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O: Oberflächenphysik
O 33: Oberfl
ächenreaktionen (II)
O 33.5: Talk
Thursday, March 25, 1999, 17:15–17:30, S1
Interaction Between Phosphorus and Oxygen in Silicon — •Jarek Dabrowski and Hans-Joachim Müssig — Institute for Semiconductor Physics, Walter-Korsing-Str. 2, 15230 Frankfurt (Oder)
Segregation of dopant atoms to the SiO2/Si interface causes a signific ant redistribution and deactivation of the implanted dopants, leading to some problems during manufacture of submicron silicon devices [1]. We present theoretical (ab initio) and experimental (Auger Electron Spectroscopy, Scanning Tunneling Microscopy) arguments suggesting a novel microscopic mechanism which can explain the segregation of phosphorus. The dopant ato ms are weakly bonded below a perfect interface, strongly bonded at certain interfacial defect sites (related with dangling bonds and strained Si–Si bonds), and moderately bonded below the interface in comple xes containing two P atoms and an oxygen atom. Chemical bonds between phospho rus and oxygen are not formed. Our results indicate that the microscopic qual ity of the interface as well as the conditions (such as partial oxygen pressu re) during the annealing of the oxide may be important factors, which control the amount of the segregated dopants.
[1] J. Dabrowski, H.-J. Müssig, M. Duane, S. T. Dunham, R. Goossens, and H.-H. Vuong, Advances in Solid State Physics 38, 595 (1998).