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:
Jun. 05, 1990
Filed:
Dec. 05, 1988
Kenichi Taguchi, Joetsu, JP;
Masataka Watanabe, Nigata, JP;
Shin-Etsu Handotai Company Limited, Tokyo, JP;
Abstract
A method of controlling a floating zone applied to a crystal manufacturing system based on the FZ method and designed to enable the diameter at the crystallization boundary and the axial length of the floating zone or other similar quantities to desired values, in which a floating zone (20) is imaged with an imaging device (30); geometric quantities of the floating zone is measured from the image thereby obtained; the electric power (P) supplied to an induction heating coil (12) and the speed (V.sub.p) at which a raw-material rod (16) is moved relative to the induction heating coil so that the geometric quantities become equal to desired values. The geometric values include one Z.sub.i of the axial length of the floating zone, the distance (L) between the induction heating coil and a crystallization boundary (24) and the diameter (D.sub.n) of a melt neck portion located on the side of the crystallization boundary at a predetermined distance from the induction heating coil, and one D.sub.i of the diameter (D.sub.s) of the crystallization boundary and the diameter (D.sub.m) of a melt shoulder portion (34) located between the crystallization boundary and the restricted portions at a predetermined distance (h.sub.m) from the crystallization boundary.