CA1243427A - Laser pattern generation apparatus - Google Patents
Laser pattern generation apparatusInfo
- Publication number
- CA1243427A CA1243427A CA000509321A CA509321A CA1243427A CA 1243427 A CA1243427 A CA 1243427A CA 000509321 A CA000509321 A CA 000509321A CA 509321 A CA509321 A CA 509321A CA 1243427 A CA1243427 A CA 1243427A
- Authority
- CA
- Canada
- Prior art keywords
- beams
- workpiece
- mirror
- rotating mirror
- apparatus defined
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
- B23K26/0604—Shaping the laser beam, e.g. by masks or multi-focusing by a combination of beams
- B23K26/0608—Shaping the laser beam, e.g. by masks or multi-focusing by a combination of beams in the same heat affected zone [HAZ]
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
- B41M5/00—Duplicating or marking methods; Sheet materials for use therein
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
- B23K26/0604—Shaping the laser beam, e.g. by masks or multi-focusing by a combination of beams
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
- B23K26/064—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
- B23K26/064—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms
- B23K26/0643—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms comprising mirrors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
- B23K26/064—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms
- B23K26/0648—Shaping the laser beam, e.g. by masks or multi-focusing by means of optical elements, e.g. lenses, mirrors or prisms comprising lenses
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
- B23K26/0665—Shaping the laser beam, e.g. by masks or multi-focusing by beam condensation on the workpiece, e.g. for focusing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
- B23K26/067—Dividing the beam into multiple beams, e.g. multifocusing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
- B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
- B23K26/073—Shaping the laser spot
- B23K26/0734—Shaping the laser spot into an annular shape
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/08—Devices involving relative movement between laser beam and workpiece
- B23K26/082—Scanning systems, i.e. devices involving movement of the laser beam relative to the laser head
- B23K26/0821—Scanning systems, i.e. devices involving movement of the laser beam relative to the laser head using multifaceted mirrors, e.g. polygonal mirror
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/70383—Direct write, i.e. pattern is written directly without the use of a mask by one or multiple beams
- G03F7/704—Scanned exposure beam, e.g. raster-, rotary- and vector scanning
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
Landscapes
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- Mechanical Engineering (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Manufacturing & Machinery (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Mechanical Optical Scanning Systems (AREA)
- Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
- Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
- Lasers (AREA)
- Laser Beam Processing (AREA)
- Optical Elements Other Than Lenses (AREA)
- Preparing Plates And Mask In Photomechanical Process (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A laser pattern generation apparatus particularly suited for semiconductor applications. The laser beam is split into a plurality of beams and modulated with acousto-optic modulators. A rotating mirror having a plurality of facets causes the beam to scan the workpiece.
A laser pattern generation apparatus particularly suited for semiconductor applications. The laser beam is split into a plurality of beams and modulated with acousto-optic modulators. A rotating mirror having a plurality of facets causes the beam to scan the workpiece.
Description
~ ~ 4 3 ~Z
1 B~CI~GnOUND O~ Tll~ INV~NTION
1. r,~ield Oe the InventLon.
The invention relates to thc f:ield of pattern generation using a laser ancl radiant sensitive i'ilm, particu],arly eor photolithography.
1 B~CI~GnOUND O~ Tll~ INV~NTION
1. r,~ield Oe the InventLon.
The invention relates to thc f:ield of pattern generation using a laser ancl radiant sensitive i'ilm, particu],arly eor photolithography.
2. Prior ~rt.
In the photol~thographi.c eabri.ca-tion of integrated circ~llts, -films sensitive to radiant or particle energy are exposed in predetermined pa-t-terns to de-fine circuit features. In some cases, the energy is passed through masks which contain -the pat-terns, thereby selectively e~posing a photoresist :eilm on a semiconduct(~r body. In other instances, the Cilm is on a mask substrate and -the ,Eilm is exposed as a step in the making of the mask. Other -times the directlon of the radiant energy itsele is controlled to define patterns in -the film. This can be done as part O:e making a mask or to directly "write" onto -the photoresist Cilm covering a semiconductor wafer.
Several sources of radiant energy have been u'sed, including ultraviolet light, visible light, coherent light, x-rays and elec-tron beam (E-Beam).
In -the very early days oE photolithographic proceesing, patterns were manually cut on a large scale when compared to the final circuit, then photographically reduced to make the -Einal masks. With today's technology, E-Beams are electrically directed to define patterns sometimes at the Cinal scale.
There have been a-ttempts to -fabricate masks by directing ~,.
~l~43~Z~7 1 laser beams an(l/or movirlg a worlc pleee reLative to laser beams.
None oi these ~ttempts are commerelalLy used. As wilL be seen, the present inventi.on is dlreeted to this area.
General pattern generat:lon is deserlbecl Ln U.,S. Patents
In the photol~thographi.c eabri.ca-tion of integrated circ~llts, -films sensitive to radiant or particle energy are exposed in predetermined pa-t-terns to de-fine circuit features. In some cases, the energy is passed through masks which contain -the pat-terns, thereby selectively e~posing a photoresist :eilm on a semiconduct(~r body. In other instances, the Cilm is on a mask substrate and -the ,Eilm is exposed as a step in the making of the mask. Other -times the directlon of the radiant energy itsele is controlled to define patterns in -the film. This can be done as part O:e making a mask or to directly "write" onto -the photoresist Cilm covering a semiconductor wafer.
Several sources of radiant energy have been u'sed, including ultraviolet light, visible light, coherent light, x-rays and elec-tron beam (E-Beam).
In -the very early days oE photolithographic proceesing, patterns were manually cut on a large scale when compared to the final circuit, then photographically reduced to make the -Einal masks. With today's technology, E-Beams are electrically directed to define patterns sometimes at the Cinal scale.
There have been a-ttempts to -fabricate masks by directing ~,.
~l~43~Z~7 1 laser beams an(l/or movirlg a worlc pleee reLative to laser beams.
None oi these ~ttempts are commerelalLy used. As wilL be seen, the present inventi.on is dlreeted to this area.
General pattern generat:lon is deserlbecl Ln U.,S. Patents
3,~65,091; 4,060,816, and 4,464,030. Some aspee-ts o~ UV masls making teehnology is deseribecl in U.S. Paten-ts ~,293,624 and ~,329,410. ~-Beam technology is d1scussed in U.S. Patents 3,679,497; 3,857,041, and 4,445,039. Laser p~ttern generatlon is deseribed in U.S. Patents 3,537,854; 3,622,742; 3,797,935;
3,925,785; 4,110,594, and 4,422,083.
The present inven-tion uses aeousto-optie modula-tors (AOM) to modulate a laser beam. In these modulators a sound wave propagating in crystal causes di~frac-tion o~ light, thereby permitting the light to be modulated. This phenomenon has been known ~or many years and, ~or e~ample, is discussed in "Acousto-optie Bragg Di~raction Devices and -their Applieations", by Walter Baronian, I~E 74 Region 6 Con~erenee, beginning at page 70. The use o~ acousto-optie modulators ~or electronic printing is diseussed in "Laser Seanning ~or ~lectronic Printing", Proeeeding oi the IE~, Vol. 70, No. 6, June 1982, beginning at page 597.
~3 ~L~'7 1 SUM~AR~ _ Tlll~ [NV~NT[ON__ _ An apparatus eor generatlng a pattern on a worlcpLece where the worlcpiece includes a ilm responsive l,o radiant energy is described. A laser is usecl or the source o racllant energy and the beam rom the laser is s~lit in-to a plurality oe beams. These beams are passecl through acousto-optic mo~lulators whlch mocluLators receive electric signals deeining -the patterns. A rota-ting mirror having a plurality o acets is used to direct -the beams rom the modulator in scan patterns as -the workpiece is moved. Thus, the workpiece is wriltten onto in a raster-like scan.
An enlarged intermediate image plane is established eollowing the rotating mirror with an F-theta lens; light is talcen rom this ~lane or system control. A beam split-ter in this plane causes a beam to be de1ec-ted from -the plane and detected to provide a -timing signal synchronized wi-th mirror rotation. The same beam splitter is used to de1ect a beam re1ected erom the workpiece into a photomultiplier tube. This beam is used to de-termine workpiece location (e.g., eor calibration).
Other aspects oi the present invention will be apparent from the detaileA description.
~Z~34Z~7 l BnIL~F DESCIlIPTrO~ OP T1113 I)n~WI~GS
____ _ _ .__ Figure 1 is an optical schemat:Lc showing the overall optlcal path in the apparatus of the present invent:ion.
I'igure 2 i.s an elevat:i.on view O:e tlle apparatus Oe the present invention in schematic .orm principally to iLl.ustrate -the location of the lenses in the opti.ca]. path and the:ir relationship to the part holder.
Figure 3 is a diagram of the beam splitter used in the presently preferred embodiment.
Figure ~ is an eleva-tion view o-f one o: the split-ters used in the beam splitter of Figure 3.
Figure 5 is a diagram showing the lenses used in the post-scan, i.n-termediate image plane.
