Carrier Head Contact Flap for Uniform Polishing Pressure
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Solution Overview
Problem
Conventional carrier heads for chemical mechanical polishing struggle to apply uniform polishing pressure to substrates, leading to variations in polishing rates across different areas, particularly at transition zones, due to the complexity of manufacturing and pressure differences between chambers.
Innovation Solution
A carrier head design featuring a contact flap with a connecting portion, side portion, and wall structure that limits expansion via fluid pressure, allowing for independent pressure application to predetermined areas without partitioning, ensuring firm contact and uniform pressure distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple inner flaps are used to partition the membrane into concentric chambers for independent pressure application, then polishing pressure can be varied in different substrate areas, but manufacturing complexity increases and polishing uniformity deteriorates at transition zones
Solution Approach 1:
The membrane is divided into multiple independent chambers (first, second, and third chambers) that can be separately pressurized. Each chamber corresponds to a different radial region of the substrate, allowing independent pressure control for center, intermediate, and edge areas respectively, thereby enabling varied polishing rates across the substrate surface
Solution Approach 2:
Different pressure levels are applied to different radial regions of the substrate through the segmented chambers. The center area receives pressure from the first chamber, the intermediate area from the second chamber, and the edge area from the third chamber, creating locally optimized polishing conditions for each region
2Adaptability or versatility
If multiple inner flaps are used to create concentric chambers for independent pressure application, then pressure can be varied across substrate areas, but manufacturing difficulty increases
Solution Approach 1:
The membrane is divided into multiple independent chambers (first, second, and third chambers) that can be separately pressurized. Each chamber corresponds to a different radial region of the substrate, allowing independent pressure control for center, intermediate, and edge areas respectively, thereby enabling varied polishing rates across the substrate surface
Solution Approach 2:
Different pressure levels are applied to different radial regions of the substrate through the segmented chambers. The center area receives pressure from the first chamber, the intermediate area from the second chamber, and the edge area from the third chamber, creating locally optimized polishing conditions for each region
3Device complexity
If conventional carrier head design is used, then structure is simple, but polishing uniformity deteriorates due to pressure differences between chambers
Solution Approach 1:
A seal ring is introduced as an intermediary component between adjacent chambers to prevent fluid leakage and pressure equalization. The seal ring ensures that pressure differences between chambers are maintained, enabling independent pressure control and improving polishing uniformity across the substrate surface
Solution Approach 2:
The system enables independent adjustment of pressure parameters in different radial regions of the substrate. By controlling the pressure in each chamber separately, the polishing rate can be optimized for different areas (center, intermediate, edge) to achieve uniform overall polishing results
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 solution effectively suppresses sudden changes in polishing uniformity at transition zones, enabling precise control of pressure across substrate areas, thereby improving polishing consistency and reducing manufacturing complexity.
Implementation Method 1
the at least one wall structure is configured to limit an expansion of the at least one contact flap for a firm contact of the contact portion with the inner surface by means of fluid pressure
Implementation Method 2
the substrate is applied with polishing pressure through the substrate receiving member formed of a flexible membrane
Data Source
AI summary
A carrier head for a chemical mechanical polishing apparatus is provided. The carrier head includes a base and a substrate receiving member connected to a lower part of the base. Inside of the substrate receiving member, at least one contact flap is connected to the lower part of the base. The at least one contact flap includes a connecting portion, a side portion extended downwardly from the connecting portion and a contact portion extended sidewardly from a bottom end of the side portion. Adjacent to the at least one contact flap, at least one wall structure is connected to the lower part of the base to limit an expansion of the at least one contact flap for a firm contact of the contact portion with an inner surface of the substrate receiving member by means of fluid pressure.