Tailoring of work function by surface segregation

Surface modification by segregation is a potential method to control the wo rk function. Property of surface with segregation is expected to be the sam e as that with adsorption. The saturated behavior of surface composition in segregation phenomena is added advantage over adsorption. The segregation behavior of Cu on Ti film/Cu substrate was studied by heating the specimen in ultra high vacuum and the change in work function for different concentr ations of segregated Cu on Ti film was measured with a Kelvin probe. Work f unction decreased linearly with increasing segregated Cu concentration and the amount of decrease in work function is about 0.3 eV for 5 at.% Cu at sa turation. (C) 2001 Published by Elsevier Science B.V.