Wafer Edge Coating Alignment for Uniform Film Width
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Solution Overview
Problem
In semiconductor device manufacturing, the substrate is sometimes placed on the substrate holding unit with its center position mismatched with the rotation axis during chemical liquid discharge processing, leading to variations in the width of the film formed or exposed at the substrate's outer edge in the circumferential direction.
Innovation Solution
A substrate processing apparatus is equipped with a detection unit to identify the outer edge of the substrate, a drive unit to adjust the position of the substrate holding unit, and a control unit to align the substrate's center position with the rotation axis, ensuring precise positioning before chemical liquid discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the substrate is placed on the substrate holding unit without position correction, then the processing flow is simple and fast, but the film width and exposed edge width vary in the circumferential direction
Solution Approach 1:
The detection unit detects the substrate outer edge position and the drive unit adjusts the substrate holding unit position before the chemical liquid discharge processing begins. This preliminary position correction ensures that the substrate center aligns with the rotation axis, preventing circumferential variations in film width and exposed edge width during subsequent processing.
2Manufacturing precision
If a position correction mechanism is added to align substrate center with rotation axis, then processing precision is improved, but apparatus size increases
Solution Approach 1:
The drive unit that rotates the substrate holding unit is also used to adjust the radial position of the substrate holding unit. By making the drive unit perform both rotation and radial positioning functions, the patent avoids adding a separate positioning mechanism, thereby maintaining high positioning accuracy while preventing increase in apparatus size.
3Manufacturing precision
If the substrate position is not corrected, then the processing throughput is high, but the film quality deteriorates due to position variation
Solution Approach 1:
The detection unit and drive unit perform rapid substrate position detection and correction before the main processing begins. This preliminary action ensures consistent film quality by aligning the substrate center with the rotation axis, while the quick execution of this correction minimizes impact on overall processing throughput.
4Manufacturing precision
If the substrate holding unit position is adjustable radially, then positioning accuracy is improved, but the mechanism complexity increases
Solution Approach 1:
The drive unit is designed to perform multiple functions: rotating the substrate holding unit and radially adjusting its position. By integrating these functions into a single mechanism, the patent achieves accurate substrate center alignment without increasing mechanism complexity, as the same drive unit components are utilized for both rotational and radial movements.
Data Source
AI summary
A substrate processing apparatus according to the embodiment includes: a substrate holding unit that holds a substrate; a rotation support unit that supports the substrate holding unit and rotates the substrate n a circumferential direction; a drive unit that drives the substrate holding unit with respect to the rotation support unit in a plane direction of the substrate; a detection unit that detects an outer edge portion of the substrate; a chemical liquid discharge unit that discharges a chemical liquid to the outer edge portion of the substrate; and a control unit that causes the drive unit to drive the substrate holding unit based on the outer edge portion detected by the detection unit in a manner that a center position in a plane of the substrate matches a rotation axis of the rotation support unit.