Dual Inductively Coupled Plasma Source for Uniform Etching
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Solution Overview
Problem
In semiconductor substrate processing, precise control of plasma ignition and distribution is challenging, leading to non-uniform ion/radical ratios and concentrations, which result in inconsistent etching rates and defects due to unstable plasma sources and high temperature generation in processing chambers.
Innovation Solution
A dual inductively coupled plasma source with a coil antenna assembly and a remote plasma source, combined with an electron beam generation system, enhances plasma distribution and ion/radical ratio control in the processing chamber, improving uniformity and reducing chamber component wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spike of power is used to ignite the gases within the chamber, then plasma ignition is achieved, but overly high temperature generation occurs which diminishes service life of chamber components and generates particles
Solution Approach 1:
The plasma generation process is segmented into two distinct sources: a remote plasma source that pre-ionizes the gas and delivers plasma into the chamber, and a coil antenna assembly that provides inductive coupling for plasma maintenance. This segmentation allows the ignition function to be separated from the heating function, enabling reliable plasma ignition without subjecting chamber components to excessive temperature spikes.
Solution Approach 2:
A remote plasma source is introduced as an intermediary device that performs the plasma ignition function outside the main chamber volume. This remote source pre-ionizes the process gas and delivers the ionized plasma into the chamber through a coupling interface, acting as a mediator that achieves reliable ignition while isolating the chamber components from the high temperature generation that would otherwise occur during direct power spiking.
2Reliability
If unstable plasma source is used, then plasma ignition is achieved, but ion/radical distribution becomes non-uniform resulting in etching rate non-uniform and film profile distortion
Solution Approach 1:
The system merges two plasma generation mechanisms: the remote plasma source that provides stable ionization and the inductively coupled coil antenna assembly that enhances plasma distribution. By combining these two sources, the system achieves both stable plasma ignition from the remote source and uniform plasma distribution across the substrate from the inductive coupling, thereby improving both plasma source stability and manufacturing precision.
Solution Approach 2:
The coil antenna assembly is configured to provide localized inductive coupling at different positions within the chamber, creating regions of enhanced plasma generation that compensate for natural distribution gradients. This local quality adjustment ensures uniform ion/radical distribution across the substrate surface, preventing etching rate non-uniformity and film profile distortion while maintaining overall plasma source stability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides enhanced control over plasma distribution and ion/radical ratios, leading to more consistent and predictable processing results, reducing defects and extending chamber component lifespan by stabilizing plasma ignition and reducing temperature spikes.
Implementation Method 1
plasma may be easily ignited in processing chambers that utilized inductively coupled power to energize the gases forming the plasma
Implementation Method 2
an electron beam source including a cathode configured to generate electrons through field emission
Data Source
AI summary
Embodiments of an apparatus having an improved coil antenna assembly with a remote plasma source and an electron beam generation system that can provide enhanced plasma in a processing chamber. In one embodiment, a plasma processing chamber includes a chamber body, a lid enclosing an interior volume of the chamber body, a substrate support disposed in the interior volume, a dual inductively coupled source including a coil antenna assembly coupled to the chamber body through the lid, and a remote plasma source coupled to the chamber body through the lid.