JP4652155B2 - Exposure apparatus and exposure method - Google Patents

Description

  The present invention relates to an exposure apparatus and an exposure method, for example, an exposure apparatus and an exposure method used in a lithography process of a semiconductor substrate.

  2. Description of the Related Art Conventionally, a reduction projection exposure apparatus that projects a predetermined exposure pattern on a substrate to form an exposure pattern has been widely used as an exposure apparatus used in a photolithography process. In the reduced projection exposure apparatus, the area where the pattern can be projected by one exposure is limited. Therefore, by moving the stage that supports the substrate, the exposure area divided on the substrate is sequentially moved to the area where the pattern can be projected. A step-and-repeat method that performs pattern exposure is employed.

Furthermore, in recent years, a scanning exposure apparatus has been proposed in response to a request for further increasing the efficiency and cost of the photolithography process. For example, an exposure apparatus that performs scanning exposure by forming an exposure pattern with a light modulation element (DMD: Digital Micro-mirror Device) that modulates output light of a light source according to pattern information and deflecting it in the main scanning direction with a polygon mirror It has been proposed (Patent Document 1). Such a scanning exposure apparatus employs a method in which an exposure area is moved by scanning light every time one pattern exposure is performed, and the exposure areas divided on the substrate are sequentially exposed.
Special table 2004-514280 gazette

  However, in the above-described scanning exposure apparatus, only one pattern can be exposed with one exposure, and when exposing a plurality of patterns, it is necessary to move the exposure area for each pattern. There was a problem that it took.

  An object of the present invention is to provide an exposure apparatus or an exposure method capable of improving the efficiency of exposure of a plurality of patterns.

  In order to solve the above-mentioned problems, an invention according to claim 1 is an exposure apparatus, wherein an exposure pattern forming unit capable of forming an exposure pattern by operation control, and controlling an operation of the exposure pattern forming unit. A control unit that forms a desired exposure pattern on the exposure pattern forming unit, and a reflection type that branches the exposure pattern into a plurality of exposure patterns that are the same as the exposure pattern, and simultaneously exposes the substrate with the plurality of branched exposure patterns. A diffractive optical element and a deflecting / reflecting means for scanning the exposure pattern on the substrate are provided.

The deflecting / reflecting means according to the first aspect of the present invention is constituted by a galvanometer mirror, and the reflection type diffractive optical element is formed on a mirror surface of the galvanometer mirror.

A second aspect of the present invention is the exposure apparatus according to the first aspect, wherein the exposure pattern forming means is configured such that mirrors having variable angles are arranged in parallel vertically and horizontally, and the angles of the mirrors can be independently controlled. The control means is a spatial light modulation means capable of forming an exposure pattern by the mirror by independently controlling the angle of each of the mirrors.

The invention according to claim 3 is an exposure method, wherein the exposure pattern is scanned on the substrate using a deflecting reflection means for deflecting and reflecting the exposure pattern, and the substrate is exposed by the exposure pattern. The substrate is exposed simultaneously with a plurality of branched exposure patterns by using a reflective diffractive optical element that branches the exposure pattern into a plurality of exposure patterns identical to the exposure pattern.

The invention according to claim 3 is characterized in that a galvano mirror in which the reflection type diffractive optical element is formed on a mirror surface is used as the deflection reflection means.

According to a fourth aspect of the present invention, in the exposure method according to the third aspect, as the exposure pattern forming means, mirrors having variable angles are arranged in parallel vertically and horizontally, and the spatial light modulation means capable of independently controlling the angles of the mirrors. , And the angle of each of the mirrors is independently controlled to form an exposure pattern by the mirrors of the spatial light modulation means.

  According to the first aspect of the present invention, various exposure patterns can be created by the exposure pattern forming means, and the exposure pattern can be quickly exposed by scanning the exposure pattern by the deflecting reflection means. It becomes. Furthermore, since the reflection type diffractive optical element for branching the exposure pattern is provided, a plurality of patterns can be exposed by one exposure, and the number of times of light scanning can be reduced. This makes it possible to increase the exposure efficiency.

