Structured high temperature implantation in diamond using maskless implantation and ion projection techniques

Doping of diamond using standard implantation techniques at room-temperature is restricted considerably by radiation conversion of diamond into graphite. A solution to avoid the graphitization and accelerate the doping process is an implantation procedure at high temperature. A drawback of this method is that it does not allow to apply contact masks because of high temperatures of the sample. Ion projection technique is suitable to overcome this problem. The principle idea of this method is the spatial separation between the mask and the substrate. Basically, the technique aims to project the structures of a stencil mask onto the sample using an ion optical lens system. Due to the high demagnification (e.g. 1:16) this technique enables to implant high doses at high temperatures on a very short time scale. An additional advantage of the ion projection method is that it can be applied for non-flat samples too. A experimental setup developed in Bochum allows to implant structures with a resolution below 300 nm using ion energies up a few MeV.