The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 26, 2010
Filed:
Jun. 27, 2007
Fritz Kirscht, 12621 Berlin, DE;
Vera Abrosimova, 12555 Berlin, DE;
Matthias Heuer, 04275 Leipzig, DE;
Dieter Linke, 12527 Berlin, DE;
Jean Patrice Rakotoniana, 12456 Berlin, DE;
Kamel Ounadjela, Belmont, CA (US);
Fritz Kirscht, 12621 Berlin, DE;
Vera Abrosimova, 12555 Berlin, DE;
Matthias Heuer, 04275 Leipzig, DE;
Dieter Linke, 12527 Berlin, DE;
Jean Patrice Rakotoniana, 12456 Berlin, DE;
Kamel Ounadjela, Belmont, CA (US);
Other;
Abstract
Techniques for controlling resistivity in the formation of a silicon ingot from compensated feedstock silicon material prepares a compensated, upgraded metallurgical silicon feedstock for being melted to form a silicon melt. The compensated, upgraded metallurgical silicon feedstock provides a predominantly p-type semiconductor for which the process assesses the concentrations of boron and phosphorus and adds a predetermined amount of aluminum or/and gallium. The process further melts the silicon feedstock together with a predetermined amount of aluminum or/and gallium to form a molten silicon solution from which to perform directional solidification and, by virtue of adding aluminum or/and gallium, maintains the homogeneity the resistivity of the silicon ingot throughout the silicon ingot. In the case of feedstock silicon leading to low resistivity in respective ingots, typically below 0.4 Ωcm, a balanced amount of phosphorus can be optionally added to aluminum or/and gallium. Adding phosphorus becomes mandatory at very low resistivity, typically close to 0.2 Ωcm and slightly below.