Remote Plasma Chamber Baffle for Uniform Active Species Delivery
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Solution Overview
Problem
Conventional plasma devices with dual chamber structures face challenges in achieving spatially uniform active species distribution and independent control of plasma characteristics 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, and a lower chamber separated by a second baffle with a multilayer structure, allowing active species to pass through while blocking charged particles, and using RF power sources to generate capacitively-coupled plasma, which reduces ion energy and maintains plasma uniformity.
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 diffusion plate is segmented into multiple layers with through-holes at different positions and orientations. This segmentation allows the plate to prevent plasma leakage while maintaining sufficient conductance for active species transport, avoiding the contamination issue of single-layer designs with small holes
Solution Approach 2:
Different regions of the diffusion plate have different through-hole configurations (positions, orientations, diameters) optimized for local requirements. This ensures effective plasma separation in critical areas while maintaining overall conductance and preventing active species deposition
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 RF power is applied in periodic pulses rather than continuously. During the power-on phase, plasma density is enhanced; during the power-off phase, electron temperature decreases and over-decomposition is prevented. This periodic action maintains etching selectivity while achieving high plasma density
Solution Approach 2:
The system dynamically adjusts RF power parameters (frequency, amplitude, pulse width) to optimize plasma characteristics. By changing these parameters, the system achieves high plasma density without excessive gas decomposition, maintaining etching selectivity
3Force
If low-frequency RF power is increased to increase ion energy, then ion energy is improved, but electrostatic chuck is easily damaged by high voltage
Solution Approach 1:
The diffusion plate acts as an intermediary between the upper and lower chambers, allowing precise control of active species flux to the lower chamber. This enables independent optimization of plasma parameters without requiring high voltage on the electrostatic chuck, protecting it from damage
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 achieves independent control of plasma characteristics and provides a uniform plasma process, reducing contamination and enhancing etching selectivity by ensuring only active species are supplied to the lower chamber, thereby improving the plasma treatment process.
Implementation Method 1
a remote plasma generator generating plasma and active species
Implementation Method 2
an upper chamber having an opening connected to an output port of the remote plasma generator and receiving and diffuses the active species of the remote plasma generator
Implementation Method 3
generating capacitively-coupled plasma within a lower chamber
Implementation Method 4
a radio-frequency (RF) power source applying RF power to the substrate holder
Data Source
AI summary
A plasma substrate treatment apparatus according to one embodiment of the present invention comprises: a remote plasma generator for generating 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 first baffle disposed on the opening of the upper chamber; a lower chamber receiving the diffused active species from the upper chamber; a second baffle partitioning the upper chamber and the lower chamber and transmitting the active species; a substrate holder for supporting a substrate disposed in the lower chamber; and an RF power source applying RF power to the substrate holder.