SiC Ingot Crucible Lid Non-Right Angle Guiding Structures
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional physical vapor transport methods for growing silicon carbide (SiC) ingots face challenges due to pressure differences causing the lid to float and improperly engage with the crucible, affecting crystal growth quality and yield.
Innovation Solution
An apparatus featuring a crucible and lid with non-right angle guiding structures, such as chamfers or arcs, that self-align and engage securely after the vacuuming process, ensuring proper contact and reducing defects in ingot growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the crucible device is used in the PVT method, then the crystal growth rate is fast and the operation is simple, but the lid floats due to pressure difference during vacuuming and drops onto the crucible causing improper contact
Solution Approach 1:
The patent applies preliminary action by providing guiding parts (annular first guiding part on the crucible and annular second guiding part on the lid) before the vacuuming process begins. These guiding parts are pre-positioned to ensure that when the lid drops after floating during vacuuming, it automatically aligns and contacts the crucible properly along the guiding surfaces, preventing improper contact and crystal defects.
2Reliability
If the lid is allowed to float during vacuuming, then the pressure difference is relieved, but the lid drops onto the crucible causing improper contact and affecting crystal quality
Solution Approach 1:
The patent uses the guiding parts as an intermediary mechanism between the lid and crucible. During vacuuming, when the lid floats and then drops, the guiding parts (annular first guiding part and annular second guiding part) act as intermediaries that guide the lid's movement and ensure proper alignment and contact with the crucible, preventing direct improper impact contact.
3Ease of manufacture
If conventional right angle structures are used for the lid and crucible, then the manufacturing is simple, but the lid and crucible do not match tightly after vacuuming
Solution Approach 1:
The patent applies asymmetry by changing the conventional right angle structure of the lid and crucible engagement surfaces to non-right angle guiding parts. The annular first guiding part and annular second guiding part are configured with specific angles and shapes that are asymmetric relative to each other, enabling them to mate together in a specific orientation that ensures tight engagement and proper alignment when the lid contacts the crucible after vacuuming.
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 solution enhances the quality and yield of ingot growth by ensuring consistent engagement of the lid and crucible, increasing single crystal formation from 50%-60% to 90%-100% and reducing defects, thereby improving the overall ingot growth process and reducing costs.
Implementation Method 1
a pressure difference across a wall of the crucible exists at an initial stage of vacuuming the chamber, from which the lid may be forced to float due to a depressurization of the process
Implementation Method 2
the crucible device may be heated to a preset temperature (for example, above 2,000° C.), the SiC powders are sublimated into various SiC molecules arise to be further attached or deposited onto the seed for forming a SiC crystal
Implementation Method 3
After the chamber is evacuated and then heated
Data Source
AI summary
An apparatus for producing an ingot includes a crucible and a lid. The crucible, as a cylindrical container for accommodating a raw crystal-growing material, has an annular top edge further having an annular non-90° first guiding part. The lid provides a bottom for disposing a seed, and the bottom is furnished thereon a bottom protrusion. An outer wall of the bottom protrusion is furnished with an annular non-90° second guiding part corresponding to the first guiding part. The lid is detachable to cover the crucible by having the bottom protrusion to fit the annular the main inner wall, the first guiding part and the annular second guiding part to contact each other, and a portion of the bottom of the lid surrounding the bottom protrusion to contact the top edge of the crucible.