INTERACTION OF SiO2 GLASSES WITH HIGH ENERGY ION BEAMS AND VACUUM UV EXCIMER LASER PULSES

Abstract

Interaction of high-energy ion beam and vacuum ultraviolet (vuv) excimer laser pulses with SiO2 glasses attracts much interest because of growing applicability of ion implantation and photolithography. Ion implantation is now a powerful technique for fabricating glasses with novel photonic functions such as nonlinear optical properties and wavelength conversion of light [1]. Excellent compatibility with microelectronic processes is a large advantage of this technique. Photolithography of semiconductors using F2 excimer laser (157nm) aiming at realization of 16GB DRAM is a very hot issue. One of the key material issues in the F2-laser lithography is to find or create optical materials exhibiting high transmittance at the wavelength of 157 nm and an excellent resistivity to F2 laser pulses [2]. Although a CaF2 single crystal meets these requirements, its application to a photomask is difficult due to its thermal expansion coefficient that is ~30 times larger than that of SiO2 glass. Thus, SiO2-based glasses would be veiy suitable as photomask materials, provided that the necessary specifications for transparency and radiation resistance can be met. In this article, we describe defect formation in SiO2 glasses by ion implantation and interaction of various types of synthetic SiO2 glasses with F2 excimer laser pulses.