Production of an atomic oxygen beam by a nozzle-beam-type microwave radical source

Abstract

Characteristics of a nozzle‐beam‐type microwave radical source are described. This source generates microwaveplasma in a space between a nozzle and a skimmer to excite a processing gas. The source has a nozzle of 0.6 mm aperture, followed by a 1.2 mm skimmer, and gases pass through the skimmer so that a molecular beam contains radicals. The total atomic oxygen flux is 1.8×1016 atoms/s at a power of 130 W and an O2 flow rate of 2 SCCM. It is possible to optimize the beam profile by varying the combination of the nozzle and the skimmer. Thus, a high‐density radical source with a compact structure and low power consumption is realized. This source is promising for oxide film growth in an ultrahigh vacuum processing.