Optical waveguides – Miscellaneous
Patent
1999-02-16
2000-07-11
Palmer, Phan T. H.
Optical waveguides
Miscellaneous
12 24, 12 31, G02B 600
Patent
active
06088505&
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus for high throughput holographic microlithography in which interferometric patterning techniques suitable for producing periodic arrays of sub-micron sized structures are adapted for and incorporated into a high-throughput, large field size manufacturing tool. The method and tool of the present invention have applications in the display, semiconductor, and optics manufacturing industries.
2. Description of the Prior Art
An unmet need exists for an efficient tool adapted for production of flat panel displays based on distributed cathode field emission display (FED) technology, a strong competitor in the flat panel display market currently dominated by liquid crystal display (LCD) manufacturers. A FED is a distributed cathode, flat panel analog to the well known cathode ray tube (CRT). Essentially, billions of miniature electron `gun` cathodes are distributed spatially over the surface of a display substrate. Electrons are emitted from the tiny cone-shaped cathodes under the influence of a high accelerating potential, and strike a phosphor screen placed over a common anode and are thereby converted to photons (i.e., light). The most critical step in the fabrication of the FED distributed cathode matrix is patterning of an array of holes or wells in which emitter cones are grown. In the prior art, a photosensitive medium such as photoresist has been employed to record an image of a hole array formed by conventional photo- lithographic techniques such as shadow masking (contact printing), optical projection, electron or laser beam direct writing. The hole array or pattern, in photoresist, can then be used as an etch mask in the process of forming the holes. In the prior art, hole patterns have been limited by resolution and field size of the imaging or writing systems, and complex, often expensive, work-around solutions have been required to achieve modest field sizes of fifty by fifty mm with hole diameters in the one to two micron range. Recent research has demonstrated that reduction in the hole size (and consequently the emitter size), below the one micron range provides numerous benefits such as a reduced gate voltage, lower power consumption, greater current densities per pixel, and built-in redundancy. Thus, to fully realize the potential of FED technology, an inexpensive, high speed, production environment lithographic tool, incorporating a patterning technology capable of producing large-area, high-density, sub-micron diameter hole arrays with few defects and at low cost, is needed.
Holographic or interferometric lithography has been proven in laboratory environments to be feasible for generating the high-resolution periodic structures suitable for flat panel FEDs and exploits the mutual coherence of multiple optical beams derived from a single light source such as a laser. The laser beams are made to overlap in some region of space and interfere to produce patterns of light and dark areas that repeat on a scale proportional to the wavelength and are subsequently recorded in photosensitive media such as photoresist. Conventional contact or projection photo masks are not required and so holographic lithography is known as a "maskless" lithography technique. In addition, by exploiting inherent photoresist and etching process non-linearities, a variety of surface relief structures can be generated with no change in the optical configuration.
Other useful surface relief structures can be patterned using holographic lithography such as a "motheye" or sub-wavelength-structure (SWS) surfaces. Motheye surface structures have been shown to be effective for nearly eliminating the reflectance of light from an optical interface such as between air and a window or a refractive optical element. The term "motheye" is derived from the insect's eye, a natural analog; it was observed that the eye of a nocturnal insect (e.g., a moth) reflected little or no light regardless of the light wavelength or the angle at
REFERENCES:
patent: 3591252 (1971-07-01), Lu
patent: 4037969 (1977-07-01), Feldman et al.
patent: 4104070 (1978-08-01), Moritz et al.
patent: 4402571 (1983-09-01), Cowan et al.
patent: 4440850 (1984-04-01), Paul et al.
patent: 4496216 (1985-01-01), Cowan
patent: 4789214 (1988-12-01), Vilhelmsson et al.
patent: 4839250 (1989-06-01), Cowan
patent: 4874213 (1989-10-01), Cowan
patent: 4888260 (1989-12-01), Cowan
patent: 5003567 (1991-03-01), Hawryluk et al.
patent: 5055383 (1991-10-01), Koblinger et al.
patent: 5142385 (1992-08-01), Anderson et al.
patent: 5176970 (1993-01-01), Hawryluk et al.
patent: 5178974 (1993-01-01), Hawryluk et al.
patent: 5216257 (1993-06-01), Brueck et al.
patent: 5334342 (1994-08-01), Harker et al.
patent: 5343292 (1994-08-01), Brueck et al.
patent: 5384464 (1995-01-01), DeFornel et al.
patent: 5415835 (1995-05-01), Brueck et al.
patent: 5430816 (1995-07-01), Furuya et al.
