Substrate Drying via IPA Liquid Film Heating and Optical Detection
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Solution Overview
Problem
In semiconductor device manufacturing, existing substrate processing apparatuses face challenges in thoroughly removing rinse liquid from substrates, particularly when patterns are present, leading to poor drying and potential pattern destruction or defects like watermarks.
Innovation Solution
A substrate processing apparatus that supplies organic solvent onto the substrate after rinse processing, heats the underside to raise a liquid film, and applies a force to remove the solvent, with a detection system to monitor the solvent condition and control the process to ensure complete drying without pattern damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-speed rotation is applied to remove rinse liquid during spin drying, then drying speed is improved, but rinse liquid trapped in patterns cannot be sufficiently removed resulting in poor drying quality
Solution Approach 1:
The patent changes the physical state parameter of the processing liquid by heating the substrate to raise the liquid film of organic solvent over the substrate surface. This phase change approach enables the liquid to be removed more effectively without relying solely on high-speed rotation, thereby resolving the contradiction between drying speed and drying quality
Solution Approach 2:
The patent replaces the purely mechanical spin drying method with a combined thermal-mechanical approach. By heating the substrate to vaporize and raise the liquid film, the system reduces reliance on mechanical centrifugal force alone, achieving better drying quality while maintaining efficient processing
2Manufacturing precision
If organic solvent is supplied to replace rinse liquid for drying, then drying quality is improved, but it becomes necessary to monitor and control the liquid film condition to prevent droplet formation
Solution Approach 1:
The patent implements a feedback control system where the liquid film condition detecting unit continuously monitors the state of the organic solvent film on the substrate. The controller adjusts processing parameters based on detection results to maintain optimal liquid film conditions, preventing droplet formation while ensuring high drying quality
Solution Approach 2:
The patent introduces an intermediary detection system between the organic solvent supply and the substrate drying process. The liquid film condition detecting unit acts as a mediator that provides real-time information about the liquid film state, enabling precise control to achieve high drying quality without excessive process complexity
3Manufacturing precision
If the liquid film of organic solvent is raised over the substrate by heating, then complete drying is achieved, but energy consumption increases
Solution Approach 1:
The patent utilizes phase transition of the organic solvent from liquid to vapor by heating the substrate. This phase change enables complete removal of the liquid film and achieves thorough drying. The system optimizes heating to only the extent necessary for phase transition, balancing drying completeness with energy efficiency
Solution Approach 2:
The patent employs periodic or controlled heating action to raise the liquid film at appropriate stages of the drying process. Rather than continuous high-energy heating, the system applies thermal energy periodically or in controlled increments, achieving complete drying while reducing overall energy consumption
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 apparatus effectively detects and controls the solvent condition to ensure thorough drying of the substrate surface, reducing the occurrence of pattern destruction and defects like watermarks, while maintaining uniform processing and efficient solvent use.
Implementation Method 1
heating the substrate to raise a liquid film of organic solvent on the upper surface of the substrate
Implementation Method 2
a processing liquid condition detecting unit arranged to detect the condition of the processing liquid on the upper surface of the substrate
Data Source
AI summary
In parallel with a substrate heating step, a liquid surface sensor is used to monitor the raising of an IPA liquid film. An organic solvent removing step is started in response to the raising of the IPA liquid film over the upper surface of the substrate. At the end of the organic solvent removing step, a visual sensor is used to determine whether or not IPA droplets remain on the upper surface of the substrate.