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:
Feb. 18, 1992
Filed:
Oct. 02, 1990
Wacker-Chemitronic Gesellschaft fur Elektronik-Grundstoffe mbH, Burghausen, DE;
Abstract
Silicon ingots, in particular, with diameters of approximately 75 mm and greater, can be produced by zone pulling with an oxygen content comparable to crucible-pulled material if a flat quartz element is brought into contact with the molten cap during the pulling operation. A quartz ring which is arranged concentrically beneath the induction heating coil and can be lowered from a rest position into its working position on the molten cap is suitable as a flat element. The ingot material obtained in this manner and also the silicon wafers produced therefrom combine the purity advantages of zone-pulled silicon with the beneficial gettering and hardening action of the incorporated oxygen which otherwise distinguishes only crucible-pulled silicon.