Plasma processing apparatus, plasma processing method, and computer readable storage medium

Abstract

The invention provides a plasma processing device and a plasma processing method. In the manner of periodically modulating the power of the high frequency used in the plasma processing, variation of plasma impedance and reflection towards the high frequency power supply are reduced as much as possible, so as to ensure the stability and reproducibility of the plasma and the safety of the high frequency power supply. In the plasma processing device, frequency modulation is carried out on the power of the high frequency (LF) for controlling bias voltage by the characteristics corresponding to the processing, and pulse modulation is synchronously carried out on the frequency (LF frequency) thereof together with the pulse modulation of the LF power, namely, the LF frequency and the LF power have the following synchronous relationship in a period: in the time interval of the period T when the LF power is maintained as a set value P of H level, the LF frequency is also maintained as the set value F of H level, and in the time interval of the period when the LF power is maintained as a set value P of L level, the LF frequency is also maintained as the set value F of L level.

Description

technical field [0001] The present invention relates to a technology for performing plasma processing on a substrate to be processed, and particularly to a plasma processing apparatus and a plasma processing method that periodically modulate high-frequency power used in plasma processing. Background technique [0002] In processes such as etching, deposition, oxidation, and sputtering in the manufacturing process of semiconductor devices and FPDs (Flat Panel Displays), plasma is often used in order to make processing gases react well at relatively low temperatures. [0003] In recent years, the design rules of the manufacturing process have become increasingly refined, especially in plasma etching, which requires higher dimensional accuracy, and requires further improvement in the selectivity and in-plane uniformity with respect to the mask or substrate in etching. Therefore, in order to achieve lower pressure and lower ion energy in the processing region in the chamber, a r...

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Problems solved by technology

[0009] However, in the method of pulse-modulating the high-frequency power used in plasma processing as described above, since the high-frequency power changes periodically at the pulse frequency, the impedance of the plasma or ion sheath periodically changes. Changes, the automatic matching function of the matching device cannot be consistent with it, resulting in changes in the plasma generation / distribution characteristics or ion energy in the processing container, the reproducibility of the process cannot be obtained, and the high-frequency power supply may be overheated or malfunctioned due to reflected waves. problems, it is difficult to apply to mass production devices

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