Generation of O2 and metalorganic cluster ion beams and its application to low-temperature thin oxide film formation

High-current O2 and N2 cluster ion beams were formed through a Laval nozzle by the combination of He mixing and gas cooling. The cluster current of 320 nA was obtained from O2 cluster ions whose mean cluster size was 7000. Consequently, the equivalent ion current was as high as 2.2 mA. The optimum He flow ratio to obtain the most intense cluster beams was lower than those reported. The high-current O2 cluster ion beams were successfully applied to the low-temperature formation of high-quality SiO2 and PbO films. Generation of Ti(i-OC3H7)4 cluster ion beams (1.7 nA) was also demonstrated with the He bubbling method for the first time.