Content deleted Content added
+link |
|||
Line 4:
[[File:Different_multipatterning_techniques.png|thumb|right|300px|'''Different techniques for multiple patterning'''<br>''Top:'' Splitting of features into groups (3 shown here), each patterned by a different mask<br>''Center:'' Use of a spacer to generate additional separate features in the gaps<br>''Bottom:'' Use of an opposite polarity feature to cut (small break) pre-existing features]]
Even with single exposure having sufficient resolution, extra masks have been implemented for better patterning quality such as by [[Intel]] for line-cutting at its 45nm node<ref>[http://download.intel.com/pressroom/kits/advancedtech/pdfs/VLSI_45nm_HiKMG-presentation.pdf Intel 45nm HKMG]</ref> or [[TSMC]] at its 28nm node.<ref>[https://support1.cadence.com/public/docs/content/11673890.html TSMC 28nm cutpoly]</ref> Even for [[electron-beam lithography]], single exposure appears insufficient at ~10 nm half-pitch, hence requiring double patterning.<ref>{{cite journal|last1=Chao|first1=Weilun|last2=Kim|first2=Jihoon|last3=Anderson|first3=Erik H.|last4=Fischer|first4=Peter|last5=Rekawa|first5=Senajith|last6=Attwood|first6=David T.|title=Double patterning HSQ processes of zone plates for 10 nm diffraction limited performance|date=2009-01-09|url=http://www.osti.gov/scitech/servlets/purl/959418-4ItigR/}}</ref><ref>{{cite journal|last1=Duan|first1=Huigao|last2=Winston|first2=Donald|last3=Yang|first3=Joel K. W.|last4=Cord|first4=Bryan M.|last5=Manfrinato|first5=Vitor R.|last6=Berggren|first6=Karl K.|author6-link=Karl K. Berggren|title=Sub-10-nm half-pitch electron-beam lithography by using poly(methyl methacrylate) as a negative resist|journal=Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena|date=November 2010|volume=28|issue=6|pages=C6C58–C6C62|doi=10.1116/1.3501353|bibcode=2010JVSTB..28C..58D |url=http://www.rle.mit.edu/qnn/documents/duan-5-2010-80.pdf|archive-url=https://web.archive.org/web/20120119131529/http://www.rle.mit.edu/qnn/documents/duan-5-2010-80.pdf|archive-date=2012-01-19|hdl=1721.1/73447|hdl-access=free}}</ref>
Double patterning lithography was first demonstrated in 1983 by D. C. Flanders and N. N. Efremow.<ref>{{cite journal |author1=D. C. Flanders |author2=N. N. Efremow | title=Generation of <50 nm period gratings using edge defined techniques | year=1983 | pages=1105–1108 | publisher=J. Vac. Sci. Technol. B}}</ref> Since then several double patterning techniques have been developed such as self alignment double patterning (SADP) and a litho-only approach to double patterning.<ref>{{cite journal |author1=Chris Bencher |author2=Yongmei Chen |author3=Huixiong Dai |author4=Warren Montgomery |author5=Lior Huli | title=22nm half-pitch patterning by CVD spacer self alignment double patterning (SADP) | journal=Optical Microlithography XXI | year=2008 | volume=6924 | pages=69244E | publisher=Optical Microlithography XXI; 69244E| doi=10.1117/12.772953 | bibcode=2008SPIE.6924E..4EB | s2cid=121968664 }}</ref><ref>{{cite journal |author1=A. Vanleenhove |author2=D. Van Steenwinckel | editor1-first=Donis G | editor1-last=Flagello | title=A litho-only approach to double patterning | journal=Society of Photo-Optical Instrumentation Engineers (Spie) Conference Series | series=Optical Microlithography XX | year=2007 | volume=6520 | pages=65202F | publisher=Optical Microlithography XX; 65202F| doi=10.1117/12.713914 | bibcode=2007SPIE.6520E..2FV | s2cid=119829809 }}</ref>
| |||