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
  • G03F7/7015—Details of optical elements
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B13/00—Optical objectives specially designed for the purposes specified below
  • G02B13/14—Optical objectives specially designed for the purposes specified below for use with infrared or ultraviolet radiation
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B13/00—Optical objectives specially designed for the purposes specified below
  • G02B13/24—Optical objectives specially designed for the purposes specified below for reproducing or copying at short object distances
• • 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
  • G03F7/70216—Mask projection systems
  • G03F7/70241—Optical aspects of refractive lens systems, i.e. comprising only refractive elements
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P76/00—Manufacture or treatment of masks on semiconductor bodies, e.g. by lithography or photolithography
  • H10P76/20—Manufacture or treatment of masks on semiconductor bodies, e.g. by lithography or photolithography of masks comprising organic materials
  • H10P76/204—Manufacture or treatment of masks on semiconductor bodies, e.g. by lithography or photolithography of masks comprising organic materials of organic photoresist masks
  • H10P76/2041—Photolithographic processes

Definitions

• the present invention relates to the field of semiconductor processing technology, and in particular to a large field of view projection objective lens in a projection optical system of a lithography machine. Background technique
• step lithography equipment usually uses a large exposure field of view, and in order to match the mask size, some optical systems use 1.25 or 1.6 times magnification.
• Japanese Patent JP2000199850 discloses a lithographic projection objective lens of 1.6x magnification.
• the exposure wavelength uses the G line and the H line, the field of view of the silicon wafer is 117.6 mm, and the numerical aperture of the silicon surface is 0.1.
• This objective lens has a multi-lens structure of 38 pieces and contains an aspherical surface.
• Japanese Patent JP2006267383 discloses a 1.25x magnification lithographic projection objective.
• the exposure wavelength is I line
• the bandwidth is + I - 3nm
• the half field of view is 93.5mm.
• Japanese Patent JP2007079015 discloses another 1.25x magnification projection objective lens which also uses an exposure wavelength of I line, a bandwidth of +/- 1.5 nm, and a half field of view of 93.5 mm.
• the invention provides a projection lithography objective lens for focusing an image of a mask onto a silicon wafer.
• the optical lens comprises, in order from the optical axis, a first lens group G31 having positive refractive power, and a first optical lens having positive refractive power.
• each lens group satisfies the following relationship:
• f G31 focal length of the first lens group G31
• f G32 focal length of the second lens group G32
• f G33 focal length of the third lens group G33
• f G34 the fourth lens group G34 The focal length.
• the first lens group G31 is composed of at least four lenses; the second lens group G32 is composed of at least six lenses; and the second lens group G32 includes at least two pairs of adjacent positive and negative lens combinations.
• the third lens group G33 is composed of at least four lenses; the third lens group G33 includes a sub-lens group G33-ln, and the sub-lens group G33-ln is positive in power, including the third lens group a lens in which at least two of the lens groups G33 are adjacent and having a positive power; the fourth lens group G34 is composed of at least six lenses; and the fourth lens group G34 includes a sub-lens group G34-ln.
• the sub-lens group G34-ln is positive in power, and includes a lens in which at least three positions of the fourth lens group G34 are adjacent and the power is positive;
• the second lens group G32 includes at least one positive lens and a negative lens adjacent thereto, and the Abbe number ratio satisfies the following relationship:
• V G32 is an Abbe number of a positive lens in the second lens group G32;
• V G32 is an Abbe number of a negative lens adjacent to the positive lens in the second lens group G32.
• the Abbe number ratio of at least one positive lens and one adjacent negative lens in the second lens group G32 satisfies the following relationship:
• V G32 is an Abbe number of a positive lens in the second lens group G32;
• V G32 is an Abbe number of a negative lens adjacent to the positive lens in the second lens group G32.
• the focal lengths of two adjacent positive lenses in the sub-lens group G33-ln of the third lens group G33 are f 41 and f 42 in order from the mask to the silicon wafer.
• the focal length satisfies the following relationship: 0.75 ⁇ f 41 ⁇ f 4 2 ⁇ l.
