US20090303454A1

US20090303454A1 - Exposure apparatus with a scanning illumination beam

Info

Publication number: US20090303454A1
Application number: US12/481,326
Authority: US
Inventors: Michael B. Binnard; Douglas C. Watson; Daniel Gene Smith; David M. Williamson
Original assignee: Nikon Corp
Current assignee: Nikon Corp
Priority date: 2008-06-10
Filing date: 2009-06-09
Publication date: 2009-12-10
Also published as: US20090305171A1; US20090316131A1; US8305559B2

Abstract

An exposure apparatus (10) for transferring a mask pattern (358) from a mask (12) to a substrate (14) includes a mask retainer (44), a substrate stage assembly (24), and an illumination system (18). The mask retainer (44) retains the mask (12). The substrate stage assembly (24) retains and positions the substrate (14). The illumination system (18) generates an illumination beam (31) that moves along a beam scan axis (35) relative to the mask (12) to scan at least a portion of the mask pattern (358). The beam scan axis (35) is substantially parallel to the mask pattern (358). The illumination system (18) can include an illumination source (32) that generates the illumination beam (31) and an illumination optical assembly (34) that guides the illumination beam (31). The illumination optical assembly (34) moves the illumination beam (31) relative to the mask (12) so that the illumination beam (31) scans substantially the entire mask pattern (358). The illumination optical assembly (34) can further include an illumination reflector (36) that is incident on the illumination beam (31), and the illumination reflector (36) can be selectively moved to move the illumination beam (31) along the beam scan axis (35).

Description

RELATED APPLICATIONS

This application claims priority on U.S. Provisional Application Ser. No. 61/060,411, filed Jun. 10, 2008 and entitled “SYSTEM ARCHITECTURE FOR ACHIEVING HIGHER SCANNER THROUGHPUT”; on U.S. Provisional Application Ser. No. 61/078,251, filed Jul. 3, 2008 and entitled “HIGH NA CATADIOPTRIC PROJECTION OPTICS FOR IMAGING TWO RETICLES ONTO ONE WAFER”; on U.S. Provisional Application Ser. No. 61/078,254 filed on Jul. 3, 2008 and entitled “X-SCANNING EXPOSURE SYSTEM WITH CONTINUOUS EXPOSURE”; and on U.S. Provisional Application Ser. No. 61/104,477 filed on Oct. 10, 2008. As far as is permitted, the contents of U.S. Provisional Application Ser. Nos. 61/060,411, 61/078,251, 61/078,254 and 61/104,477 are incorporated herein by reference.

BACKGROUND

Exposure apparatuses for semiconductor processing are commonly used to transfer features from a reticle onto a semiconductor wafer during semiconductor processing. A typical exposure apparatus includes an illumination source, a reticle stage assembly that positions a reticle, an optical assembly, and a wafer stage assembly that positions a semiconductor wafer. Typically, the wafer is divided into a plurality of rectangular shaped integrated circuits.
There are two kinds of exposure apparatuses that are generally known and currently used. The first kind is commonly referred to as a Stepper lithography system. In a Stepper lithography system, the reticle is fixed (except for slight corrections in position) and the wafer stage assembly moves the wafer to fixed chip sites where the illumination source directs an illumination beam at an entire reticle pattern on the reticle. This causes the entire reticle pattern to be exposed onto one of the chip sites of the wafer at one time. At the time of exposure, the reticle and the wafer are stationary. After the exposure, the wafer is moved (“stepped”) to the next site for subsequent exposure. In this type of system, the throughput of the apparatus is largely governed by how quickly the wafer stage assembly accelerates and decelerates the wafer between exposures during movement between sites.
The second kind of system is commonly referred to as a Scanner lithography system. In a Scanner lithography system, the reticle stage assembly moves the reticle concurrently with the wafer stage assembly moving the wafer during the exposure process. With this system, the illumination beam is slit shaped and illuminates only a portion of the reticle pattern on the reticle. With this design, only a portion of the reticle pattern is exposed and transferred to the site on the wafer at a given moment, and the entire reticle is exposed and transferred to the site on the wafer over time as the reticle pattern is moved through the exposure slit. After the entire site is exposed, (i) the wafer stage assembly decelerates the wafer and subsequently accelerates the wafer in the opposite direction during movement of the wafer to the next site, and (ii) the reticle stage assembly decelerates the reticle and subsequently accelerates the reticle in the opposite direction so that the reticle is moving in the opposite direction during the exposure of the next site. In this type of system, the throughput of the apparatus is largely governed by how quickly the wafer stage assembly accelerates and decelerates the wafer, and how quickly the reticle stage assembly accelerates and decelerates the reticle.
There is a never ending search to increase the throughput in terms of exposures per hour for the exposure apparatuses. With the current exposure apparatuses, assuming that there is sufficient light to adequately expose the wafer, in order to gain higher throughput, it is necessary to move the wafer and/or reticle at higher speeds, and accelerations. Unfortunately, it is not always easy to merely increase the velocities and accelerations of the wafer and the reticle.

SUMMARY

The present invention is directed to an exposure apparatus for transferring a mask pattern from a mask to a substrate. The exposure apparatus includes a mask retainer, a substrate stage assembly, an illumination system, and a projection optical assembly. The mask retainer retains the mask. The substrate stage assembly retains and positions the substrate. The illumination system generates an illumination beam that moves relative to the mask to scan at least a portion of the mask pattern. The projection optical assembly receives a pattern beam and directs the pattern beam at the substrate along a stationary projection outlet axis.
With this design, in certain embodiments, the throughput of the exposure apparatus can be increased because the mask is not being moved and/or the mask is being moved at a slower rate during exposure. Thus, the throughput is not as tied to the acceleration limitations of a mask stage assembly.
In some embodiments, the illumination system includes an illumination source that generates the illumination beam and an illumination optical assembly that guides the illumination beam. In such embodiments, the illumination optical assembly moves the illumination beam relative to the mask so that the illumination beam scans substantially the entire mask pattern. Additionally, in one embodiment, the illumination optical assembly further includes an illumination reflector and the illumination beam is incident on the illumination reflector, and an illumination reflector mover that selectively moves the illumination reflector so that the illumination beam is moved along the beam scan axis.
In certain embodiments, the illumination optical assembly includes a plurality of illumination inlet elements that are aligned along an illumination inlet axis and a plurality of illumination outlet elements that are aligned along an illumination outlet axis. In one such embodiment, the illumination outlet axis is different than the illumination inlet axis. For example, the illumination inlet axis can be approximately perpendicular to the illumination outlet axis. Further, the illumination beam is directed at and passes through the illumination inlet elements, and is subsequently redirected by the illumination reflector at the illumination outlet elements. In one embodiment, the illumination reflector redirects the illumination beam approximately ninety degrees.
In one embodiment, the substrate stage assembly positions the substrate along the substrate scan axis. Additionally, in certain embodiments, the exposure apparatus can include a mask stage assembly that moves the mask relative to the substrate along the scan axis.
The pattern beam is created by the illumination beam on the mask pattern. The projection optical assembly can include a projection reflector that is positioned so that the pattern beam is incident on the projection reflector, and a projection reflector mover. The projection reflector mover selectively moves the projection reflector so that the pattern beam exits the projection optical assembly at a stationary projection outlet used field.
In certain embodiments, the projection optical assembly includes a plurality of projection inlet elements that are aligned along a projection inlet axis and a plurality of projection outlet elements that are aligned along a projection outlet axis. In one such embodiment, the projection outlet axis is at an angle (e.g. substantially perpendicular) relative to the projection inlet axis. The pattern beam is directed at and passes through the projection inlet elements, and is subsequently redirected by the projection reflector at the projection outlet elements. In one embodiment, the projection reflector redirects the pattern beam approximately ninety degrees.
The present invention is further directed to a method for transferring a mask pattern from a mask to a substrate, a method for making an exposure apparatus, and a method of manufacturing a wafer with the exposure apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which:

FIG. 1 is a schematic illustration of an exposure apparatus having features of the present invention;

FIG. 2 is a simplified illustration of a substrate exposed by the apparatus of FIG. 1;

FIG. 3A is a simplified side illustration of the illumination system, the projection optical assembly, a mask and a portion of the substrate at the start of an exposure of a first site;

FIG. 3B is a simplified side illustration of the illumination system, the projection optical assembly, the mask and a portion of the substrate near the middle of the exposure of the first site;

FIG. 3C is a simplified side illustration of the illumination system, the projection optical assembly, the mask and a portion of the substrate near the end of the exposure of the first site;

FIG. 4A is a simplified top illustration of the mask and a portion of the substrate in a side-by-side arrangement at the start of the exposure of the first site;

FIG. 4B is a simplified top illustration of the mask and a portion of the substrate in a side-by-side arrangement near the middle of the exposure of the first site;

FIG. 4C is a simplified top illustration of the mask and a portion of the substrate in a side-by-side arrangement near the end of the exposure of the first site;

FIG. 5 is a simplified side illustration of another embodiment of a mask and a portion of the substrate at the start of an exposure of a first site;

FIG. 6 is a simplified side illustration of yet another embodiment of a mask and a portion of the substrate at the start of an exposure of a first site;

FIG. 7 is a simplified illustration of one embodiment of an illumination source, an illumination optical assembly and a mask;

FIG. 8 is a simplified illustration of one embodiment of a mask, a projection optical assembly, and a substrate;

FIGS. 9A and 9B illustrate one embodiment of a reflector having features of the present invention;

FIGS. 10A and 10B illustrate another embodiment of a reflector having features of the present invention;

FIG. 11A is a flow chart that outlines a process for manufacturing a device in accordance with the present invention; and

FIG. 11B is a flow chart that outlines device processing in more detail.

