SURFACE SEGREGATION EFFECTS IN AL2O3 IMPLANTED WITH HIGH DOSE INDIUM

SURFACE SEGREGATION EFFECTS IN AL₂O₃ IMPLANTED WITH HIGH DOSE INDIUM

Cao Dexin，

D.K. Sood

Nuclear Science and Techniques

pp.99-104

Published in print 01 May 1990

29800

Implantations of 100 keV In ions to high dose of 6×10¹⁶In/cm² were performed into a-axis oriented crystals of Al₂O₃ held at a liquid nitrogen temperature. The implantation produced about 80nm thick amorphous surface layer. Isothermal annealing in flowing Ar gas ambient was done at the temperatures of 600, 700, 800, and 900℃. Rutherford backscattering and channeling (RBS-C), scanning electron microscope (SEM) and reflection high energy electron diffraction (RHEED) have been employed to investigate the annealing behaviors.

The indium shows anomalous diffusion in amorphous layer. The migration of indium was composed of two parts: (a) some broadening of In profile corresponding to diffusion within the amorphous layer, (b) segregation of In to surface to form In₂O₃ which appears as islands on the surface. When the ambient is made oxygen free, the segregated In is lost by evaporation at the surface.

Surface segregation effectsIon implantedIsothermal annealing

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