Segmented Electrostatic Chuck Layout for Etch Uniformity
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Solution Overview
Problem
Conventional electrostatic chucks in plasma processing apparatuses cause process non-uniformities due to the layout of electrodes, leading to side-to-side etch rate non-uniformity patterns, which existing designs fail to adequately address.
Innovation Solution
The electrostatic chuck features a unique radial layout with thermally isolated and electrically connected clamping electrodes forming four zones, accompanied by a thermal control system with radially arranged heating zones and release apertures, and a robust sealing band to enhance temperature control and uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional electrode layout is used in electrostatic chuck, then device complexity is reduced, but process uniformity deteriorates due to side-to-side etch rate non-uniformity patterns
Solution Approach 1:
The electrostatic chuck is segmented into multiple independently controllable electrode zones (typically four quadrants) that can be controlled separately. This segmentation allows different regions of the substrate to receive different power levels, enabling compensation for edge effects and non-uniform plasma distribution, thereby improving process uniformity without excessive complexity increase.
Solution Approach 2:
Different zones of the electrostatic chuck are assigned different electrical characteristics and power levels according to their specific requirements. The edge zones receive different power compared to center zones to compensate for edge effects, achieving local optimization of process uniformity across the substrate surface.
2Manufacturing precision
If simple thermal control is used, then device complexity is reduced, but temperature uniformity deteriorates leading to process non-uniformities
Solution Approach 1:
The thermal control system is segmented into multiple heating zones corresponding to the electrode zones, with each zone independently controllable. This allows differential heating across the substrate surface to compensate for heat loss variations, improving temperature uniformity.
Solution Approach 2:
The thermal control system dynamically adjusts heating parameters (power levels, timing) in different zones based on real-time temperature feedback and process requirements. This parameter optimization ensures uniform temperature distribution across the substrate despite variations in heat loss and plasma loading.
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 configuration improves process uniformity by allowing active control of etch rate and chemical deposition, while the sealing band ensures durability and prevents leakage of heat exchange gas, maintaining consistent temperature and reducing erosion.
Implementation Method 1
The clamping electrodes are connected to a voltage source and generate electrostatic forces to hold a workpiece on a workpiece support surface of the electrostatic chuck
Implementation Method 2
The electrostatic chuck can include a plurality of heating zones defined in a heating layer with heating electrodes
Data Source
AI summary
An electrostatic chuck including a clamping layer having a first clamping electrode and a second clamping electrode is disclosed. A first clamping electrode defining a first clamping zone and a second clamping zone is provided. The first clamping zone and the second clamping zone are separated by a first gap and are electrically connected by at least one electrical connection extending across the first gap. A second clamping electrode disposed radially outward from the first clamping electrode. The second clamping electrode defining a third clamping zone and a fourth clamping zone that are separated by a second gap. The third clamping zone and the fourth clamping zone are electrically connected by at least one electrical connection extending across the second gap. Plasma processing apparatuses and systems incorporating the electrostatic chuck are also provided.