METHOD OF PREPARING SILICON CRYSTALS WITH CYCLIC TWIN STRUCTURE Russian patent published in 2003 - IPC

FIELD: crystal growing. SUBSTANCE: silicon crystals with cyclic twin structure appropriate for fabrication of semiconductor ingots or plates are grown by Chokhralsky method from melt onto seed with cyclic twin structure varying from basic three-seed structure formed by two coherent first-order twinning surfaces and one second-order twinning border to full cyclic twin structure formed by twenty coherent first-order twinning surfaces, four second-order twinning borders, six third-order twinning borders, and even number of additional first-order twinning surfaces in parallel to above-mentioned twenty surfaces. Growing is performed by adding to silicon melt additives selected from germanium, tin, and lead at concentration 1,0•10^-7 to 15% of the weight of silicon. EFFECT: increased length of grown crystals with cyclic twin structure and thereby increased productivity of growing these crystals. 1 tbl