Semiconductor Wafer Carrier Arrangement for Plane-Parallelism
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Solution Overview
Problem
Existing double-side processing methods for semiconductor wafers, particularly those with large diameters like 450 mm, often fail to achieve the required plane-parallelism due to insufficient carrier size and arrangement, leading to suboptimal flatness and thickness uniformity.
Innovation Solution
The method involves arranging semiconductor wafers such that each carrier has a single opening with a specific eccentricity and distance configuration, ensuring the ratio x/e is less than or equal to 1.2, allowing for efficient processing of at least three wafers between rotating ring-shaped working disks, which enhances plane-parallelism and thickness homogeneity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional carrier arrangements with multiple openings are used for processing large-diameter semiconductor wafers, then the carrier size and arrangement can accommodate the wafers, but the required plane-parallelism and thickness uniformity cannot be achieved
Solution Approach 1:
The patent divides the processing system into multiple carriers, each with a single opening, arranged in a specific geometric configuration. This segmentation allows precise control of each wafer's position and movement trajectory, enabling the achievement of required plane-parallelism for large-diameter wafers while managing device complexity through modular carrier design
Solution Approach 2:
The patent employs an asymmetric arrangement of carriers with single openings at specific eccentricities relative to the pitch circle. This asymmetric configuration optimizes the cycloidal trajectory of each wafer, ensuring uniform material removal and improved plane-parallelism that cannot be achieved with symmetric multi-opening carriers
2Productivity
If the number of carriers and wafers processed simultaneously is increased, then processing efficiency improves, but the arrangement complexity and difficulty in achieving uniform thickness increase
Solution Approach 1:
The patent combines multiple carriers with single openings into a coordinated system where all carriers follow the same cycloidal trajectory pattern. This merging approach allows simultaneous processing of multiple wafers with consistent quality, achieving both high productivity and thickness uniformity through synchronized planetary motion of all carriers
Solution Approach 2:
The patent optimizes specific parameters including the eccentricity e of carrier openings, the pitch circle radius R, and the ratio x/e ≤ 1.2 to ensure uniform material removal across all wafers. By carefully controlling these parameters, the system achieves thickness uniformity while processing multiple wafers simultaneously, resolving the contradiction between productivity and precision
3Manufacturing precision
If carriers with single openings and specific eccentricity arrangements are used, then plane-parallelism and thickness uniformity improve, but the device complexity and arrangement constraints increase
Solution Approach 1:
The patent specifies predetermined geometric relationships for carrier arrangements, including the eccentricity e and pitch circle radius R, that must be established before processing. This preliminary configuration ensures optimal cycloidal trajectories and uniform material removal, achieving high flatness while simplifying the manufacturing process by providing clear design guidelines that must be followed
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 enables the production of semiconductor wafers with improved flatness and thickness uniformity, suitable for demanding applications, by optimizing the arrangement of carriers and wafers within the processing apparatus, thereby reducing material removal rates and maintaining high processing quality and efficiency.
Implementation Method 1
each of the carriers has precisely one opening, into which a semiconductor wafer is respectively inserted in a freely movable fashion, such that the semiconductor wafers are moved on a cycloidal trajectory between the working disks
Data Source
AI summary
A method for the simultaneous material-removing processing of both sides of at least three semiconductor wafers includes providing a double-side processing apparatus including two rotating ring-shaped working disks and a rolling apparatus. The carriers are arranged in the double-side processing apparatus and the openings are disposed in the carriers so as to satisfy the inequality:R/e·sin(π/N*)−r/e−1≦1.2where N* denotes a ratio of the round angle and an angle at which adjacent carriers are inserted into the rolling apparatus with the greatest distance with respect to one another, r denotes a radius of each opening for receiving a respective semiconductor wafer, e denotes a radius of a pitch circle around a midpoint of the carrier on which the opening is arranged, and R denotes a radius of the pitch circle on which the carriers move between the working disks by means of the rolling apparatus.