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:
Feb. 06, 2001
Filed:
Jul. 21, 1999
Other;
Abstract
A plasma generating apparatus and a method for controlling plasma-generating high frequency power capable of appropriately and easily controlling plasma density over the long term are disclosed. Measuring high frequency power is supplied to plasma through a dielectric tube. Apart from a supply system of plasma-generating high frequency power, there is provided a plasma density information obtaining section having long lifetime no hot filament. The plasma density information obtaining section obtains the plasma density information by measuring a physical amount related to reflection or absorption of the high frequency power. An actually measured plasma density monitored by the plasma density information obtaining section from moment to moment and a target plasma density held in a plasma density setting section are compared. Based on this compared result, an impedance matching device is changed, and an impedance matching state between the electric source side and the plasma side, thereby appropriately controlling the generating high frequency power output from the high frequency electric source.