Method of controlled, uniform doping of floating zone silicon

Abstract From the Canadian patent

A two-step process for fabricating impurity doped float-zoned single crystal silicon boules which exhibit substantially controlled and uniform concentrations of the impurity is disclosed. This process when, applied to polycrystalline silicon rods in a controlled environment of oxygen results in the production of high purity float-zoned silicon crystals with substantially uniform oxygen concentrations of up to 32 ppma which are not currently attainable utilizing the conventional Czochralski silicon boule fabrication methods of the semiconductor industry.