According to the first aspect of the present invention, since the reflection type diffractive optical element is formed on the mirror surface of the galvanometer mirror as the deflection reflection means, the deflection reflection means and the reflection type diffractive optical element are integrated. Thus, the space of the exposure apparatus can be saved. Further, it is not necessary to separately use an optical system such as a plurality of lenses between the deflecting / reflecting means and the reflective diffractive optical element, and the configuration of the exposure apparatus is simplified.

According to the second aspect of the present invention, since the exposure pattern forming means is a spatial light modulation means, various exposure patterns can be easily created in a short time. This further increases the efficiency of mask manufacturing.

According to the third aspect of the present invention, it is possible to perform exposure promptly by scanning light using the deflection reflection means. Furthermore, by using a reflection type diffractive optical element for branching the exposure pattern, it is possible to expose a plurality of patterns in one exposure, thereby reducing the number of times of light scanning. This makes it possible to increase the efficiency of the exposure method.

According to the third aspect of the present invention, since the galvanometer mirror having a reflection type diffractive optical element formed on the mirror surface is used as the deflection reflection means, the deflection reflection means and the reflection type diffractive optical element are integrated. Therefore, it is possible to save the space of an apparatus used for exposure. Further, it is not necessary to separately use an optical system such as a plurality of lenses between the deflecting / reflecting means and the reflective diffractive optical element, and the configuration of the apparatus used for exposure is simplified.

According to the fourth aspect of the present invention, since the spatial light modulation means is used as the exposure pattern forming means, various exposure patterns can be easily created in a short time. This further increases the efficiency of mask manufacturing.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an optical system of an exposure apparatus 1 according to this embodiment.

  The exposure apparatus 1 according to this embodiment is a spatial light modulation unit that forms an optical image by modulating output light from a light source 2 (see FIG. 2) according to pattern information as an exposure pattern forming unit. Micro-mirror Device) 3.

  The DMD 3 is formed as a single panel by laying fine mirror elements on a semiconductor element in a lattice pattern, and each mirror independently changes the tilt angle, thereby projecting the output light of the light source 2. Can be turned ON / OFF.

  As the light source 2, a known light source generally used for DMD can be used. For example, a metal halide lamp, a xenon lamp, a halogen lamp, or a light emitting diode can be used.

  In addition to the DMD 3, a semiconductor laser array or a light emitting diode array can be used as the exposure pattern forming means.

  As shown in FIG. 1, in the optical path of light projected from the DMD 3, a collimator lens 4, lenses 5 and 6 constituting a telecentric optical system, diaphragm surfaces 7 and 8, a galvano mirror 9 as a deflecting reflection means, and an image forming unit. A lens 10 is provided.

  The collimator lens 4 shapes the divergent light projected from the DMD 3 into parallel light, and the diaphragm surface 7 narrows the light transmitted through the collimator lens 4. The lenses 5 and 6 constituting the telecentric optical system are arranged so that the rear focal point of the front lens 5 and the front focal point of the rear lens 6 coincide with each other, and a diaphragm surface 8 is provided at this focal position. The size of the image is not changed even if the distance between the lenses 5 and 6 and the image plane is slightly changed.

  The galvanometer mirror 9 moves the principal ray of the output light from the light source 2 in parallel with the optical axis according to the swing angle of the mirror. Thereby, as shown in FIG. 1, the output light from the light source 2 is scanned in the direction from the exposure area (a) to the exposure area (c) on the substrate.

In addition, the galvano mirror 9 of the present embodiment has a reflective diffractive optical element formed on the mirror surface. The reflective diffractive optical element of this embodiment is a DM
It has a function of reflecting the light projected from D3 by branching it into three. Thereby, as shown in FIG. 1, the pattern formed by DMD 3 is branched into three, and the same three patterns are exposed on the substrate at predetermined intervals.

  Here, the reflection type diffractive optical element can also be formed to have a function of branching light into three or more. The function of controlling the direction of light in addition to the branching of light, It is also possible to form so as to have a function of shaping. For example, as light direction control, exposure can be performed so that there is no interval between three patterns. Further, as light shaping, it is possible to shape the light emitted in an elliptical shape into a substantially rectangular or rectangular shape.

