Ongoing Projects at ITC
Implantation doping of silicon carbide
Silicon carbide (SiC) semiconductor devices are now commercially available for applications in high power switching and rectification. ITC has been involved in the development of implantation and annealing processes for n- and p-type doping of this material for more than 10 years. Almost half of our implantations are today for SiC applications.
A. Hallén, M.S. Janson, A. Yu. Kuznetsov, D. Åberg, M.K. Linnarsson, B.G. Svensson, P.O. Persson, F.H.C. Carlsson, L. Storasta, J.P. Bergman, S.G. Sridhara, and Y. Zhang: Ion implantation of silicon carbide, Nucl. Instr. and Meth. in Phys. Res. B 186, p. 186 (2002)
A. Galeckas, A. Hallén, S. Majdi, J. Linnros, and P. Pirouz: Combined photoluminescence-imaging and deep-level transient spectroscopy of recombination processes at stacking faults in 4H-SiC, Phys. Rev. B 74, p. 233203 (2006)
Advances in Selective Doping of SiC Via Ion Implantation, A. Hallén, R. Nipoti, S.E. Saddow, S. Rao and B.G. Svensson, in Advances in Silicon Carbide Processing and Applications edited by S.E Saddow and A. Agarwal, Artech House 2004, ISBN 1-58053-740-5
Y. Zhang, W.J. Weber, W. Jiang, C.M. Wang, V. Shutthanandan, and A. Hallén: Effects of implantation temperature on damage accumulation in Al-implanted 4H-SiC, J. Appl. Phys.95, p. 4012 (2004)
A.Yu. Kuznetsov, J. Wong-Leung, A. Hallén, C. Jagadish and B.G. Svensson: Dynamic annealing in ion implanted SiC: flux versus temperature dependence, J. Appl. Phys. 94, p. 7112 (2003)
A. Hallén, M. Nawaz, C. Zaring, M. Usman, M. Domeij, and M. Östling, “Low-temperature annealing of radiation-induced damage degradation in 4H SiC bipolar junction transistors, IEEE Electron Device Lett., 31, 707 (2010)
Implant isolation in III-V devices
One often used method to isolate active opto electronic device areas from other areas on a wafer is to ”kill” the material in between by a sufficiently high dose of ions. By a proper choice of ions, energies and doses, a highly resistive region can be created. ITC participates in both commercial implantations on a routine base and development of recipies for new applications.
G. Moschetti, P.-Å. Nilsson, A. Hallén, L. Desplanque, X. Wallart, and J. Grahn, Planar InAs/AlSb HEMTs with ion implanted isolation, IEEE Electron Device Letters 33, 507 (2012)
Medium energy ion scattering (MEIS)
The same high voltage platform used for producing ions for implantations is also used for accelerating ions for the purpose of ion beam analysis. Recently, a new beamline for medium energy ion scattering has been taken into use. The beam is pulsed for time-of-flight energy detection and also features a large area surface sensitive detector.
M.K. Linnarsson, A. Hallén, J. Åström, D. Primetzhofer, S. Legendre, and G. Possnert, New beam line for time-of-flight medium energy ion scattering with large area position sensitive detector. Rev. Sci. Instr. Sep;83(9):095107 (2012)
Implantation damage studies in ZnO
Zinc oxide (ZnO) is a wide bandgap semiconductor with applications, for instance, as LEDs, diluted magnetic materials and for transparent contacts in solar cells. The material has proven to be extremely resistant to ion implantation, which enables the use of material modification by ion implantation utilizing high doses.
J.M. Wikberg, R. Knut, A. Audren, M. Ottosson, M.K. Linnarsson, O. Karis, A. Hallén, and P. Svedlindh”, Annealing effects on structural and magnetic properties of Co implanted ZnO single crystals”, J. Appl. Phys. 109, 083918(2011)
P.T. Neuvonen, L. Vines, V. Venkatachalapathy, A. Zubiaga, F. Toumisto, A. Hallén, B.G. Svensson, and A. Yu. Kuznetsov, “Defect evolution and impurity migration in Na implanted ZnO”, Phys. Rev. B 84, 205202 (2011)