A compact and low power microwave ECR broad ion beam source for low pressure materials processing

Summary Form only given, as follows. To meet industrial and research requirements for a physically compact, long-life, high-current-density, broad-beam ion source capable of operating with chemically active gases such as CF/sub 4/ and O/sub 2/, the multicusp ECR ion source concept has been redesigned to increase output beam current while reducing its physical size. The physical size of the cylindrical applicator has been reduced to an outside diameter of 3.75 in. and a cavity inside diameter of 3.5 in. while retaining a discharge diameter of 5 cm. The multicusp magnets have been removed from the microwave excitation region. Improved water and gas cooling allow for higher-power (>200 W) operation. The double extraction grids have been redesigned for greater transparency and, hence, greater beam current densities. The discharge is now self-starting at low pressures. When excited with the TE/sub 111/ mode at 2.45 GHz, the source operates efficiently and easily at low input gas flows (1-5 sccm) and pressures in Ar, O/sub 2/, and N/sub 2/ gases. Ion densities of 10/sup 11/-10/sup 12/ cm/sup -3/ have been achieved with input power levels of less than 200 W, and beam current densities in excess of 10 mA/cm/sup 2/ are produced with multigrid-extraction optics.<>