{"id":1920,"date":"2010-07-13T16:03:29","date_gmt":"2010-07-13T20:03:29","guid":{"rendered":"https:\/\/wpmu2.mit.local\/?p=1920"},"modified":"2010-07-13T16:03:29","modified_gmt":"2010-07-13T20:03:29","slug":"scanning-beam-interference-lithography","status":"publish","type":"post","link":"https:\/\/wpmu2.mit.local\/scanning-beam-interference-lithography\/","title":{"rendered":"Scanning-beam Interference Lithography"},"content":{"rendered":"
\"Figure<\/a>

Figure 1: Photograph of the Nanoruler lithography and metrology system built by MIT students. This unique tool is the most precise grating patterning and metrology system in the world.<\/p><\/div>\n

Traditional methods of fabricating gratings, such as diamond-tip ruling, electron- and laser-beam scanning, or holography, are generally very slow and expensive and result in gratings with poor control of phase and period.\u00a0 More complex periodic patterns, such as gratings with chirped or curved, lines, or 2D and 3D photonic patterns, are even more difficult to pattern.\u00a0 This research program seeks to develop advanced interference lithography tools and techniques to enable the rapid patterning of general periodic patterns with much lower cost and higher fidelity than current technology.<\/p>\n

\"Figure<\/a>

Figure 2: A 50-nm-pitch (25-nm line\/space) grating pattern fabricated by 4X overlaid interference lithography.<\/p><\/div>\n

Interference lithography (IL) is a maskless lithography technique based on the interference of coherent beams.\u00a0 Interfering beams from an ultra-violet laser generates interference fringes that are captured in a photo-sensitive polymer resist.\u00a0 Much of the technology used in modern IL practice is borrowed from technology used to fabricate computer chips.\u00a0 Traditional IL methods result in gratings with large phase and period errors.\u00a0 We are developing new technology based on interference of phase-locked scanning beams, called scanning-beam interference lithography (SBIL).\u00a0 The SBIL technique has been realized in a tool called the MIT Nanoruler, which recently won a R&D 100 award (Figure 1).\u00a0 Large gratings can be patterned in a matter of minutes with a grating phase precision of only a few nanometers and a period error in the ppb range.<\/p>\n

Current research efforts seek to generalize the SBIL concept to pattern more complex periodic patterns, such as variable period (chirped) gratings, 2D metrology grids, and photonic patterns [1<\/a>]<\/sup> . Important applications of large, high-fidelity gratings are for high-resolution x-ray spectroscopes on NASA x-ray astronomy missions, high-energy laser pulse compression optics, and length metrology standards. We have recently developed a new grating patterning technique called aligned multiple overlay SBIL, which uses multiple (up to four) precisely overlaid IL images to divide the fundamental grating pattern down to very short periods, in this case 50-nm pitch, over large areas (Figure 2). This type of pattern has many applications including nanomagnetics, semiconductor, and nanobiological manufacturing.
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References<\/p>\n

    \n
  1. \u201cDoppler writing and linewidth control for scanning beam interference lithography,\u201d <\/strong>J. Montoya, C.-H. Chang, R.K. Heilmann and M.L. Schattenburg, J. Vac. Sci. Technol. B<\/em> 23<\/strong>, 2640-2645 (2005). [\u21a9<\/a>]<\/li>\n
  2. \u201cPhase control in multiexposure spatial frequency multiplication,\u201d Y. Zhao, C.-H. Chang, R.K. Heilmann and M.L. Schattenburg, J. Vac. Sci. Technol. B <\/em>25<\/strong>, 2439-2443 (2007).<\/li>\n
  3. \u201cDesign of a double-pass shear mode acousto-optical modulator,\u201d C.-H. Chang, R.K. Heilmann, M.L. Schattenburg and P. Glenn, Rev. Sci. Instr.<\/em> 79<\/strong>, pp. 033104-1-5 (2008).<\/li>\n
  4. \u201cFabrication of 50 nm-period gratings with multilevel interference lithography,\u201d C.-H. Chang, Y. Zhao, R.K. Heilmann and M.L. Schattenburg, Opt. Lett<\/em>. 33,<\/strong> 1572-1574 (2008).<\/li>\n
  5. \u201cSpatial-frequency multiplication with multilayer interference lithography,\u201d C.-H. Chang, Y. Zhao, R.K. Heilmann and M.L. Schattenburg, J. Vac. Sci. Technol. B<\/em> 26<\/strong>, 2135-2138 (2008).<\/li>\n<\/ol>\n<\/div>","protected":false},"excerpt":{"rendered":"

    Traditional methods of fabricating gratings, such as diamond-tip ruling, electron- and laser-beam scanning, or holography, are generally very slow and…<\/p>\n<\/div>","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[11],"tags":[66],"_links":{"self":[{"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/posts\/1920"}],"collection":[{"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/comments?post=1920"}],"version-history":[{"count":12,"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/posts\/1920\/revisions"}],"predecessor-version":[{"id":1937,"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/posts\/1920\/revisions\/1937"}],"wp:attachment":[{"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/media?parent=1920"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/categories?post=1920"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpmu2.mit.local\/wp-json\/wp\/v2\/tags?post=1920"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}