C.O. Bozler, C.T. Harris, S. Rabe, D.D. Rathman, M.A. Hollis, and H.I. Smith, "Arrays of gated field-emitter cones having 0.32 um tip-to-tip spacing", J. Vac. Sci. Technol. B 12(2), Mar./Apr. 1994, pp. 629-632.
C.A. Spindt, "Field Emitter Arrays for Vacuum Microelectronics", IEEE Transactions On Electron Devices, vol. 38, No. 10, Oct. 1991, pp. 2355-2363.
Z. Huang, N.E. McGruer, and K. Warner, "200 nm Gated Field Emitters", IEEE Electron Device Letters, vol. 14, No. 3, Mar. 1993.
J.W. Goodman, Introduction to Fourier Optics, McGraw-Hill, San Fran., 1968 No Month.
C.G. Bernhard, "Structural and functional adaptation in a visual system.", Endeavor, 26, pp. 79-84, 1967.
P.B. Clapham and M.C. Hutley, "Reduction of lens reflexion by the `Moth Eye` principle", Nature, 244, pp. 281-282, Aug. 3, 1973.
M.C. Hutley & S.J. Wilson, "The optical properties of `moth-eye` antireflection surfaces", Optica Acta, vol. 29, No. 7, pp. 993-1009, 1982.
W.H. Southwell, "Pyramid-array surface relief structures producing antireflection index matching on optical surfaces", JOSA A, vol. 8, No. 3, 549-553, Mar. 1991.
J.F. DeNatale et. al., "Fabrication and characterization of diamond moth eye antireflection surfaces on Ge", J. Appl. Phys., 71, (3), pp. 1388-1393, Feb. 1, 1992.
A.B. Harker and J.F. DeNatale, "Diamond gradient index `moth eye` antireflection surfaces for LWIR windows", SPIE vol. 1760, Window and Dome Technologies and Materials III, pp. 261-267, Jul. 1992.
Murakami, T., Togari, H., & Steinman, A., "Electrostatic problems and ionization solutions in TFT-LCD production", Solid State Technology, Jan. 1997, pp. 99-102.
Hatoh, H., et al., "Dependence of pretilt angle on the topography of substrate in liquid crystal alignment brought about by rubbing technique", Appl. Phys. Lett., 64, (9), pp. 1103-1104, Feb. 28, 1994.
Coherent laser company specifications, Innova argon-ion laser lifetime data, 1997.
J.J. Cowan, "Holographic honeycomb microlens", Optical Engineering, vol. 24, No. 5, Sep./Oct. 1985, pp. 796-802.
Dammann, H., and Klotz, E., Optica Acta, 1977, vol. 24 pp. 505-515 Coherent Optical Generation and Inspection of Two-Dimensional Periodic Structures.
Leith, E.N., Hershey, R.R., and Chen, H.S., "Techniques for high quality fringe generation", SPIE vol. 1211, Computer and Optically Formed Holographic Optics (1990) pp. 158-165.
K. Derbyshire, "Beyond AMLCDs: Field Emission Displays?", Solid State Technology, Nov. 1994, pp. 55-63.
G.P. Bryan-Brown, et. al., "Grating Aligned Bistable Nematic Device", SID 97 Symposium Digest vol. XXVIIII, May 11-16, 1997, pp. 37-40.
J.P. Ryan and M. Steinberg, WDM and Optical Networks: Market Directions, Optics and Photonics News, OSA, Feb. 1998, p. 25.
M.L. Schattenburg, H.I. Smith, et. al., "Fabrication of high energy x-ray transmission gratings for AXAF", SPIE Proceedings 2280, San Diego, CA, Jul. 24-29, 1994.
J. Ferrera, M.L., Schattenberg, H.I. Smith, "Analysis of distortion in interferometric lithography", J. Vac. Sci. Technol. B, 14(6), p. 4009, Nov./Dec. 1996.
H. Hock, C. King, and J. Helbert, "Resist Image Reversal for Next-generation VLSI
Holographic Lithography Systems, Inc.
Palmer Phan T. H.
LandOfFree
Holographic patterning method and tool for production environmen does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Holographic patterning method and tool for production environmen, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Holographic patterning method and tool for production environmen will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-550380