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:
Nov. 18, 1997
Filed:
May. 15, 1995
Junichi Kobayashi, Sagamihara, JP;
Eiichiro Takanabe, Shiroyama, JP;
Tokyo Electron Limited, , JP;
Abstract
A number of semiconductor wafers are held in a ladder boat at, e.g., a 3/16 inch arrangement pitch of wafers W, and the ladder boat is loaded into a vertical heat treatment furnace. Then an interior of the heat treatment furnace is heated up to 900.degree. C. at a high temperature raising rate of, e.g., 30.degree. C./minute. Subsequently the interior is heated in steps at low temperature raising rates, e.g., at below 14.degree. C./minute up to a temperature region of, e.g., 980.degree. C. and at below 5.degree. C./minute up to a heating temperature of 1100.degree. C. These temperature raising rates are determined, based on results given by observation of presence and absence of slips in the wafers W heat-treated in various temperature raising patterns for different wafer arrangement pitches, so that the wafers can be heat-treated effectively without occurrence of slips. Widening said arrangement pitch to 3/8 inches allows higher temperature raising rates to be set.