초록 ▼

In an RF plasma reactor including a reactor chamber with a process gas inlet, a workpiece support, an RF signal applicator facing a portion of the interior of the chamber and an RF signal generator having a controllable RF frequency and an RF signal output coupled to an input of the RF signal applic

In an RF plasma reactor including a reactor chamber with a process gas inlet, a workpiece support, an RF signal applicator facing a portion of the interior of the chamber and an RF signal generator having a controllable RF frequency and an RF signal output coupled to an input of the RF signal applicator, the invention tunes the RF signal generator to the plasma-loaded RF signal applicator by sensing an RF parameter at the RF signal generator or at the RF signal applicator and then adjusting the frequency of the RF signal generator so as to optimize the parameter. The invention further controls the RF signal generator output magnitude (power, current or voltage) by optimizing the value of the same RF parameter or another RF parameter. The reactor preferably includes a fixed tuning circuit between the RF signal generator and the RF signal applicator.

대표청구항 ▼

[ What is claimed is:] [31.]31. An RF plasma reactor comprising:a reactor chamber with a process gas inlet;a workpiece support inside said chamber;an RF signal applicator facing a portion of the interior of said chamber overlying said support;an RF signal generator having a frequency control input,

[ What is claimed is:] [31.]31. An RF plasma reactor comprising:a reactor chamber with a process gas inlet;a workpiece support inside said chamber;an RF signal applicator facing a portion of the interior of said chamber overlying said support;an RF signal generator having a frequency control input, a controllable output power and an RF signal output coupled to an input of said RF signal applicator;a sensor coupled to a current path to said RF signal applicator, said sensor being responsive to a parameter affecting plasma ion density related to RF current flow in said RF signal applicator, wherein said parameter consists of one of:(a) a Fourier component of the magnitude of the RF current flow to said RF signal applicator,(b) the magnitude of the time rate of chancre in RF current flow to said RF signal applicator;a frequency servo connected to said frequency control input, said frequency servo being programmed to adjust said frequency of said RF signal generator within a frequency range so as to at least nearly optimize said parameter to a value corresponding to a desired plasma ion density value; anda power servo connected to said RF signal generator capable of changing said output power.