Alternating asymmetrical plasma generation in a process chamber

Abstract

Embodiments of the invention generally provide etch or CVD plasma processing methods and apparatus used to generate a uniform plasma across the surface of a substrate by modulation pulsing the power delivered to a plurality of plasma controlling devices found in a plasma processing chamber. The plasma generated and / or sustained in the plasma processing chamber is created by the one or more plasma controlling devices that are used to control, generate, enhance, and / or shape the plasma during the plasma processing steps by use of energy delivered from a RF power source. Plasma controlling devices may include, for example, one or more coils (inductively coupled plasma), one or more electrodes (capacitively coupled plasma), and / or any other energy inputting device such as a microwave source.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional of U.S. patent application Ser. No. 11 / 060,980, filed Feb. 18, 2005 which claims benefit of provisional U.S. Patent Application Ser. No. 60 / 566,718, filed Apr. 30, 2004, entitled “Alternating Asymmetrical Plasma Generation In A Process Chamber,” [Attorney Docket No. 8459L] which are incorporated by reference.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] Embodiments of the invention generally relate to plasma processing systems and materials and apparatus for controlling plasma uniformity in plasma processing systems. [0004] 2. Description of the Related Art [0005] Plasma chambers are regularly utilized in various electronic device fabrication processes, such as etching processes, chemical vapor deposition (CVD) processes, and other processes related to the manufacture of electronic devices on substrates. Many ways have been employed to generate and / or control the plasma density, sha...

AI Technical Summary

Benefits of technology

The invention provides an apparatus and method for plasma processing a substrate in a plasma chamber. The apparatus includes first and second plasma controlling devices that are connected to a first and second RF power source, respectively. A controller synchronizes and controls the amplitude modulation of the RF power supplied to the first and second plasma controlling devices, ensuring uniformity of the plasma process on the substrate. The method includes modulating the RF power and synchronizing the modulation with the first and second plasma controlling devices to control the overlap of the RF power and improve the uniformity of the plasma process. The invention also provides a method for plasma processing a substrate by generating first and second torroidal paths of plasma and varying the plasma density in the first and second regions to improve the uniformity of the plasma process.

Problems solved by technology

This is undesirable for some processing sequences, because the plasma uniformity over the surface of the substrate generated in a particular processing chamber may be acceptable for one portion of a sequence, while causing substrate damage during another portion of the sequence.

However, varying the gas flow is also undesirable, since the gas flow affects the plasma composition and is harder to control due to transient effects created due to the pressure changes.

Overlapping fields will constructively interfere, thus increasing the ion density in places where the fields interact and decreasing uniformity and the ability to control the process uniformity.

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