The distribution and depth of ion doses implanted into wedges by plasma immersion ion implantation in drifting and stationary plasmas

The distribution of ion dose arising from plasma immersion ion implantation (PIII) of a complex shape in the form of a wedge is measured. Two types of plasma are considered: a drifting titanium plasma derived from a pulsed cathodic arc and a stationary plasma generated by PIII pulses in oxygen or nitrogen gas. The distributions of the implanted material over the surface of the aluminium wedge were studied using secondary ion mass spectroscopy and Rutherford backscattering. The effects of varying the apex angles of the wedge and the plasma density are investigated. We conclude that ion-focusing effects at the apex of the wedge were more important for the drifting plasma than for the stationary plasmas. In a drifting plasma, the ion drift velocity directed towards the apex of the wedge compresses the sheath close to the apex and enhances the concentration of the dose. For the stationary plasma, the dose is more uniform