DESCRIPTION

FIG. 1 is a schematic illustration of a precision assembly, namely an exposure apparatus 10 that transfers features from a mask 12 to a substrate 14 such as a semiconductor wafer that includes a plurality of sites 15. The design of the exposure apparatus 10 can be varied to achieve the desired throughput, and quality and density of the features on the substrate 14. In FIG. 1, the exposure apparatus 10 includes an apparatus frame 16, an illumination system 18 (irradiation apparatus), a projection optical assembly 20, a mask stage assembly 22, a substrate stage assembly 24, a measurement system 26, and a control system 28. Further, the exposure apparatus 10 mounts to a mounting base 30, e.g., the ground, a base, or a floor, or some other supporting structure.
As an overview, in certain embodiments, the illumination system 18 generates an illumination beam 31 that scans the mask 12 while the substrate stage assembly 24 is moving the substrate 14. With this design, the mask 12 can be scanned without moving the mask 12, or the mask 12 can be scanned while the mask 12 is moved at a slower rate. This eliminates or reduces the acceleration requirements of the mask stage assembly 22. This can allow for higher overall throughput for the exposure apparatus 10.
A number of Figures include an orientation system that illustrates an X axis, a Y axis that is orthogonal to the X axis, and a Z axis that is orthogonal to the X and Y axes. It should be noted that any of these axes can also be referred to as the first, second, and/or third axes.
The exposure apparatus 10 discussed herein is particularly useful as a photolithography system for semiconductor manufacturing that transfers features from a reticle (the mask 12) to a wafer (the substrate 14). However, the exposure apparatus 10 provided herein is not limited to a photolithography system for semiconductor manufacturing. The exposure apparatus 10, for example, can be used as an LCD photolithography system that exposes a liquid crystal display device pattern onto a rectangular glass plate or a photolithography system for manufacturing a thin film magnetic head.
A discussion on a multiple mask exposure system is disclosed in concurrently filed application Ser. No. ______, entitled “EXPOSURE APPARATUS THAT UTILZES MULTIPLE MASKS” (PA1017-00/4990/Roeder Ref. No.11269.156), which is assigned to the assignee of the present invention, and is incorporated by reference herein as far as permitted.
An additional discussion regarding another type of exposure apparatus is disclosed in concurrently filed application Ser. No. ______, entitled “APPARATUS FOR SCANNING SITES ON A WAFER ALONG A SHORT DIMENSION OF THE SITES” (PAO1016-00/04959/Roeder Ref. No. 11269.151), which is assigned to the assignee of the present invention, and is incorporated by reference herein as far as permitted.
Yet another exposure apparatus is disclosed in concurrently filed application Ser. No. ______, entitled “Optical Imaging System and Method for Imaging Up to Four Reticles to a Single Imaging Location” (PAO1041-00/045004/Oremland Ref. No. 6162.118US), which is assigned to the assignee of the present invention, and is incorporated by reference herein as far as permitted.
The apparatus frame 16 is rigid and supports the components of the exposure apparatus 10. The apparatus frame 16 illustrated in FIG. 1 supports the mask stage assembly 22, the projection optical assembly 20, the illumination system 18, and the substrate stage assembly 24 above the mounting base 30. Alternatively, one or more of these components can be independently suspended.
The illumination system 18 includes an illumination source 32 and an illumination optical assembly 34. The illumination source 32 emits an illumination beam 31 (irradiation) of light energy. The illumination optical assembly 34 directs and guides the illumination beam 31 from the illumination source 32 to near the mask 12. Further, in certain embodiments, the illumination optical assembly 34 scans and moves the illumination beam 31 relative to the mask 12. In the embodiment illustrated in FIG. 1, the illumination optical assembly 34 moves the illumination beam 31 along a beam scan axis 35 (e.g. the Z axis in FIG. 1 and parallel to a mask pattern on the mask 12) during the exposure of each site 15. In one non-exclusive embodiment, the illumination optical assembly 34 includes an illumination reflector 36 (illustrated in phantom) that is selectively movable so that the illumination beam 31 scans the mask 12.
In certain embodiments, the illumination optical assembly 34 includes an illumination optical assembly inlet 34I and an illumination optical assembly outlet 34O, wherein the illumination beam 31 enters the illumination optical assembly 34 at the illumination optical assembly inlet 34I and the illumination beam 31 exits the illumination optical assembly 34 at the illumination optical assembly outlet 34O. In the embodiment illustrated in FIG. 1, in this embodiment, the illumination beam 31 always enters the illumination optical assembly inlet 34I at the same location, whereas the illumination beam 31 exits the illumination optical assembly outlet 34O from a plurality of alternative locations, depending upon the orientation of the illumination reflector 36.
As used herein, an illumination field of view of the illumination optical assembly 34 is the illuminated portion (slit) of the mask 12. In this embodiment, the illumination field of view of the illumination optical assembly 34 scans the mask 12 (e.g. is moving relative to the mask 12) during the transfer of the mask pattern to the substrate 14.
In the embodiment illustrated in FIG. 1, the illumination beam 31 is initially directed in a generally downward direction along the Z axis. Subsequently, the illumination beam 31 strikes the surface of the illumination reflector 36 from where the illumination beam 31 is redirected at an angle (e.g. approximately 90 degrees in FIG. 1) so that the illumination beam 31 is now directed substantially transversely along the Y axis toward the mask 12. Alternatively, the illumination optical assembly 34 can be designed so that the angle is different than 90 degrees, and/or the illumination beam 31 can be directed and/or redirected toward the mask 12 in another manner.
The illumination beam 31 illuminates the mask 12 to generate a pattern beam 38 (e.g. images from the mask 12) that exposes the substrate 14. In one embodiment, the illumination beam 31 is generally slit shaped and illuminates only a portion of the mask 12 at any given moment. Similarly, the pattern beam 38 is generally slit shaped and exposes only a portion of the substrate 14 at any given moment.
In FIG. 1, the mask 12 is at least partly transparent, and the illumination beam 31 is transmitted through a portion of the mask 12. Alternatively, the mask 12 can be reflective, and the illumination beam 31 can be directed at the pattern surface of the mask 12 such that the pattern beam 38 reflects off of the mask 12.
The illumination source 32 can be a g-line source (436 nm), an i-line source (365 nm), a KrF excimer laser (248 nm), an ArF excimer laser (193 nm), an F₂laser (157 nm), or an EUV light source (13 nm). Alternatively, the illumination source 32 can generate charged particle beams such as an electron beam.
The projection optical assembly 20 projects and/or focuses the pattern beam 38 from the mask 12 to the substrate 14. Depending upon the design of the exposure apparatus 10, the projection optical assembly 20 can magnify or reduce the pattern beam 38. In one non-exclusive embodiment, the projection optical assembly 20 reduces the pattern beam 38 by a reduction factor of four. As a result thereof, during the exposure of a site 15, in certain embodiments, the illumination beam 31 must scan the mask 12 at a rate that is four times greater than which the substrate stage assembly 24 moves the substrate 14.
In certain embodiments, the projection optical assembly 20 includes a projection optical assembly inlet 20I and a projection optical assembly outlet 20O, wherein the pattern beam 38 enters the projection optical assembly 20 at the projection optical assembly inlet 20I and the pattern beam 38 exits the projection optical assembly 20 at the projection optical assembly outlet 20O. In the embodiment illustrated in FIG. 1, the pattern beam 38 enters the projection optical assembly 20 at different positions relative to the mask 12, and the pattern beam 38 exits the projection optical assembly 20 at substantially the same position. Stated another way, in this embodiment, the pattern beam 38 enters the projection optical assembly inlet 20I at a plurality of alternative locations, depending upon the orientation of the illumination reflector 36, and the pattern beam 38 exits the projection optical assembly outlet 20O at the same, stationary location.
As used herein, a projection field of view of the projection optical assembly 20 is the illuminated portion (slit) of the substrate 14. In this embodiment, the projection field of view of the projection optical assembly 20 is stationary and the substrate 14 is moved relative to the stationary projection filed of view during the transfer of the mask pattern to the substrate 14.
In one non-exclusive embodiment, the projection optical assembly 20 includes a projection reflector 40 (illustrated in phantom) that is selectively movable so that the moving pattern beam 38 exits the projection optical assembly 20 at the same location. In the embodiment illustrated in FIG. 1, the pattern beam 38 is initially directed in a generally transverse direction along the Y axis toward the projection optical assembly 20. Subsequently, the pattern beam 38 strikes the surface of the projection reflector 40 from where the pattern beam 38 is redirected at an angle (approximately 90 degrees in FIG. 1) so that the pattern beam 38 is now directed in a generally downward direction along the Z axis toward the substrate 14. Alternatively, the projection optical assembly 20 can be designed so that the angle is different than 90 degrees.
The mask stage assembly 22 holds the mask 12, and in certain embodiments, positions the mask 12. For example, in the embodiment in which the mask 12 is scanned without moving the mask 12, the mask stage assembly 22 can be used to make slight corrections to the position of the mask 12. Alternatively, in the embodiment in which the mask 12 is scanned while the mask 12 is moved at a slower rate, the mask stage assembly 22 can be used to move the mask 12 along a mask scan axis 42 (e.g. the Z axis in FIG. 1). The mask stage assembly 22 can include (i) a mask retainer 44 having a chuck (not shown) for holding the mask 12, and (ii) a mask stage mover assembly 46 that moves and positions the mask retainer 44 and the mask 12. For example, in the embodiment illustrated in FIG. 1, the mask stage mover assembly 46 can move the mask retainer 44 and the mask 12 along the Z axis, along the X axis, and about the Y axis. Alternatively, for example, the mask stage mover assembly 46 could be designed to move the mask retainer 44 and the mask 12 with more than three degrees of freedom, or less than three degrees of freedom. For example, the mask stage mover assembly 46 can include one or more linear motors, rotary motors, planar motors, voice coil actuators, or other type of actuators.
The substrate stage assembly 24 holds and positions the substrate 14 with respect to the pattern beam 38. The substrate stage assembly 24 can include (i) a substrate stage 48 having a chuck (not shown) for holding the substrate 14, and (ii) a substrate stage mover assembly 50 that moves and positions the substrate stage 48 and the substrate 14. For example, in the embodiment illustrated in FIG. 1, the substrate stage mover assembly 50 can move the substrate stage 48 and the substrate 14 along the Y axis, along the X axis, and about the Z axis. Alternatively, for example, the substrate stage mover assembly 50 could be designed to move the substrate stage 48 and the substrate 14 with more than three degrees of freedom, or less than three degrees of freedom. For example, the substrate stage mover assembly 50 can include one or more linear motors, rotary motors, planar motors, voice coil actuators, or other type of actuators. In the embodiment illustrated in FIG. 1, the substrate stage mover assembly 50 moves the substrate 14 along the first axis (e.g. the Y axis) during scanning of the sites 15 and moves the substrate 14 along the second axis (e.g. the X axis) while stepping in between scanning of the sites 15.
The measurement system 26 monitors movement of the mask 12 and the substrate 14 relative to the projection optical assembly 20 or some other reference. Further, the measurement system 26 can include one or more sensors (not shown) that monitor the position of the reflectors 36, 40. With this information, the control system 28 can control the mask stage assembly 22 to precisely position the mask 12, and the substrate stage assembly 24 to precisely position the substrate 14. Further, the control system 28 can precisely control the position of the reflectors 36, 40. For example, the measurement system 26 can utilize multiple laser interferometers, encoders, and/or other measuring devices.
The control system 28 is connected to the illumination system 18, the projection optical assembly 20, the mask stage assembly 22, the substrate stage assembly 24, and the measurement system 26. The control system 28 receives information from the measurement system 26, and controls the illumination system 18, the projection optical assembly 20, and the stage assemblies 22, 24 to precisely position the mask 12 and the substrate 14 and expose the sites 15. The control system 28 can include one or more processors and circuits. In FIG. 1, the control system 28 is illustrated as a single unit. It should be noted that in alternative embodiments the control system 28 can be designed with multiple, spaced apart controllers.
FIG. 2 is a simplified top view of one non-exclusive embodiment of a substrate 14 that has been processed with the exposure apparatus 10 of FIG. 1. In this embodiment, the substrate 14 is a generally disk shaped, thin slice of semiconductor material, e.g. a semiconductor wafer, that serves as a substrate for photolithographic patterning. Typically, the disk shaped substrate 14 is divided into a plurality of rectangular shaped sites 15 (e.g. chips) that are organized into a plurality of rows (along the X axis) and channels (along the Y axis). As used herein the term “site” shall mean an area on the substrate 14 in which the entire or a portion of the mask pattern has been transferred. For example, for a semiconductor wafer, each site 15 is one or more integrated circuits that include a number of connected circuit elements that were transferred to the substrate 14 by the exposure apparatus 10 of FIG. 1. In this example, each site 15 contains one or more integral die piece(s) that can be sliced from the wafer.
