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:
Sep. 17, 2002
Filed:
Jun. 19, 2000
Yoshinobu Kawai, Fukuoka, JP;
Yoko Ueda, Fukuoka, JP;
Nobuo Ishii, Minoo, JP;
Satoru Kawakami, Sagamihara, JP;
Tokyo Electron Limited, Tokyo, JP;
Abstract
A probe ( ) is brought into contact with a plasma produced by ionizing Ar gas, a saturation current (I ) at which current flowing through the probe is saturated when the potential of the probe is changed in a potential region where the potential of the probe is higher than a ground potential, and a saturation current (I ) at which current flowing through the probe is saturated when the potential of the probe is changed in a potential region where the potential of the probe is lower than the ground potential. Similarly, saturation currents (I , I ) are measured by bringing the probe ( ) into contact with a plasma produced by ionizing a mixed gas containing Ar gas and a process gas, such as C F gas, and changing the potential of the probe ( ). The negative ion density of the plasma produced by ionizing C F gas is determined by using saturation current ratios (I /I , I /I ).