Homogeneous Dopant Distribution of Silicon Crystal Grown by Vertical Magnetic Field-Applied Czochralski Method

Abstract

Phosphorus-doped Czochralski (CZ) silicon crystals with less than 5% macroscopic radial and microscopic axial resistivity variations are grown in the presence of 1000 Oe vertical magnetic field strength. Crystals with extremely improved dopant homogeneity are facilitated by determining the appropriate crystal and crucible rotation rates corresponding to the residual thermal convection in the molten silicon. Experimental results can be consistently explained by flow model of forced and thermal convections which are stabilized by a magnetic field.

Magnetically Damped Convection During Solidification of a Binary Metal Alloy

“…Magnetic damping has been studied both experimentally (e.g., Hoshikawa et al, 1984;Hirata and Inoue, 1985;Kim and Smetana, 1985) and numerically (e.g., Oreper and Szekely, 1984;Langlois, 1984;Lee etal., 1984;Mihelcic and Wingerath, 1985;Organ, 1985;Kim and Langlois, 1986) for the growth of single crystals, as in the Czochralski or Bridgman-Stockbarger processes. The effect of magnetic damping on the metallurgical grain structure in a solidified metal alloy has been investigated experimentally (Uhlmann et al, 1966), and experiments have been performed under more controlled conditions to study the effects of a magnetic field on convection during solidification (Vives and Perry, 1987).…”

Growth of 2 inch Si0.5Ge0.5bulk single crystals

“…Magnetic field application is one means of suppressing convection in a melt. [27][28][29] A further increase in the crystal diameter is also necessary for the development of SiGe bulk crystal substrates. In the present experiments, a vacuum adiabatic layer was introduced between the BN crucible and the quartz ampoule as described in Sect.…”

Computer Simulation of Boron Transport in Magnetic Czochralski Growth of Silicon

“…It is the application of this family of techniques where heating times of 1-100s are utilized that is reviewed in the present work (7)(8). Most popular of these techniques is the use of banks of halogen lamps 1Present address: Department of Electronic and Electrical Engineering, University of Surrey, Guildford, Surrey, England placed above and below the wafer being processed, as first reported by Nishiyama et al (9). Resistive heating using a graphite strip heater (GSH) has also been used (10) where the system was the same as the pyrolytic Si3N4 deposition system first described by Donnelly et al (11).…”

“…Orienting the magnetic field parallel to the axis of the crystal (8) offers the advantage that the axial symmetry of the configuration is not disturbed, thus minimizing azimuthal variations in the homogeneity of the crystal. However, it has been found (9) that the radial distribution of dopant then becomes more pronounced than in nonmagnetic Czochralski growth. The present paper describes a series of digital simulations that offer some insight as to why this is the case.…”