Figure 6 is a plan view of the part holder and its relationship -to interferometers which are used in the determination of part holder or workpiece position.
Figure 7 is an elevation view of the structure of Figure 6 and also illustra-tes the structure's position relative to the reduction o-f the optical path.
Figure 8 is a diagram used to illustra-te the scan patterns 12/~3~h~
1 (plate write strategy) ust-~l in the presentl.y pre:eer:re~l e~bo(l:lmen-t.
Figure 9 ill~lstrates the :I.ast-3r beams used -to ~orm a "brusll".
Figllre 10 is a timing diagram used -to describe certain aspects O e the present invention.
~Zg~3~
1 DETAILED DESC~IPTION OF T~E INVENTION
A laser pattern generating apparatus is described which is particularly suitable for selectively exposing photosensitive layers such as photoresist layers used in the fabrication of integrated circuits. In the following description, numerous specific details are set forth such as specific wave].ength, lenses, etc., in order to provide - a thorough understanding of the present invention. It will be obvious, however, to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known structures, support members, etc., not necessary to the present invention, are not been set forth in detail in order not to unnecessarily obscure the present invention.
OVERVIEW OF THE INVENTION
The pat~ern generation apparatus of the present invention uses a laser beam to expose a radiant sensitive film. The laser beam is split into eight beams to create a brush. The brush scans the workpiece through use of a rotating mirror. Each beam of the brush is modulated through acousto-optical modulators. The electrical signals coupled to these modulators determine the specific pattern which is generated. The "rasterizer" system used for providing the electrical signals to the modulators is described in copending Canadian application, Serial No. 508,739, filed May 8, 1986 which is assigned to the assignee of the present invention.
:~'Z~ J
1 The workpiece containing the photosensitive film is mounted on a movable table which moves in one axis during scanning (stripe axis). The table also moves in the scan axis when writing is not occurring.
Interferometers detect movement of the workpiece in 1~4~
1 -these axe.s. ~ determlnatlon o~ wor]cpiece po~itlon relatLve to he~m posltlon is made from rei'lccted llgh-t ln a tel~cerltrlc enLarged lmage plane. This same image ~l~ne Is ll.Se(l I'or rn;irror facet detection, thus permittlng data syncllron:lzatLorl to the acousto-optical modulators.
OP'rICAL PATII OF TIIF~ IMV~JNT~ APP~R~TUS
~ cferring to ~igure 1 in the currently preferrecl embodiment a continuous wave laser lO providing lOO 200 milliwatts of radiation at a frequency of 363.8nm is used. The beam from laser lO is compressed through ordinary beam compressor 12 to ~repare the beam ~or splitting.
The multiple beam splitter 13 splits the beam from the laser 10 in-to eight beams. The specific optical arrangement -for providing this splitting is described in conjunction with Figures 3 and ~.
The eight beams ~rom the spli-tter 13 (sometimes re-ferred to collectively as the "brush") passes through the -relay lenses l~. This three elemen-t lens (shown in Figure 2), in effect, focuses and shrinks the beams from -the splitter 13 by approximately a factor of -two.
Commercially available acousto-optical modulators (AOMs) 16 are employed -to modula-te -the light beams. In -the presently preferred embodiment, eight transducers are -formed on the surface of a single crystal. A carrier of 160 MIIz is used, that is, the presence o-f -the carrier determines whether the beam will be diffracted through the crys-tal onto the workpiece; the amplitude of the carrier determines the intensity o-f the beam. (The zero order beam is no-t used.) ~ight modulated beams may be obtained -from a single beam using a single AOM where eight carrier frequencies are used. The .~2434~'~
1 de:elect:ion :erom the AOM i.s a :~unct:lon o:~ ere~lucncy and each carrler erequency creates ~ separate beam. ~lternatlvely, electro-optic modulators may be employecl ln ~lace Oe the AOMs. Nel-l:her o~ thesc are usecl ln the currently preferred embodlment.
The eigh-t beams erom the AO~ are directed through a dove prism 17. rhis prism is used -to rota-te the brush of: beams, and while not easily demonstrable in the view O:e Figure l the beams ln eeEec-t are tLI-ted out o~ the plane Oe the :eigure. Tlle ul-tLma-te brush eormed by the beams cornprises overlapping projections o~ each of the beams without interference between the beams since in addition to the ro-tation ~rom prism 17 a -time delay is used between the activation of each Oe the beams. If this is not done non-uni~orm exposùre Oe the photoresist can result.
The beams ~rom prism 17 pass through -the single relay lens 18 to converge to a spot on the steering mirror 20. In -the currently preferred embodiment -this spot is approximately 1.5mm in diameter. The steering mirror 20 is an elec-trically controllable mirror which permits the beams' angles to be moved (adjusted) on the facets comprising mi.rror 24. The beams reelecting erom mirror 20 pass througl~ the zoom lens 22 which comprises eour elemen-ts shown in Figure 2. This zoom lens perm-~ts -the beams to be made larger and moved further apart or to be made smaller and closer together on the workpiece. This zoom is elec-trically controlled and is set ~or each workpiece.
The rotating polygon mirror 24 in the curren-tly preferred embodiment comprises 24 eacets each of which de-~lect the beams from the zoom lens 22 into the F-theta lens 26. I-t is this mirror which provides the scanning action o~ the beams. In the currently 1 preferrecl embo(liment, this mlrror rotates between l2,000 -to 20,000 rpms; thlls, ~lle ~cans occur a-t a rate between ~kllz and ~OkllY. r~er second. llowever, the mirror rotat:e.s at a con.stan-t rate eor a given pat-tern.
The beams :erom mirror 24 are enlarged in a post-scan, intermediate imaGe plane (lOx image plane) as shown in Figure 1. ~t one end o:E this p]ane, F--theta lens 26 is use(l to ~orm the l~lane ancl at the other end a reduction lens 32 is used to provlde the Einal beams. The Einal reduced beam scans the plate or workpiece 34. The lenses oE the F-theta lens arrangement and reduction lens 32 are shown in Figllre 5.
A spli-tter 28 is disposed in the lOx image plane. As will be described later, one o~ the beams is activated prior to each scan and is used to detect the mirror Eacets. The beam is re~lected from -15 splitter 28 to a ~acet de-tect circui-t which provides a pulse indicating -Eacet position. This permits the pattern clata to the A0~l 16 to be synchronized ~ith the mirror rotation. ReElections Erom -the workpiece 3~ (or its part holder) are also reflected by the splitter 28 and -Eocused into a photomultiplier tube. These re~lections are used Eor calibration and other purposes as will be described la-ter.
A shut-ter 30 operates in the lOx image plane. This shutter prevents light :Erom reaching the workpiece except during scanning or other selected -times such as at calibration.
In Fig~lre 2 the ac-tual optical path as curren-tly realized is shown. The laser, lenses, rotating mirror, etc., are mounted to a rigid metal -t`rame ~5. The Erame is supported by metal su~ports 46 and 47 wllicil are mounted on a sin~le grani-te member to minimize ~LZ~34Z~
1 movemen-t. The worlcpiece or plate ls secured on the part holder and this assem~ly, as will be described, moves below the redllctLorl len.s 32.
In the optical path of Figure 2, the designa-t:ion "L" refers to lenses, the designa-tion "F" refers to eocal pOilltS, and the designation "AF" refer -to aeocal points.
The beam from -the laser passes through lenses Ll ancl L2 which are the beam compressor 12 sho\vn in ~igure 1. The beam is then -focusecl lnto the beam splitter 13 which, as mentioned, will be described later with Figures 3 and ~.
The relay lenses 1~ of Figure 1 are formed by lenses L3, L,~
and L5 which include the afocal pOillt AFl between lenses L~ and L5.
The AOM 16 is again shown and receives the eight beams from the lenses l~. The modulated light from the AOM passes -through the dove prism 17 and then through -the beam folding prism 37, relay lens 18 (L6), beam folding prism 38, and onto the steering mirror 20. From there the beams are reflected from mirror 39, pass through the beam folding prism 40 and are directed to -the zoom lens assembly which comprises lenses L7, L8, L9, L10 and the beam folding prism ~l. A
focal point F3 is loca-ted within the prism 41. The beams :Erom the zoom lens assembly then are re-flected by mirror ~8 onto the rotating mirror (polygon) 2~. .
The pos-t-scan optics are again shown in Figure 2 which includes the F-theta lens 26, the beam splitter 28, shutter 30 and reduction lens 32.
All the lenses discussed above are commercially obtainable.
B~AM SPLITT~R 13 OF FIG~RFS 1 ~ND 2 Figure ~ shows one O:e the three similar plates 50 used in ~2~34Z7 1 -the beam splitter. The bocly 55 :is an ordLnary botly such as ~lass which transmi-ts the beam. The upper surEace~ oL' -the body Lncllldes an anti-reflective coating 52. Partially covering thls coating is a 50% reflective coating or layer 53. On the lower surEace Oe hody 55 a 100% re-1ective coating or layer 51 is -formed.
