Patent Number: 6,254,674

Title: Method of controllably delivering dopant by limiting the release rate of dopant from a submerged vessel

Abstract: A time-released dopant delivery system and method are provided in a Czochralski-type crystal-growing furnace to enable continuous doping of the melt over time. The dopant delivery system and method adjusts dopant levels within the melt as a function of time such that a controlled amount of dopant and, more typically, a substantially constant amount of dopant can be incorporated into the ingot over its length. By controlling the doping level in the ingot, the resistivity profile of the ingot can also be controlled over its length. In order to provide controlled dopant delivery, the dopant delivery system generally includes a vessel defining an internal cavity within which the dopant is disposed and an orifice through which the dopant, typically a molten dopant, is released. The dopant delivery system can also include means for submerging the vessel within the melt such that heat from the melt melts and therefore releases the dopant into the melt. Alternatively, the vessel can be at least partially defined by the crucible so as to be disposed within the melt. By properly configuring the orifice defined by the vessel, however, the release of dopant into the melt can be regulated.

Inventors: Aydelott; Richard M. (Ridgefield, WA)

Assignee: SEH America, Inc.

International Classification: C30B 35/00 (20060101); C30B 11/00 (20060101); C30B 15/02 (20060101); C30B 11/04 (20060101); C30B 15/04 (20060101); C30B 015/04 ()

Expiration Date: 07/03/2018