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Silicon wafers were preamorphized with 60 keV Ge+ or 70 keV Si+ at a dose of 11015 atoms/cm2. F+ was then implanted into some samples at 6 keV at doses ranging from 11014 to 51015 atoms/cm2, followed by 11B+ implants at 500 eV, 11015 atoms/cm2. Secondary-ion-mass spectrometry confirmed that fluorine enhances boron motion in germanium-preamorphized materials in the absence of annealing. The magnitude of boron diffusion scales with increasing fluorine dose. Boron motion in as-implanted samples occurs when fluorine is concentrated above 11020 atoms/cm3. Boron atoms are mobile in as-implanted, amorphous material at concentrations up to 11019 atoms/cm3. Fluorine directly influences boron motion only prior to activation annealing. During the solid-phase epitaxial regrowth process, fluorine does not directly influence boron motion, it simply alters the recrystallization rate of the silicon substrate. Boron atoms can diffuse in germanium-amorphized silicon during recrystallization at elevated temperatures without the assistance of additional dopants. Mobile boron concentrations up to 11020 atoms/cm3 are observed during annealing of germanium-preamorphized wafers.© 2005 American Institute of Physics.[DOI: 10.1063/1.2084336]
Publication date: 
1 Jan 2005

JM Jacquesa, KS Jones, LS Robertson, A Li-Fatou, CM Hazelton, E Napolitani, LM Rubin

Biblio References: 
Volume: 98 Pages: 073521