ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Inhibition of fluid flow instabilities in the melt by the axial magnetic field in Czochralski silicon crystal growth (AMCZ) is investigated precisely by a high-sensitivity striation etch in conjunction with temperature measurements. The magnetic field strength (B) was varied up to 4.0 kG, incremented mostly in 0.5-kG/2.5-cm crystal length. The convection flow was substantially suppressed at B≥1.0 kG. A low oxygen level of 2–3 ppm and a high resistivity of 400 Ω cm is achieved in the AMCZ silicon crystals at B≥1.0 kG. Random striations at B=0, characteristic of turbulent convection, assumed progressively a periodicity, indicative of oscillatory convection at 0.35〈B≤4.0 kG. The striation contrast or "intensity'' decreased steadily with the increase in B. At B=4 kG, most of the crystal was free of striations, although some weak, localized periodic striations persisted near the crystal periphery. Spreading-resistance measurement shows, however, a uniform dopant distribution in all crystal sections grown at 0.35〈B≤4.0 kG within a few percent.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.335883
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