SYNCHROTRON-RADIATION-INDUCED FORMATION OF SALT PARTICLES ON AN X-RAY-LITHOGRAPHY MASK

The suppression and removal of contaminants on X-ray masks are require d for the application of X-ray Lithography to practical semiconductor production, because contamination is easily transferred to the replica ted resist patterns and degrades the LSI patterns In order to study co ntamination of a Ta/SiN X-ray mask, its growth process was investigate d using an atmospheric reaction chamber and in situ observation appara tus for gases at atmospheric pressure. It was found that the contamina tion particles were ammonium sulfate and oxalate. The sources of the s alt particle were also identified.