SiC Crystal Growth Partitioned Chamber PVT
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Solution Overview
Problem
The existing Physical Vapor Transport (PVT) method for growing silicon carbide crystals faces challenges such as low purity of feedstock components, unsatisfactory seed crystal surface quality, porosities leading to planar hexagonal defects, difficulty in controlling temperature and sublimation, and low utilization rate of silicon carbide powder.
Innovation Solution
A crystal growth method and device that involves placing a feedstock in a material zone and a seed crystal in a growth zone of a growth chamber, separated by a partition with outlets. The method utilizes a PVT process, with a heating assembly to control temperature and promote sublimation, improving crystal quality and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the PVT method is used to grow silicon carbide crystals, then crystal growth is achieved, but the purity of feedstock components is low and crystal quality is affected
Solution Approach 1:
The growth chamber is divided into a material zone and a growth zone by a partition with outlets. This segmentation allows the feedstock to be processed in the material zone while the crystal grows in the growth zone, preventing impurity contamination and improving crystal quality.
Solution Approach 2:
A partition with outlets is introduced as an intermediary between the material zone and growth zone. This partition allows controlled transport of vaporized feedstock while blocking physical contact between impure feedstock and the growing crystal, thereby improving crystal purity.
2Manufacturing precision
If bonding process is used to attach seed crystal, then crystal growth is enabled, but porosities form leading to planar hexagonal defects
Solution Approach 1:
The feedstock undergoes sublimation (solid to vapor phase transition) and the vapor deposits onto the seed crystal. This phase transition process allows for pore-free bonding and crystal growth without the planar hexagonal defects that occur with traditional bonding methods.
Solution Approach 2:
The traditional mechanical bonding process is replaced with a vapor deposition process. Instead of physically bonding the seed crystal through mechanical means that create porosity, the vaporized feedstock directly deposits and bonds to the seed crystal surface, eliminating porosity-related defects.
3Productivity
If temperature control is attempted during crystal growth, then growth is promoted, but it is difficult to control temperature conditions and sublimation leading to dislocations and polymorphism defects
Solution Approach 1:
The growth chamber is segmented into a material zone for feedstock processing and a growth zone for crystal formation. This allows independent temperature control in each zone, enabling precise control of sublimation temperature in the material zone and growth temperature in the growth zone, thereby reducing thermal defects.
Solution Approach 2:
The partition with outlets acts as a thermal intermediary, allowing controlled heat and vapor transfer from the material zone to the growth zone while maintaining temperature gradients. This enables precise temperature control for both sublimation and crystal growth processes, reducing dislocations and polymorphism defects.
4Productivity
If traditional PVT process is used, then crystal growth occurs, but the utilization rate of silicon carbide powder is low
Solution Approach 1:
The system monitors the crystal growth process and adjusts the vapor flow and temperature parameters accordingly. This feedback control ensures optimal utilization of the vaporized silicon carbide powder, reducing waste and improving the utilization rate of feedstock material.
Solution Approach 2:
The partition with outlets ensures continuous and controlled transport of vaporized feedstock from the material zone to the growth zone. This continuous action maximizes the utilization of silicon carbide powder by ensuring that vaporized material is efficiently delivered to the growth interface without loss or waste.
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 proposed method enhances the quality and purity of silicon carbide crystals by improving the control over the growth process, reducing defects, and increasing the utilization rate of silicon carbide powder.
Implementation Method 1
The crystal growth method further includes growing a crystal based on the seed crystal and the feedstock by a physical vapor transport (PVT) manner
Implementation Method 2
growing a crystal based on the seed crystal and the feedstock by a physical vapor transport (PVT) manner
Implementation Method 3
The material zone and the growth zone are separated by a partition, and the partition includes at least one outlet
Data Source
AI summary
Embodiments of the present disclosure provide crystal growth methods and devices. The crystal growth methods include placing a feedstock in a material zone of a growth chamber and placing a seed crystal in a growth zone of the growth chamber. The material zone and the growth zone are separated by a partition, and the partition includes at least one outlet. The crystal growth methods further include growing a crystal based on the seed crystal and the feedstock by a physical vapor transport (PVT) manner.