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:
Aug. 16, 1994
Filed:
Jul. 21, 1992
Kunihiko Takeyama, Kyoto, JP;
Nissin High Voltage Co., Ltd., Kyoto, JP;
Abstract
Wafer disk holds wafers in position by centrifugal force and its rotating shaft is supported by a bearing capable of magnetic levitation that has a thrust bearing and radial bearings. An annular groove providing a heat radiating zone is formed under the wafer receiving faces of the wafer disk. A cooling plate cooled to a temperature not exceeding the temperature of liquid nitrogen is inserted into the groove in a contactless manner so that the wafer disk is cooled by heat radiation. In the absence of any area of physical contact in the mechanisms for axially supporting and cooling the wafer disk, ions can be implanted in low dose into wafers on the fast rotating disk while improving the quality of wafers after implantation. Further, no triboelectricity will develop, thereby contributing to an improvement in the precision of ion beam current measurement.