The size of the substrate 14 and the number of sites 15 on the substrate 14 can be varied. For example, the substrate 14 can have a diameter of approximately three hundred millimeters. Alternatively, the substrate 14 can have a diameter that is greater than or less than three hundred millimeters and/or the substrate 14 can have a shape that is different than disk shaped (e.g. rectangular shaped). For example, the substrate 14 can have a diameter of four hundred fifty millimeters.
In one embodiment, each site 15 is generally rectangular shaped and has a first site dimension 15A (measured along the X axis) that is less than a second site dimension 15B (measured along the Y axis). In one non-exclusive embodiment, each site 15 has a first site dimension 15A of approximately twenty-six (26) millimeters, and a second site dimension 15B of approximately thirty-three (33) millimeters. Alternatively, for example, each site 15 can have a first site dimension 15A that is greater than or less than twenty-six (26) millimeters, and a second site dimension 15B that is greater than or less than thirty-three (33) millimeters. For example, each site 15 can have a first site dimension 15A of approximately sixteen (16) millimeters, and a second site dimension 15B of approximately thirty-two (32) millimeters.
Further, in the embodiment illustrated in FIG. 2, the substrate 14 is illustrated as having thirty-two separate sites 15. Alternatively, for example, the substrate 14 can be separated into greater than or fewer than thirty-two sites 15.
In this embodiment, four of the sites 15 on the substrate 14 are labeled “1” through “4” (one through four). In this example, the labels “1” through “4” represent one non-exclusive embodiment of a portion of the sequence in which mask patterns from the mask 12 (illustrated in FIG. 1) can be transferred to the sites 15 on the substrate 14.
Moreover, FIG. 2 includes a portion of an exposure pattern 252A (illustrated with a dashed line) which further illustrates the order in which the mask patterns are transferred to sites 15. In this example, the exposure pattern 252A comprises a plurality of scanning operations 252B and a plurality of stepping operations 252C, wherein the scanning operations 252B and the stepping operations 252C alternate so that the exposure proceeds in a scan-step-scan-step-scan fashion (boustrophedonic fashion). In this embodiment, the scanning 252B occurs as the substrate 14 is moved along a scan axis 254 (the Y axis), and the stepping 252C occurs as the substrate 14 is moved along a step axis 256 (the X axis).
It should be noted that in this example, the site 15 that is exposed first and the order in which the sites 15 are exposed can be different than that illustrated in FIG. 2. Further, the site 15 that is first exposed can be located away from the edge of the substrate 14. Further, the sites 15 can be stepped between exposures.
FIG. 3A is a simplified side illustration of the illumination system 18, the projection optical assembly 20, the mask 12 and a portion of the substrate 14 illustrated in FIG. 1, at the start of an exposure of a first site 1 (illustrated as a box). It should be noted that only the illumination system 18 and the projection optical assembly 20 of the exposure apparatus 10 (illustrated in FIG. 1) are shown in FIGS. 3A-3C for clarity. Additionally, it should be noted that FIGS. 3A-3C illustrate the mask 12 being substantially directly above at least a portion of the substrate 14 during exposure. FIGS. 3A-3C are illustrated in this configuration so that the relative positions of these components can be better understood, and the mask 12 is not necessarily positioned substantially directly above at least a portion of the substrate 14 (e.g. as illustrated in FIG. 1).
FIG. 3A illustrates that the mask 12 includes a mask pattern 358 (illustrated as a box) that includes the features that are to be transferred to the substrate 14. In this embodiment, the mask pattern 358 includes a pattern left side 358A, an opposed pattern right side 358B, and a pattern center 358C (illustrated as with a “+”).
Additionally, in these Figures, the mask pattern 358 is illustrated as being approximately twice the size of each site 15 on the substrate 14. However, in the event that the projection optical assembly 20 has a reduction factor of 4, the mask pattern 358 can be four times larger than the size of each site 15. In this embodiment, each site 15 includes a site left side 315A, an opposed site right side 315B, and a site center 315C (only one is illustrated with a “+”).
At the start of exposure of the first site 1, the control system 28 (illustrated in FIG. 1) controls the illumination system 18 to generate the slit shaped illumination beam 31 (illustrated as a dashed arrow), and controls the illumination reflector 35 (illustrated in FIG. 1) of the illumination system 18 to direct the illumination beam 31 at the mask 12 so that the mask pattern 358 is illuminated near the pattern left side 358A. Additionally, the control system 28 controls the projection optical assembly 20 so that the resulting pattern beam 38 (illustrated as a dashed arrow) is redirected at a portion of the first site 1 near the site left side 315A.
Further, at the beginning of the exposure of the first site 1, the control system 28 (illustrated in FIG. 1) (i) controls the illumination system 18 so that the illumination beam 31 is being moved at a constant velocity relative to the mask 12 in a first beam scan direction 360A (from left to right in FIG. 3A) along the beam scan axis 35 (illustrated in FIG. 1), and (ii) controls the substrate stage assembly 24 (illustrated in FIG. 1) so that the substrate 14 is being moved at a constant velocity in a first substrate scan direction 362A (from right to left in FIG. 3A) along the substrate scan axis 33 (illustrated in FIG. 1). With the present design, in certain embodiments, the illumination beam 31 and the substrate 14 are moved synchronously so that the mask 12 and the substrate 14 are scanned in the same direction (from left to right in FIG. 3A). Further, for example, if the projection optical assembly 20 has a reduction factor of four, the illumination beam 31 is moved at a rate that is four times greater than that of the substrate 14. Alternatively, the illumination beam 31 and substrate 14 can be moved so that the mask 12 and the substrate 14 are scanned in opposite directions during scanning of the sites 15.
It should be noted that in FIG. 3A, (i) the illumination beam 31 exits the illumination optical assembly outlet 34O at a first illumination outlet 359A, (ii) the pattern beam 38 enters the projection optical assembly inlet 20I at a first projection inlet location 361A, and (iii) the pattern beam 38 exits the projection optical assembly outlet 20O at a projection outlet location 363.
FIG. 3B is a simplified top illustration of the illumination system 18, the projection optical assembly 20, the mask 12 and a portion of the substrate 14 near the middle of an exposure of the first site 1. At this time, the control system 28 (illustrated in FIG. 1) controls the illumination system 18 to generate the slit shaped illumination beam 31 (illustrated as a dashed arrow), and controls the illumination reflector 35 (illustrated in FIG. 1) of the illumination system 18 to direct the illumination beam 31 at the mask 12 so that the mask pattern 358 is being illuminated near the pattern center 358C. Additionally, the control system 28 controls the projection optical assembly 20 so that the resulting pattern beam 38 (illustrated as a dashed arrow) is redirected at a portion of the first site 1 near the site center 315C.
In FIG. 3B, (i) the illumination beam 31 exits the illumination optical assembly outlet 34O at a second illumination outlet location 359B (that is different than the first illumination outlet location 359A illustrated in FIG. 3A), (ii) the pattern beam 38 enters the projection optical assembly inlet 20I at a second projection inlet location 361B (that is different than the first projection outlet location 361A illustrated in FIG. 3A), and (iii) the pattern beam 38 exits the projection optical assembly outlet 20O at the stationary projection outlet location 363.
FIG. 3C is a simplified top illustration of the illumination system 18, the projection optical assembly 20, the mask 12 and a portion of the substrate 14 at the end of the exposure of the first site 1. At this time, the control system 28 (illustrated in FIG. 1) controls the illumination system 18 to generate the slit shaped illumination beam 31 (illustrated as a dashed arrow), and controls the illumination reflector 35 (illustrated in FIG. 1) of the illumination system 18 to direct the illumination beam 31 at the mask 12 so that the mask pattern 358 is illuminated near the pattern right side 358B. Additionally, the control system 28 controls the projection optical assembly 20 so that the resulting pattern beam 38 (illustrated as a dashed arrow) is redirected at a portion of the first site 1 near the site right side 315B.
In FIG. 3C, (i) the illumination beam 31 exits the illumination optical assembly outlet 34O at a third illumination outlet location 359C (that is different than the first illumination outlet location 359A illustrated in FIG. 3A and the second illumination outlet location 359B illustrated in FIG. 3B), (ii) the pattern beam 38 enters the projection optical assembly inlet 20I at a third projection inlet location 361C (that is different than the first projection outlet location 361A illustrated in FIG. 3A and the second projection outlet location 361B), and (iii) the pattern beam 38 still exits the projection optical assembly outlet 20O at the stationary projection outlet location 363.
Referring to FIGS. 3A-3C, it should be noted that the entire mask pattern 358 is scanned to the first site 1 during movement of the illumination beam 31 from when the mask pattern 358 is illuminated near the pattern left side 358A to when the mask pattern 358 is illuminated near the pattern right side 358B. Additionally, the exposure of the first site 1 is halted once the illumination beam 31 is directed at the pattern right side 358B.
Upon completion of the exposure of the first site 1, the substrate 14 is stepped and subsequently the second site 2 is scanned while moving the substrate 14 in the opposite direction and with the illumination beam 31 scanning the mask 12 in the opposite direction as illustrated in FIGS. 3A-3C. More specifically, at the beginning of the exposure of the second site 2, the control system 28 (i) controls the illumination system 18 so that the illumination beam 31 is being moved at a constant velocity relative to the mask 12 in a second beam scan direction (from right to left), and (ii) controls the substrate stage assembly 24 (illustrated in FIG. 1) so that the substrate 14 is being moved at a constant velocity in a second substrate scan direction (from left to right) along the substrate scan axis 33 (illustrated in FIG. 1).
FIG. 4A is a simplified top illustration of the mask 12 and a portion of the substrate 14 in a side-by-side arrangement at the start of the exposure of the first site 1. It should be noted that the mask 12 and the substrate 14 are illustrated in FIGS. 4A-4C in this configuration so that the relative functions of these components can be better understood. Further, the components of the exposure apparatus 10 (illustrated in FIG. 1) are not shown in FIGS. 4A-4C for clarity.
FIG. 4A illustrates that the mask 12 includes the mask pattern 358 (illustrated with “/'s”) that includes the features that are to be transferred to the substrate 14. FIG. 4A further shows the slit shaped illumination beam 31 (illustrated with “o's”) that selectively illuminates the mask pattern 358.
Additionally, FIG. 4A illustrates a field of view 466 (illustrated with a dashed circle) of the projection optical assembly 20 (illustrated in FIG. 1), and the slit shaped pattern beam 38 (illustrated with “X's”) that is projected onto the substrate 14.
In this embodiment, the mask pattern 358 includes the pattern left side 358A, the opposed pattern right side 358B, and the pattern center 358C (illustrated as with a “+”).
Further, in FIG. 4A, the second site 2 and the third site 3 of the substrate 14, are also illustrated. In this embodiment, each site 15 includes the site left side 315A, the opposed site right side 315B, and the site center 315C (only one is illustrated with a “+”).
At the start of exposure of the first site 1, the control system 28 (illustrated in FIG. 1) controls the illumination system 18 (illustrated in FIG. 1) to generate the slit shaped illumination beam 31, and controls the illumination reflector 35 (illustrated in FIG. 1) of the illumination system 18 to direct the illumination beam 31 at the mask 12 so that the mask pattern 358 is illuminated near the pattern left side 358A.
Additionally, at the start of the exposure of the first site 1, the control system 28 controls the projection optical assembly 20 (illustrated in FIG. 1) so that the resulting pattern beam 38 is redirected at a portion of the first site 1 near the site left side 315A.
FIG. 4A further illustrates (i) the beam axis 35, (ii) the position of the illumination beam (noted as IB1) along the beam axis 35, and (iii) the position of the pattern beam (noted as PB) is also referenced on the beam axis 35 at the start of exposure of the first site 1.
FIG. 4B is a simplified top illustration of the mask 12 and a portion of the substrate 14 in a side-by-side arrangement near the middle of the exposure of the first site 1. At this time, the control system 28 (illustrated in FIG. 1) controls the illumination system 18 (illustrated in FIG. 1) to generate the slit shaped illumination beam 31, and controls the illumination reflector 35 (illustrated in FIG. 1) of the illumination system 18 to direct the illumination beam 31 at the mask 12 so that the mask pattern 358 is illuminated near the pattern center 358C.
Additionally, the control system 28 controls the projection optical assembly 20 (illustrated in FIG. 1), and the substrate 14 has been moved so that the resulting pattern beam 38 is redirected at a portion of the first site 1 near the site center 415C.