As is seen, a beam 53 inciden-t on layer 53 is re-Elected as shown by beam 59. A portion oE the beam 53 shown as beam 60 enters the body 55 and is reflec-ted Erom the coa-ting 51 (beam 61). Note that the beam 61 upon e~iting the plate 50 does not stril~e the layer 53.
Three p]a-tes such as plate 50 o-E Figure 4 are shown in Figure 3 (plates 50a, 50b and 50c) and are used to provide eight beams in -the presently pre-ferred embocliment. Plate 50b is twice as thick as plate 50a; plate 50c is twice as thick as plate 50b. The plates are mollnted parallel to one another in the curren-tly pre-Eerred embodiment.
As seen in Figure 3 a beam 63 -firs-t striking plate 50a provides two beams. (This is also shown in Figure ~.) The two beams are then incident on the layer 53 of plate 50b. }lalE o-E each of these beams is reflected Erom layer 53. The portions o~ the beams which pass through layer 53 are reElec-ted by layer 51 to provide two additional beams, thus a total oE Eour beams leave the plate 50b. In a similar -fashion, all :Eour beams Erom plate 50b are partly reElected Erom the laver 53 oE plate 50c and four beams are reflected -from layer 51 of plate 50c to provide the eight beams ~Ised in the presently pre:Eerred embodiment.
i~4~ 7 1 10~ IMAGE PLANE OPTICS
One aspec-t oE the present ap~aratlls is its llSe Oe an enlarged ima~e plane :eollowin~ the scan optics. In the currentl~
preferred embodiment, a 10~ image plane is used between the rota-ting mirror and the workpiece. This intermediate telecentric image plane assists in -facet detection, calibration and workpiece position determination, particularly for direc-t write applications.
Referring to Figure 5, the intermedia-te plane is created by the F--theta lenses 26. Known F-theta lens technology is used to create the intermedia-te plane -following the rotating mirror.
A beam splitter 28 is disposed in the light path following the F-theta lenses. This beam splitter is used to spli-t away a small portioll of the light directed at the workpiece to a facet detector 67. An ordinar~ photodiode or like device is s-uitable eor the facet detector 67. Beams 66 of Figure 5 are shown re-~lected from-the sur-face 28a of the beam splitter and are incident on the detector 67. As will be discussed in more detail, one o-E -the beam channels is turned on throueh the AOM prior to each scan oi the workpiece. The -facet detector de-tects this beam and this information is used to time the data couplecl to the AO~.
This is shown in Figure 10. The other sur-face 28b of the beam splitter 28 is used to split a portion of the beam re~lected -~rom the workpiece. This light which is coupled -to a photomultiplier tube 71 is used for calibration and position detection.
A shutter 30 is positioned within the intermediate image plane as shown in ~igure 5. The AOM, when ofe, still permits a small amount o-f light (e.g., 1%~ to be diffrac-ted onto the workpiece.
3~;27 1 When the stage carrylng the worlcpiece Is stopped, this light can cause unwan-ted exposure o~ the pho-toresJst. The electrically operated shutter is closed when scanning onto the workpiece is not -, occurring. (The beam o~ channel 1 which is turned on be~ore actual scanning ~or Eacet detection, as previously mentioned, does not eall onto the worlcpiece.
The shutter 30 is positioned past the splitter 2~ slnce ~acet detect signals are used ~or moving the table. Note that i~
the shutter were ~urther upstream in -the optical path, ~acet detec-t signals would not be received when the shut-ter was closed, thereby preventing generation o-f timing signals used to move the table.
The reduction lens assembly 32 is a cornmercially ob-tainable reduction lens which ~ocuses the beams -From the lOx plane onto the workpiece.
WORI~PIEC~ _ ITING FORM~T_ The scan pattern and workpiece movement permit the eight beams to wri-te virtually any pattern. While the particular ~vri-ting format employed is not crucial to the optical path, an explanatLon o-~ the format assists in understanding the overall opera-tion o~ the invention.
The patterns are generated in blochs on the workpiece such as block 68 shown in Figure ~. Each block uses 256K address uni-ts o~ data in the scan axis and 256g address uni-ts in -the s-tripe axis.
A single address in both axes de~ines a 0.5 micron square.
The bearns are caused to scan by the rota-ting mirror in the scan axis clirection. The eight beams are shown within circle 69.
The brush ~ormed by -these beams pain-ts a scan line 70 shown within circle 73. ~s this scanning occurs, -the workpiece is moved in the 3~Z~
l stripe dlrection. Th~ls, the scanning proceeds in a ras-ter-llke manner. ~ach scan line, as preserl-tly irnplemen-tecl, is ~L096 adtlress units wide with one bit being used in each address unit ~or controlling each o-f the beams. Therefore, the scan line itself is 8 "bits" wide. The binary code is used to either turn on or turn of~
its respectlve beam. A gray scale may also be used where a plurality of bits are associated with each beam -to provide ~rada-tion hetween the on and o-fI s-tates.
In tlle rasterizer used with the pat-tern generation apparat~ls, ~rames are generateA which are 102~ address units lon~ in the stripe axis direction. Ilowever, this delineation is not de-tectable within the beam or table movement itself, but ra-ther is confined to the rasterizer. A plurali-ty of -frames are used to provide a pass such as defined by the rec-tangle 72. The number oE
the -frames in a pass is arbitrary.
Assume for purposes O-e discussion that four identical patterns (pattern 2) are to be written within the block 6~. In ~he presen-tly preeerred embodiment, pass 72 is first written into block 7~ and then the table is moved so that the same in-Pormation contained in -that pass can be rewritten into the bloclcs 73, 76 and then 75. Another pass is then made in each oi -the blocks until the entire pattern has been writ-ten four times within block 68. 0-ther patterns may be writ-ten on the workpiece in blocks adjacen-t to blocks 68 such as shown by pattern l to the left of block 68. The ~a-ttern l or 2 o~ Figure 8 may represent, by way o~ example, 5x or lOx masks, or as mentioned, may represent circuit elements ~enerated directly on a semiconductor wafer.
As currently implemented, -the beams only write in 1~4~4;~
1 conjunction with stripe axis movement an~l no wrlti.ng occur.s wherl the table is movecl in the scan axis. Workpiece movement in the scan axis occurs, for instance, to reposition the workpiece for each pass.
SC~N LIN~ BEAMS
In circle 69 o-~ Figure 3 the eight beam3 which paint -the pattern in each scan are shown overlapping one another. In reali-ty, the beams do not overlap although tlleir projections on the workpiece overlap. The dove prism 17 of Figure 1 orients the beams so that they are spacially displaced as mentioned. This displacement is shown in Figure 9 by the beams 77. (The beams 77 represent the projection oc the beams, ie -they were t-lrned on be~ore they reached line 78.) Line 78 represents a line perpendicular to the scan axis and this line is sho~vn in Figure 8 -through scan line 70. As each of the beams reach line 78 they are activated (one at a time) as a function of the in~ormation (binary one or zero) accessed ~or address unit at that posi-tion along the sc~n axis and stripe axis.
In opera-tion, the data signals controlling the beams are sequenti~lly applied to the AOM 16 of Figure 1; each signal is delayed by an appropriate amount so that the beam is turned on (i~
needed for the pattern) along line 73 and the equidistant lines.
This allows -the projection o~ the beams to overlap withou-t having the beams themselves overlap. I~ the beams themselves overlap, uncontrolled in-ter-~erence occurs, preventing a "clean" scan line -~rom being written.
TABLF ~SSF.M~LY
Referring ~irst to Figure 7, the plate 3~ which is monnted in the partholder can be moved in three a~es. Movement to and ~rom t ~34~ ;~
1 the reduction lenses 32 (Z axis) is not 111us-tra-ted Ln the drawlngs. This movement is done for foc-llsing.
D~lring pattern generation, as men-tioned, ~,he plate 34 and partholder are moved along the s-tr:Lpe a~is by mo-tor 83 since they are moun-ted on the stripe stage 82. This axis for the view of Figure 7 is into and out of the drawing. The stripe stage 82 is moun-ted on the scan stage 80, thereby causing the plate 3~ to move when the stage 80 moves. The stage 80 moves along the scan axis and is driven by mo-tor 81. As mentioned, this movement does not occur during scanning, but rather, for instance, between scans to reposition for each pass. The partholder may also be adjusted (tilted) to level the workpiece rela-tive to the beams.
Referring to Figures 6 and 7, a mirror 88 is mounted perpendicular on the stage 82, and similarly, a mirror 92 is mounted on stage 82 perpendicular -to the stripe a~is. A mirror is mounted on the reduction lens 32 perpendicular to the scan axis, and similarly, a mirror 43 is mountecl on the reduction lens 32 perpendicular -to the stripe axis. Relative movement in the scan d:Lrection between the stage 82 and lens 32 is detected by a differential interferometer 89. This differential interferometer reflects a pair of beams from each of the mirrors ~4 and 88.
Similarly, relative movemen-t in -the stripe direction is detec-ted by the differential interferometer 9~ as light is reflected ~or mirrors 43 and 92. The light is reflected from mirrors 82 and 92 at -the level of the plate 3~ to obtain accurate relative movement of the pla-te.
