Substrate Processing Liquid Puddle Dynamics
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Solution Overview
Problem
Existing substrate processing methods experience non-uniformity in processing progression due to variations in the thickness of the mixed solution layer across the substrate, leading to uneven processing outcomes.
Innovation Solution
A substrate processing apparatus and method that involves forming a liquid puddle of a diluting liquid and a processing liquid, rotating the substrate at specific speeds to distribute the mixed solution uniformly, and adjusting the nozzle position to ensure even contact and distribution, thereby reducing non-uniformity in processing progression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the substrate is rotated at a high rotation speed to distribute the mixed solution, then the processing uniformity is improved, but the mixed solution layer becomes too thin at the inner region, causing non-uniform processing progression
Solution Approach 1:
The patent applies dynamic control by rotating the substrate at two different rotation speeds in sequence. First, a high rotation speed is used to distribute the mixed solution and prevent excessive thickness at the inner region. Then, the rotation speed is reduced to allow the mixed solution layer to maintain adequate thickness for uniform processing progression. This dynamic adjustment of rotation speed resolves the contradiction between achieving processing uniformity and maintaining sufficient mixed solution layer thickness.
2Reliability
If the nozzle is positioned closer to the substrate to improve liquid contact, then the mixed solution formation is enhanced, but the distribution uniformity across the substrate surface deteriorates
Solution Approach 1:
The patent resolves the contradiction between liquid contact effectiveness and distribution uniformity by transitioning from a vertical positioning approach to a radial distribution approach. Instead of simply adjusting the vertical distance between the nozzle and substrate, the patent utilizes the radial dimension by rotating the substrate. This rotational movement distributes the mixed solution radially across the substrate surface, achieving both effective liquid contact and uniform distribution simultaneously.
3Productivity
If the processing liquid is supplied immediately without forming a liquid puddle, then the processing productivity is improved, but the processing progression becomes non-uniform across different positions
Solution Approach 1:
The patent applies preliminary action by forming a liquid puddle of the mixed solution on the substrate surface before supplying the processing liquid. This preliminary formation of the mixed solution layer ensures that the processing liquid will be distributed uniformly when subsequently supplied. The liquid puddle acts as a preparatory step that prevents non-uniform processing progression, allowing both high productivity and processing uniformity to be achieved.
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
The approach effectively suppresses non-uniformity in processing progression across the substrate by maintaining a thicker mixed solution layer at the inner region and ensuring uniform distribution, leading to consistent processing outcomes.
Implementation Method 1
rotating the substrate at a first rotation speed which allows the mixed solution located at an inner side than an edge of the liquid contact surface to stay between the liquid contact surface and the surface of the substrate and allows the mixed solution located at an outer side than the edge of the liquid contact surface to be diffused toward an edge of the substrate
Implementation Method 2
rotating the substrate at a second rotation speed smaller than the first rotation speed after the substrate is rotated at the first rotation speed
Data Source
AI summary
A method includes forming a liquid puddle of a mixed solution of the diluting liquid and the processing liquid; rotating the substrate at a first rotation speed which allows the mixed solution located at a region facing an inner side than an edge of the liquid contact surface to stay between the liquid contact surface and the surface of the substrate and allows the mixed solution located at a region facing an outer side than the edge of the liquid contact surface to be diffused toward an edge of the substrate; rotating the substrate at a second rotation speed smaller than the first rotation speed after the substrate is rotated at the first rotation speed; and moving the nozzle toward the edge of the substrate while discharging the processing liquid from the discharge hole in a state that the substrate is rotated at the second rotation speed.