Spin Head Chuck Pin Tapered Support Rod Design
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Solution Overview
Problem
Existing spin heads for semiconductor processes face challenges in uniformly supplying process liquids to substrates due to the design of chuck pins and support pins, leading to non-uniform treatment, instability, and potential damage from stress concentration and centrifugal forces during high-speed rotation.
Innovation Solution
The spin head design includes chuck pins with tapered and streamlined support rods that maintain contact with the substrate edge, a chuck pin moving unit to ensure uniform contact, and a gas nozzle system to prevent process liquids from reaching undesired regions, ensuring stable and uniform treatment of both top and bottom surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If circular support rods are used in chuck pins, then the substrate can be supported, but process liquid streams are largely separated and not smoothly supplied to regions close to the support rods
Solution Approach 1:
The support rod is designed with a streamlined cross-sectional shape (circular at the base transitioning to a point at the tip) rather than a simple circular cylinder. This curved/streamlined geometry allows process liquid streams to flow smoothly along the substrate surface without being blocked, while still providing effective mechanical support contact at the tip.
Solution Approach 2:
The support rod has varying cross-sectional dimensions along its length - wider at the base for structural strength and connection, tapering to a narrow tip for minimal interference with liquid streams. This local variation in geometry optimizes both support function and liquid flow characteristics in different regions of the same component.
2Reliability
If support pins are disposed between the substrate and rotatable body, then the substrate can be supported, but gas streams supplied to the bottom surface are separated and process liquid can permeate to undesired regions
Solution Approach 1:
The support function previously performed by pins between the substrate and rotatable body is extracted and relocated to the chuck pins positioned at the substrate edge. This removes the obstruction to gas streams on the substrate bottom surface, allowing uniform gas distribution without blocking that would cause harmful liquid permeation to undesired regions.
Solution Approach 2:
The chuck pin with its streamlined support rod acts as an intermediary element that provides mechanical support while being aerodynamically/hydrodynamically optimized. The tapered geometry mediates between the need for structural support and the need for unobstructed fluid (gas and liquid) flow, allowing gas to reach the substrate bottom surface uniformly without being blocked.
3Device complexity
If a single driving mechanism moves all support rods together, then the mechanism is simple, but machining tolerances cause non-uniform contact with the substrate edge leading to stress concentration
Solution Approach 1:
The chuck pin actuation is segmented into individual independent units rather than a single collective mechanism. Each chuck pin can be independently positioned and adjusted, allowing compensation for machining tolerances and substrate variations. This segmentation enables each pin to make optimal contact with the substrate edge without stress concentration from non-uniform positioning.
Solution Approach 2:
The chuck pins are designed with movable and adjustable characteristics rather than fixed rigid positioning. The ability to independently adjust each pin's position dynamically compensates for tolerances in machining and substrate dimensions, ensuring uniform contact and stable support without the stress concentration problems of rigid fixed-position systems.
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 design enables uniform and stable treatment of substrates, preventing stress concentration on chuck pins and ensuring consistent processing even at high speeds, with improved liquid and gas distribution to all regions of the substrate.
Implementation Method 1
gas is supplied to the bottom surface of the substrate (W) to prevent the process liquid from reaching a predetermined region of the bottom surface of the substrate (W)
Implementation Method 2
since a strong centrifugal force is applied to the support rods 944 in a direction from the supporting positions to the rest positions
Data Source
AI summary
Provided is a spin head for supporting a substrate. The spin head includes a rotatable body, and chuck pins protruding upward from the body and configured to support an edge of a substrate placed at the body when the body is rotated. Each of the chuck pins includes a vertical rod vertically disposed at the body, and a support rod extending from a side of the vertical rod and configured to make contact with the edge of the substrate placed at the body when the body is rotated. When the substrate is rotated, the vertical rod is spaced apart from the edge of the substrate. The contact portion includes a streamlined side surface. The support rod includes a contact portion. The contact portion tapers toward the end of the support rod when viewed from the top of the support rod.