The differential interferometers 89 and 94 are commercially available inter-ferometers.
~LZ~3~
l The intereerometers along with the photomul-tiplier tube oe Figure 5 which receives the light reflected -erom the wor1splece (see sureace 28b Oe beam splitter 2~, Figure ~) play an important role In the calibration o e the apparatus and in position determina-tion of the workpiece.
Calibra-tion marks 97 and 98 are ~ormed on the upper sur~ace of the part holder. These marlss can al-ternatively be formed on -the plate itsele ~e.g., with chrome disposi-tion and etching steps).
These mar1cs have a known displacement from a pattern origin. The pat-tern data is generated relative to -this origin. When one Oe the eight beams is turned on, reelection erom the markers 97 or 98 can be sensed by the photomultiplier tube. This provides accura-te data on the relative position o-~ the pattern origin and beam. When the workpiece is moved either in the scan or stripe direc-tions, accurate position data is available -from -the intereerometers, thus providing a continuous s-tream of position data.
There are numerous other uses ~or -the combina-tion of the data -from the interferometer and photomultiplier tube. For instance, as previously mentioned~ a scan line is ~096 address l1nits in length. ~eam l :~or address unit one can :eirs-t be activated and its coordinates de-termined by the pho-tomultiplier -tube in conjunction with a marker. Then beam l can again be turnec1 on eor the ~096 address unit o-f -the scan and this posi-tion determined with a marlcer. From this da-ta the length o-f a scan line can be deter1nined. Similarly, the width Oe the brush can be determined by activating beams l and 8. The skew in the stripe axis caused by workpiece mo-tion d~lring scanning can also be determined and adjus-ted for electrically by adjusting the -time at which data is applied to ~;
34Z~
1 the ~OM. Other applicat:Lons include s~ot s:iz,e measurelnent, cr-Ltlcal dimension measurements, ro-tating mirror rota-tion stahility -tests, s-teering mirror positioning, ~oom lens calibra-tion, timing , calibration, F-the-ta trans~er function measurements, determina-t:Lon of lens linearity throughout the entlre optics system, focal field flatness measurement, column orthogonality testing and auto focus calibration.
The telecentric arrangement of the intermedia-te field plane with the combina-tion of the beam splitter and photomultipller -tube along with the in-terferometers and marlss on the moving assembly provide precise coordination between these otherwise independent subsystems.
DATA T~MING
The -timing of the data relative to mirror position is important. If the beams are turned on too early or too late relative to the position of each o-f the facets on the rota-ting mirror, one scan line can be displaced -from the next. As previously mentioned, the timing signals ~or -the data and the enabling oE the AOM, are developed through the facet detector. Channel one is turned on before the eacet is in a posi-tion to cause a beam or beams to be directed onto the workpiece. The beam is reflected erom splitter 28 onto a photodetector to generate a timing pulse. Tile turning on of this beam is illustrated by pulse 105 in Figure l0.
The facet detection is shown by pulse 106 in Figure lO. This detection ini-tia-tes a time seq~lence which consists of a fixed delay, a scan correction and a skew correction. The total delay is shown as delay 108 in ~igure 10.
A-fter the delay the print clock enal)le signal 107 enables ~2~3~27 1 the pixel clock 109 to ~enerate the si~nals ~or clocking the date (~096 address units) in-to the AOM. ~s shown by waveEorm 110 the data selectively enables -the beams -to prin-t the ~attern.
~ stripe 111 which comprises a plurali-ty oc scans l.s shown in Figure 10. Line 112 represents a time axis Eor the s-tripe 111.
Line 113 illustrates an angle added to line 112; this angle represents -the skew introduced in-to each scan line caused by the movement in the stripe direction durirlg scanning. This is the "skew Eactor increment" in the delay 108. The dot-ted line represents scan direction deviation erom true stripe a~is movemen-t. This deviation is measured by interferometer 9~. The diiference between the dotted line and line 112 represents the "scan correction" for the delay 108. The "-fixed" delay is the average expec-ted delay. The computed clelay 108 thus allows the printing to occur where intended despite -facet deviation, the raster nature of the scanning and stripe table movement deviation.
During scanning, non-constant velocity table movement may also occur in the stripe a~is direction. These variations are detected by interferometer 89. The information from inter-Eerometer 89 controls the steering mirror 20 and corrects rela-tive beam-wor~piece movement in the stripe direction.
Thus, a laser pattern generation apparatus has been described which includes numerous unique Eeatures, both in its optical path and as part o-E its mechanical subsystem.
3,925,785; 4,110,594, and 4,422,083.
The present inven-tion uses aeousto-optie modula-tors (AOM) to modulate a laser beam. In these modulators a sound wave propagating in crystal causes di~frac-tion o~ light, thereby permitting the light to be modulated. This phenomenon has been known ~or many years and, ~or e~ample, is discussed in "Acousto-optie Bragg Di~raction Devices and -their Applieations", by Walter Baronian, I~E 74 Region 6 Con~erenee, beginning at page 70. The use o~ acousto-optie modulators ~or electronic printing is diseussed in "Laser Seanning ~or ~lectronic Printing", Proeeeding oi the IE~, Vol. 70, No. 6, June 1982, beginning at page 597.
~3 ~L~'7 1 SUM~AR~ _ Tlll~ [NV~NT[ON__ _ An apparatus eor generatlng a pattern on a worlcpLece where the worlcpiece includes a ilm responsive l,o radiant energy is described. A laser is usecl or the source o racllant energy and the beam rom the laser is s~lit in-to a plurality oe beams. These beams are passecl through acousto-optic mo~lulators whlch mocluLators receive electric signals deeining -the patterns. A rota-ting mirror having a plurality o acets is used to direct -the beams rom the modulator in scan patterns as -the workpiece is moved. Thus, the workpiece is wriltten onto in a raster-like scan.
An enlarged intermediate image plane is established eollowing the rotating mirror with an F-theta lens; light is talcen rom this ~lane or system control. A beam split-ter in this plane causes a beam to be de1ec-ted from -the plane and detected to provide a -timing signal synchronized wi-th mirror rotation. The same beam splitter is used to de1ect a beam re1ected erom the workpiece into a photomultiplier tube. This beam is used to de-termine workpiece location (e.g., eor calibration).
Other aspects oi the present invention will be apparent from the detaileA description.
~Z~34Z~7 l BnIL~F DESCIlIPTrO~ OP T1113 I)n~WI~GS
____ _ _ .__ Figure 1 is an optical schemat:Lc showing the overall optlcal path in the apparatus of the present invent:ion.
I'igure 2 i.s an elevat:i.on view O:e tlle apparatus Oe the present invention in schematic .orm principally to iLl.ustrate -the location of the lenses in the opti.ca]. path and the:ir relationship to the part holder.
Figure 3 is a diagram of the beam splitter used in the presently preferred embodiment.
Figure ~ is an eleva-tion view o-f one o: the split-ters used in the beam splitter of Figure 3.
Figure 5 is a diagram showing the lenses used in the post-scan, i.n-termediate image plane.
Figure 6 is a plan view of the part holder and its relationship -to interferometers which are used in the determination of part holder or workpiece position.
Figure 7 is an elevation view of the structure of Figure 6 and also illustra-tes the structure's position relative to the reduction o-f the optical path.
Figure 8 is a diagram used to illustra-te the scan patterns 12/~3~h~
1 (plate write strategy) ust-~l in the presentl.y pre:eer:re~l e~bo(l:lmen-t.
Figure 9 ill~lstrates the :I.ast-3r beams used -to ~orm a "brusll".
Figllre 10 is a timing diagram used -to describe certain aspects O e the present invention.
~Zg~3~
1 DETAILED DESC~IPTION OF T~E INVENTION
A laser pattern generating apparatus is described which is particularly suitable for selectively exposing photosensitive layers such as photoresist layers used in the fabrication of integrated circuits. In the following description, numerous specific details are set forth such as specific wave].ength, lenses, etc., in order to provide - a thorough understanding of the present invention. It will be obvious, however, to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known structures, support members, etc., not necessary to the present invention, are not been set forth in detail in order not to unnecessarily obscure the present invention.
OVERVIEW OF THE INVENTION
The pat~ern generation apparatus of the present invention uses a laser beam to expose a radiant sensitive film. The laser beam is split into eight beams to create a brush. The brush scans the workpiece through use of a rotating mirror. Each beam of the brush is modulated through acousto-optical modulators. The electrical signals coupled to these modulators determine the specific pattern which is generated. The "rasterizer" system used for providing the electrical signals to the modulators is described in copending Canadian application, Serial No. 508,739, filed May 8, 1986 which is assigned to the assignee of the present invention.
:~'Z~ J
1 The workpiece containing the photosensitive film is mounted on a movable table which moves in one axis during scanning (stripe axis). The table also moves in the scan axis when writing is not occurring.
