Metal arc plasma ion implantation of materials used in aerospace applications

Summary form only given, as follows. Nowadays the improvement of spacecrafts and the increasing payloads of launchings have increased their costs. In view of that, the search for means of prolonging the effective lifetime of new spacecrafts has been pursued. For instance, launching small space devices (micro and nanosatellites) to low earth orbit are being preferred for reasons of cost and efficiency. But, in that region (200-800 km altitude), degradation of certain spacecraft materials such as polymers by atomic oxygen and vacuum ultraviolet radiation becomes a relevant issue. To avoid this problem, many surface protection techniques have been considered, ion beam modification being one of them. Recently we have proposed the use of metallic arc plasma ion implantation (MAPII) of the polymeric materials by aluminum. High density (10/sup 13/ cm/sup -3/), 2 eV, high ionization rate (>50%), metallic plasma made of Al is produced in this device with a pulse duration of 10-15 ms. Arc voltages less than 100 V and currents of 600 A are typically used for MAPII, with a low discharge rate of 1 pulse/min. High negative voltage pulses of 10-20 kV are continuously applied to the sample to be processed at a repetition frequency of about 700 Hz with duration of 100 ms. Both discharges (with and without B-field) are used and to attain high implantation doses (> 10/sup 16/ cm/sup -2/) more than 100 plasma discharges are applied. Preliminary MAPII processing have been tested on Si wafers. For the above experimental conditions, high resolution X-ray analysis of the samples have indicated significant implantation of Al into the Si lattice. Also metal deposition can be obtained depending on the MAPII operation conditions. These MAPII results are addressed at the conference as well as other new ones expected, especially for polymeric materials used in fabrication of space components.