• the projection objective is composed of at least two high refractive index materials and at least two low refractive index materials.
• the high refractive index material refers to a material having an I-line refractive index greater than 1.55, including a first material having an I-line refractive index greater than 1.55 and an Abbe number less than 45, and an I-line refractive index greater than 1.55 and an Abbe number greater than The second material of 50;
• the low refractive index material refers to a material having an I-line refractive index of less than 1.55, including a third material having an I-line refractive index of less than 1.55 and an Abbe number of less than 55, and an I-line refractive index of less than 1.55.
• the fourth material with an Abbe number greater than 60.
• the first lens of the first lens group G31 and the last lens of the fourth lens group G34 are each composed of the first material.
• the first, second, third, and fourth lens groups each include at least one lens composed of a first or second material.
• the first, second, and fourth lens groups comprise at least one lens constructed from a first material to make.
• the third lens group comprises at least one lens composed of a second material.
• the second lens group includes at least one pair of concave opposing lenses; the third lens group includes at least one meniscus lens, and the concave surface faces the image surface; and the fourth lens group includes at least one piece A meniscus lens with a concave surface facing the object surface.
• the large field of view projection lithography objective lens of the present invention uses a less lens to complete the 2 ⁇ magnification design, the half field of view is not less than 100 mm, and the I line bandwidth of ⁇ 5 nm ensures sufficient exposure light intensity.
• the present invention achieves the required micron pole resolution with a relatively simple structure, and is capable of correcting distortion, field curvature, astigmatism, and chromatic aberration in a large field of view.
• FIG. 1 is a schematic view showing the optical structure of an embodiment of a lithography objective lens of the present invention
• FIG. 2 is a graph showing an imaging distortion curve according to an embodiment of the present invention.
• FIG. 3 is a telecentric diagram of an object side and an image side according to an embodiment of the present invention.
• Fig. 4 is a diagram showing aberration curves of an embodiment of the present invention. detailed description
• the number of lenses of the projection objective lens 30 of the embodiment of the present invention is 20, and the parameters of each parameter are as shown in Table 1:
• Projection objective lens 30 consists of 20 lenses, all 20 lenses are spherical. Divided into four lens groups G31, G32, G33, G34, the power is positive.
• the first lens group G31 is composed of four lenses, and the refractive powers are negative, positive, positive, and positive, respectively.
• the second lens group G32 is composed of six lenses, and the power is sequentially positive, negative, negative, positive, positive, and negative.
• the second lens group G32 includes at least two pairs of adjacent positive and negative lens combinations.
• the second lens group G32 includes at least one pair of 1HJ surface opposing lenses.
• the third lens group G33 is composed of four lenses, and the power is sequentially positive, positive, negative, and negative.
• the third lens group G33 includes a sub-lens group G33-ln, and the sub-lens group G33-ln has a positive power, and includes at least two lenses of the third lens group G33 adjacent to each other and having a positive power;
• the three lens group G33 includes at least one meniscus lens, and the concave surface faces the image plane.
• the fourth lens group G34 is composed of six lenses, and the refractive power is negative, positive, positive, positive, positive, and negative in order.
• the fourth lens group G34 includes a sub-lens group G34-ln, and the sub-lens group G34-ln has a positive power, and includes at least three lenses of the fourth lens group G34 adjacent to each other and having a positive power;
• the four lens group G34 includes at least one meniscus lens, and the concave surface faces the object surface.
• the projection objective 30 of the present invention is constructed of at least two high refractive index materials and at least two low refractive index materials.
• the high refractive index material refers to a material having an I-line refractive index greater than 1.55, including a first material having an I-line refractive index greater than 1.55 and an Abbe number less than 45, and a second material having an I-line refractive index greater than 1.55 and an Abbe number greater than 50.
