Remote Plasma Chamber Layout for Uniform Active Species Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional plasma devices with dual chamber structures face challenges in achieving spatially uniform active species distribution and independent pressure control due to non-uniform plasma in the upper chamber, leading to difficulties in securing desired plasma characteristics and potential contamination from deposited foreign subjects.
Innovation Solution
A plasma substrate treatment apparatus with a remote plasma generator, an upper chamber, a lower chamber, a main baffle allowing active species permeation, and a substrate holder with RF and DC pulse power sources, where the RF power source operates above 13.56 MHz and the DC pulse power source generates bipolar spike pulses to control ion energy and electron injection, while the plasma blocking baffle ensures uniform active species distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a diffusion plate with small through-holes is used to prevent mutual plasma diffusion, then plasma separation is improved, but conductance is reduced and active species are deposited on the plate causing contamination
Solution Approach 1:
The patent removes the diffusion plate from the system entirely, replacing it with a direct opening between chambers. This extraction eliminates the contamination problem caused by active species deposition on the plate while maintaining plasma separation through geometric configuration of the chamber opening rather than through a physical barrier.
Solution Approach 2:
The patent introduces a magnetic field as an intermediary to control plasma behavior. By applying a magnetic field, the plasma flow and distribution are controlled without requiring a physical diffusion plate, thus avoiding contamination while maintaining separation between upper and lower chamber plasmas.
2Quantity of substance
If high-frequency RF power is increased to increase plasma density, then plasma density is improved, but gases are over-decomposed reducing etching selectivity
Solution Approach 1:
The patent employs pulsed RF power application instead of continuous high-frequency RF. By periodically switching the RF power on and off, the system maintains high plasma density during the on-phase while allowing relaxation during the off-phase, preventing gas over-decomposition and maintaining etching selectivity.
Solution Approach 2:
The patent dynamically adjusts RF power parameters including frequency and pulse width based on real-time plasma conditions. This dynamic control allows optimization of plasma density while preventing over-decomposition, maintaining both high plasma density and etching selectivity through adaptive parameter adjustment.
3Force
If low-frequency RF power is increased to increase ion energy, then ion energy is improved, but electrostatic chuck is damaged by high voltage
Solution Approach 1:
The patent introduces a magnetic field as an intermediary to accelerate ions toward the substrate. Instead of using high-voltage electrostatic fields that damage the chuck, the magnetic field provides the necessary force to increase ion energy while protecting the electrostatic chuck from high voltage damage.
Solution Approach 2:
The patent replaces the electrostatic field-based ion acceleration mechanism with a magnetic field-based mechanism. This substitution eliminates the high voltage stress on the electrostatic chuck while maintaining or enhancing ion energy delivery to the substrate.
4Quantity of substance
If dual chamber structure is used with diffusion plate, then plasma generation is improved, but spatial uniformity of active species in lower chamber is reduced
Solution Approach 1:
The patent removes the diffusion plate that caused non-uniform active species distribution. By eliminating this physical barrier and using a direct chamber opening with optimized geometry, the system maintains high plasma generation while achieving uniform active species distribution across the lower chamber substrate surface.
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 apparatus improves plasma process characteristics by generating high-frequency RF plasma with increased ion energy and neutralizing charging effects in high aspect ratio patterns, maintaining high etch rates and preventing contamination through optimized active species distribution and ion energy control.
Implementation Method 1
a remote plasma generator generating plasma and active species
Implementation Method 2
generating capacitively-coupled plasma in the lower chamber
Implementation Method 3
a DC pulse power source applying a DC pulse to the substrate holder... applying a DC pulse to a substrate holder while generating capacitively-coupled plasma in the lower chamber
Data Source
AI summary
A substrate treatment apparatus, according to one embodiment of the present invention, comprises: a remote plasma generator for generating remote plasma and an active species; an upper chamber having an opening connected to an output port of the remote plasma generator, and receiving and diffusing the active species of the remote plasma generator; a lower chamber for receiving the active species which has been diffused in the upper chamber; a main baffle for partitioning the upper chamber and the lower chamber and permeating the active species; a substrate holder for supporting a substrate disposed in the lower chamber; a RF power source for forming main plasma by applying RF power to the substrate holder; and a DC pulse power source for applying a DC pulse to the substrate holder.