Lateral pulling growth of crystal ribbons and apparatus therefor

Claim 1

A method of laterally growing a thin single crystal ribbon of a semiconductor substance from a melt surface of said substance which comprises the steps of heating said melt in a crucible with a heating means, contacting the undersurface of one end of a seed crystal to said melt surface, melting back slightly said undersurface by adjusting heating thereof with said heating means, cooling the uppersurface of a limited domain of said seed above said seed-melt contacting interface and defining a crystal growing domain on the surface of the melt in contact with said interface by blowing a gaseous cooling medium through at least one nozzle provided at the undesirside of a cooling apparatus located over said uppersurface, laterally pulling said seed and successively grown crystal away from said melt surface over a peripheral edge of said crucible at a gradually-increasing rate, while changing said crystal growing domain from a short one to a long one by shifting the cooling apparatus in the direction opposite to the pulling direction, increasing the blow rate of said gaseous cooling medium to maintain successive crystallization at a rate commensurate with an increasing pulling rate, and controlling the area over which said gaseous cooling medium is blown as said crystal is grown to provide a crystal growing domain having a predetermined size and position, thereby growing said single crystal ribbon of semiconductor substance of controlled size under stabilized conditions at a high growth rate.

Claim 2

A method of laterally growing a thin single crystal ribbon of a semiconductor substance from a melt surface of said substance which comprises the steps of heating said melt in a crucible with a heating means, contacting the undersurface of one end of a seed crystal to said melt surface, melting back slightly said undersurface by adjusting heating thereof with said heating means, cooling the uppersurface of a limited domain of said seed above said seed-melt contacting interface and defining a crystal growing domain on the surface of the melt in contact with said interface by blowing a gaseous cooling medium through at least one nozzle provided at the undesirside of a cooling apparatus located over said uppersurface, laterally pulling said seed and successively grown crystal away from said melt surface over a peripheral edge of said crucible at a gradually-increasing rate, while changing said crystal growing domain from a short one to a long one by shifting the cooling apparatus in the direction opposite to the pulling direction, increasing the blow rate of said gaseous cooling medium to maintain successive crystallization at a rate commensurate with an increasing pulling rate, and controlling the area over which said gaseous cooling medium is blown as said crystal is grown to provide a crystal growing domain having a predetermined size and position, thereby growing said single crystal ribbon of semiconductor substance of controlled size under stabilized conditions at a high growth rate.