Editing Immersion lithography (section)

{{short description|Photolithography technique where there is a layer of water between a lens and a microchip}}
[[Image:Immersion lithography illustration.svg|right|thumb|In immersion lithography, light travels down through a system of lenses and then a pool of water before reaching the [[photoresist]] on top of the [[wafer (electronics)|wafer.]]]]

'''Immersion lithography''' is a technique used in [[Semiconductor device fabrication|semiconductor manufacturing]] to enhance the resolution and accuracy of the [[Photolithography|lithographic process]]. It involves using a liquid medium, typically water, between the lens and the [[Wafer (electronics)|wafer]] during exposure. By using a liquid with a higher [[refractive index]] than air, immersion lithography allows for smaller features to be created on the wafer.<ref>{{Cite journal |last=Flagello |first=Donis |date=2004-01-01 |title=Benefits and limitations of immersion lithography |url=http://nanolithography.spiedigitallibrary.org/article.aspx?doi=10.1117/1.1636768 |journal=Journal of Micro/Nanolithography, MEMS, and MOEMS |language=en |volume=3 |issue=1 |pages=104 |doi=10.1117/1.1636768 |bibcode=2004JMM&M...3..104M |issn=1932-5150|url-access=subscription }}</ref>

Immersion lithography replaces the usual air gap between the final lens and the wafer surface with a liquid medium that has a refractive index greater than one. The [[angular resolution]] is increased by a factor equal to the refractive index of the liquid. Current immersion lithography tools use highly purified water for this liquid, achieving feature sizes below 45 nanometers.<ref>{{Cite web |url=http://www.dailytech.com/IDF09+Intel+Demonstrates+First+22nm+Chips+Discusses+Die+Shrink+Roadmap/article16312.htm |title=DailyTech - IDF09 Intel Demonstrates First 22nm Chips Discusses Die Shrink Roadmap |access-date=2009-12-07 |archive-url=https://web.archive.org/web/20100828220949/http://www.dailytech.com/IDF09+Intel+Demonstrates+First+22nm+Chips+Discusses+Die+Shrink+Roadmap/article16312.htm |archive-date=2010-08-28 |url-status=dead }}</ref>