• the low refractive index material refers to a material having an I-line refractive index of less than 1.55, including a third material having an I-line refractive index of less than 1.55 and an Abbe number of less than 55, and a fourth refractive index of less than 1.55 and an Abbe number greater than 60. Materials.
• the design optimization scheme consists of at least one lens in the first, second, third, and fourth groups by the first or the first Two materials are formed.
• the first, second, and fourth lens groups include at least one lens composed of a first material.
• the third lens group comprises at least one lens consisting of a second material. Further, the first lens group G33 and the last lens of the fourth lens group are optimally composed of the first material.
• the first lens group G31 is composed of four lenses 31, 32, 33, and 34.
• the lens 31 is a double concave negative lens
• the lens 32 is a meniscus positive lens having a 1HJ surface facing the mask surface R
• the lenses 33 and 34 are front lenses.
• the lenses 31, 32, 34 are composed of a first or third material
• the lens 33 is composed of a second or fourth material.
• the second lens group G32 is composed of six lenses 35, 36, 37, 38, 39, 40.
• the lens 35 is a biconvex positive lens
• the lenses 36, 37 are negative lenses
• the concave surface 362 of the lens 36 and the concave surface 371 of the lens 37 are opposed.
• the lenses 38, 39 are positive lenses and the lens 40 is a negative lens.
• the lenses 35, 36, 38, 39 are all composed of a second or fourth material
• the lenses 37, 40 are composed of a first or third material.
• the third lens group G33 is composed of four lenses 41, 42, 43, and 44, the lenses 41 and 42 are positive powers, and the lenses 43 and 44 are negative power.
• the lens 43 is a meniscus lens having a 1HJ face 432 bent toward the silicon wafer face.
• the lenses 41, 42, 43, 44 are all second or fourth materials.
• the fourth lens group G34 is composed of six lenses 45, 46, 47, 48, 49, 50, and the refractive powers are negative, positive, positive, positive, positive, and negative, respectively.
• the rear surface of the lens 45 is a flat surface, and its concave surface 451 faces the mask surface.
• the lenses 45, 47 are constructed of a second or fourth material, and the lenses 46, 48, 49, 50 are constructed of a first or third material.
• lens groups G33, G32, G33, G34, and their sub-lens lenses further establishes the basis for object image quality optimization.
• the focal lengths of the two lenses 41 and 42 in the sub-lens group G33-In of the third lens group G33 of the present embodiment are f 41 and f 42 in order from the mask to the silicon wafer, and the focal lengths of the two positive lenses are satisfied.
• the two positive lens functions are to gradually compress the light emitted from the second lens group, thereby benefiting the field curvature correction.
• the relational expressions (1) - (9) define the structural relationship of the lens groups G33, G32, G33, G34 and their sub-lens groups, and lens correction aberrations.
• Table 2 shows the specific design values of the projection objective of this example.
• a positive radius value indicates that the center of curvature is on the right side of the surface, and a negative radius value indicates that the center of curvature is on the left side of the surface.
• the thickness of the optical element or the spacing between the two optical elements is the on-axis distance to the next surface. All dimensions are in millimeters.
• Example 30 is well-distorted.
• Fig. 3 shows that the object side correction of the embodiment 30 is about 3 mrad, and the image center telecentricity is corrected at about 10 mrad.
• the ray aberration curve in Fig. 4 shows that the image quality correction in the present embodiment 30 is good, and a good image quality in the i line +/- 5 nm is achieved.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Lenses (AREA)
• Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)

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Publications (1)

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Citations (9)

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• 2010
  • 2010-12-31 CN CN201010619283.XA patent/CN102540419B/zh active Active
• 2011
  • 2011-12-07 EP EP11852300.0A patent/EP2660638B1/en active Active
  • 2011-12-07 JP JP2013546574A patent/JP2014506341A/ja active Pending
  • 2011-12-07 KR KR1020137018676A patent/KR101685655B1/ko active Active
  • 2011-12-07 WO PCT/CN2011/083616 patent/WO2012089002A1/zh not_active Ceased
  • 2011-12-07 US US13/976,353 patent/US20130293859A1/en not_active Abandoned
  • 2011-12-27 TW TW100148828A patent/TW201235729A/zh unknown

Patent Citations (9)

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