CMP Pad Groove Segmentation for Uniform Pressure
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Solution Overview
Problem
Existing chemical mechanical polishing pads lack consistency in polishing rate and uniform pressure application during the semiconductor manufacturing process, leading to inefficiencies and potential substrate damage.
Innovation Solution
A chemical mechanical polishing pad with a cylindrical body featuring a plurality of first grooves extending downward from the upper surface and second grooves inside the body, where at least two first grooves have different depths and the upper surfaces of second grooves are at different vertical levels, ensuring a constant polishing rate and uniform pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional polishing pads with uniform groove structures are used, then the structure is simple and easy to manufacture, but the polishing rate is inconsistent and pressure distribution is non-uniform
Solution Approach 1:
The polishing pad is segmented into multiple groove types (first grooves extending from upper surface, second grooves extending from lower surface, third grooves extending laterally) with varying depths and orientations. This segmentation creates distinct functional zones that control slurry flow and pressure distribution independently, enabling consistent polishing rates across the substrate surface.
Solution Approach 2:
Different regions of the polishing pad are assigned different groove characteristics. First grooves have varying depths (2-5mm) to create localized pressure zones, second grooves provide lateral slurry distribution, and third grooves offer additional flow paths. This local differentiation ensures uniform pressure and slurry delivery across the entire polishing surface.
2Reliability
If grooves with varying depths are implemented to improve polishing uniformity, then polishing consistency improves, but manufacturing complexity increases
Solution Approach 1:
The grooves are pre-formed into the polishing pad structure before the pad is put into service. The varying depths of first grooves (2-5mm) and the positioning of second and third grooves are established during manufacturing, creating a ready-to-use pressure distribution system that ensures reliable polishing from the first use without requiring adjustment or modification.
3Productivity
If multiple groove types with different orientations are added to ensure uniform slurry distribution, then polishing uniformity improves, but the device complexity increases
Solution Approach 1:
The groove system extends into the lateral dimension with third grooves running perpendicular to the radial direction, in addition to the vertical depth dimension created by first and second grooves. This multi-dimensional groove architecture creates a three-dimensional slurry distribution network that enhances polishing efficiency by ensuring uniform slurry delivery across the entire substrate surface from multiple directions.
Data Source
AI summary
A chemical mechanical polishing pad includes a body having a cylindrical shape and extending in a vertical direction, the body including a plurality of first grooves extending downward in the vertical direction from an upper surface of the body, and a plurality of second grooves extending downward in the vertical direction inside the body. Each of the plurality of first grooves is exposed upward in the vertical direction from the upper surface of the body, each of the plurality of second grooves is located inside the body such that upper ends of the plurality of second grooves is below the upper surface of the body, and at least two of the plurality of first grooves have different depths from each other.