Atomic force microscopy and friction force microscopy of chemically modified surfaces

We describe the study of a chemically modified quartz surface by atomic force microscopy and friction force microscopy. The chemically modified surface was covered with hydrocarbon (HC) and fluorocarbon (FC) in different parts. The region selective surface chemical modification with two different silanization reagents was successfully accomplished by the following procedure: exposed quartz surfaces of a quartz plate covered with microlithographically prepared patterns of chromium film were first modified with one of the silanization reagents, then the patterns of chromium film were etched, and finally, newly exposed quartz surfaces were modified with the other silanization reagent. The chemical modification with such etching allowed patterning with a submicrometer scale. Since the location of the surfaces covered with two different chemical species was known in the chemically modified surfaces, assignment of the measured frictions to the individual surfaces was definite. The relative values of the difference in friction between HC and FC regions were roughly 1:4.