Nonchemically amplified positive photoresist for synchrotron radiation x-ray lithography

Abstract

Iodine containing diazoquinone photoactive compounds (PAC) were synthesized and formulated with novolak and other resins in an effort to develop a positive photoresist for the synchrotron beam line at IBM's Advanced Lithography Facility. The studies focused on the effect of synchrotron radiation on the PACs themselves and in various halogenated resins. These materials were tested by exposing the resist materials to various doses of radiation and then measuring the loss of diazo from the PAC. An enhanced sensitivity x-ray (ESX) photoresist system was developed by combining an iodinated PAC with a novolak resin. ESX was compared to a conventional DQ/novolak photoresist system TNS. ESX was able to print at approximately half the dose needed for TNS. Features as small as 175 nm resolved. These set of experiments demonstrate the potential of significantly improving the photospeed of DQ/novolak photoresist system by utilizing a more x-ray efficient PAC.