A compact radio-frequency ion source for high brightness and low energy spread negative oxygen ion beam production

A high brightness and low energy spread (Delta E) ion source is essential to the production of a high-quality primary ion beam applied in secondary ion mass spectrometry (SIMS). A compact 13.56 MHz radio-frequency (RF) ion source with an external planar spiral antenna has been developed as a candidate ion source for the production of negative oxygen ion beams for SIMS application. This ion source is designed with a three-and-a-half-turn water-cooled planar antenna for RF power coupling, a multi-cusp magnetic field for effective plasma confinement, and a three-electrode extraction system. The experimental results show that more than 50 mu A negative oxygen ion beams have been extracted, which consist of 56% O-, 25% O-2(-), and 19% O-3(-). The ion energy distribution of the negative oxygen ion beam exhibits a Gaussian distribution with a minimum.E of 6.3 eV. The brightness of the O- beam is estimated to be 82.4 A m(-2) Sr-1 V-1. The simulation, design, and experimental study results of this RF ion source will be presented in this paper.

Automated summary

In this paper, a compact RF ion source is presented for the production of negative oxygen ion beams for SIMS application. Experimental results show that this ion source can extract high brightness and low energy spread negative oxygen ion beams.