Interferometers detect movement of the workpiece in 1~4~
1 -these axe.s. ~ determlnatlon o~ wor]cpiece po~itlon relatLve to he~m posltlon is made from rei'lccted llgh-t ln a tel~cerltrlc enLarged lmage plane. This same image ~l~ne Is ll.Se(l I'or rn;irror facet detection, thus permittlng data syncllron:lzatLorl to the acousto-optical modulators.
OP'rICAL PATII OF TIIF~ IMV~JNT~ APP~R~TUS
~ cferring to ~igure 1 in the currently preferrecl embodiment a continuous wave laser lO providing lOO 200 milliwatts of radiation at a frequency of 363.8nm is used. The beam from laser lO is compressed through ordinary beam compressor 12 to ~repare the beam ~or splitting.
The multiple beam splitter 13 splits the beam from the laser 10 in-to eight beams. The specific optical arrangement -for providing this splitting is described in conjunction with Figures 3 and ~.
The eight beams ~rom the spli-tter 13 (sometimes re-ferred to collectively as the "brush") passes through the -relay lenses l~. This three elemen-t lens (shown in Figure 2), in effect, focuses and shrinks the beams from -the splitter 13 by approximately a factor of -two.
Commercially available acousto-optical modulators (AOMs) 16 are employed -to modula-te -the light beams. In -the presently preferred embodiment, eight transducers are -formed on the surface of a single crystal. A carrier of 160 MIIz is used, that is, the presence o-f -the carrier determines whether the beam will be diffracted through the crys-tal onto the workpiece; the amplitude of the carrier determines the intensity o-f the beam. (The zero order beam is no-t used.) ~ight modulated beams may be obtained -from a single beam using a single AOM where eight carrier frequencies are used. The .~2434~'~
1 de:elect:ion :erom the AOM i.s a :~unct:lon o:~ ere~lucncy and each carrler erequency creates ~ separate beam. ~lternatlvely, electro-optic modulators may be employecl ln ~lace Oe the AOMs. Nel-l:her o~ thesc are usecl ln the currently preferred embodlment.
The eigh-t beams erom the AO~ are directed through a dove prism 17. rhis prism is used -to rota-te the brush of: beams, and while not easily demonstrable in the view O:e Figure l the beams ln eeEec-t are tLI-ted out o~ the plane Oe the :eigure. Tlle ul-tLma-te brush eormed by the beams cornprises overlapping projections o~ each of the beams without interference between the beams since in addition to the ro-tation ~rom prism 17 a -time delay is used between the activation of each Oe the beams. If this is not done non-uni~orm exposùre Oe the photoresist can result.
The beams ~rom prism 17 pass through -the single relay lens 18 to converge to a spot on the steering mirror 20. In -the currently preferred embodiment -this spot is approximately 1.5mm in diameter. The steering mirror 20 is an elec-trically controllable mirror which permits the beams' angles to be moved (adjusted) on the facets comprising mi.rror 24. The beams reelecting erom mirror 20 pass througl~ the zoom lens 22 which comprises eour elemen-ts shown in Figure 2. This zoom lens perm-~ts -the beams to be made larger and moved further apart or to be made smaller and closer together on the workpiece. This zoom is elec-trically controlled and is set ~or each workpiece.
The rotating polygon mirror 24 in the curren-tly preferred embodiment comprises 24 eacets each of which de-~lect the beams from the zoom lens 22 into the F-theta lens 26. I-t is this mirror which provides the scanning action o~ the beams. In the currently 1 preferrecl embo(liment, this mlrror rotates between l2,000 -to 20,000 rpms; thlls, ~lle ~cans occur a-t a rate between ~kllz and ~OkllY. r~er second. llowever, the mirror rotat:e.s at a con.stan-t rate eor a given pat-tern.
The beams :erom mirror 24 are enlarged in a post-scan, intermediate imaGe plane (lOx image plane) as shown in Figure 1. ~t one end o:E this p]ane, F--theta lens 26 is use(l to ~orm the l~lane ancl at the other end a reduction lens 32 is used to provlde the Einal beams. The Einal reduced beam scans the plate or workpiece 34. The lenses oE the F-theta lens arrangement and reduction lens 32 are shown in Figllre 5.
A spli-tter 28 is disposed in the lOx image plane. As will be described later, one o~ the beams is activated prior to each scan and is used to detect the mirror Eacets. The beam is re~lected from -15 splitter 28 to a ~acet de-tect circui-t which provides a pulse indicating -Eacet position. This permits the pattern clata to the A0~l 16 to be synchronized ~ith the mirror rotation. ReElections Erom -the workpiece 3~ (or its part holder) are also reflected by the splitter 28 and -Eocused into a photomultiplier tube. These re~lections are used Eor calibration and other purposes as will be described la-ter.
A shut-ter 30 operates in the lOx image plane. This shutter prevents light :Erom reaching the workpiece except during scanning or other selected -times such as at calibration.
In Fig~lre 2 the ac-tual optical path as curren-tly realized is shown. The laser, lenses, rotating mirror, etc., are mounted to a rigid metal -t`rame ~5. The Erame is supported by metal su~ports 46 and 47 wllicil are mounted on a sin~le grani-te member to minimize ~LZ~34Z~
1 movemen-t. The worlcpiece or plate ls secured on the part holder and this assem~ly, as will be described, moves below the redllctLorl len.s 32.
In the optical path of Figure 2, the designa-t:ion "L" refers to lenses, the designa-tion "F" refers to eocal pOilltS, and the designation "AF" refer -to aeocal points.
The beam from -the laser passes through lenses Ll ancl L2 which are the beam compressor 12 sho\vn in ~igure 1. The beam is then -focusecl lnto the beam splitter 13 which, as mentioned, will be described later with Figures 3 and ~.
The relay lenses 1~ of Figure 1 are formed by lenses L3, L,~
and L5 which include the afocal pOillt AFl between lenses L~ and L5.
The AOM 16 is again shown and receives the eight beams from the lenses l~. The modulated light from the AOM passes -through the dove prism 17 and then through -the beam folding prism 37, relay lens 18 (L6), beam folding prism 38, and onto the steering mirror 20. From there the beams are reflected from mirror 39, pass through the beam folding prism 40 and are directed to -the zoom lens assembly which comprises lenses L7, L8, L9, L10 and the beam folding prism ~l. A
focal point F3 is loca-ted within the prism 41. The beams :Erom the zoom lens assembly then are re-flected by mirror ~8 onto the rotating mirror (polygon) 2~. .
The pos-t-scan optics are again shown in Figure 2 which includes the F-theta lens 26, the beam splitter 28, shutter 30 and reduction lens 32.
All the lenses discussed above are commercially obtainable.
B~AM SPLITT~R 13 OF FIG~RFS 1 ~ND 2 Figure ~ shows one O:e the three similar plates 50 used in ~2~34Z7 1 -the beam splitter. The bocly 55 :is an ordLnary botly such as ~lass which transmi-ts the beam. The upper surEace~ oL' -the body Lncllldes an anti-reflective coating 52. Partially covering thls coating is a 50% reflective coating or layer 53. On the lower surEace Oe hody 55 a 100% re-1ective coating or layer 51 is -formed.
As is seen, a beam 53 inciden-t on layer 53 is re-Elected as shown by beam 59. A portion oE the beam 53 shown as beam 60 enters the body 55 and is reflec-ted Erom the coa-ting 51 (beam 61). Note that the beam 61 upon e~iting the plate 50 does not stril~e the layer 53.
Three p]a-tes such as plate 50 o-E Figure 4 are shown in Figure 3 (plates 50a, 50b and 50c) and are used to provide eight beams in -the presently pre-ferred embocliment. Plate 50b is twice as thick as plate 50a; plate 50c is twice as thick as plate 50b. The plates are mollnted parallel to one another in the curren-tly pre-Eerred embodiment.
As seen in Figure 3 a beam 63 -firs-t striking plate 50a provides two beams. (This is also shown in Figure ~.) The two beams are then incident on the layer 53 of plate 50b. }lalE o-E each of these beams is reflected Erom layer 53. The portions o~ the beams which pass through layer 53 are reElec-ted by layer 51 to provide two additional beams, thus a total oE Eour beams leave the plate 50b. In a similar -fashion, all :Eour beams Erom plate 50b are partly reElected Erom the laver 53 oE plate 50c and four beams are reflected -from layer 51 of plate 50c to provide the eight beams ~Ised in the presently pre:Eerred embodiment.
i~4~ 7 1 10~ IMAGE PLANE OPTICS
One aspec-t oE the present ap~aratlls is its llSe Oe an enlarged ima~e plane :eollowin~ the scan optics. In the currentl~
preferred embodiment, a 10~ image plane is used between the rota-ting mirror and the workpiece. This intermediate telecentric image plane assists in -facet detection, calibration and workpiece position determination, particularly for direc-t write applications.
Referring to Figure 5, the intermedia-te plane is created by the F--theta lenses 26. Known F-theta lens technology is used to create the intermedia-te plane -following the rotating mirror.
