Synthetic Quartz Glass Ingot Growth via Dynamic Target Movement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing synthetic quartz glass ingots face challenges in maintaining optical homogeneity and preventing striae formation, especially as substrate sizes increase, which can lead to optical problems in the LCD field.
Innovation Solution
A direct process involving continuous vapor phase hydrolysis of a silica feedstock in a burner flame, with the target moved back and forth along a central axis, ensuring constant flame contact and controlled feed rates to maintain ingot shape and prevent striae, followed by shaping, annealing, and polishing to produce high-quality synthetic quartz glass substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the diameter of the ingot is increased to produce large-sized substrates, then the substrate size increases, but the shape of the growing face becomes distorted and irregular
Solution Approach 1:
The target is moved back and forth along the central growth axis direction during the ingot growth process. This dynamic movement prevents the growing face shape from becoming distorted when producing large-diameter ingots, maintaining a consistent shape throughout the growth process.
Solution Approach 2:
The target undergoes periodic back-and-forth movement along the central growth axis. This periodic action ensures uniform distribution of the flame heat and silica feedstock across the growing face, preventing shape distortion in large-diameter ingots while maintaining growth continuity.
2Stability of the object's composition
If the target is moved back and forth along the central growth axis, then striae formation is prevented and optical homogeneity is improved, but the process complexity increases
Solution Approach 1:
The back-and-forth movement of the target creates dynamic mixing and uniform distribution of silica particles and flame energy across the growing face, preventing striae formation and ensuring optical homogeneity without requiring complex additional equipment.
Solution Approach 2:
The target movement is continuously performed throughout the ingot growth process, ensuring that the flame and feedstock are constantly redistributed to prevent striae. This continuous action maintains optical homogeneity throughout the entire growth period.
3Productivity
If the growing face shape is maintained unchanged, then continuous growth is enabled and productivity is improved, but control precision requirements increase
Solution Approach 1:
The periodic back-and-forth movement of the target dynamically maintains the growing face shape by redistributing heat and material flux. This dynamic control enables continuous growth without shape distortion while managing precision requirements through rhythmic motion rather than static control.
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 method achieves synthetic quartz glass ingots with no observable striae, meeting grade A optical standards, suitable for large-sized photomasks in the LCD field, ensuring high optical homogeneity and quality.
Implementation Method 1
vapor phase hydrolyzing or oxidatively decomposing a silica feedstock in a burner flame to form fine particles of silica
Implementation Method 2
vapor phase hydrolyzing or oxidatively decomposing a silica feedstock in a burner flame to form fine particles of silica
Implementation Method 3
burner flame
Implementation Method 4
depositing the silica particles on a target
Implementation Method 5
concurrently melting and vitrifying the particles to form synthetic quartz glass ingot
Implementation Method 6
concurrently melting and vitrifying the particles to form synthetic quartz glass ingot
Implementation Method 7
keeping the flame in constant contact with an overall growing face
Data Source
Figure 1~2
AI summary
A synthetic quartz glass ingot is prepared by vapor phase hydrolyzing or oxidatively decomposing a silica feedstock in a flame to form fine particles of silica, depositing the silica particles on a target and melting and vitrifying the particles to form a synthetic quartz glass ingot on the target while the target is moved back and forth. The method further comprises: (i) continuously feeding the silica feedstock at a predetermined rate, (ii) keeping the flame in constant contact with an overall growing face, (iii) cyclically repeating the back and forth movement of the target at a predetermined speed, and (iv) maintaining the shape of the growing ingot unchanged.