Edge Electrode Coupling Compensation for Uniform Substrate Processing
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Solution Overview
Problem
The existing substrate processing apparatuses face challenges with electrical coupling between the chuck member and the edge electrode, leading to power leakage and reduced edge impedance control efficiency, which affects processing speed and uniformity, and the maintenance period due to focus ring erosion.
Innovation Solution
A substrate processing apparatus with a coupling compensator, comprising an inductor and a variable capacitor connected in parallel, is introduced to cancel or adjust the coupling between the chuck member and the edge electrode, allowing independent adjustment of the edge electrode's electric potential without increasing the distance between them, thereby improving edge impedance control efficiency and extending the maintenance period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the distance between the chuck member and the edge electrode is increased to reduce coupling effect, then power leakage from chuck member to edge electrode is reduced, but the edge impedance control efficiency is reduced because the plasma sheath adjustment region moves away from the substrate edge
Solution Approach 1:
The patent introduces a coupling compensator as an intermediary device between the chuck member and the edge electrode. This compensator includes adjustable impedance elements that actively compensate for the electrical coupling effect, allowing the edge electrode to be positioned close to the chuck member for high control efficiency while preventing power leakage through impedance matching and coupling cancellation.
2Manufacturing precision
If the electric potential of the edge electrode is adjusted low to control the plasma sheath position in the edge region, then the plasma characteristic and ion directivity in the edge region are controlled, but power leakage occurs from the chuck member to the edge electrode affecting substrate processing speed and uniformity
Solution Approach 1:
The coupling compensator incorporates feedback mechanisms that continuously monitor and adjust the impedance between the chuck member and edge electrode. This feedback system detects power leakage conditions and dynamically adjusts the compensator's impedance elements to cancel coupling effects, enabling low electric potential adjustment for plasma sheath control without suffering from power leakage to the edge electrode.
3Manufacturing precision
If the focus ring is used to concentrate plasma on the substrate region, then plasma characteristic and ion directivity uniformity is improved, but erosion of the focus ring due to ion bombardment proceeds changing plasma characteristic and ion directivity
Solution Approach 1:
The edge electrode system with coupling compensation enables active control and adjustment of plasma characteristics in the edge region. This self-adjusting capability compensates for changes caused by focus ring erosion, maintaining plasma uniformity without requiring frequent replacement of the focus ring, thereby extending its effective service life.
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 coupling compensator minimizes power leakage and enhances the capacity to adjust the plasma sheath in the edge region, ensuring uniform substrate processing and extending the maintenance period by allowing independent electric potential adjustment of the edge electrode, thus improving processing efficiency and maintaining uniformity.
Implementation Method 1
a coupling compensator connected between the chuck member and the edge electrode and provided to cancel or adjust coupling between the chuck member and the edge electrode
Implementation Method 2
an inductor and a variable capacitor that are connected to each other in parallel
Implementation Method 3
a plasma sheath position may be controlled by adjusting an electric potential of the edge electrode
Implementation Method 4
radio frequency power is applied between an upper electrode and a lower electrode which are provided in the process chamber to generate plasma
Data Source
AI summary
The substrate processing apparatus includes a process chamber providing a space for processing a substrate, a chuck member provided in the process chamber and supporting the substrate, a ring member provided to surround the chuck member, an edge electrode disposed in the ring member to be electrically insulated from the chuck member, an edge impedance controller electrically connected to the edge electrode and controlling an electric potential of the edge electrode, and a coupling compensator connected between the chuck member and the edge electrode and provided to cancel or adjust coupling between the chuck member and the edge electrode.