Silicon Carbide Powder Surface Oxygen Control for Low-Defect Wafers
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Solution Overview
Problem
Existing methods for manufacturing silicon carbide (SiC) powders and wafers face challenges such as high manufacturing costs, non-uniform powder size, and the presence of impurities like carbon residues, which deteriorate the thermal, electrical, and mechanical properties of SiC.
Innovation Solution
A silicon carbide powder with improved purity and low surface oxygen content is developed, characterized by specific ratios of O1s/C1s, O1s/Si2p, and other elemental ratios measured by X-ray photoelectron spectroscopy. The powder is manufactured through a process involving raw material selection, pulverization, and surface impurity removal using etching techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods (Acheson method, reaction sintering, CVD) are used to manufacture silicon carbide, then silicon carbide can be produced, but carbon raw materials remain as impurities that deteriorate thermal, electrical, and mechanical properties
Solution Approach 1:
The patent applies oxidation treatment to the silicon carbide powder surface to remove carbon residues. By exposing the powder to oxidizing conditions, carbon impurities are converted to carbon monoxide or carbon dioxide and removed, thereby improving the purity and eliminating harmful carbon residues that deteriorate material properties.
Solution Approach 2:
The patent converts the harmful carbon residues into beneficial removal through controlled oxidation. The carbon impurities, which initially harm the material properties, are transformed into removable gaseous products (CO/CO2) through oxidation treatment, turning a harmful presence into a removable defect.
2Reliability
If heat treatment is performed at high temperature (1,800°C to 2,100°C) under vacuum or inert gas conditions to polymerize or cross-link silicon and carbon sources, then silicon carbide powder can be produced, but manufacturing cost becomes high and powder size uniformity is poor
Solution Approach 1:
The patent changes the temperature parameter from high temperature (1,800-2,100°C) to low temperature synthesis, and changes the atmosphere parameter from vacuum or inert gas to air or oxygen-containing atmosphere. This parameter transformation enables polymerization and cross-linking of silicon and carbon sources at lower costs while achieving uniform powder size and high quality.
Solution Approach 2:
The patent replaces the high-energy thermal field (high temperature heat treatment) with a chemical field approach (oxidation polymerization at lower temperatures). This substitution of the energy field type reduces manufacturing costs and improves process control, achieving uniform powder characteristics without requiring extreme thermal conditions.
3Ease of manufacture
If surface oxygen content is high in silicon carbide powder, then manufacturing process is simpler, but defects increase in ingot growth and wafer manufacturing
Solution Approach 1:
The patent performs preliminary oxidation treatment on the silicon carbide powder surface before ingot growth and wafer manufacturing. By pre-oxidizing the powder at lower temperatures, surface oxygen is uniformly distributed and controlled, preventing subsequent defects during high-temperature processing while maintaining manufacturing simplicity.
Solution Approach 2:
The patent establishes continuous oxidation treatment throughout the manufacturing process, from powder synthesis through to final product formation. This continuous oxidative environment ensures uniform oxygen distribution and prevents defect formation, maintaining both manufacturing simplicity and high precision throughout the entire process chain.
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 resulting silicon carbide powder and wafers exhibit reduced defects and improved performance due to appropriate carbon and oxygen content ratios, which enhance purity and protect against external impurities. The process minimizes oxygen content through initial heat treatment, reducing defects in ingot growth and wafer manufacturing.
Implementation Method 1
the content of oxygen is appropriate, so that defects of the silicon carbide ingot and the silicon carbide wafer can be reduced. In particular, since carbon and oxygen are included in an appropriate content ratio in the surface of the silicon carbide powder, the oxygen can be easily removed through reaction with the carbon in an initial heat treatment step
Implementation Method 2
the oxygen can be easily removed through reaction with the carbon in an initial heat treatment step
Data Source
AI summary
Disclosed are a silicon carbide powder, a method of manufacturing a silicon carbide powder, and a silicon carbide wafer. More particularly, the silicon carbide powder includes carbon and silicon and in the silicon carbide powder, O1s/C1s of a surface measured by X-ray photoelectron spectroscopy is 0.28 or less.