Classifications

• • 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
  • G03F7/70058—Mask illumination systems
  • G03F7/70075—Homogenization of illumination intensity in the mask plane by using an integrator, e.g. fly's eye lens, facet mirror or glass rod, by using a diffusing optical element or by beam deflection
• • 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
  • G03F7/70058—Mask illumination systems
  • G03F7/70091—Illumination settings, i.e. intensity distribution in the pupil plane or angular distribution in the field plane; On-axis or off-axis settings, e.g. annular, dipole or quadrupole settings; Partial coherence control, i.e. sigma or numerical aperture [NA]
  • G03F7/70108—Off-axis setting using a light-guiding element, e.g. diffractive optical elements [DOEs] or light guides
• • 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
  • G03F7/70058—Mask illumination systems
  • G03F7/70141—Illumination system adjustment, e.g. adjustments during exposure or alignment during assembly of illumination system
• • 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
  • G03F7/70058—Mask illumination systems
  • G03F7/7015—Details of optical elements
  • G03F7/70158—Diffractive optical elements

Definitions

• Illumination system in particular for a projection exposure machine in semiconductor lithography
• the purpose of homogenizing the intensity of a light produced by a light source is served in an illumination system of a proj ection exposure machine in semiconductor lithography by a so-called rod integrator by means of which the light is guided and which is preferably arranged with its longitudinal axis parallel to an optical axis of the illumination system. Reflections occur at the walls of the rod, which generally has a flat rectangular shape, the effect being that downstream of the rod pupil distributions , also termed settings , are reflected relative to the x-axis and relative to the y-axis , and therefore symmetrically with reference to this coordinate system.
• a light source for example a laser
• the xyz-coordinate system is defined as a Cartesian coordinate system whose z-axis runs in the longitudinal direction of the rod and through the center of the rod cross section, while the x, y-axes run parallel to the edges of the rectangular illuminated field on the wafer or parallel to the rod edges of the rod cross section when the latter are parallel to the rectangular illuminated field on the wafer .
• the optical axis runs through the center of the rod cross section .
• an asymmetric pupil distribution requires that the setting produced by the optical element correspondingly provided therefor be seated outside the x- or y-axis (or the pupil distribution is asymmetric with reference to at least one axis) , as a result of which the rod would give rise to corresponding reflections in all four quadrants of the coordinate system.
• the coordinate system of the rotated homogenizing element is denoted by x' , y' , • in order to distinguish it from that of the non-rotated one .
• the adjustment of the asymmetrically acting optical elements and of the homogenizing element (the rod) can be performed synchronously (at the same time) or sequentially .
• the adjustment angle or rotational angle of the elements or of the homogenizing element can be the same or different, depending on the initial pupil distribution and the desired obliquity that is prescribed by the patterns . It is also possible in this case for an adjustment angle or rotational angle to vanish .
• the illumination system is designed such that the rod integrator is exchangeable .
• the rod integrator is exchangeable .
• the optical elements which can be, for example, refractive and/or diffractive optical elements in the illumination system, to be provided in a changing device, for example, so that they can be exchanged or else supported rotatably.
• the length of the diagonal of an end face of the rod corresponds to the edge length of the rod .
• the advantage of the solution with the exchangeable rod integrator by comparison with a rod integrator that is set at an angle consists in that the scanning field can retain the original size, and therefore results in no additional factor that leads to a reduction in throughput .
• figure 3a shows a diagram of two poles of a dipole setting that are located on the y-axis
• a proj ection light bundle 8 traverses an incoupling optics 9.
• the incoupling optics 9 transmits the proj ection light bundle 8 onto an end-face entrance surface 10a of a rod integrator 10 as homogenizing element .
• the rod integrator 10 mixes and homogenizes the light by means of multiple internal reflection .
• a field plane of the illumination optics in which a reticle/mask system (ReMa) is arranged .
• An adjustable field stop 11 is provided for this purpose .
• rod integrators 10 have a decidedly rectangular shape . If such a rod integrator 10 is also used to image oblique patterns of an appropriate rotation, it is unavoidably necessary in the case of prescribed rotational angles to accept a light loss owing to the reduction of the field that turns out to be greater the flatter the rectangular rod integrator 10.
• the rod integrator 10' ' In order to adapt to the new, now square cross section of the rod integrator 10' ' , it can also be necessary in this case likewise to find ways to exchange the other optical elements such as , for example, the refractive optical element 7 , for a correspondingly adapted refractive optical element 7 ' .
• the size of the scanning field can be maintained in this case .
• the rectangular rod integrator 10 need not be rotatably supported in this case, since, after all , it is exchanged for the rod integrator 10' ' with the square cross section in the case of imaging of obliquely situated patterns .
• the square rod In order to achieve maximum freedom of a possible rotational angle a and, at the same time, not to have to accept any limitations on the size of the scanning field, the square rod should have the length of the diagonal of the end face of the rod integrator of a rectangular cross section as edge length .
• Figure 7 shows this refinement .
• the rod integrator of square cross section is provided with the reference numeral 21.
• An "optimized” rotatable rod of not entirely square cross section is indicated with “22" in a non-rotated position, and with “22' “ with a maximum rotation .
• the reference numeral 23 represents the scanning field resulting from a rotation of the optimized rod integrator .
• Figure 8 shows an exemplary embodiment having a honeycomb condenser 24 as homogenizing element instead of the rod integrator according to the above-described exemplary embodiment .
• the same design is present in principle, and for this reason the same reference numerals have also been used for the same parts .
• the refractive optimum element 7 is not necessary, but is replaced instead by the honeycomb condenser 24.
• a field lens 25 arranged downstream of the honeycomb condenser 24 in the beam direction acts like the incoupling optics 9 in accordance with figure 4.
• the light mixing is carried out in the honeycomb condenser 24 together with the field lens 25.
• a desired scanning slot or a field variable is set at the field stop 11 downstream of the honeycomb condenser 24 and the field lens 25.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
• Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
• Lenses (AREA)
• Optical Elements Other Than Lenses (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (2)

Family

ID=36084237

Family Applications (1)

Country Status (6)

Cited By (3)

Families Citing this family (5)

Family Cites Families (16)

• 2005
  • 2005-01-29 DE DE102005004216A patent/DE102005004216A1/de not_active Withdrawn
• 2006
  • 2006-01-21 EP EP06722978A patent/EP1842102A2/en not_active Withdrawn
  • 2006-01-21 US US11/814,685 patent/US20080273186A1/en not_active Abandoned
  • 2006-01-21 JP JP2007552559A patent/JP2008529290A/ja active Pending
  • 2006-01-21 WO PCT/EP2006/000535 patent/WO2006079486A2/en not_active Ceased
  • 2006-01-21 KR KR1020077019609A patent/KR20070100905A/ko not_active Withdrawn

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