure equipment, a pattern engraved on the reticle is formed on the plate, thereby forming the same pattern as the reticle. At this time, one plate is formed with a pattern of the entire circuit required by selectively exposing the fine patterns of several reticles.

Therefore, the blind serves to block unnecessary light so that only the pattern to be exposed to light is formed among the various patterns of the reticle thus needed.

In addition, when exposing a large plate, one large plate must be divided into several exposures. In this case of exposing several times, the patterns of the previously exposed portion and the next exposed portion need to be continuous with each other.

The exposure apparatus includes a blind unit that serves to block unnecessary light so that only the pattern to be exposed is formed on the plate among the various patterns of the required reticle.

In the conventional blind unit, the blinds are adjusted by the stepping motors to determine the exposure range. In this case, the driving range of the blinds is checked only at a regular PM. That is, it carries out by visual confirmation after exposure of a board | substrate manually (it takes about 1 hour). Therefore, there is no management method of the blind unit during the PM period, and thus it is not possible to prevent a process accident due to a poor driving of the stepping motor.

The present invention is to solve such a conventional problem, the object is to provide a blind unit of a new type of projection exposure system that can prevent the process accident in advance by monitoring the movement (driving) range of the blind in real time. It is.

The blind unit of the present invention for achieving the above technical problem is a movable blade for blocking or opening the opening through which the illumination light passes; Drive members respectively supporting said moving blades and moving said moving blades respectively; A blind control member controlling the driving of the driving members so that the moving blades move by a predetermined moving distance; And a detecting member for automatically detecting a moving position of the moving blade.

According to an embodiment of the present invention, the detecting member comprises: a sensor for detecting a moving distance of the moving blade; A comparison unit comparing the measured value input from the sensor with a predetermined moving distance in the blind control unit; The comparison unit includes an alarm generating unit for generating an alarm when the measured value and the predetermined moving distance are different.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed subject matter is thorough and complete, and that the spirit of the present invention to those skilled in the art will fully convey. Portions denoted by like reference numerals denote like elements throughout the specification.

1 and 2 show a blind unit of a projection exposure system according to a preferred embodiment of the present invention.

As shown in FIG. 1, the projection exposure system 100 to which the blind unit of the present invention is applied includes a light source 112, an illumination optical system 120, a reticle stage 20, and a projection optical system. (Projection Optical System) 30, and a wafer stage (Wafer State) 40.

Referring to FIG. 1, the light source 112 for supplying exposure light (illumination light) may be, for example, a KrF excimer laser light source supplying light with a wavelength of 248 nm, or an ArF excimer laser light source supplying light with a wavelength of 193 nm, or It may be a laser beam emitted from a pulsed laser light source such as a high frequency generator of the YAG laser. The substantially parallel laser light emitted from the light source 112 along the Z direction has a rectangular cross section extending elongated along the X direction.

The laser light (hereinafter referred to as illumination light) is enlarged in cross-sectional shape by a beam expander 122 composed of lenses 122a and 122b of the illumination optical system 120 and passes through the light amount variable filter plate 123. The first eye is incident on the first eye group 124A. The light quantity variable filter plate 123 forms a plurality of light amount attenuation filters whose transmittance changes in a step shape around the circumference of the rotating plate, and is ejected by rotating the light amount variable filter plate 123 through the drive motor 125. The light amount of the illumination light to be attenuated can be reduced in a plurality of steps. The drive motor 125 is controlled by the exposure dose control system 160. The exposure amount control system 160 also performs continuous adjustment of the emission timing of the pulsed laser light source 112 and the amount of emitted light via the power supply system 114 for the laser light source.

The exposure amount control system 160 is a control system for making the integrated exposure amount with respect to the wafer w into an appropriate exposure amount. The exposure dose control system 160 may be a main control system which oversees the operation of the entire apparatus, and stores exposure mode determination means and various data for determining the exposure mode (daylight exposure mode or scan exposure mode) and the target integrated exposure mode. It may be a computer including a memory for.

The prieye lens 124B is disposed to be exchanged via the first group of prieye lenses 124A and the prieye lens exchange device 130. The illumination light is deflected by the vibrating mirror 127 via the collimator lens 126 and then incident through the second group of prieye lenses 128A. In the above-mentioned second group of eye-eye lenses 128A, the eye-eye lens 128B is disposed so as to be exchangeable via the eye-eye lens exchange device 130.

