Impedance Matching Networks for Plasma Reactors

Abstract

The present invention provides an impedance matching network for a plasma reactor, which comprises at least one inductor and at least one variable capacitor unit, wherein the variable capacitor unit comprises at least one variable vacuum capacitor; the variable vacuum capacitor comprises two parallel electrode plates; an annular piezoelectric ceramic plate is arranged between the two electrode plates; the annular piezoelectric ceramic plate is connected with a driving power supply; and an arc-shaped electrode plate is arranged in the hollow region of the annular piezoelectric ceramic plate. The variable vacuum capacitor in the impedance matching network described in the present invention uses the inverse piezoelectric effect of piezoelectric ceramic material; when alternating driving voltage is applied to piezoelectric ceramics, the piezoelectric ceramics can rapidly generate telescopic motion along a voltage loading direction, so that the distance of the arc-shaped electrode plate relative to the other electrode plate is changed; accordingly, the capacitance value of the variable vacuum capacitor is rapidly changed to realize that the size of the variable vacuum capacitor can be regulated within microsecond magnitude; and the need that plasma impedance is rapidly changed with the output of a radio frequency power source is satisfied.

Description

technical field [0001] The invention relates to the field of manufacturing semiconductor devices, in particular to the technical field of impedance matching of plasma reactors. Background technique [0002] Plasma processing devices are widely used in manufacturing processes for manufacturing integrated circuits (ICs) or MEMS devices. One notable use is in plasma reactors for etching semiconductor substrates. Plasma contains a large number of active particles such as electrons, ions, excited atoms, molecules, and free radicals. These active particles undergo various physical and chemical reactions on the surface of the semiconductor substrate, thereby changing the surface properties of the semiconductor substrate. Generally, for a plasma processing module, methods of generating plasma can be roughly divided into methods using corona (glow) discharge or high-frequency discharge, and methods using microwaves. [0003] In the plasma processing module of high-frequency dischar...

AI Technical Summary

Problems solved by technology

The variable capacitor in the traditional matching network is driven by a motor, which cannot satisfy the rapid adjustment of the variable capacitor in the order of microseconds, resulting in the impedance matching network being unable to adjust its own size in time, so that the RF power cannot be effectively loaded in time On the discharge system, the plasma distribution required for the process cannot be generated

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