IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Surface Science Tuesday Sessions
       Session SS3-TuP

Paper SS3-TuP17
Phosphorus Behaviors upon the Annealing of the Heavily Phosphorus Doped Silicon with Thin Native Oxide Film Evaluated by XPS and AFM

Tuesday, October 30, 2001, 5:30 pm, Room 134/135

Session: Adsorption/Desorption Poster Session
Presenter: Y. Mizokawa, Osaka Prefecture University, Japan
Authors: Y. Mizokawa, Osaka Prefecture University, Japan
W.B. Ying, Osaka Prefecture University, Japan
H. Iguchi, Osaka Prefecture University, Japan
Y. Kamiura, Osaka Prefecture University, Japan
K. Kawamoto, Denso Co. Ltd., Japan
Correspondent: Click to Email
Phosphorus redistribution and its chemical structure of the heavily phosphorus doped Si(100) upon the annealing were investigated using x-ray photoelectron spectroscopy (XPS) and atomic force microscope (AFM). The samples were prepared by predeposition of POCl@sub 3@, and annealing was performed on the HF-treated samples with about 2nm-thick native oxide film in nitrogen atmosphere at 450°C, 660°C and 750°C for 1 hour. The depth profiling was carried out by the chemical etching using 0.1-1% HF solutions. The true in-depth profiles of P obtained after correcting the mean free path effect showed that the segregated-P was piled up at the interface, and its concentration decayed exponentially toward both directions of oxide film and substrate. Although the dominant chemical structure of P was unoxidized states throughout the oxide/Si, the peak position of the P2p photoelectron shifted toward higher binding energy side with approaching the interface. The results suggest that upon annealing a part of the segregated P atoms located in the top surface region of silicon lattice protrude into the oxide film as a form of P-cluster with P-P bonding. The amount of protruded-P in the oxide film increased with annealing temperature, where the activation energy was about 1 eV. The amount was estimated to be about 1x10@super 15@ P-atoms/cm@super 2@ after 750°C annealing. The AFM image showed an unique pattern of various-sized plateaus of about 2nm height, and after 750°C annealing, some of the plateaus grew in height keeping their lateral shape. The total increments were in rough accord with the estimated volume of protruded-P in the oxide film.