A radio frequency power supply system, plasma processor and frequency modulation matching method thereof

Abstract

The invention provides a radio frequency power supply system, a plasma processor and a frequency modulation matching method thereof, which are applied to a plasma processor with an ultra-low frequency bias radio frequency power source. Including an impedance segmentation frequency matching acquisition step, dividing the low-frequency radio frequency power output cycle into a plurality of impedance matching sections, adjusting the output frequency of the high-frequency radio frequency source in each impedance matching section, and detecting the reflected power of the high-frequency radio frequency power supply, The segment matching frequency of each impedance matching segment is obtained and stored after experiencing one or more low-frequency radio frequency power output cycles. Then, in the frequency conversion matching step, the output frequency of the high-frequency radio frequency power supply is set to change periodically in the above-mentioned stored multiple section matching frequencies, so as to match the characteristic impedance in each impedance matching section.

Description

technical field [0001] The invention relates to the field of semiconductor processing equipment, in particular to a frequency modulation matching method in a plasma processor. Background technique [0002] Vacuum processing equipment is widely used in the semiconductor industry, among which plasma processing equipment and chemical vapor deposition equipment are the most important vacuum processing equipment. Plasma processing equipment generates plasma by means of radio frequency coupling discharge, and then uses plasma for deposition, etching and other processing processes. [0003] Such as figure 1 Shown is a capacitively coupled plasma processing device, including a reaction chamber 100, the reaction chamber includes a conductive base 22, and the base is used as a lower electrode connected to two radio frequency power sources 32, 31, wherein the source radio frequency power source 32 is output through a matching device 2 The high frequency radio frequency power (HF) is ...

AI Technical Summary

Problems solved by technology

This method of using the movable parts in the matcher for mechanical motion compensation can be applied to applications where the plasma impedance changes slowly, but for plasma impedance that changes rapidly in a very short time, such as a sharp change in impedance that occurs within 1ms , the mechanically driven variable capacitor in the traditional matcher cannot achieve such a response speed, so the effective matching of impedance cannot be achieved

Once it cannot be effectively matched, a large amount of power will be wasted in the incident and reflected circuits, and at the same time, a large amount of redundant reflected current will flow into the RF power supply, which will cause the temperature of the RF power supply to be too high, which will affect the life of the internal electronic components, resulting in frequent replacement of expensive RF power supplies. The cost of using plasma processors has increased significantly

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