A beam splitter 28 is disposed in the light path following the F-theta lenses. This beam splitter is used to spli-t away a small portioll of the light directed at the workpiece to a facet detector 67. An ordinar~ photodiode or like device is s-uitable eor the facet detector 67. Beams 66 of Figure 5 are shown re-~lected from-the sur-face 28a of the beam splitter and are incident on the detector 67. As will be discussed in more detail, one o-E -the beam channels is turned on throueh the AOM prior to each scan oi the workpiece. The -facet detector de-tects this beam and this information is used to time the data couplecl to the AO~.
This is shown in Figure 10. The other sur-face 28b of the beam splitter 28 is used to split a portion of the beam re~lected -~rom the workpiece. This light which is coupled -to a photomultiplier tube 71 is used for calibration and position detection.
A shutter 30 is positioned within the intermediate image plane as shown in ~igure 5. The AOM, when ofe, still permits a small amount o-f light (e.g., 1%~ to be diffrac-ted onto the workpiece.
3~;27 1 When the stage carrylng the worlcpiece Is stopped, this light can cause unwan-ted exposure o~ the pho-toresJst. The electrically operated shutter is closed when scanning onto the workpiece is not -, occurring. (The beam o~ channel 1 which is turned on be~ore actual scanning ~or Eacet detection, as previously mentioned, does not eall onto the worlcpiece.
The shutter 30 is positioned past the splitter 2~ slnce ~acet detect signals are used ~or moving the table. Note that i~
the shutter were ~urther upstream in -the optical path, ~acet detec-t signals would not be received when the shut-ter was closed, thereby preventing generation o-f timing signals used to move the table.
The reduction lens assembly 32 is a cornmercially ob-tainable reduction lens which ~ocuses the beams -From the lOx plane onto the workpiece.
WORI~PIEC~ _ ITING FORM~T_ The scan pattern and workpiece movement permit the eight beams to wri-te virtually any pattern. While the particular ~vri-ting format employed is not crucial to the optical path, an explanatLon o-~ the format assists in understanding the overall opera-tion o~ the invention.
The patterns are generated in blochs on the workpiece such as block 68 shown in Figure ~. Each block uses 256K address uni-ts o~ data in the scan axis and 256g address uni-ts in -the s-tripe axis.
A single address in both axes de~ines a 0.5 micron square.
The bearns are caused to scan by the rota-ting mirror in the scan axis clirection. The eight beams are shown within circle 69.
The brush ~ormed by -these beams pain-ts a scan line 70 shown within circle 73. ~s this scanning occurs, -the workpiece is moved in the 3~Z~
l stripe dlrection. Th~ls, the scanning proceeds in a ras-ter-llke manner. ~ach scan line, as preserl-tly irnplemen-tecl, is ~L096 adtlress units wide with one bit being used in each address unit ~or controlling each o-f the beams. Therefore, the scan line itself is 8 "bits" wide. The binary code is used to either turn on or turn of~
its respectlve beam. A gray scale may also be used where a plurality of bits are associated with each beam -to provide ~rada-tion hetween the on and o-fI s-tates.
In tlle rasterizer used with the pat-tern generation apparat~ls, ~rames are generateA which are 102~ address units lon~ in the stripe axis direction. Ilowever, this delineation is not de-tectable within the beam or table movement itself, but ra-ther is confined to the rasterizer. A plurali-ty of -frames are used to provide a pass such as defined by the rec-tangle 72. The number oE
the -frames in a pass is arbitrary.
Assume for purposes O-e discussion that four identical patterns (pattern 2) are to be written within the block 6~. In ~he presen-tly preeerred embodiment, pass 72 is first written into block 7~ and then the table is moved so that the same in-Pormation contained in -that pass can be rewritten into the bloclcs 73, 76 and then 75. Another pass is then made in each oi -the blocks until the entire pattern has been writ-ten four times within block 68. 0-ther patterns may be writ-ten on the workpiece in blocks adjacen-t to blocks 68 such as shown by pattern l to the left of block 68. The ~a-ttern l or 2 o~ Figure 8 may represent, by way o~ example, 5x or lOx masks, or as mentioned, may represent circuit elements ~enerated directly on a semiconductor wafer.
As currently implemented, -the beams only write in 1~4~4;~
1 conjunction with stripe axis movement an~l no wrlti.ng occur.s wherl the table is movecl in the scan axis. Workpiece movement in the scan axis occurs, for instance, to reposition the workpiece for each pass.
SC~N LIN~ BEAMS
In circle 69 o-~ Figure 3 the eight beam3 which paint -the pattern in each scan are shown overlapping one another. In reali-ty, the beams do not overlap although tlleir projections on the workpiece overlap. The dove prism 17 of Figure 1 orients the beams so that they are spacially displaced as mentioned. This displacement is shown in Figure 9 by the beams 77. (The beams 77 represent the projection oc the beams, ie -they were t-lrned on be~ore they reached line 78.) Line 78 represents a line perpendicular to the scan axis and this line is sho~vn in Figure 8 -through scan line 70. As each of the beams reach line 78 they are activated (one at a time) as a function of the in~ormation (binary one or zero) accessed ~or address unit at that posi-tion along the sc~n axis and stripe axis.
In opera-tion, the data signals controlling the beams are sequenti~lly applied to the AOM 16 of Figure 1; each signal is delayed by an appropriate amount so that the beam is turned on (i~
needed for the pattern) along line 73 and the equidistant lines.
This allows -the projection o~ the beams to overlap withou-t having the beams themselves overlap. I~ the beams themselves overlap, uncontrolled in-ter-~erence occurs, preventing a "clean" scan line -~rom being written.
TABLF ~SSF.M~LY
Referring ~irst to Figure 7, the plate 3~ which is monnted in the partholder can be moved in three a~es. Movement to and ~rom t ~34~ ;~
1 the reduction lenses 32 (Z axis) is not 111us-tra-ted Ln the drawlngs. This movement is done for foc-llsing.
D~lring pattern generation, as men-tioned, ~,he plate 34 and partholder are moved along the s-tr:Lpe a~is by mo-tor 83 since they are moun-ted on the stripe stage 82. This axis for the view of Figure 7 is into and out of the drawing. The stripe stage 82 is moun-ted on the scan stage 80, thereby causing the plate 3~ to move when the stage 80 moves. The stage 80 moves along the scan axis and is driven by mo-tor 81. As mentioned, this movement does not occur during scanning, but rather, for instance, between scans to reposition for each pass. The partholder may also be adjusted (tilted) to level the workpiece rela-tive to the beams.
Referring to Figures 6 and 7, a mirror 88 is mounted perpendicular on the stage 82, and similarly, a mirror 92 is mounted on stage 82 perpendicular -to the stripe a~is. A mirror is mounted on the reduction lens 32 perpendicular to the scan axis, and similarly, a mirror 43 is mountecl on the reduction lens 32 perpendicular -to the stripe axis. Relative movement in the scan d:Lrection between the stage 82 and lens 32 is detected by a differential interferometer 89. This differential interferometer reflects a pair of beams from each of the mirrors ~4 and 88.
Similarly, relative movemen-t in -the stripe direction is detec-ted by the differential interferometer 9~ as light is reflected ~or mirrors 43 and 92. The light is reflected from mirrors 82 and 92 at -the level of the plate 3~ to obtain accurate relative movement of the pla-te.
The differential interferometers 89 and 94 are commercially available inter-ferometers.
~LZ~3~
l The intereerometers along with the photomul-tiplier tube oe Figure 5 which receives the light reflected -erom the wor1splece (see sureace 28b Oe beam splitter 2~, Figure ~) play an important role In the calibration o e the apparatus and in position determina-tion of the workpiece.
Calibra-tion marks 97 and 98 are ~ormed on the upper sur~ace of the part holder. These marlss can al-ternatively be formed on -the plate itsele ~e.g., with chrome disposi-tion and etching steps).
These mar1cs have a known displacement from a pattern origin. The pat-tern data is generated relative to -this origin. When one Oe the eight beams is turned on, reelection erom the markers 97 or 98 can be sensed by the photomultiplier tube. This provides accura-te data on the relative position o-~ the pattern origin and beam. When the workpiece is moved either in the scan or stripe direc-tions, accurate position data is available -from -the intereerometers, thus providing a continuous s-tream of position data.
There are numerous other uses ~or -the combina-tion of the data -from the interferometer and photomultiplier tube. For instance, as previously mentioned~ a scan line is ~096 address l1nits in length. ~eam l :~or address unit one can :eirs-t be activated and its coordinates de-termined by the pho-tomultiplier -tube in conjunction with a marker. Then beam l can again be turnec1 on eor the ~096 address unit o-f -the scan and this posi-tion determined with a marlcer. From this da-ta the length o-f a scan line can be deter1nined. Similarly, the width Oe the brush can be determined by activating beams l and 8. The skew in the stripe axis caused by workpiece mo-tion d~lring scanning can also be determined and adjus-ted for electrically by adjusting the -time at which data is applied to ~;
34Z~
1 the ~OM. Other applicat:Lons include s~ot s:iz,e measurelnent, cr-Ltlcal dimension measurements, ro-tating mirror rota-tion stahility -tests, s-teering mirror positioning, ~oom lens calibra-tion, timing , calibration, F-the-ta trans~er function measurements, determina-t:Lon of lens linearity throughout the entlre optics system, focal field flatness measurement, column orthogonality testing and auto focus calibration.