FIG. 4B also illustrates (i) the beam axis 35, (ii) the position of the illumination beam (noted as IB2) along the beam axis 35, and (iii) the position of the pattern beam (noted as PB) is also referenced on the beam axis 35 at this time. As can be seen on the beam axis 35, because the illumination beam 31 is being moved relative to the mask 12, the position of the illumination beam 31 has moved along the beam axis 35 from IB1 to IB2, and the position of the pattern beam 38 has not changed. It should be noted that the substrate 14 is being moved relative to the pattern beam 38, rather than having the pattern beam 38 being moved relative to the substrate 14.
FIG. 4C is a simplified top illustration of the mask 12 and a portion of the substrate 14 in a side-by-side arrangement near the end of the exposure of the first site 1. At this time, the control system 28 (illustrated in FIG. 1) controls the illumination system 18 (illustrated in FIG. 1) to generate the slit shaped illumination beam 31, and controls the illumination reflector 35 (illustrated in FIG. 1) of the illumination system 18 to direct the illumination beam 31 at the mask 12 so that the mask pattern 358 is illuminated near the pattern right side 358B.
Additionally, the control system 28 controls the projection optical assembly 20 (illustrated in FIG. 1), and the substrate 14 has been moved so that the resulting pattern beam 38 is directed at a portion of the first site 1 near the site right side 415B.
FIG. 4C also illustrates (i) the beam axis 35, (ii) the position of the illumination beam (noted as IB3) along the beam axis 35, and (iii) the position of the pattern beam (noted as PB) is also referenced on the beam axis 35 at this time. As can be seen on the beam axis 35, because the illumination beam 31 is being moved relative to the mask 12, the position of the illumination beam 31 has moved along the beam axis 35 from IB1 to IB2 to IB3, and the position of the pattern beam 38 has not changed.
It should be noted that only three positions of the illumination beam are illustrated in FIGS. 4A-4C. These positions illustrate the location of the illumination beam at three different specific times and the illumination beam actually scans the mask pattern during the exposure of each site.
FIG. 5 is a simplified side illustration of another embodiment of a mask 512 and a portion of the substrate 514 at the start of an exposure of a first site (illustrated as a box). It should be noted that only the illumination system 18 and the projection optical assembly 20 of the exposure apparatus 10 (illustrated in FIG. 1) are shown in FIG. 5 for clarity. Additionally, it should be noted that FIG. 5 illustrates the mask 512 being substantially directly above at least a portion of the substrate 514 during exposure. FIG. 5 is only illustrated in this configuration so that the relative positions of these components can be better understood, and the mask 512 is not necessarily positioned substantially directly above at least a portion of the substrate 514 (e.g. as illustrated in FIG. 1).
The embodiment illustrated in FIG. 5 is somewhat similar to the embodiment illustrated in FIG. 3A. However, in this embodiment, the illumination beam 531 is scanned in the opposite direction than illustrated in FIG. 3A.
FIG. 5 illustrates that the mask 512 includes the mask pattern 558 having the pattern left side 558A, the opposed pattern right side 558B, and the pattern center 558C (illustrated as with a “+”). In this embodiment, each site 515 includes a site left side 515A, an opposed site right side 515B, and a site center 515C (only one is illustrated with a “+”).
At the start of exposure of the first site 1, the control system 28 (illustrated in FIG. 1) controls the illumination system 18 to generate the slit shaped illumination beam 531 (illustrated as a dashed arrow), and controls the illumination reflector 35 (illustrated in FIG. 1) of the illumination system 18 to direct the illumination beam 531 at the mask 512 so that the mask pattern 558 is illuminated near the pattern right side 558B. Additionally, the control system 28 controls the projection optical assembly 20 so that the resulting pattern beam 538 (illustrated as a dashed arrow) is redirected at a portion of the first site 1 near the site left side 515A.
Further, at the beginning of the exposure of the first site 1, the control system 28 (i) controls the illumination system 18 so that the illumination beam 531 is being moved at a constant velocity relative to the mask 12 in a second beam scan direction 560B (from right to left in FIG. 5) along the beam scan axis 35 (illustrated in FIG. 1), and (ii) controls the substrate stage assembly 24 (illustrated in FIG. 1) so that the substrate 14 is being moved at a constant velocity in a first substrate scan direction 562A (from right to left in FIG. 5) along the substrate scan axis 33 (illustrated in FIG. 1). With the present design, in certain embodiments, the illumination beam 531 and the substrate 514 are moved synchronously so that the mask 512 is scanned in one direction (from right to left in FIG. 5) and the substrate 514 is scanned in the opposite direction (from left to right in FIG. 5). Further, for example, if the projection optical assembly 20 has a reduction factor of four, the illumination beam 531 is moved at a rate that is four times greater than that of the substrate 514.
FIG. 6 is a simplified side illustration of yet another embodiment of a mask 612 and a portion of the substrate 614 at the start of an exposure of a first site (illustrated as a box). It should be noted that only the illumination system 18 and the projection optical assembly 20 of the exposure apparatus 10 (illustrated in FIG. 1) are shown in FIG. 6 for clarity. Additionally, it should be noted that FIG. 6 illustrates the mask 612 being substantially directly above at least a portion of the substrate 614 during exposure. FIG. 6 is illustrated in this configuration so that the relative positions of these components can be better understood, and the mask 612 is not necessarily positioned substantially directly above at least a portion of the substrate 614 (e.g. as illustrated in FIG. 1).
The embodiment illustrated in FIG. 6 is somewhat similar to the embodiment illustrated in FIG. 3A. However, in this embodiment, the mask 612 is also being moved concurrently with the illumination beam 631 scanning the mask 612.
FIG. 6 illustrates that the mask 612 includes the mask pattern 658 having the pattern left side 658A, the opposed pattern right side 658B, and the pattern center 658C (illustrated as with a “+”). In this embodiment, each site 615 includes the site left side 615A, the opposed site right side 615B, and the site center 615C (only one is illustrated with a “+”).
At the start of exposure of the first site 1, the control system 28 (illustrated in FIG. 1) controls the illumination system 18 to generate the slit shaped illumination beam 631 (illustrated as a dashed arrow), controls the mask stage assembly 22 (illustrated in FIG. 1) to position the mask 612 along the mask scan axis 42 (illustrated in FIG. 1), and controls the illumination reflector 35 (illustrated in FIG. 1) of the illumination system 18 to direct the illumination beam 631 at the mask 612 so that the mask pattern 658 is illuminated near the pattern left side 658A. Additionally, the control system 28 controls the projection optical assembly 20 so that the resulting pattern beam 638 (illustrated as a dashed arrow) is redirected at a portion of the first site 1 near the site left side 615A.
Further, at the beginning of the exposure of the first site 1, the control system 28 (i) controls the illumination system 18 so that the illumination beam 631 is being moved at a constant velocity relative to the mask 612 in a first beam scan direction 660A (from left to right in FIG. 6) along the beam scan axis 35 (illustrated in FIG. 1), (ii) controls the mask stage assembly 22 (illustrated in FIG. 1) so that the mask 612 is being moved at a constant velocity in a first mask scan direction 664A (from right to left in FIG. 6) along the mask scan axis 42, and (iii) controls the substrate stage assembly 24 (illustrated in FIG. 1) so that the substrate 614 is being moved at a constant velocity in a first substrate scan direction 662A (from right to left in FIG. 6) along the substrate scan axis 33 (illustrated in FIG. 1). With the present design, in certain embodiments, the illumination beam 631, the mask 612 and the substrate 614 are moved synchronously so that the mask 612 and the substrate 614 are scanned in the same direction (from left to right in FIG. 6).
Alternatively, the mask 612, the illumination beam 631 and/or the substrate 614 can be moved in opposite directions than those illustrated in FIG. 6. For example, the mask 612 and the substrate 614 can be moved so that the mask 612 and the substrate 614 are scanned in opposite directions during scanning of the sites 615.
It should be noted that with the embodiment illustrated in FIG. 6, the acceleration and velocity requirements of the mask stage assembly is less than prior art systems because the illumination system is also scanning the mask. This lowers the chucking requirements of the mask stage and reduces power consumed and heat generated by the mask stage assembly. Further, in certain embodiments, the present invention allows for higher throughputs with the same or lesser velocity and acceleration rates of the mask stage assembly.
FIG. 7 is a simplified illustration of an illumination source 32, a mask 12, and one non-exclusive embodiment of an illumination optical assembly 734 having features of the present invention. As noted above, the illumination optical assembly 734 directs and guides the illumination beam 31 from the illumination source 32 to near the mask 12.
As illustrated, the illumination optical assembly 734 includes (i) the illumination optical assembly inlet 734I, (ii) the illumination optical assembly outlet 734O, (iii) a plurality of illumination inlet elements 734A that are positioned along an illumination inlet axis 735A, (iv) the illumination reflector 36, and (v) a plurality of illumination outlet elements 734B that are positioned along an illumination outlet axis 735B that is substantially perpendicular to the illumination inlet axis 735A. Alternatively, the illumination optical assembly 734 can be designed so that the illumination outlet axis 735B is at an angle other than perpendicular to the illumination inlet axis 735A.
During directing and guiding of the illumination beam 31 from the illumination source 32 to near the mask 12, the illumination beam 12 is initially directed through the illumination optical assembly inlet 34I and through the plurality of illumination inlet elements 734A. Subsequently, the illumination beam 31 strikes the surface of the illumination reflector 36 and is redirected toward the plurality of illumination outlet elements 734B. Next, the illumination beam 31 passes through the plurality of illumination outlet elements 734B and is directed through the illumination optical assembly outlet 734O to near the mask 12.
In the embodiment illustrated in FIG. 7, the illumination reflector 36 redirects the illumination beam 31 approximately ninety degrees. As one non-exclusive embodiment, for example, to scan the mask 12, the reflector 36 can redirect the illumination beam 31 between approximately −5 and +5 degrees. However, the amount of movement can vary significantly based on the design of the illumination reflector 36 and is approximately equal to the scan width divided by the focal length. In FIG. 7, the illumination reflector 36 is illustrated in a first position 736A and a second position 736B.
The illumination inlet elements 734A include a plurality of individual optical elements labeled E1 through E14. In this embodiment, the illumination beam 31 is altered and/or focused as it initially passes in a generally downward direction through optical elements E1 through E14. Optical elements E1 through E14 are optical lenses that can be made from material such as silicon dioxide (SiO₂). Subsequently, the illumination beam 31 is reflected off the illumination reflector 36 so that it is now directed in a generally transverse direction toward the illumination outlet elements 734B.
The illumination outlet elements 734B include a plurality of individual optical elements E15 through E28. In this embodiment, the illumination beam 31 is altered and/or refocused as it passes in a generally transverse or horizontal direction through optical elements E15 through E28. Optical elements E15 through E28 are optical lenses that can be made from material such as silicon dioxide (SiO₂). Subsequently, the illumination beam 31 is directed and guided to near the mask 12.
It should be noted that in the embodiment illustrated in FIG. 7, the illumination beam 31 enters the illumination optical assembly 34 at the same stationary illumination inlet location 765 relative to the illumination inlet axis 735A. Further, with the moving illumination reflector 36, the illumination beam 31 exits the illumination optical assembly 34 at a plurality of different illumination outlet locations 759A, 759B (two of which are illustrated in FIG. 7) relative to the illumination outlet axis 735B as the illumination beam 31 scans the mask 12.
FIG. 8 is a simplified illustration of a mask 12, a substrate 14, and one, non-exclusive embodiment of a projection optical assembly 820 having features of the present invention. As noted above, the projection optical assembly 820 projects and/or focuses the pattern beam 38 onto the substrate 14.
As illustrated, the projection optical assembly 820 includes (i) the projection optical assembly inlet 820I, (ii) the projection optical assembly outlet 820O, (iii) a plurality of projection inlet elements 820A that are positioned along a projection inlet axis 821A, (iv) the projection reflector 40, and (v) a plurality of projection outlet elements 820B that are positioned along a projection outlet axis 821B that is substantially perpendicular to the projection inlet axis 821A in the embodiment illustrated in FIG. 8. Alternatively, the projection optical assembly 820 can be designed so that the projection outlet axis 821B is at an angle other than perpendicular to the projection inlet axis 821A.
