Multi-Zone Polishing Platform for Atomic Layer Uniformity
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Solution Overview
Problem
Existing semiconductor substrate polishing processes face challenges in achieving uniformity and precision, particularly for thin film removals, with across-wafer removal variations as high as 50%-100% for films thinner than 250 Angstroms, necessitating improved control over material removal.
Innovation Solution
A substrate polishing apparatus and method utilizing a polishing platform with multiple zones, each containing a different slurry component for oxidation, material removal, and corrosion inhibition, allowing for precise control through spatial separation or timed sequence application of these components to achieve uniform film removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single slurry is used for polishing, then the process is simple and continuous, but uniformity of material removal deteriorates with variations as high as 50%-100% for thin films
Solution Approach 1:
The polishing platform is divided into multiple zones (e.g., first zone with oxidizing slurry, second zone with abrasive slurry, third zone with corrosion inhibitor slurry). Each zone performs a specific function in the polishing sequence, enabling precise control over material removal uniformity while reducing across-wafer variations to atomic layer levels.
Solution Approach 2:
Different slurry components are applied to different spatial zones of the polishing platform. The oxidizing slurry is applied in the first zone to prepare the surface, the abrasive slurry in the second zone for material removal, and the corrosion inhibitor slurry in the third zone for protection. This local differentiation enables precise control of polishing uniformity.
2Manufacturing precision
If multiple slurry components are applied in a timed sequence, then precision of thin film removal improves to atomic layer uniformity, but the complexity of slurry distribution system increases
Solution Approach 1:
The slurry distribution system is segmented into multiple independent delivery mechanisms, each responsible for supplying a specific slurry component to its designated zone. This segmentation enables precise timed sequencing of slurry application while maintaining system manageability through modular architecture.
Solution Approach 2:
The polishing process employs periodic action by sequentially applying different slurry components in timed intervals as the substrate moves through the polishing platform. The oxidizing slurry is applied first, followed by the abrasive slurry, and then the corrosion inhibitor slurry, creating a periodic chemical-mechanical-polishing cycle that achieves atomic layer precision.
3Manufacturing precision
If traditional CMP process is used, then material removal is achieved, but control over removal amount deteriorates with high variation for small layer thicknesses
Solution Approach 1:
The traditional single-step CMP process is segmented into multiple sequential steps, each performed in a dedicated zone with a specific slurry component. This segmentation provides independent control over oxidation, material removal, and corrosion inhibition, enabling precise control of material removal amount and consistency even for thin films with variations reduced to atomic layer levels.
Solution Approach 2:
The polishing process utilizes parameter changes by varying the chemical composition and physical properties of slurry components across different zones. The oxidizing slurry changes the surface chemistry, the abrasive slurry removes material at a controlled rate, and the corrosion inhibitor slurry prevents unwanted reactions. These parameter changes enable precise control over material removal consistency.
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
Enables high uniformity and precise control of material removal, capable of removing thin films with variations reduced to the order of an atomic layer, improving the precision of the polishing process.
Implementation Method 1
pressing a rotating substrate held in a holder (e.g., polishing head or carrier) against a rotating polishing pad
Implementation Method 2
pressing a rotating substrate held in a holder against a rotating polishing pad
Implementation Method 3
a continuous process of oxidation by oxidants and material removal by abrasive particles and etchants is carried out by the slurry
Data Source
AI summary
A substrate polishing apparatus is disclosed that includes a polishing platform having two or more zones, each zone adapted to receive a different slurry component. A substrate polishing system is provided having a holder to hold a substrate, a polishing platform having a polishing pad, and a distribution system adapted to dispense, in a timed sequence, at least two different slurry components selected from a group consisting of an oxidation slurry component, a material removal slurry component, and a corrosion inhibiting slurry component. Polishing methods and systems adapted to polish substrates are provided, as are numerous other aspects.