The telecentric arrangement of the intermedia-te field plane with the combina-tion of the beam splitter and photomultipller -tube along with the in-terferometers and marlss on the moving assembly provide precise coordination between these otherwise independent subsystems.
DATA T~MING
The -timing of the data relative to mirror position is important. If the beams are turned on too early or too late relative to the position of each o-f the facets on the rota-ting mirror, one scan line can be displaced -from the next. As previously mentioned, the timing signals ~or -the data and the enabling oE the AOM, are developed through the facet detector. Channel one is turned on before the eacet is in a posi-tion to cause a beam or beams to be directed onto the workpiece. The beam is reflected erom splitter 28 onto a photodetector to generate a timing pulse. Tile turning on of this beam is illustrated by pulse 105 in Figure l0.
The facet detection is shown by pulse 106 in Figure lO. This detection ini-tia-tes a time seq~lence which consists of a fixed delay, a scan correction and a skew correction. The total delay is shown as delay 108 in ~igure 10.
A-fter the delay the print clock enal)le signal 107 enables ~2~3~27 1 the pixel clock 109 to ~enerate the si~nals ~or clocking the date (~096 address units) in-to the AOM. ~s shown by waveEorm 110 the data selectively enables -the beams -to prin-t the ~attern.
~ stripe 111 which comprises a plurali-ty oc scans l.s shown in Figure 10. Line 112 represents a time axis Eor the s-tripe 111.
Line 113 illustrates an angle added to line 112; this angle represents -the skew introduced in-to each scan line caused by the movement in the stripe direction durirlg scanning. This is the "skew Eactor increment" in the delay 108. The dot-ted line represents scan direction deviation erom true stripe a~is movemen-t. This deviation is measured by interferometer 9~. The diiference between the dotted line and line 112 represents the "scan correction" for the delay 108. The "-fixed" delay is the average expec-ted delay. The computed clelay 108 thus allows the printing to occur where intended despite -facet deviation, the raster nature of the scanning and stripe table movement deviation.
During scanning, non-constant velocity table movement may also occur in the stripe a~is direction. These variations are detected by interferometer 89. The information from inter-Eerometer 89 controls the steering mirror 20 and corrects rela-tive beam-wor~piece movement in the stripe direction.
Thus, a laser pattern generation apparatus has been described which includes numerous unique Eeatures, both in its optical path and as part o-E its mechanical subsystem.
Claims (29)
1. An apparatus for generating a pattern on a workpiece which includes a film responsive to radiant energy comprising:
a laser for providing a radiant energy beam;
beam splitting means for splitting a beam into a plurality of beams, said beam splitting means being optically coupled to said laser;
modulation means for independently modulating each of said plurality of beams, said modulation means being optically coupled to said beam splitting means;
rotating mirror having a plurality of facets for causing said beams to scan said workpiece, said beams from said modulation means being directed onto said rotating mirror;
focusing means for receiving said beams from said rotating mirror and for focusing said beams onto said workpiece, and a steering mirror for adjusting the position of said beams on said rotating mirror to compensate for move-ment between said workpiece and said beams, said steering mirror being optically disposed between said modulation means and said rotating mirror;
whereby a pattern is generated on said workpiece.
a laser for providing a radiant energy beam;
beam splitting means for splitting a beam into a plurality of beams, said beam splitting means being optically coupled to said laser;
modulation means for independently modulating each of said plurality of beams, said modulation means being optically coupled to said beam splitting means;
rotating mirror having a plurality of facets for causing said beams to scan said workpiece, said beams from said modulation means being directed onto said rotating mirror;
focusing means for receiving said beams from said rotating mirror and for focusing said beams onto said workpiece, and a steering mirror for adjusting the position of said beams on said rotating mirror to compensate for move-ment between said workpiece and said beams, said steering mirror being optically disposed between said modulation means and said rotating mirror;
whereby a pattern is generated on said workpiece.
2. The apparatus defined by Claim 1 including optical means for providing an enlarged image plane between said rotating mirror and said workpiece.
3. The apparatus defined by Claim 2 wherein said optical means includes a beam splitter in said enlarged image plane for reflecting a beam from said rotating mirror to a facet detection means for providing synchronization signals synchronized with said facets of said rotating mirror.
4. The apparatus defined by Claim 3 wherein at least one of said plurality of beams is reflected from said workpiece and reflected by said beam splitter to a detector to provide an indication of the position of said workpiece.
5. The apparatus defined by Claim 2 wherein said optical means includes an f-theta lens.
6. The apparatus defined by Claim 1 including a dove prism disposed between said modulation means and said rotating mirror, said prism for providing separation between said plurality of beams to prevent interference between said beams.
7. The apparatus defined by Claim 1 including a zoom lens disposed between said modulation means and said rotating mirror.
8. The apparatus defined by Claim 1 or Claim 4 wherein said modulation means comprises an acousto-optical device.
9. An apparatus for generating a pattern on a workpiece which includes a film responsive to radiant energy comprising:
at least one laser for providing a radiant energy beams;
a splitting and modulation means for receiving said beam from said laser and for providing a plurality of modulated laser beams;
rotating mirror having a plurality of facets, said beams from said modulator means being directed onto said rotating mirror;
focusing means for receiving said beams from said rotating mirror and for focusing said beams onto said workpiece, said focusing means including optical means for providing an enlarged image plane between said rotating mirror and said workpiece;
a beam splitter in said enlarged image plane for reflecting a beam from said rotating mirror to a facet detection means for providing synchronization signals synchronized with said facets of said rotating mirror;
whereby said rotating mirror causes said plurality of beams to scan said workpiece.
10. The apparatus defined by Claim 9 wherein at least one of said plurality of beams is reflected from said workpiece and reflected by said beam splitter to a
at least one laser for providing a radiant energy beams;
a splitting and modulation means for receiving said beam from said laser and for providing a plurality of modulated laser beams;
rotating mirror having a plurality of facets, said beams from said modulator means being directed onto said rotating mirror;
focusing means for receiving said beams from said rotating mirror and for focusing said beams onto said workpiece, said focusing means including optical means for providing an enlarged image plane between said rotating mirror and said workpiece;
a beam splitter in said enlarged image plane for reflecting a beam from said rotating mirror to a facet detection means for providing synchronization signals synchronized with said facets of said rotating mirror;
whereby said rotating mirror causes said plurality of beams to scan said workpiece.
10. The apparatus defined by Claim 9 wherein at least one of said plurality of beams is reflected from said workpiece and reflected by said beam splitter to a
Claim 10 continued....
detector to provide an indication of the position of said workpiece.
detector to provide an indication of the position of said workpiece.
11. The apparatus defined by Claim 9 wherein said optical means for providing said enlarged image plane includes an F-theta lens.
12. The apparatus defined by Claim 9 including a dove prism disposed between said modulation means and said rotating mirror, said prism for providing separation between said plurality of beams to prevent interference between said beams.
13. The apparatus defined by Claim 9 including a zoom lens disposed between said modulation means and said rotating mirror.
14. The apparatus defined by Claim 9 including a steering mirror disposed between said modulation means and said rotating mirror for adjusting the position of said beams on said rotating mirror to compensate for movement between said workpiece and said beams.
15. An apparatus for generating a pattern on a workpiece which includes a film responsive to radiant energy comprising:
15. An apparatus for generating a pattern on a workpiece which includes a film responsive to radiant energy comprising:
Claim 15 continued....
a laser for providing a radiant energy beam;
beam splitting means for splitting a beam into a plurality of beams, said beam splitting means being optically coupled to said laser;
acousto-optic modulation means for independently modulating each of said plurality of beams, said modulator means being optically coupled to said beam splitting means;
rotating mirror having a plurality of facets, said beams from said modulation means being directed onto said rotating mirror;
focusing means for receiving said beams from said rotating mirror and for focusing said beams onto said workpiece;
a partholder for receiving said workpiece said partholder being mounted for movement in a direction perpend-icular to said scan direction, and a steering mirror disposed between said modulation means and said rotating mirror, said beams striking said steering mirror at an afocal point with respect to said pattern image on said workpiece to compensate for relative beam-workpiece movement in said direction perpendicular to said scan direction;
whereby said rotating mirror and said partholder movement causes said workpiece to be raster scanned in a predetermined path in said direction perpendicular to said scan direction.
a laser for providing a radiant energy beam;
beam splitting means for splitting a beam into a plurality of beams, said beam splitting means being optically coupled to said laser;
acousto-optic modulation means for independently modulating each of said plurality of beams, said modulator means being optically coupled to said beam splitting means;
rotating mirror having a plurality of facets, said beams from said modulation means being directed onto said rotating mirror;
focusing means for receiving said beams from said rotating mirror and for focusing said beams onto said workpiece;
a partholder for receiving said workpiece said partholder being mounted for movement in a direction perpend-icular to said scan direction, and a steering mirror disposed between said modulation means and said rotating mirror, said beams striking said steering mirror at an afocal point with respect to said pattern image on said workpiece to compensate for relative beam-workpiece movement in said direction perpendicular to said scan direction;
whereby said rotating mirror and said partholder movement causes said workpiece to be raster scanned in a predetermined path in said direction perpendicular to said scan direction.