During projection and/or focusing of the pattern beam 38 from the mask 12 onto the substrate 14, the pattern beam 38 is initially directed through the projection optical assembly inlet 820I and through the plurality of projection inlet optical elements 820A. Subsequently, the pattern beam 38 strikes the surface of the projection reflector 40 and is redirected toward the plurality of projection outlet elements 820B. Next, the pattern beam 38 passes through the plurality of projection outlet elements 820B and is projected onto the substrate 14.
In the embodiment illustrated in FIG. 8, the projection reflector 40 redirects the pattern beam 38 approximately ninety degrees. As one non-exclusive embodiment, for example, the projection reflector 40 can redirect the pattern beam 38 between approximately −5 and +5 degrees. However, the amount of movement can vary significantly based on the design of the projection reflector 40 and is approximately equal to the scan width divided by the focal length. In FIG. 8, the projection reflector 40 is illustrated in a first position 840A and a second position 840B.
The projection inlet elements 820A include a plurality of individual optical elements labeled E29 through E42. In this embodiment, the pattern beam 38 is altered and/or focused as it initially passes in a generally transverse or horizontal direction through optical elements E29 through E42. Optical elements E29 through E42 are optical lenses that can be made from material such as silicon dioxide (SiO₂). Subsequently, the pattern beam 38 is reflected off the projection reflector 40 so that it is now directed in a generally downward direction toward the projection outlet elements 820B.
The projection outlet elements 820B include a plurality of individual optical elements E43 through E56. In this embodiment, the pattern beam 38 is altered and/or refocused as it passes in a generally downward direction through optical elements E43 through E56. Optical elements E43 through E56 are optical lenses that can be made from material such as silicon dioxide (SiO₂). Subsequently, the pattern beam 38 is projected and/or focused onto the substrate 14.
It should be noted that the projection optical assembly 820 illustrated in FIG. 8 is a 1× magnification system. For example, if a 4× reduction system is desired, a separate reduction optical assembly (not shown) can be added to the bottom of the projection optical assembly 820 before the substrate 14, one or more optical elements (not shown) can be added to the projection optical assembly 820, and/or one or more of the optical elements illustrated in FIG. 8 can be modified.
It should also be noted that in the embodiment illustrated in FIG. 8, the pattern beam 38 enters the projection optical assembly 820 at a plurality of different locations 861A, 861B (two of which are illustrated in FIG. 8) relative to the projection inlet axis 821A as the pattern beam 38 exits the mask 12. Further, with the moving projection reflector 40, the pattern beam 38 exits the projection optical assembly 820 at a single projection outlet location 863 relative to the projection outlet axis 821B.
Comparing FIGS. 7 and 8, in certain embodiments, the design of the illumination optical assembly 734 can be similar to the design of the projection optical assembly 820. In these Figures, the projection optical assembly 820 is similar to the illumination optical assembly 734, however, the orientation of the optical assemblies 734, 820 are different. More specifically, in this embodiment, the orientation of the projection optical assembly 820 is rotated one hundred and eighty degrees from the illumination optical assembly 734.
It should be noted that in one embodiment, each optical assembly 734, 820 is an anamorphic f-theta scanning lens assembly. Stated in another fashion, in one embodiment, one or more of the elements of each of the optical assemblies 734, 820 are not rotationally symmetric because symmetric elements can produce distortion error when using the moving reflectors to shift the fields.
As provided herein, each optical assembly 734, 820 will not produce distortion if:
X=F*Sin θ Cos φ; and
Y=F*Arc Tan [Sin θ Sin φ].
In these equations, (i) Theta (“θ”) is the angle of the chief ray (ray that passes through the intersection of the optical axis and the scan mirror) from the optical axis; (ii) Phi (“φ”) is the angle from the axis perpendicular to the optical axis and out of the page; and (iii) F is the focal length of the lens. In these equations, lens means the lens group on one side of the reflector or the other side of the reflector.
In one embodiment, each of (i) the illumination inlet elements 734A, (ii) the illumination outlet elements 734B, (iii) the projection inlet elements 820A, and (iv) the projection outlet elements 820B can be divided into two groups. The elements of the first group contain the power of the lens and can be rotationally symmetric, while the elements of the second group are responsible for producing the correct distortion and at least one of these elements are anamorphic elements. In one embodiment, the elements of the first group make up an F-Sin θ lens, and the elements of the second group are F-Zeta anamorphic corrector lens that provide the needed distortion correction.
For example, (i) for the illumination inlet elements 734A, elements E1-E5 make up the first group, and elements E6-E14 make up the second group; (ii) the illumination outlet elements 734B, elements E24-E28 make up the first group, and elements E15-E23 make up the second group; (iii) the projection inlet elements 820A, elements E29-E33 make up the first group, and elements E34-E42 make up the second group; and (iv) the projection outlet elements 820B, elements E52-E56 make up the first group, and elements E43-E51 make up the second group.
It should be noted that the optical assemblies described herein are meant as merely a non-exclusive example of a suitable system. In other embodiments, elements can be grouped or arranged in a different fashion.
FIGS. 9A and 9B illustrate one embodiment of a reflector 972 having features of the present invention. In particular, the reflector 972 can be used as the illumination reflector 36 (illustrated in FIG. 1) and/or the projection reflector 40 (illustrated in FIG. 1).
The design of the reflector 972 can be varied depending on the requirements of the exposure apparatus 10 (illustrated in FIG. 1), the illumination optical assembly 34 (illustrated in FIG. 1), and/or the projection optical assembly 20 (illustrated in FIG. 1). In this embodiment, the reflector 972 includes a reflective surface 974, a reflector mover 976 (illustrated in phantom), and a reflector measurer 978 (illustrated in phantom).
The reflective surface 974 is designed to reflect and redirect light 980 that is the wavelength of the illumination beam 31 (illustrated in FIG. 1) and the pattern beam 38 (illustrated in FIG. 1). In the embodiment, illustrated in FIGS. 9A and 9B, is a substantially flat, and is made of a reflective material, and the beam 980 is incident on the reflective surface 974. In alternative embodiments, the reflective surface 974 can be curved and/or the reflective surface 974 can be made from a different material.
The reflector mover 976 selectively moves the reflective surface 974 relative to the beam 980 so that the beam 980 can be utilized to scan the mask 12 (illustrated in FIG. 1) or to be focused on the stationary projection outlet used field. In one embodiment, the reflector mover 976 is controlled by the control system 28 (illustrated in FIG. 1) to precisely rotate and pivot the reflective surface 974 relative to the beam 980 and the optical elements so as to change the angle of incidence between the reflective surface 974 and the beam 980. For example, the reflector mover 976 can include one or more rotary motors, or other type of actuators. In the embodiment illustrated in FIGS. 9A and 9B, the reflective surface 974 should rotate about an axis that is located where a center ray of the beam is incident on the reflective surface 974. Thus, the center ray always is incident on the same location on the reflective surface 974. In this embodiment, the rotation of the reflective surface 974 is centered on the point where the center of the beam is incident on the reflective surface 974.
During exposure of a site 15 (illustrated in FIG. 1), the reflector mover 976 will gradually rotate the reflective surface 974 so as to properly position the beam 980 at all times during the exposure. In one embodiment, at the end of the exposure of the site 15, the reflector mover 976 will move in the opposite direction during the exposure of the next site 15.
The reflector measurer 978 monitors movement and positioning of the reflective surface 974 relative to the beam 980 or some other reference. With this information, the control system 28 can precisely control the position of the reflective surface 974 so that the beam 980 is redirected as required. For example, the reflector measurer 978 can utilize multiple laser interferometers, encoders, and/or other measuring devices.
FIG. 9A illustrates the reflector 972 wherein the reflective surface 974 is in a first position 981A relative to the beam 980. The beam 980 is initially directed in a generally downward direction toward the reflective surface 974 and it is subsequently redirected in a generally transverse direction by the reflective surface 974. In FIG. 9A, the beam 980 contacts the reflective surface 974 at an angle of approximately forty-five degrees relative to the reflective surface 974, and the beam is subsequently redirected away from the reflective surface 974 at an angle of approximately forty-five degrees relative to the reflective surface 974. Stated another way, in the first position 981A, the reflective surface 974 redirects the beam 980 by approximately ninety degrees.
FIG. 9B illustrates the reflector 972 wherein the reflective surface 974 is in a second position 981B relative to the beam 980. The beam 980 is initially directed in a generally downward direction toward the reflective surface 974 and it is subsequently redirected by the reflective surface 974. In FIG. 9B, the beam 980 contacts the reflective surface 974 at an angle of approximately forty degrees relative to the reflective surface 974, and the beam is subsequently redirected away from the reflective surface 974 at an angle of approximately forty degrees relative to the reflective surface 974. Stated another way, in the second position 981B, the reflective surface 974 redirects the beam 980 by approximately one hundred ten (100) degrees.
It should be noted that the first position 981A and the second position 981B of the reflective surface 974, as illustrated in FIGS. 9A and 9B, is merely for purposes of example and clarity, and the difference in angles is likely to be much smaller during operation of the exposure apparatus 10.
FIGS. 10A and 10B illustrate another embodiment of a reflector 1072 having features of the present invention. In particular, the reflector 1072 can be used as the illumination reflector 36 (illustrated in FIG. 1) and/or the projection reflector 40 (illustrated in FIG. 1). In this embodiment, the reflector 1072 includes a plurality of reflective surfaces 1074A, a reflector mover 1076 (illustrated in phantom), and a reflector measurer 1078 (illustrated in phantom).
As illustrated in FIGS. 10A and 10B, the reflector 1072 is substantially octagon shaped and includes eight reflective surfaces 1074A. Alternatively, the reflector 1072 can be designed with more than eight or fewer than eight reflective surfaces 1074A.
Each reflective surface 1074A is a substantially flat, and is designed to reflect and redirect a beam 1080 (illustrated as a dashed line), such as the illumination beam 31 (illustrated in FIG. 1) and/or the pattern beam 38 (illustrated in FIG. 1). Stated another way, the beam 1080 is incident on the reflective surfaces 1074A. In alternative embodiments, the reflective surfaces 1074A can be curved and/or the reflective surfaces 1074A.
The reflector mover 1076 selectively moves the reflective surfaces 1074A relative to the beam 1080 so that the beam 1080 can be utilized to scan the mask 12 (illustrated in FIG. 1) or to be focused on the stationary projection outlet used field. In this embodiment, the reflector mover 1076 rotates the reflector 1072 about a reflector axis 1082 so that one of the reflective surfaces 1074A is positioned to receive the beam 1080 at all times, and so that the angle of incidence between the reflective surface 1074A being then utilized and the beam 1080 changes so that the beam 1080 can be properly redirected.
Additionally, the reflector mover 1076 can shift the reflective surfaces 1074A up and down and side to side so that the center ray of the beam 1080 is always incident on the reflector 1072 same location in space.
For example, the reflector mover 1076 can include one or more rotary motors, one or more linear movers, and/or other type of actuators.
During exposure of a site 15 (illustrated in FIG. 1), the reflector mover 1076 will rotate and shift the reflector 1072 so that one of the reflective surfaces 1074A can be utilized to properly position the beam 980 at all times during the exposure. At the end of the exposure of the site 15, the reflector mover 976 continues to rotate and shift the reflector 1072 so that the adjacent reflective surface 1074A is now in position so that the beam 1080 can be properly directed for the start of exposure of the next site 15.
The reflector measurer 1078 monitors movement and positioning of the reflective surfaces 1074A relative to the beam 1080 or some other reference. With this information, the control system 28 (illustrated in FIG. 1) can precisely control the position of the reflective surfaces 1074 so that the beam 1080 is redirected as required.
FIGS. 10A and 10B illustrate the reflector 1072 in slightly different positions, wherein the reflective surface 1074A facing the beam 1080 is at a somewhat different angle relative to the beam 1080 so as to be able to properly and accurately redirect the beam 1080 as desired.
Table 1, as provided below, illustrates one, non-exclusive example of a prescription for the optical elements E1 through E28 of the illumination optical assembly 734 illustrated in FIG. 7, and of the optical elements E29 through E56 of the projection optical assembly 820 illustrated in FIG. 8. More particularly, for each optical element E1 through E56, the charts in Table 1 show a prescription for (i) the radius of curvature for the front of the optical element, (ii) the radius of curvature for the back of the optical element, (iii) the thickness or separation, (iv) the aperture description, (v) the shape, and (vi) the material.