  The imaging lens 10 irradiates the pattern projected from the galvanometer mirror 9 onto the substrate supported by the stage. In the present embodiment, a plurality of branched lights are incident on one imaging lens 10, but a plurality of imaging lenses 10 corresponding to each branched light may be provided.

  Next, FIG. 2 shows a functional configuration of the exposure apparatus 1 of the present embodiment.

  As shown in FIG. 2, the exposure apparatus 1 of the present embodiment includes a control device 11.

  The control device 11 includes a control unit 12 as control means for controlling the operation of the DMD 3, and the control unit 12 develops a processing program recorded in the ROM on the RAM and executes the processing program by the CPU. Each component of the exposure apparatus 1 is driven and controlled.

  In addition, the control device 11 includes an input unit 13 composed of a keyboard or a mouse, and the user can input an instruction regarding an exposure pattern. It is also possible to load a recording medium such as a disk in a recording medium loading unit (not shown) provided in the control device 11 and read information on the exposure pattern from the recording medium.

  In addition, the control device 11 includes a storage unit 14 made of a semiconductor memory or the like, and the storage unit 14 has a recording area for recording information relating to an exposure pattern input from the input unit 13. The storage unit 14 may be, for example, a built-in memory such as a flash memory, a removable memory card or a memory stick, or a magnetic recording medium such as a hard disk or a floppy (registered trademark) disk. Good.

  As shown in FIG. 2, a light source 2, a DMD 3, a galvano mirror 9 serving as a deflection reflection means, and a stage driving unit 15 are connected to the control device 11.

  The light source 2 is controlled to be turned ON / OFF by the control unit 12.

  The DMD 3 can form various exposure patterns by changing the tilt angle of the mirror based on the instruction signal of the control unit 12 and turning on the projection of the light of the mirror corresponding to the predetermined exposure pattern. It has become.

  The galvanometer mirror 9 scans the output light of the light source 2 by moving the principal ray of the output light of the light source 2 in parallel with the optical axis according to the swing angle based on the instruction signal from the control unit 12. The exposure area is moved.

  The stage drive unit 15 adjusts the position of light incident on the substrate from the imaging lens 10 by controlling the vertical movement and tilt of the stage that supports the substrate.

  Next, an exposure method using the exposure apparatus 1 according to this embodiment will be described.

  The storage unit 14 of the control device 11 stores the exposure pattern previously input by the user using the input unit 13 or the exposure pattern read from the recording medium using the input unit 13.

  Further, the user supports the substrate on the stage.

  When the exposure is started, the control unit 12 reads a predetermined exposure pattern corresponding to the purpose from the storage unit 14 based on an instruction signal from the input unit 13 or the like.

  Subsequently, when the control unit 12 turns on the light source 2, the output light of the light source 2 is irradiated to the DMD 3. The DMD 3 turns on the projection of the light of the mirror corresponding to the predetermined exposure pattern by changing the tilt angle of the mirror based on the instruction signal of the control unit 12. Thereby, a predetermined exposure pattern is formed by the DMD 3.

  Next, the light projected from the DMD 3 is shaped into parallel light by the collimator lens 4, passes through the diaphragm surface 7, the lenses 5 and 6 constituting the telecentric optical system, and the diaphragm surface 8 and irradiates the galvanometer mirror 9. .

  When the galvanometer mirror 9 is irradiated with light, the reflection type diffractive optical element formed on the mirror surface divides the light into three and reflects it. As a result, as shown in FIG. 1, the exposure pattern formed by the DMD 3 is branched into three, passes through the imaging lens 10, and is irradiated onto the exposure region (a) on the substrate supported by the stage. . Thus, first, the exposure area (a) on the substrate is exposed with three identical patterns with a predetermined interval.

