CLUSTER DEPOSITION AND CLUSTER EROSION WITH HIGH-INTENSITY IONIZED CLUSTER BEAMS

Cluster beams of high intensity as resulting from condensation in adia batic nozzle expansions of pure gases or vapors can be used either for thin film deposition or for substrate erosion, depending on the clust er impact energy. For deposition, high-intensity cluster beams of zinc and of silver have been obtained for the first time from pure metal v apor nozzle expansions. The clusters contain several thousand atoms of zinc, or several hundred atoms of silver, respectively. Reflecting th in films have been deposited without ionizing and accelerating the clu ster beams. For purposes of erosion, ionized clusters have to be accel erated to impact speeds larger than about 10 km/s in order to get surf ace erosion via shock wave induced crater formation. Crater dimensions of some nanometers are estimated, providing a limit for the spatial r esolution of cluster impact lithography (CIL).