Abstract: A layer-structured oxide exhibiting a paraelectric characteristic and a layer-structured oxide having a preferable remanent polarization, and a process of producing the same. A layer-structured oxide containing Bi, a first component Me, a second component R, and O is produced by heating raw materials at a high temperature of about 1400° C. for several ten minutes by a self-flux method using Bi2O3 as a flux. The first component Me is composed of at least one kind selected from a group consisting of Sr, Pb, Ba, and Ca, and the second component R is composed of at least one kind selected from a group consisting of Nb and Ta. The composition formula of the oxide is expressed by Bi2−aMe1+bR2O9+c where a, b, and c are values in ranges of 0<a<2, 0<b≦0.4, and −0.3≦c≦1.4. The layer-structured oxide exhibits a paraelectric characteristic or a ferroelectric characteristic at a composition in a specific range out of the stoichiometric composition.

Abstract: A system that employs thermophoresis to protect lithographic surfaces from particle deposition and operates in an environment where the pressure is substantially constant and can be sub-atmospheric. The system (thermophoretic pellicle) comprises an enclosure that surrounds a lithographic component whose surface is being protected from particle deposition. The enclosure is provided with means for introducing a flow of gas into the chamber and at least one aperture that provides for access to the lithographic surface for the entry and exit of a beam of radiation, for example, and further controls gas flow into a surrounding low pressure environment such that a higher pressure is maintained within the enclosure and over the surface being protected.