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US 2003/0224265 A1Published application
System and method for reducing photoresist photo-oxidative degradation in 193 nm photolithography
OwnerUzodinma Okoroanyanwuinventor
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Abstract
An exposure section of a 193 nm photolithography system is purged with a purge gas containing substantially no oxygen, such as nitrogen or an inert gas. This prevents oxidation of photoresist by photo-induced oxygen species that are produced in conventional 193 nm systems purged by clean dry air. A scanner and a stepper of the system are preferably calibrated to the optical properties of the purge gas. A protective layer may be provided over the photoresist to further protect the photoresist.
Claims20
A projection lithography system comprising:
- an exposure section;
- a stage located in the exposure section for supporting a photoresist coated substrate;
- a 193 nm radiation source;
- a projection optical system for projecting a pattern of said 193 nm radiation toward said platform;
- and
- a gas delivery system for providing a purge gas to the exposure section, the gas delivery system including a purge gas source providing a purge gas containing substantially no oxygen to thereby reduce an amount of oxygen species induced by the 193 nm radiation in the exposure section.
3 more elements
A method of performing photolithography, comprising:
- providing a 193 nm lithography system having an exposure section;
- providing a substrate comprising a photoresist layer in the exposure section;
- and
- exposing the photoresist layer to 193 nm radiation while purging the exposure section with a purge gas containing substantially no oxygen to thereby reduce an amount of oxygen species induced by the 193 nm radiation in the exposure section.
1 more element
Dependencies are inferred from the claim text.