Method for fast and repeatable plasma ignition and tuning in plasma chambers

Abstract

Embodiments of the present disclosure include methods and apparatus for plasma processing in a process chamber using an RF power supply coupled to the process chamber via a matching network. In some embodiments, the method includes providing RF power to the process chamber by the RF power supply at a first frequency while the matching network is in a hold mode, adjusting the first frequency, using the RF power supply, to a second frequency during a first time period to ignite the plasma, adjusting the second frequency, using the RF power supply, to a known third frequency during a second time period while maintaining the plasma, and changing an operational mode of the matching network to an automatic tuning mode to reduce a reflected power of the RF power provided by the RF power supply.

Description

technical field [0001] Embodiments of the present disclosure relate generally to substrate processing systems and, more particularly, to methods and apparatus for fast and repeatable plasma ignition and tuning in plasma chambers. Background technique [0002] In integrated circuit fabrication, plasma chambers are used to process substrates. A plasma chamber is generally coupled to a radio frequency (RF) source to provide energy to ignite a plasma and / or maintain a plasma during substrate processing. In order to efficiently couple RF energy into the chamber, a matching network (also known as a tunable matching circuit or matching box) is connected between the RF source and the plasma chamber. [0003] Prior techniques for igniting a plasma in a plasma chamber (ie, striking the plasma) or tuning across plasma transitions include using a matching box with a motorized variable capacitor to ignite the plasma. However, the inventors have observed that this method can be slow due...

AI Technical Summary

Problems solved by technology

The inventors have observed that while this method can ignite the plasma rapidly (<0.5 seconds), variations in generator frequency can lead to variations in on-wafer process results and to variations in RF measurements

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