Spin Chuck Segmentation for Resist Cross-Contamination
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Solution Overview
Problem
Conventional coating processes for semiconductor and LCD manufacturing often result in resist solution contamination due to its adherence to the back and side surfaces of mask substrates, leading to cross-contamination during substrate transfer, especially at the corner portions.
Innovation Solution
A coating and processing apparatus featuring a spin chuck that rotates a quadrangular substrate horizontally, accompanied by a rinse liquid supply unit that utilizes centrifugal force and surface tension to efficiently remove coating solution from the back and side surfaces, particularly at the corner portions, preventing transfer arm contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a resist solution is supplied to a spin-rotating substrate by conventional spin coating, then the upper surface of the substrate is coated with resist solution, but the resist solution enters the clearance between the side surface and inner peripheral surface of the recess, reaching the back surface and causing cross contamination
Solution Approach 1:
The spin chuck is divided into an upper chuck and a lower chuck, with the upper chuck having a recess and the lower chuck having a protrusion that fits into the recess. This segmentation creates a sealed structure that prevents resist solution from entering the clearance and reaching the back surface of the substrate, thereby eliminating cross contamination while maintaining proper coating on the upper surface
Solution Approach 2:
A seal member is introduced as an intermediary element between the upper chuck and lower chuck to prevent the resist solution from penetrating through the clearance. The seal member acts as a barrier that allows the coating process to proceed normally on the upper surface while blocking the harmful flow of resist solution toward the back surface
2Object-affected harmful factors
If the transfer arm member is prohibited from being in touch with the back surface and side surface of the mask substrate, then particle attachment is reduced, but the support piece can only contact the chamfered C plane, limiting the contact regions to four corners and middles of four sides
Solution Approach 1:
The back surface of the substrate is cleaned of resist solution before the transfer arm member makes contact. By performing the cleaning action in advance through the sealed spin chuck structure, the substrate is prepared in a contamination-free state, allowing the transfer arm to safely contact the limited regions (four corners and middles of sides) without risking particle attachment
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 solution effectively prevents cross-contamination by ensuring the resist solution is removed from the substrate corners during the coating process, maintaining the cleanliness of the transfer arm and reducing particle deposition on subsequent substrates.
Implementation Method 1
When a resist solution is supplied to a spin-rotating substrate G, it is radially dispersed along the surface (upper surface) 13a of the substrate G and shaken off from the substrate G by centrifugal force
Implementation Method 2
a rinse liquid supply unit that utilizes centrifugal force and surface tension to efficiently remove coating solution from the back and side surfaces, particularly at the corner portions
Implementation Method 3
a rinse liquid supply unit that utilizes centrifugal force and surface tension to efficiently remove coating solution from the back and side surfaces
Data Source
AI summary
There is provided a coating and processing apparatus including a spin chuck horizontally holding a quadrangular substrate and rotating the substrate in a horizontal plane, a coating solution nozzle for supplying a coating solution to a front surface of the substrate horizontally held by the spin chuck, and a solvent supply mechanism provided in the spin chuck for supplying a solvent to a back surface of the substrate, in which the solvent supplied to the back surface of the substrate is allowed to reach the back surface and side surface of each of corners of the substrate by centrifugal force, thereby removing the coating solution attached.