Adjustable Plasma Exclusion Zone Ring for Edge Control
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Solution Overview
Problem
The existing methods for edge exclusion control in plasma processing chambers require changes in hardware, leading to increased costs and efforts, and result in plasma unconfinement issues due to gaps between the upper plasma exclusion zone (PEZ) ring and the substrate, affecting the precision of edge processing operations.
Innovation Solution
An adjustable upper PEZ ring is independently movable within the plasma processing chamber, allowing for precise control of the gap between the ring and the substrate, thereby maintaining a consistent plasma confinement and minimizing edge exclusion, without the need for multiple PEZ rings or changes in the upper electrode's position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the upper PEZ ring is clamped to the upper electrode to move with the upper electrode, then the PEZ ring moves with the electrode, but the gap between the PEZ ring and substrate increases beyond 0.6mm causing plasma unconfinement
Solution Approach 1:
The system separates the PEZ ring from the upper electrode assembly, allowing independent positioning of the PEZ ring relative to the electrode and substrate. This segmentation enables the PEZ ring to maintain a consistent gap (0.35-0.4mm) from the substrate while the electrode can move independently for different processing operations.
Solution Approach 2:
The PEZ ring is made independently adjustable and movable relative to both the upper electrode and substrate through a dedicated positioning mechanism. This dynamic positioning capability allows the system to maintain optimal plasma confinement by keeping the PEZ ring at the correct distance from the substrate regardless of electrode position changes.
2Adaptability or versatility
If different upper PEZ rings are used to clean different areas of substrate surface, then different cleaning areas are achieved, but hardware cost and complexity increase
Solution Approach 1:
A single upper PEZ ring is made dynamically positionable with respect to the substrate through independent vertical movement capability. By adjusting the PEZ ring's vertical position, different radial distances from the substrate center are exposed to plasma, enabling variable cleaning areas without requiring multiple physical rings.
Solution Approach 2:
The single upper PEZ ring serves multiple functions by being independently positionable: it can clean different areas of the substrate surface (center, mid-radius, edge regions) and maintain proper plasma confinement simultaneously. This multi-functionality eliminates the need for multiple specialized PEZ rings.
3Object-affected harmful factors
If the gap between upper PEZ ring and substrate is increased, then plasma encroachment increases leading to large edge exclusion, but processing precision decreases
Solution Approach 1:
The system incorporates positioning mechanisms that maintain the upper PEZ ring at a precise, consistent distance (0.35-0.4mm) from the substrate surface. This controlled positioning provides feedback-based plasma confinement, ensuring the gap remains within the optimal range to prevent excessive plasma encroachment while maintaining processing precision.
Solution Approach 2:
The vertical position of the upper PEZ ring is precisely controlled and adjusted to maintain optimal gap parameters (0.35-0.4mm) from the substrate. By changing and controlling this critical parameter, the system achieves proper plasma confinement that prevents harmful plasma encroachment while preserving edge processing precision.
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 enables precise control over the edge exclusion region, reducing plasma encroachment and maintaining optimal processing conditions for operations like cleaning and etching, without increasing hardware costs or complexity.
Implementation Method 1
The manufacturing of integrated circuits includes immersing silicon substrates (wafers) containing regions of doped silicon in chemically-reactive plasmas, where the submicron device features (e.g., transistors, capacitors, etc.) are etched onto the surface.
Implementation Method 2
The lower electrode is coupled with a radio frequency (RF) power supply.
Data Source
AI summary
A system for controlling a size of an edge exclusion region is described. The system includes an upper electrode, an upper plasma exclusion zone (PEZ) ring located beside the upper electrode, an upper electrode extension located beside the upper PEZ ring, and a system controller configured to generate signals regarding a first position and a second position of the upper PEZ ring. The system further includes an actuator and a position controller coupled to the system controller and the actuator. The position controller is configured to receive the signals from the system controller, and to control the actuator based on the signals to achieve the first position and the second position The first and second positions are achieved independent of any movement of the upper electrode.