US 5,621,605 AGranted

Neutralizing apparatus for charged body

AssigneesTadahiro Ohmi, Takasago Netsugaku Kogyo Kabushiki Kaisha

InventorsHitoshi Inaba, Tadahiro Ohmi

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Abstract

A neutralizing apparatus is provided to facilitate and efficiently implement electric charge removal from a charged body such as a wafer which is easily charged. When the easily charged body such as a wafer is transported in a housing, a neutralizing charge generator, typically light sources for projecting exciting ultraviolet rays into the housing, are operated. Accordingly, the housing is filled with ions and a gas such as non-reactive gas. The neutralizing charge generator can generate positive or negative ions and electrons. When the charged body is positively charged, the electrons or negative ions move toward the charged body to neutralize the charged body with positive charge. When the charged body is negatively charged, positive ions move toward the charged body to neutralize the negative charge.

Claims12

Dependent claims

A neutralizing apparatus for a charged body, said neutralizing apparatus comprising:

a housing for containing an electrically charged body;
a gas introducing means for introducing gas into said housing, said gas being non-reactive with respect to a said charged body;
a probe for detecting the amplitude of a charge on a said charged body;
a first neutralizing charge generating means for generating negatively charged ions or electrons in said housings;
a second neutralizing charge generating means for generating positively charged ions in said housing;
and
a control means for controlling said first and second neutralizing charge generating means, said control means connected to said probe, whereby said first neutralizing charge generating means is activated when said body is positively charged and the said positive charge on said body exceeds a predetermined voltage, and said second neutralizing charge generating means is activated when said body is negatively charged and said negative charge on said body exceeds a predetermined voltage.

4 more elements

Dependencies are inferred from the claim text.