TABLE 1

		APERTURE
SURFACE DESCRIPTION	THICKNESS	DESCRIPTION

ELT

SUR

RADIUS

OR

DIMENSION

NO.	NO.	X	Y	SHAPE	SEPARATION	X Y	SHAPE	MATERIAL

OBJECT	INF	FLT	0.0000
			0.0000	132.061	CIR
			0.0000	132.061	CIR
			35.0000	132.061	CIR

1	1	741.692	617.394	X-1	37.4432	142.954	CIR	SIO2
1	2	−854.975	726.171	X-2	59.8984	146.314	CIR
2	3	−1603.582	−524.167	X-3	24.2858	150.281	CIR	SIO2
2	4	−201.984	−220.746	X-4	12.3724	151.141	CIR
3	5	−179.748	−182.379	X-5	5.5000	146.959	CIR	SIO2
3	6	243.814	*********	X-6	33.5894	150.257	CIR
4	7	407.104	INF	X-7	18.6035	165.662	CIR	SIO2
4	8	−1058.359	−518.893	X-8	23.3109	166.797	CIR
5	9	−129.905	−372.168	X-9	20.1824	166.538	CIR	SIO2
5	10	−144.922	−385.539	X-10	15.7023	177.891	CIR
6	11	134.768		A-1	53.6769	192.621	CIR	SIO2
6	12	−5224.479	CX	SPH	0.1000	185.646	CIR
7	13	152.334	CX	SPH	7.0000	169.024	CIR	SIO2
7	14	93.590		A-2	56.6988	154.268	CIR
8	15	−384.328	CC	SPH	7.0000	149.994	CIR	SIO2
8	16	187.641		A-3	154.1851	148.340	CIR
9	17	579.893	CX	SPH	49.6743	231.050	CIR	SIO2
9	18	−346.481	CX	SPH	0.1000	234.400	CIR
10	19	404.950	CX	SPH	37.7272	230.537	CIR	SIO2
10	20	−675.682	CX	SPH	0.1000	227.395	CIR
11	21	440.573	CX	SPH	60.0000	212.267	CIR	SIO2
11	22	161.388		A-4	95.5716	169.299	CIR
12	23	−207.758		A-5	7.0000	153.166	CIR	SIO2
12	24	343.776	CC	SPH	0.1000	153.243	CIR
13	25	134.757	CX	SPH	43.0000	157.769	CIR	SIO2
13	26	654.395	CC	SPH	0.1000	150.318	CIR
14	27	265.342	CX	SPH	25.0436	147.786	CIR	SIO2
14	28	464.202		A-6	150.0000	136.614	CIR
					0.0000	100.810	CIR
					0.0000	100.810	CIR
29					0.0000	100.810	CIR	(STOP)

