Surface photochemistry induced by x-ray irradiation

The high-intensity, high-energy x rays produced by third-generation synchrotron radiation sources have made possible many new applications, such as deep x-ray lithography, that take advantage of the long penetration lengths of the x rays in lower-Z materials. Recently, we have initiated a program to evaluate the prospects for using x rays for materials processing by performing surface photochemistry induced by x-ray irradiation (SPIXI). The x rays induce reactions on the surfaces of solids immersed in potentially reactive liquids or gases. In this article we present results that demonstrate the feasibility of the SPIXI approach for both etching and deposition. Using a fluorochlorocarbon-based solvent and a Mo substrate we find indications of an etching-type reaction. Au and Ag films and nanocrystalline particles were produced from the irradiation of a Mo substrate immersed in their respective salt solutions. A Au film was also deposited on Kapton by back irradiation. These preliminary results indicate that this approach has great potential for room-temperature, atmospheric, patterned, materials processing. (C) 1998 American Vacuum Society. [S0734-211X(98)06706-7].