Silica Glass Crucible with Segmented Inner Surface for Silicon Crystal Growth
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The production of silicon single crystals in silica glass crucibles often results in cavity defects due to gas bubbles, which are difficult to detect and significantly impact the quality and yield of semiconductor devices, leading to defective products.
Innovation Solution
A silica glass crucible with a two-layer structure, featuring an opaque outer layer with many bubbles and a transparent inner layer with minimal bubbles, where the inner surface of the crucible's wall and corner parts have uneven damage to actively generate and remove SiO gas bubbles, while the bottom part has a smooth surface to prevent bubble incorporation into the crystal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If natural silica is used for the crucible outer layer, then heat resistance strength is improved, but purity is worsened
Solution Approach 1:
The crucible is divided into an outer layer made of natural silica for heat resistance and an inner layer made of synthetic silica for purity, allowing each material to perform its optimal function without compromise
Solution Approach 2:
Different regions of the crucible are assigned different material compositions: the outer layer uses natural silica with high heat resistance, while the inner layer uses synthetic silica with high purity, matching material properties to functional requirements at each location
2Reliability
If the crucible inner surface is smooth, then bubble incorporation is reduced, but gas bubble removal is insufficient
Solution Approach 1:
The crucible inner surface is divided into two zones: a lower region with an uneven surface that promotes gas bubble detachment and removal, and an upper region with a smooth surface that prevents bubble incorporation into the crystal, with each zone optimized for its specific function
Solution Approach 2:
The inner surface is segmented into functional zones based on height position, with the lower portion having damage-induced unevenness for bubble removal and the upper portion being smooth for bubble prevention, allowing simultaneous achievement of both bubble removal and incorporation prevention
3Productivity
If the crucible inner surface has uneven damage, then gas bubble removal is improved, but bubble incorporation may increase
Solution Approach 1:
The uneven surface damage is localized to the lower region of the crucible inner surface where it promotes bubble detachment, while the upper region maintains smoothness to prevent bubble incorporation, ensuring that bubble removal benefits are achieved without the risk of incorporation
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
This design effectively reduces the incorporation of gas bubbles into the silicon single crystal, preventing cavity defects and enhancing the quality and yield of silicon single crystals.
Implementation Method 1
silicon monoxide (SiO) gas which is produced by a reaction between the silica glass crucible and silicon melt
Implementation Method 2
a region within a fixed range from the center of the bottom part is a smooth surface in which damage is substantially not formed among the inner surfaces of the bottom part
Data Source
AI summary
A silica glass crucible for pulling up a silicon single crystal including a wall part, a corner part and a bottom part is provided with an outer layer formed from an opaque silica glass layer which includes many bubbles, and an inner layer formed from a transparent silica glass layer which substantially does not include bubbles, wherein at least one part of an inner surface of the wall part and the corner part being an uneven surface formed with multiple damaged parts having a depth of 50 μm or more and 450 μm or less, and wherein a region among the inner surface of the bottom part within a certain range from the center of the bottom part being a smooth surface which does is substantially not formed with damage.