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.

Date of Patent:
Dec. 10, 1991

Filed:

Oct. 04, 1990
Applicant:
Inventors:

Koichiro Nakanishi, Hyogo, JP;

Haruhisa Fujii, Hyogo, JP;

Hirotaka Muto, Hyogo, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
2504922 ; 2504923 ; 250398 ;
Abstract

An ion implanter has a sample table on which a sample is placed, and means for injecting ions into the sample by applying an ion beam to the sample on the sample table. The ion implanter has magnetic field applying means for generating radial magnetic fields on the surface of the sample from near the center of the sample to outside of the outer periphery of the sample. The secondary electrons generated when the ion beam irradiates the sample table or the sample, including the secondary electrons generated from the sample table near the outer periphery of the sample, are trapped in the magnetic fields and transferred to the central portion of the sample. The secondary electrons are attracted by the electrostatic charge of the ions injected to the surface of the sample and recombine with the ions. Consequently, the electrostatic charge on the surface of the sample is decreased, preventing generation of device defects caused by electrostatic discharge damage.


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