C.Jeynes 1, A.J.Smith 1, N.Peng 1, M.Zier 2, A. Morel 3, Q.Zhao 3, K.Temst 3, W.Vandervorst 3,4, A.Vantomme 3, A.Cassimi 5, I.Monnet 5, E.Balanzat 5, R.Elliman 6 1 University of Surrey Ion Beam Centre, Guildford, England* 2 Forschungszentrum Dresden, Rossendorf, Saxony, Germany* 3 Instituut voor Kern- en Stralingsfysica, Katholieke Universiteit Leuven, Belgium* 4 IMEC Kapeldreef 75, Leuven, Belgium* 5 Commissariat à L’Energie Atomique, Caen, France* 6Australian National University, Canberra, Australia* SPIRIT partner providing Trans-National Access Fluence Control in several European Ion Implanters Ion Beam Centre Fluence Control Ion Implantation is one of the basic enabling technologies for our huge semiconductor processing industry, because in principle we can “count the ions in”. This project is designed to demonstrate that the SPIRIT partners (and others) can indeed supply their users with a specified implanted fluence. Surrey : 2 implanters, 2 MV, 200 kV (2 beam lines) Rossendorf : 4 implanters, 40 kV, 500 kV, 200 kV, 3 MV Tandem Leuven : 2 implanters, 90 kV, 200 kV Caen : 1 MeV/amu cyclotron ANU : 2 implanters, 150 kV, 1.7 MV Tandem Fluence Control and SPIRIT SPIRIT SPIRIT (“Support of Public and Industrial Research Using Ion Beam Technology”) is supported by the European Community as an Integrating Activity under EC contract SPIRIT integrates 11 leading ion beam facilities from 6 European Member States and 2 Associated States. 7 partners provide Trans- National Access to their facilities, offering highly complementary equipment and areas of specialization to European scientists. Ions are supplied in an energy range from below 10 keV to more than 100 MeV for modification and analysis of solid surfaces, interfaces, thin films, and soft matter. SPIRIT will increase the quality of research by sharing best practice, harmonizing procedures and establishing rigorous quality control measures. Accurate Analysis (Right) Analysis Protocol based on accurate stopping powers We have demonstrated previously that a-Si stopping powers are given correctly by SRIM03 for 1.5 MeV He, by comparison with a CRM (certified reference material). Therefore the a-Si yield determines the charge.solid-angle product for each spectrum at 0.6%, far better than the ~2% common in charge integration equipment. Detector electronic gain is critical to accuracy. It is astonishingly easy to make large errors (much larger than expected) in the determination of this parameter. A double-detector configuration is always used specifically to validate the detector gain calibration. It also is a double check on internal consistency of the measurements, essential for analyses like these. Surrey will carry out the measurements for the whole project using (mostly) a published protocol. High energy implants require protocol variation. C. Jeynes et al, Quality assurance in an implantation laboratory by high accuracy RBS, Nucl. Instrum. Meth. B, 249 (2006) 482–485 (Below) Uncertainty Budget Traceably accurate analysis must be accompanied by a systematic analysis of all the contributions to the uncertainty. In most analyses this is dominated by uncertainty in either collected charge or stopping power. Symbols: data; Lines: fit Samples and Analyses Surrey 100 mm wafers used in systematic QA programme, fluence measurements for each beam line every quarter 100 mm wafers used in systematic QA programme, fluence measurements for each beam line every quarter Faraday cup validation required Faraday cup validation required Measurements of three wafers (one cycle) is completed Measurements of three wafers (one cycle) is completed Analysis of data almost complete Analysis of data almost complete Target is 2% accuracy and 2% uniformity Target is 2% accuracy and 2% uniformity Rossendorf 100 mm wafers used. 100 mm wafers used. Faraday cup validation required for three implanters and current measurement assembly for the 4thFaraday cup validation required for three implanters and current measurement assembly for the 4th Measurements of four wafers is completed Measurements of four wafers is completed Target is 2% accuracy and 2% uniformity for 2 implanters (FCs), 5% & 5% (FC on 3 MV), 10% and 10% on 200 kVTarget is 2% accuracy and 2% uniformity for 2 implanters (FCs), 5% & 5% (FC on 3 MV), 10% and 10% on 200 kV Leuven Machine problems have precluded preparation of test samples so far. Machine problems have precluded preparation of test samples so far. Caen Small targets (10 mm) Al foil samples Small targets (10 mm) Al foil samples Charge collection validation required Charge collection validation required Samples are prepared : 40 MeV Xe/cm 2 Samples are prepared : 40 MeV Xe/cm 2 Analysis of sample is complex : using PIXE calibrated against low energy Xe standard implants by Surrey, validated as standards by RBS under this programme Analysis of sample is complex : using PIXE calibrated against low energy Xe standard implants by Surrey, validated as standards by RBS under this programme Target is 10% accuracy and 5% uniformity Target is 10% accuracy and 5% uniformity ANU Four 20 x 20 mm samples used. Four 20 x 20 mm samples used. Current collection validation required for two implanters at both low and high energies for eachCurrent collection validation required for two implanters at both low and high energies for each Measurement of four samples is completed Measurement of four samples is completed Target is 5% accuracy and 5% uniformityTarget is 5% accuracy and 5% uniformity One Example of Measurements Conclusions 0.980(5) As/cm (5) As/cm 2 No significant uniformity (better than 2%) No significant uniformity (better than 2%) Absolute measurement accuracy of mean value is 0.9% Absolute measurement accuracy of mean value is 0.9% Detectors agree within expected uncertainty Detectors agree within expected uncertainty 2% (1  ) fluence accuracy achieved 2% (1  ) fluence accuracy achieved TFU = “thin film units” = atoms/cm keV As/cm 2 (Surrey) Line 1, DF (Danfysik) 200 kV implanter Line 1, DF (Danfysik) 200 kV implanter Wafer QA59P#25 (measured March 2010) Wafer QA59P#25 (measured March 2010) 13 spots over 100 mm wafer measured at 2% 13 spots over 100 mm wafer measured at 2% 2 detectors (1,5.3) msr, 40 uC per spot 2 detectors (1,5.3) msr, 40 uC per spot Channelled on substrate Channelled on substrate Charge.solid-angle product determined per detector from the a-Si height in the implanted region Charge.solid-angle product determined per detector from the a-Si height in the implanted region Weighted average of detectors used due to poor counting statistics on the small detector A Weighted average of detectors used due to poor counting statistics on the small detector A