Liquid Processing Apparatus Downflow and Exhaust Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid processing apparatuses face contamination issues due to swirling flows that re-attach chemical liquid components to substrates after drying, as mists or vapor remain around the recovery cup and are blown back by the swirling flow.
Innovation Solution
A liquid processing apparatus with a rotatable substrate holding unit, a cup body, a surrounding member, an air flow forming portion, and an exhaust port to create a descending air flow and exhaust the atmosphere, effectively blocking the space between the cup body and surrounding member to prevent chemical components from re-attaching to the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a recovery cup is provided around the wafer to recover processing liquid and form a downflow, then liquid processing can be performed under a clean atmosphere, but mists or vapor containing chemical liquid remain around the recovery cup and are blown up by the swirling flow, causing contamination of the dried wafer
Solution Approach 1:
The processing chamber is divided into two distinct regions by a partition wall: a first region containing the recovery cup where chemical liquid components are allowed to swirl and be exhausted, and a second region where the wafer is processed under clean atmosphere. This spatial segmentation prevents the harmful swirling flow from reaching the wafer while maintaining effective chemical component removal in the first region
Solution Approach 2:
A partition wall acts as an intermediary barrier between the recovery cup region and the wafer processing region. This partition wall blocks the direct path of the swirling flow that would otherwise carry chemical mists and vapor to the wafer, while still allowing the system to maintain pressure balance and functional operation
2Productivity
If the supply of rinse liquid is stopped while rotating the wafer to dry it, then the wafer can be dried efficiently, but the remaining rinse liquid is scattered and may be re-attached by swirling flow causing contamination
Solution Approach 1:
The partition wall segments the chamber so that the drying process can occur in the second region under controlled clean atmosphere, while any scattered liquid or harmful flows are contained in the first region and exhausted through the exhaust port, preventing re-attachment to the wafer
Solution Approach 2:
The harmful swirling flow containing scattered chemical liquid components is extracted from the wafer processing environment by directing it towards the exhaust port in the first region. The partition wall ensures this extracted flow does not return to contaminate the dried wafer in the second region
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 maintains a clean atmosphere around the cup body by efficiently discharging chemical liquid components using the swirling flow, reducing contamination of the substrate during the liquid processing and drying processes.
Implementation Method 1
an air flow forming portion configured to form a descending air flow from in the cup body an upper side of the cup body
Implementation Method 2
an exhaust port provided above the bottom surface portion and outside the cup body to exhaust an atmosphere in a region surrounded by the surrounding member and the bottom surface portion
Implementation Method 3
a bottom surface portion provided along a circumferential direction of the cup body and configured to block a space between the cup body and the surrounding member
Data Source
AI summary
A liquid processing apparatus performs a liquid processing on a rotating substrate by supplying a processing liquid. Surrounding members surround a region including an upper space of a cup body surrounding the rotating substrate and provided with an opening above the substrate. An air flow forming portion forms a descending air flow from an upper side of the cup body. A bottom surface portion blocks between the cup body and the surrounding member along a circumferential direction. An exhaust port is provided above the bottom surface portion and outside the cup body to exhaust an atmosphere in a region surrounded by the surrounding members and the bottom surface portion.