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 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] and is herein 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, shape, and electrical characteristics in processing chambers, such as capacitively or ind...

AI Technical Summary

Benefits of technology

[0010] Embodiments of the invention provide an apparatus for plasma processing a substrate, wherein the apparatus includes first and second plasma controlling devices that are in communication with a processing region of a plasma chamber. The first plasma controlling device and second plasma controlling device are connected to a first RF power source and a second RF power source, respectively. A controller that is connected to the first RF power source and the second RF power source controls the modulation of the amplitude of the RF power supplied to the first plasma controlling device and the second plasma controlling device such that the overlap in time of the RF power supplied to the first and second plasma controlling devices is controlled to improve the uniformity of the plasma process completed on a substrate mounted in the processing region.

[0012] Embodiments of the invention further provide an apparatus for plasma processing a substrate, wherein the apparatus includes first, second and third plasma controlling devices that are in communication with a processing region of a plasma chamber. The first plasma controlling device, the second plasma controlling device and the third plasma controlling device are connected to a first RF power source, a second RF power source, and a third RF power source, respectively. A controller that is connected to the first RF power source, the second RF power source and third RF power source controls the modulation of the amplitude of the RF power supplied to the first, the second and the third plasma controlling devices such that the overlap in time of the RF power supplied to the first and second plasma controlling devices is controlled to improve the uniformity of the plasma process completed on a substrate mounted in the processing region.

[0013] Embodiments of the invention further provide a method for processing a substrate in a plasma chamber, wherein the method includes amplitude modulating the RF power to a first plasma controlling device and a second plasma controlling device. The method generally includes modulating the pulse frequency and RF power level, to each of the plasma controlling devices, synchronizing the amplitude modulation of the RF power to the first plasma controlling device and the second plasma controlling device; and controlling the amplitude modulation of the RF power such that the overlap of the amplitude modulated RF power delivered to the first and second plasma controlling devices is controlled to improve the uniformity of the process completed on the substrate.

[0018] Embodiments of the invention further provide a method for processing a substrate in a plasma chamber, wherein the method includes amplitude modulating the RF power to a first plasma controlling device and a second plasma controlling device. The method also includes amplitude modulating the RF power delivered to each of the plasma controlling devices, synchronizing the amplitude modulation of the RF power to the first and the second plasma controlling devices, controlling the shape of the amplitude modulation of the RF power, and controlling the overlap and / or gap between the amplitude modulated RF power to the first and second plasma controlling devices.

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.

Images