Oxygen-assisted purification of platinum structures deposited by ion and electron beam induced processes

Abstract

Purification in the presence of O2 flux is investigated in platinum structures grown by ion and electron beam induced deposition processes using a standard precursor, MeCpPtMe3. Two different room temperature purification processes are evaluated. In the first process, the purification is obtained by simultaneously supplying oxygen and precursor gas during the deposition. In the second process, an in situ post-treatment is performed on deposited structures by electron irradiation in the presence of oxygen. The first process applied to electron beam deposition requires a high flux of oxygen to improve the purification efficiency, while application to ion beam deposition requires a lower oxygen flux to enhance purification while avoiding an additional increase of the milling process. Both purification processes result in high purity Pt depositions and a reduction of deposition yields. For the ion beam, the electrical resistivity only drops for the first purification process: deposition supplying simultaneously oxygen and gas precursor. The second process of electron post irradiation does result in compositional changes, including reduced amounts of carbon but does not result in improvements in resistivity. For the electron beam, the resistivity shows a significant reduction applying both purification processes in sequence: in this way a resistivity of 22.5 µΩ cm has been obtained which is only twice the bulk value for Pt.