Dielectric Liner Electrode for Plasma Confinement
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Solution Overview
Problem
Existing plasma processing systems struggle to confine plasma within the wafer region due to high electric fields, which are exacerbated by increased RF power and substrate size, leading to uncontrollable substrate processing and potential plasma ignition in the outer region.
Innovation Solution
A reduced electric field arrangement is achieved by using a dielectric liner electrode encapsulated within a cylindrical electrode, coupled with an inductive circuitry that adjusts impedance to match the RF frequency, reducing the voltage potential difference and minimizing plasma unconfinement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If RF power is increased to enhance plasma density and processing efficiency, then productivity is improved, but the electric field amplitude increases causing plasma to ignite in the outer region
Solution Approach 1:
A dielectric liner is introduced as an intermediary layer between the plasma and the reactor wall. This dielectric liner acts as a mediator that reduces the electric field amplitude in the outer region by providing electrical isolation, thereby preventing plasma ignition while allowing high RF power to be applied for enhanced processing efficiency
Solution Approach 2:
The patent replaces mechanical plasma confinement (using physical barriers or magnetic fields) with an electrical field management approach using dielectric materials. The dielectric liner modifies the electrical field distribution to confine plasma within the wafer region, substituting mechanical confinement methods with field-based control
2Productivity
If substrate size is increased to process more devices, then productivity is improved, but the distance between plasma edge and reactor wall decreases increasing electric field amplitude
Solution Approach 1:
The dielectric liner serves as an intermediary that decouples the relationship between substrate size and electric field amplitude. By providing electrical isolation between the plasma and reactor wall, the liner allows larger substrates to be processed without the electric field amplitude increasing to dangerous levels
3Reliability
If confinement rings are used to mechanically confine plasma, then plasma confinement is improved, but they are insufficient when electric field is high enough to ignite plasma in outer region
Solution Approach 1:
The dielectric liner acts as an intermediary layer that provides electrical isolation between the plasma and the reactor wall, complementing the mechanical confinement provided by the confinement rings. This dual approach ensures reliable plasma confinement even when high electric fields are present
Solution Approach 2:
The patent employs a composite confinement system combining mechanical elements (confinement rings) with electrical field management elements (dielectric liner). This composite approach leverages both mechanical and electrical properties to achieve robust plasma confinement under varying operating conditions
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
This solution effectively confines plasma within the wafer region, allowing for increased RF power and substrate size without plasma ignition in the outer region, enhancing processing efficiency and control while being cost-effective and compatible with existing plasma tools.
Implementation Method 1
an inductive circuit arrangement, which is coupled between the cylindrical electrode and the chamber wall
Implementation Method 2
a dielectric liner electrode encapsulated within a cylindrical electrode
Data Source
AI summary
A method for confining plasma within a plasma processing chamber while processing a substrate is provided. The method includes igniting the plasma within a plasma generating area, wherein the plasma generating area is surrounded by a set of confinement rings. The method also includes providing a chamber wall outside of the set of confinement rings. The method further includes providing a dielectric liner electrode arrangement positioned between the chamber wall and the set of confinement rings, wherein the dielectric liner electrode arrangement having an electrode encapsulated within a dielectric liner, the dielectric liner electrode arrangement being coupled with the chamber wall to create a modified chamber wall. The method yet also includes providing a parallel LC circuit arrangement, the parallel LC circuit arrangement being coupled between the dielectric liner electrode arrangement and the chamber wall.