		DECENTER(1)*1
15	30	INF	FLT	0.0000	151.344	CIR	REFL
		RETURN(1)
		DECENTER(2)

					−150.0000	101.324	CIR
16	31	464.202		A-7	−25.0436	140.627	CIR	SIO2
16	32	265.342	CX	SPH	−0.1000	152.989	CIR
17	33	654.395	CC	SPH	−43.0000	156.110	CIR	SIO2
17	34	134.757	CX	SPH	−0.1000	163.774	CIR
18	35	343.776	CC	SPH	−7.0000	159.370	CIR	SIO2
18	36	−207.758		A-8	−95.5716	160.038	CIR
19	37	161.388		A-9	−60.0000	177.676	CIR	SIO2
19	38	440.573	CX	SPH	−0.1000	225.915	CIR
20	39	−675.682	CX	SPH	−37.7272	245.491	CIR	SIO2
20	40	404.950	CX	SPH	−0.1000	247.692	CIR
21	41	−346.781	CX	SPH	−49.6743	253.360	CIR	SIO2
21	42	579.893	CX	SPH	−154.1851	251.010	CIR
22	43	187.641		A-10	−7.0000	164.382	CIR	SIO2
22	44	−384.328	CC	SPH	−56.6988	168.454	CIR
23	45	93.590		A-11	−7.0000	169.763	CIR	SIO2
23	46	152.334	CX	SPH	−0.1000	188.886	CIR
24	47	−5224.479	CX	SPH	−53.6769	214.824	CIR	SIO2
24	48	134.768		A-12	−15.7023	218.633	CIR
25	49	−144.922	−385.539	X-11	−20.1824	204.571	CIR	SIO2
25	50	−129.905	−372.168	X-12	−23.3109	193.961	CIR
26	51	−1058.359	−518.893	X-13	−18.6035	194.280	CIR	SIO2
26	52	407.104	INF	X-14	−33.5894	193.512	CIR
27	53	243.814	*********	X-15	−5.5000	178.469	CIR	SIO2
27	54	−179.748	−182.379	X-16	−12.3724	173.611	CIR
28	55	−201.984	−220.746	X-17	−24.2858	178.435	CIR	SIO2
28	56	−1603.582	−524.167	X-18	−59.8984	177.715	CIR
29	57	−854.975	726.171	X-19	−37.4432	175.750	CIR	SIO2
29	58	741.692	617.394	X-20	−35.0000	174.310	CIR
					0.0000	165.691	CIR

IMAGE	INF	FLT		165.691

It should be noted that in Table 1, (i) the positive radius indicates the center of curvature is to the right, (ii) the negative radius indicates the center of curvature is to the left, (iii) the dimensions are given in millimeters, (iv) the thickness is the axial distance to next surface, and (v) the image diameter shown is a paraxial value, it is not a ray traced value.
Table 2, as provided below, illustrates the calculation of aspheric shapes of certain of the optical elements. More particularly, aspheric constants A-1 relates to the shape of the front of optical element E6; aspheric constant A-2 relates to the shape of the back of optical element E7; aspheric constant A-3 relates to the shape of the back of optical element E8; aspheric constant A-4 relates to the shape of the back of optical element E11; aspheric constant A-5 relates to the shape of the front of optical element E12; aspheric constant A-6 relates to the shape of the back of optical element E14; aspheric constant A-7 relates to the shape of the front of optical element E16; aspheric constant A-8 relates to the shape of the back of optical element E18; aspheric constant A-9 relates to the shape of the front of optical element E19; aspheric constant A-10 relates to the shape of the front of optical element E22; aspheric constant A-11 relates to the shape of the front of optical element E23; and aspheric constant A-12 relates to the shape of the back of optical element E24.
Additionally, within the formula for the aspheric constants, Y represents the distance from the optical axis (i.e., the first inlet axis, a first transverse axis, or the outlet axis), CURV represents (1/radius of curvature), and K represents the conic constant.

TABLE 2

ASPHERIC CONSTANTS
$\begin{matrix} Z = \frac{(CURV) Y^{2}}{1 + {(1 - (1 + K) {(CURV)}^{2} Y^{2})}^{1 / 2}} + (A) Y^{4} + {B (Y)}^{6} + \\ (C) Y^{8} + {D (Y)}^{10} + (E) Y^{12} + (F) Y^{14} + (G) Y^{16} + (H) Y^{18} + (J) Y^{20} \end{matrix}$

		K	A	B	C	D
ASPHERIC	CURV	E	F	G	H	J

A-1	0.00742018	−0.463422	−2.58401E−08	−7.44039E−13	−1.37849E−18	0.00000E+00
		0.00000E+00	0.00000E+00	0.00000E+00	0.00000E+00	0.00000E+00
A-2	0.01068494	−0.625175	3.90460E−08	8.97441E−13	1.07575E−17	1.11576E−21
		−3.39463E−25	0.00000E+00	0.00000E+00	0.00000E+00	0.00000E+00
A-3	0.00532933	−0.940929	6.61051E−08	1.03407E−12	−1.74225E−17	2.40593E−21
		−2.12065E−25	0.00000E+00	0.00000E+00	0.00000E+00	0.00000E+00
A-4	0.00619624	0.875193	−2.72698E−08	−1.35171E−12	−5.60234E−17	−1.82101E−21
		−1.25351E−25	0.00000E+00	0.00000E+00	0.00000E+00	0.00000E+00
A-5	−0.00481330	−2.067322	5.68003E−08	8.51985E−14	−7.84748E−18	2.97986E−22
		5.08475E−25	0.00000E+00	0.00000E+00	0.00000E+00	0.00000E+00
A-6	0.00215424	20.995031	1.56403E−07	7.78103E−13	1.36246E−16	4.16690E−21
		1.31323E-24	0.00000E+00	0.00000E+00	0.00000E+00	0.00000E+00
A-7	0.00215424	20.995031	1.56403E−07	7.78103E−13	1.36246E−16	4.16690E−21
		1.31323E−24	0.00000E+00	0.00000E+00	0.00000E+00	0.00000E+00
A-8	−0.00481330	−2.067322	5.68003E−08	8.51985E−14	−7.84748E−18	2.97986E−22
		5.08475E−25	0.00000E+00	0.00000E+00	0.00000E+00	0.00000E+00
A-9	0.00619624	0.875193	−2.72698E−08	−1.35171E−12	−5.60234E−17	−1.82101E−21
		−1.25351E−25	0.00000E+00	0.00000E+00	0.00000E+00	0.00000E+00
A-10	0.00532933	−0.940929	6.61051E−08	1.03407E−12	−1.74225E−17	2.40593E−21
		−2.12065E−25	0.00000E+00	0.00000E+00	0.00000E+00	0.00000E+00
A-11	0.01068494	−0.625175	3.90460E−08	8.97441E−13	1.07575E−17	1.11576E−21
		−3.39463E−25	0.00000E+00	0.00000E+00	0.00000E+00	0.00000E+00
A-12	0.00742018	−0.463422	−2.58401E−08	−7.44039E−13	−1.37849E−18	0.00000E+00
		0.00000E+00	0.00000E+00	0.00000E+00	0.00000E+00	0.00000E+00

Table 3, as provided below, provides the Anamorphic asphere for certain of these optical elements.