In other words, in the present embodiment, the second group of prieye lenses 128A and 128B are used for exposure in a batch exposure method and a scanning exposure method, respectively. Similarly, the first group of prieye lenses 124A and 124B are also used. It is used when performing exposure by a batch system and a scanning exposure system, respectively.

The illumination light passing through the second group of prieye lenses 128A and 17B is collected by the first relay lens 132 to reach the fixed blind (fixed field stop) 134. The fixed blind 134 is retracted out of the optical path of the illumination light 1 via the blind control part 136 by the exposure control system 160 at any time. The illumination light 1 passing through the opening of the fixed blind 134 is incident on the blind unit 140 having two moving blades 142A and 142B, and the opening 143 of the moving blade 143; The illumination light 1 having passed through the exposure range passes through the second relay lens 152 optical path bending mirror 153 and the main condenser lens 154 with a uniform illuminance distribution of the reticle 172 of the reticle stage 170. The illumination area 174 of the bottom surface (pattern surface) of () is illuminated. The image of the pattern in the illumination region 174 of the reticle 172 is projected into the exposure region of the wafer w placed on the wafer stage 190 via the projection optical system 180.

The fixed blind 134 defines a slit-shaped illumination area on the reticle 172 when exposed in the scanning exposure mode. Therefore, in the case of exposing in the batch exposure mode, the fixed blind 134 may be retracted out of the optical path of the illumination light 1 via the blind control unit 136. In the case of exposure in the scanning exposure mode, the pulse illumination light 1 passing through the outside of the light shielding band surrounding the transfer pattern of the reticle 172 at the start and the end of the scanning exposure has a photo on the wafer w. There exists a possibility of photosensitive resist. Therefore, at the start or the end of the scanning exposure, unnecessary movement of the pattern can be prevented by sequentially opening or closing the moving blades 142A and 142B in the scanning direction, respectively, in synchronization with the scanning of the reticle stage and the wafer stage. . That is, it can be said that the moving blades 142A and 142B replace the shutter during the scanning exposure. On the other hand, when exposing in a batch exposure mode, the shape and size of the illumination area on the reticle 172 can be defined by the moving blades 142A and 142B.

In more detail with respect to the blind unit 140 having such a very important function, as shown in Figure 2, the blind unit 140 is two moving blades for blocking or opening the opening through which the illumination light passes. (142A, 142B). The moving blades 142A and 142B have a shape of “┓” corresponding to each other, and a rectangular opening 143 is formed in the center by the combination thereof. The two moving blades 142A and 142B are supported by the driving members 144A and 144B to be moved in a direction perpendicular to the optical axis AX. The driving members 144A and 144B are controlled by the blind control unit 136, and the moving positions of the moving blades 142A and 142B are automatically detected by the detection member 146 in real time.

The detection member 146 may include a sensor 146A for detecting a movement distance of the moving blades 142A and 142B, a measured value input from the sensor 146A, and a predetermined movement distance from the blind control unit 136. The comparator 146B for comparing and the alarm generator 146C for generating an alarm when the measured value and the predetermined moving distance in the comparison unit 146B is different.

If the moving position of the moving blades 142A and 142B is wrong due to a failure of the driving members 144A and 144B, the detection member 146 detects this and generates an alarm.

In the above, the configuration and operation of the blind unit according to the present invention has been shown in accordance with the above description and drawings, but this is only an example, and various changes and modifications are possible without departing from the spirit of the present invention. to be.

As described above, according to the present invention, the moving position of the moving blade is automatically detected in real time, so that a process error due to a malfunction or failure of the driving member can be prevented in advance.

Claims (3)

delete In the blind unit of the projection exposure system: Moving blades for blocking or opening an opening through which the illumination light passes; Drive members respectively supporting said moving blades and moving said moving blades respectively; A blind control member controlling the driving of the driving members so that the moving blades move by a predetermined moving distance; And A detection member for automatically detecting the moving position of the moving blade, The detecting member includes a sensor for detecting a moving distance of the moving blade; A comparison unit comparing the measured value input from the sensor with a predetermined moving distance in the blind control unit; And a warning generating unit for generating an alarm when the measured value and the predetermined moving distance in the comparing unit are different. In the blind unit of the projection exposure system: Moving blades for blocking or opening an opening through which the illumination light passes; Drive members respectively supporting said moving blades and moving said moving blades respectively; A blind control member controlling the driving of the driving members so that the moving blades move by a predetermined moving distance; And A detection member for automatically detecting the moving position of the moving blade, And the opening is square or rectangular in shape.

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