  Subsequently, the galvanometer mirror 9 moves the principal ray of the output light of the light source 2 in parallel with the optical axis according to the swing angle based on the instruction signal from the control unit 12. Thereby, as shown in FIG. 1, the output light of the light source 2 is scanned from the exposure region (a) on the substrate to the exposure region (b). Next, when the exposure area (b) is exposed by three identical patterns with a predetermined interval, the output light of the light source 2 is scanned from the exposure area (b) on the substrate to the exposure area (c). As described above, the galvanometer mirror 9 scans the light every time the three patterns branched by the reflective diffractive optical element are exposed to light, and then, on the substrate in the order of (a), (b), and (c). The exposure area is sequentially exposed.

  As described above, according to the exposure apparatus 1 of the present embodiment, since the DMD 3 is used as the exposure pattern forming unit, various exposure patterns can be easily created in a short time. Further, by scanning light with the galvanometer mirror 9, exposure can be performed quickly. Further, since the reflection type diffractive optical element for branching the exposure pattern into three is provided, it is possible to expose the three patterns with one exposure, and to reduce the number of times of light scanning. Thereby, the exposure can be made highly efficient.

  Further, by forming the reflective diffractive optical element on the mirror surface of the galvano mirror 9, the galvano mirror 9 and the reflective diffractive optical element can be integrated to save space in the exposure apparatus 1. Thereby, it is not necessary to separately use an optical system such as a plurality of lenses between the galvanometer mirror 9 and the reflective diffractive optical element, and the configuration of the exposure apparatus 1 is simplified.

  As described above in detail, according to the exposure apparatus of the present invention, it is possible to increase the efficiency of exposure and reduce the number of scans, and to obtain an exposure apparatus that is highly convenient.

  Further, the space of the exposure apparatus can be saved, and the configuration of the exposure apparatus is simplified.

  Furthermore, since various exposure patterns can be easily created in a short time, the mask manufacturing is further improved in efficiency.

It is a figure which shows the optical system of the exposure apparatus which concerns on embodiment of this invention. It is a block diagram which shows the functional structure of the exposure apparatus which concerns on embodiment of this invention.

DESCRIPTION OF SYMBOLS 1 Exposure apparatus 2 Light source 3 DMD
4 Collimator lenses 5, 6 Lens 7, 8 Aperture surface 9 Galvanometer mirror 10 Imaging lens 11 Controller 12 Controller 13 Input unit 14 Storage unit 15 Stage drive unit

Claims (4)

Exposure pattern forming means capable of forming an exposure pattern by operation control; control means for controlling the operation of the exposure pattern forming means to form a desired exposure pattern on the exposure pattern forming means; and is branched into a plurality of identical exposure pattern and the exposure pattern, the exposure comprising a reflective diffractive optical element for simultaneously exposing a substrate with a plurality of exposure patterns branched, and deflecting reflector means for scanning said exposure pattern on a substrate An exposure apparatus , wherein the deflecting / reflecting means comprises a galvanometer mirror, and the reflection type diffractive optical element is formed on a mirror surface of the galvanometer mirror . In the exposure pattern forming means, mirrors with variable angles are arranged side by side, and the angles of the mirrors can be controlled independently. The control means controls the angles of the mirrors independently, thereby controlling the angles of the mirrors. 2. The exposure apparatus according to claim 1, wherein the exposure apparatus is a spatial light modulator capable of forming an exposure pattern . An exposure method that scans the exposure pattern on a substrate using a deflecting / reflecting unit that deflects and reflects the exposure pattern, and exposes the substrate with the exposure pattern, wherein the exposure pattern is a plurality of exposures identical to the exposure pattern. An exposure method in which a substrate is exposed simultaneously with a plurality of branched exposure patterns by using a reflective diffractive optical element branched into a pattern, wherein the reflective diffractive optical element is formed on a mirror surface as the deflecting reflecting means An exposure method characterized by using a galvanometer mirror . As the exposure pattern forming means, variable angle mirrors are arranged in parallel vertically and horizontally, and spatial light modulation means capable of independently controlling the angles of the mirrors are used, and the angles of the mirrors are independently controlled to control the spatial light. 4. An exposure method according to claim 3, wherein an exposure pattern is formed by the mirror of the modulating means .

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