16. The apparatus defined by Claim 15 wherein said partholder is mounted on a table which moves in said scan direction.
17. The apparatus defined by Claim 16 including a beam splitter for reflecting a beam from said rotating mirror to a facet detection means for providing synchroniz-ation signals synchronized with said facets of said rotating mirror.
18. The apparatus defined by claim 15 wherein at least one of said plurality of beams is reflected from said workpiece and reflected by a beam splitter to provide an indication of the position of said workpiece.
19. The apparatus defined by Claim 15 including a fourth mirror mounted for movement with said partholder and a first interferometer to permit detection of movement of said partholder in said direction perpendicular to said scan direction.
20. The apparatus defined by Claim 19 including a fifth mirror mounted for movement with said partholder and a second interferometer to permit detection of movement of said partholder in said scan direction.
21. The apparatus defined by Claim 15 including an enlarged image plane between said rotating mirror and said workpiece.
22. The apparatus defined by Claim 21 including a beam splitter in said enlarged image plane for reflecting one of said beams from said rotating mirror to a facet detection means for providing synchronization signals synchronized with said facets of said rotating mirror, said one beam being turned on prior to said beams scanning said workpiece.
23. The apparatus defined by Claim 22 wherein at least one of said plurality of beams is reflected from said workpiece and reflected by said beam splitter to provide an indication of the position of said workpiece.
24. The apparatus defined by claim 21 wherein for said enlarged image plane includes an F-theta lens.
25. The apparatus defined by Claim 15 including a dove prism disposed between said acousto-optic modulation means and said rotating mirror, said prism for providing separation between said plurality of beams to prevent interference between said beams.
26. The apparatus defined by Claim 15 including a zoom lens disposed between said acousto-optic modulation means and said rotating mirror.
27. The apparatus defined by Claim 15 wherein said beam splitting means includes a first beam splitting mirror for receiving said beam from said laser and for splitting said beam into two beams, a second beam splitting means
27. The apparatus defined by Claim 15 wherein said beam splitting means includes a first beam splitting mirror for receiving said beam from said laser and for splitting said beam into two beams, a second beam splitting means
Claim 27 continued....
for receiving said two beams from said first mirror and for splitting said two beams into four beams, and a third beam splitting means for receiving said four beams from said second mirror and for splitting said four beams into eight beams.
for receiving said two beams from said first mirror and for splitting said two beams into four beams, and a third beam splitting means for receiving said four beams from said second mirror and for splitting said four beams into eight beams.
28. The apparatus defined by claim 1 wherein said beam splitting means includes a first beam splitting mirror for receiving said beam from said laser and for splitting said beam into two beams, a second beam splitting means for receiving said two beams from said first mirror and for splitting said two beams into four beams, and a third beam splitting means for receiving said four beams from said second mirror and for splitting said four beams into eight beams.
29. The apparatus defined by Claim 9 wherein said splitting and modulation means includes a first beam splitting mirror for receiving said beam from said laser and for splitting said beam into two beams, a second beam splitting means for receiving said two beams from said first mirror and for splitting said two beams into four beams, and a third beam splitting means for receiving said four beams from said second mirror and for splitting said four beams into eight beams.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US75834485A | 1985-07-24 | 1985-07-24 | |
| US758,344 | 1985-07-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1243427A true CA1243427A (en) | 1988-10-18 |
Family
ID=25051404
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000509321A Expired CA1243427A (en) | 1985-07-24 | 1986-05-16 | Laser pattern generation apparatus |
Country Status (5)
| Country | Link |
|---|---|
| JP (2) | JPH0658873B2 (en) |
| KR (1) | KR940008359B1 (en) |
| CA (1) | CA1243427A (en) |
| FR (1) | FR2585480B1 (en) |
| GB (1) | GB2178548B (en) |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2589295B2 (en) * | 1986-11-14 | 1997-03-12 | キヤノン株式会社 | Image forming device |
| JPH0778576B2 (en) * | 1988-05-17 | 1995-08-23 | 株式会社シンク・ラボラトリー | Light beam splitting method and light beam splitting modulation method |
| US5221422A (en) * | 1988-06-06 | 1993-06-22 | Digital Equipment Corporation | Lithographic technique using laser scanning for fabrication of electronic components and the like |
| US4956650A (en) * | 1988-08-26 | 1990-09-11 | Ateq Corporation | Pattern generation system |
| JP3052587B2 (en) * | 1992-07-28 | 2000-06-12 | 日本電気株式会社 | Exposure equipment |
| DE19840926B4 (en) * | 1998-09-08 | 2013-07-11 | Hell Gravure Systems Gmbh & Co. Kg | Arrangement for material processing by means of laser beams and their use |
| DE19904592C2 (en) * | 1999-02-05 | 2001-03-08 | Lavision Gmbh | Beam splitter device |
| US6271514B1 (en) * | 1999-03-19 | 2001-08-07 | Etec Systems, Inc. | Multi-beam scanner including a dove prism array |
| JP4201178B2 (en) * | 2002-05-30 | 2008-12-24 | 大日本スクリーン製造株式会社 | Image recording device |
| US7298478B2 (en) * | 2003-08-14 | 2007-11-20 | Cytonome, Inc. | Optical detector for a particle sorting system |
| US7190434B2 (en) * | 2004-02-18 | 2007-03-13 | Asml Netherlands B.V. | Lithographic apparatus and device manufacturing method |
| GB2425846A (en) * | 2005-04-20 | 2006-11-08 | Bookham Technology Plc | Multi component beam splitter with individual surface coatings |
| KR100862481B1 (en) * | 2007-07-10 | 2008-10-08 | 삼성전기주식회사 | Multi beam laser apparatus |
| WO2011104179A1 (en) * | 2010-02-23 | 2011-09-01 | Asml Netherlands B.V. | Lithographic apparatus and device manufacturing method |
| DE102014200633B3 (en) * | 2014-01-15 | 2015-05-07 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Machining apparatus and method for laser processing a surface |
| KR101990447B1 (en) * | 2017-04-20 | 2019-06-18 | 정종택 | A ridar for sensing multi-distance point |
| KR20240050452A (en) * | 2018-06-05 | 2024-04-18 | 일렉트로 싸이언티픽 인더스트리이즈 인코포레이티드 | Laser-processing apparatus, methods of operating the same, and methods of processing workpieces using the same |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49119643A (en) * | 1973-03-16 | 1974-11-15 | ||
| US4060323A (en) * | 1974-07-10 | 1977-11-29 | Canon Kabushiki Kaisha | Image information handling method and device |
| US4170028A (en) * | 1977-04-06 | 1979-10-02 | Xerox Corporation | Facet tracking in laser scanning |
| JPS5472049A (en) * | 1977-11-18 | 1979-06-09 | Ricoh Co Ltd | Simultaneous scanning system of plural beams |
| GB2096335B (en) * | 1978-07-07 | 1983-06-02 | Pitney Bowes Inc | Light-scanning |
| US4306242A (en) * | 1980-03-18 | 1981-12-15 | Data General Corporation | Laser recording system |
| US4541712A (en) * | 1981-12-21 | 1985-09-17 | Tre Semiconductor Equipment Corporation | Laser pattern generating system |
| JPS59146015A (en) * | 1983-02-09 | 1984-08-21 | Matsushita Electric Ind Co Ltd | Optical path splitting device |
| DE3371946D1 (en) * | 1983-06-17 | 1987-07-09 | Lasarray Holding Ag | Reference determining process for correcting mechanical movements when writing lines in a metallized grid by means of a laser, and apparatus therefor |
-
1986
- 1986-04-15 FR FR8605374A patent/FR2585480B1/en not_active Expired - Fee Related
- 1986-04-21 GB GB8609685A patent/GB2178548B/en not_active Expired
- 1986-05-13 KR KR1019860003730A patent/KR940008359B1/en not_active IP Right Cessation
- 1986-05-16 CA CA000509321A patent/CA1243427A/en not_active Expired
- 1986-07-15 JP JP61164877A patent/JPH0658873B2/en not_active Expired - Lifetime
-
1991
- 1991-07-31 JP JP21323891A patent/JPH05297318A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| GB2178548A (en) | 1987-02-11 |
| JPH0658873B2 (en) | 1994-08-03 |
| GB8609685D0 (en) | 1986-05-29 |
| KR940008359B1 (en) | 1994-09-12 |
| FR2585480A1 (en) | 1987-01-30 |
| KR870001045A (en) | 1987-03-11 |
| GB2178548B (en) | 1989-08-09 |
| JPH05297318A (en) | 1993-11-12 |
| FR2585480B1 (en) | 1994-01-07 |
| JPS6226819A (en) | 1987-02-04 |
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