Inactivation of low-dose implanted phosphorus pileup in the silicon side of an Si/SiO2 interface after oxidation

Precise phosphorus profiles were obtained in the region of an Si/SiO2 inter face by means of inductively coupled plasma mass spectrometry (ICPMS), seco ndary ion mass spectroscopy (SIMS), and spreading resistance profiling (SRP ) measurements. Samples were prepared by implanting phosphorous at low dose , annealing, and oxidizing by wet oxidation. According to ICP-MS, the total amounts of phosphorus were extremely low in the SiO2 side. The same result s held when the oxidation temperature was changed from 800 to 900 degrees C . SIMS measurement in conjunction with ICP mass measurement showed that the pileup of phosphorus occurred in the silicon side at the Si/SiO2 interface . SRP confirmed that the pileup of phosphorus was electrically inactive. As a result, the active amount of phosphorus in the Si side was reduced to ab out 60%. The simulation based on the monolayer formation at the the SiO2/Si interface was proposed to describe the observed pileup phenomenon of phosp horus. (C) 1999 The Electrochemical Society. S0013-4651(98)03-117-6. All ri ghts reserved.