Silicon crystal growth by the electromagnetic Czochralski (EMCZ) method

A new method for growing silicon crystals by using electromagnetic force to rotate the melt without crucible rotation has been developed. We call it e lectromagnetic Czochralski (EMCZ) growth. An electromagnetic force in the a zimuthal direction is generated in the melt by the interaction between an e lectric current (I) through the melt in the radial direction and a vertical magnetic field (B). The rotation rate (omega(m)) of the silicon melt is co ntinuously changed from 0 to over 105 rpm under I = 0 to 8 A and B = 0 to 0 .1 T. Thirty-mm-diameter silicon single crystals free of dislocations could be grown under two conditions: I = 2.0 A and B = 0.05 T (omega(m) = 105 rp m); and I = 0.2 A and B = 0.1 T (omega(m) = 15 rpm). The oxygen concentrati on in the crystals was 8 x 10(17) atoms/cm(3) for the high rotation rate an d 1 x 10(17) atoms/cm(3) for the low rotation rate. The oxygen-concentratio n distributions in the radial direction in both crystals were more homogene ous than those in the crystals grown by conventional CZ and/or MCZ growth. This new crystal-growth method can be easily adopted for growing large-diam eter silicon crystals.