Impedance matching method of pulse RF power supply and matching method of plasma equipment

Abstract

The invention relates to an impedance matching method of a pulse RF power supply and a matching method of plasma equipment. The impedance matching method of the pulse RF power supply comprises a step of (S1) setting an impedance adjusting element at a preset value and setting the pulse frequency of the pulse RF power supply as a preset pulse frequency, (S2) judging whether the preset pulse frequency is larger than a pulse threshold frequency or not, and going to (S3) if so, (S3) allowing the pulse frequency of the RF power supply to be equal to the pulse threshold frequency, starting the pulse RF power supply, realizing sweep frequency matching under an automatic RF sweep frequency function, and switching the pulse frequency of the pulse RF power supply as a preset pulse frequency after matching, (S4) starting the pulse RF power supply, and realizing sweep frequency matching under the automatic RF sweep frequency function. According to the impedance matching method of the pulse RF power supply, the difficulty of realizing impedance matching by the RF power supply can be reduced, thus the matching precision and matching stability of the pulse RF power supply can be improved, and thus the stability of the process is improved.

Description

technical field [0001] The invention belongs to the technical field of semiconductor equipment manufacturing, and in particular relates to an impedance matching method of a pulsed radio frequency power supply and a matching method of plasma equipment. Background technique [0002] Plasma equipment is widely used in the preparation process of manufacturing integrated circuits IC or MEMS devices, mainly by means of RF power output RF power to excite the process gas to form plasma. [0003] Currently, plasma devices include capacitively coupled plasma (CCP) devices, inductively coupled plasma (ICP) devices, surface wave or electron cyclotron resonance plasma (ECR) devices. Among them, CCP equipment uses capacitive coupling to generate plasma. It has a simple structure, low cost, and is easy to generate large-area and uniformly divided plasma. It is suitable for the etching process of dielectric and other types of films; ECR equipment can High density plasma can be obtained und...

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Problems solved by technology

[0005] The above-mentioned ICP equipment is used to etch the wafer. When the characteristic size of the etching process reaches 20nm and below, since the first radio frequency power supply 14 and the second radio frequency power supply 17 are continuous wave radio frequency power supplies, plasma-induced damage will be caused to the wafer. (PID), in order to avoid the generation of PID, then the first radio frequency power supply 14 and / or the second radio frequency power supply 17 adopts the pulsed radio frequency power supply, yet, there is the problem of poor stability and low matching precision to the impedance matching of the pulsed radio frequency power supply in existing

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