Round-Robin Ion-Implanter And 4-Point Probes

A round-robin of the “ German Implant User Group” was carried out in order to compare the performance and absolute setting of ion implanters and 4-point probes. For the round-robin of the 4-point probes 52 test wafers with a very low standard deviation were processed ( R s = 47.55 Ω/ σ = 0.25% ). The wafers were measured at Siemens before shipment to the participants, and remeasured afterwards. The values derived by the 20 tested probers were all within ± 3% R s . The 12 Prometrix probers in this comparison showed a good reproducibility of nearly ± 1% R s . The ion implanter round-robin was arsenic, 80 keV, dose 3 × 10 15 and phosphorus, 130 keV, dose 5 × 10 13 , 70 nm oxide. The tests were carried out on commercially available medium current and high current implanters. Wafer sizes varied from 3 in. to 150 mm. The wafers were annealed at the FHG Eriangen and tested at Siemens. For the arsenic test all implanters were within ± 5% R s , for the phosphorus test within ±6%.