TABLE 3

ANAMORPHIC ASPHERE
$\begin{matrix} Z = \frac{(CX) X^{2} + (CY) Y^{2}}{1 + {(1 - (1 + KX) {(CX)}^{2} X^{2} - (1 + KY) {(CY)}^{2} Y^{2})}^{1 / 2}} + \\ AR {((1 - AP) X^{2} + (1 + AP) Y^{2})}^{2} + BR {((1 - BP) X^{2} + (1 + BP) Y^{2})}^{3} + \\ CR {((1 - CP) X^{2} + (1 + CP) Y^{2})}^{4} + {DR ((1 - DP) X^{2} + (1 + DP) Y^{2})}^{5} \end{matrix}$

X-1	CY = 0.00161971	KY = 0.000000	CX = 0.00134827	KX = 0.000000
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-2	CY = 0.00137709	KY = −7.347507	CX = −0.00116962	KX = 24.747071
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-3	CY = −0.00190779	KY = 11.861982	CX = −0.00062360	KX = 37.130522
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-4	CY = −0.00453009	KY = 0.292673	CX = −0.00495088	KX = 0.338452
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-5	CY = −0.00548309	KY = −0.413227	CX = −0.00556335	KX = 0.061851
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-6	CY = −0.00000013	KY = ***********	CX = 0.00410149	KX = −3.684836
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-7	CY = 0.00000000	KY = ***********	CX = 0.00245637	KX = −2.738895
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-8	CY = −0.00192718	KY = 6.255491	CX = −0.00094486	KX = 12.609542
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-9	CY = −0.00268696	KY = −2.359912	CX = −0.00769792	KX = −0.482562
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-10	CY = −0.00259377	KY = −1.541833	CX = −0.00690026	KX = −0.401289
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-11	CY = −0.00259377	KY = −1.541833	CX = −0.00690026	KX = −0.401289
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-12	CY = −0.00268696	KY = −2.359912	CX = −0.00769792	KX = −0.482562
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-13	CY = −0.00192718	KY = 6.255491	CX = −0.00094486	KX = 12.609542
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-14	CY = 0.00000000	KY = ***********	CX = 0.00245637	KX = −2.738895
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-15	CY = −0.00000013	KY = ***********	CX = 0.00410149	KX = −3.684836
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-16	CY = −0.00548309	KY = −0.413227	CX = −0.00556335	KX = 0.061851
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-17	CY = −0.00453009	KY = 0.292673	CX = −0.00495088	KX = 0.338452
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-18	CY = −0.00190779	KY = 11.861982	CX = −0.00062360	KX = 37.130522
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-19	CY = 0.00137709	KY = −7.347507	CX = −0.00116962	KX = 24.747071
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00
X-20	CY = 0.00161971	KY = 0.000000	CX = 0.00134827	KX = 0.000000
	AR = 0.00000E+00	BR = 0.00000E+00	CR = 0.00000E+00	DR = 0.00000E+00
	AP = 0.00000E+00	BP = 0.00000E+00	CP = 0.00000E+00	DP = 0.00000E+00

Table 4, illustrates the decentering information as it relates to certain of the optical elements. Table 4 further provides additional element characteristics for the illumination optical assembly 734 and the projection optical assembly 820.

TABLE 4

DECENTERING CONSTANTS

DECENTER	X	Y	Z	ALPHA	BETA	GAMMA

D (1)	0.0000	0.0000	0.0000	42.2456*1	0.0000	0.0000	(RETU)
D (2)	0.0000	0.0000	0.0000	90.0000	0.0000	0.0000

A decenter defines a new coordinate system (displaced and/or rotated)

in which subsequent surfaces are defined. Surfaces following a decenter

are aligned on the local mechanical axis (z-axis) of the new coordinate

system. The new mechanical axis remains in use until changed by another

decenter. The order in which displacements and tilts are applied on a

given surface is specified using different decenter types and these

generate different new coordinate systems; those used here are explained

below. Alpha, beta, and gamma are in degrees.

DECENTERING CONSTANT KEY:

TYPE	TRAILING CODE	ORDER OF APPLICATION

DECENTER		DISPLACE (X, Y, Z)
		TILT (ALPHA, BETA, GAMMA)
		REFRACT AT SURFACE
		THICKNESS TO NEXT SURFACE
DECENTER & RETURN	RETU	DECENTER (X, Y, Z, ALPHA, BETA, GAMMA)
		REFRACT AT SURFACE
		RETURN (−GAMMA, −BETA, −ALPHA, −Z, −Y, −X)
		THICKNESS TO NEXT SURFACE

REFERENCE WAVELENGTH = 193.3 NM

*ZOOM PARAMETERS POS. 1 POS. 2 POS. 3 POS. 4 POS. 5 POS. 6 POS. 7 POS. 8 POS. 9

*1= 42.2456 42.9356 43.6244 44.3124 45.0000 45.6876 46.3756 47.0644 47.7544

Semiconductor devices can be fabricated using the above described systems, by the process shown generally in FIG. 11A. In step 1101 the device's function and performance characteristics are designed. Next, in step 1102, a mask (reticle) having a pattern is designed according to the previous designing step, and in a parallel step 1103 a wafer is made from a silicon material. The mask pattern designed in step 1102 is exposed onto the wafer from step 1103 in step 1104 by a photolithography system described hereinabove in accordance with the present invention. In step 1105, the semiconductor device is assembled (including the dicing process, bonding process and packaging process), finally, the device is then inspected in step 1106.
FIG. 11B illustrates a detailed flowchart example of the above-mentioned step 1104 in the case of fabricating semiconductor devices. In FIG. 11B, in step 1111 (oxidation step), the wafer surface is oxidized. In step 1112 (CVD step), an insulation film is formed on the wafer surface. In step 1113 (electrode formation step), electrodes are formed on the wafer by vapor deposition. In step 1114 (ion implantation step), ions are implanted in the wafer. The above mentioned steps 1111-1114 form the preprocessing steps for wafers during wafer processing, and selection is made at each step according to processing requirements.
At each stage of wafer processing, when the above-mentioned preprocessing steps have been completed, the following post-processing steps are implemented. During post-processing, first, in step 1115 (photoresist formation step), photoresist is applied to a wafer. Next, in step 1116 (exposure step), the above-mentioned exposure device is used to transfer the circuit pattern of a mask (reticle) to a wafer. Then in step 1117 (developing step), the exposed wafer is developed, and in step 1118 (etching step), parts other than residual photoresist (exposed material surface) are removed by etching. In step 1118 (photoresist removal step), unnecessary photoresist remaining after etching is removed. Multiple circuit patterns are formed by repetition of these preprocessing and post-processing steps.
It is to be understood that the exposure apparatuses 10 disclosed herein are merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims.

Claims

1. An exposure apparatus for transferring a mask pattern from a mask to a substrate, the substrate including a site, the exposure apparatus comprising:

a mask retainer that retains the mask;

a substrate stage assembly that retains and positions the substrate;

an illumination system that directs an illumination beam that moves relative to the mask to scan at least a portion of the mask pattern and to generate a pattern beam; and

a projection optical assembly that receives the pattern beam and that directs the pattern beam at the substrate from a stationary projection outlet location.

2. The exposure apparatus of claim 1 wherein the illumination system includes an illumination source that generates the illumination beam and an illumination optical assembly that guides the illumination beam, wherein the illumination optical assembly moves the illumination beam relative to the mask so that the illumination beam scans substantially the entire mask pattern.

3. The exposure apparatus of claim 2 wherein the illumination optical assembly includes an illumination reflector that is positioned so that the illumination beam is incident on the illumination reflector, and an illumination reflector mover that selectively moves the illumination reflector so that the illumination beam is moved along the mask.

4. The exposure apparatus of claim 3 wherein the illumination optical assembly includes a plurality of illumination inlet elements that are aligned along an illumination inlet axis and a plurality of illumination outlet elements that are aligned along an illumination outlet axis, the illumination outlet axis being at an angle relative to the illumination inlet axis and wherein the illumination beam that passes through the illumination inlet elements is redirected by the illumination reflector at the illumination outlet elements.

5. The exposure apparatus of claim 1 wherein the projection optical assembly includes a projection reflector that is positioned so that the pattern beam is incident on the projection reflector, and a projection reflector mover that selectively moves the projection reflector so that the pattern beam exits the projection outlet at the stationary projection outlet location.

6. The exposure apparatus of claim 5 wherein the projection optical assembly includes a plurality of projection inlet elements that are aligned along a projection inlet axis and a plurality of projection outlet elements that are aligned along a projection outlet axis, the projection outlet axis being at an angle relative to the projection inlet axis, and wherein the pattern beam that passes through the projection inlet elements is redirected by the projection reflector at the projection outlet elements.

7. The exposure apparatus of claim 1 wherein the substrate stage assembly positions the substrate along a substrate scan axis.

8. The exposure apparatus of claim 1 further comprising a mask stage assembly that moves the mask along an axis relative to the substrate as the illumination beam scans the mask.

9. A process for manufacturing a wafer that includes the steps of providing a substrate having a first site and a second site, and transferring the first mask pattern to the first site and the second site of the substrate with the exposure apparatus of claim 1.

10. A method for transferring a mask pattern from a mask to a substrate, the substrate including a site, the method comprising the steps of:

retaining the mask with a mask retainer;

positioning the substrate with a substrate stage assembly;

generating an illumination beam with an illumination system;

moving the illumination beam relative to the mask to scan the mask pattern and generate a pattern beam; and

directing the pattern beam from a stationary projection outlet location of a projection optical assembly at the substrate.

11. The method of claim 10 wherein the step of generating includes the step of generating the illumination beam with an illumination source, and wherein the step of moving includes the step of guiding the illumination beam with an illumination optical assembly, wherein the illumination optical assembly moves the illumination beam relative to the mask so that the illumination beam scans the mask pattern.

12. The method of claim 11 wherein the step of moving includes the illumination optical assembly having an illumination reflector that is positioned so that the illumination beam is incident on the illumination reflector, and an illumination reflector mover that selectively moves the illumination reflector so that the illumination beam is moved relative to the mask.

13. The method of claim 11 wherein the step of moving includes the illumination optical assembly having a plurality of illumination inlet elements that are aligned along an illumination inlet axis and a plurality of illumination outlet elements that are aligned along an illumination outlet axis, the illumination outlet axis being at an angle relative to the illumination inlet axis.

14. The method of claim 13 further comprising the steps of directing the illumination beam through the illumination inlet elements and redirecting the illumination beam at the illumination outlet elements with the illumination reflector.

15. The method of claim 10 wherein the step of positioning the substrate includes the step of positioning the substrate along a substrate scan axis with the substrate stage assembly.

16. The method of claim 10 further comprising the step of moving the mask relative to the substrate with a mask stage assembly.

17. The method of claim 10 wherein the step of directing the pattern beam includes the projection optical assembly having a projection reflector that is positioned so that the pattern beam is incident on the projection reflector, and a projection reflector mover, and selectively moving the projection reflector so that the pattern beam exits the projection optical assembly at the stationary projection outlet location.

18. The method of claim 17 wherein the step of directing the pattern beam includes the projection optical assembly having a plurality of projection inlet elements that are aligned along a projection inlet axis and a plurality of projection outlet elements that are aligned along a projection outlet axis, the projection outlet axis being at an angle relative to the projection inlet axis.

19. The method of claim 18 further comprising the steps of directing the pattern beam through the projection inlet elements and redirecting the pattern beam at the projection outlet elements with the projection reflector.

20. A method of making a wafer including the steps of providing a substrate, and transferring the mask pattern from the mask by the method of claim 10.