6Inch Ultra-High Voltage SiC Epitaxial Wafer 100–500 μm For MOSFET Devices

6Inch Ultra-High Voltage SiC Epitaxial Wafer 100–500 μm For MOSFET Devices

This product is a high-purity, low-defect silicon carbide (SiC) epitaxial layer with a thickness ranging from 100 to 500 μm, grown on a 6-inch N-type 4H-SiC conductive substrate via high-temperature chemical vapor deposition (HT-CVD) technology.

Its core design purpose is to meet the manufacturing requirements of ultra-high-voltage (typically ≥10 kV) silicon carbide metal-oxide-semiconductor field-effect transistors (SiC MOSFETs). Ultra-high-voltage devices place extremely stringent demands on the quality of epitaxial materials, such as thickness, doping uniformity, and defect control. This epitaxial wafer represents a high-end material solution developed to address these challenges.

6Inch SiC Epitaxial Wafer Key Data

6Inch SiC Epitaxial Wafer Key Features

To meet ultra-high-voltage applications, this epitaxial wafer must possess the following core characteristics:

1. Ultra-Thick Epitaxial Layer

• Reason: According to device physics principles, the blocking voltage (BV) of a MOSFET is primarily determined by the thickness and doping concentration of the epitaxial layer. To withstand voltages of 10 kV or higher, the epitaxial layer must be sufficiently thick (typically, every 100 μm of thickness supports approximately 10 kV of blocking voltage) to deplete and establish an electric field, preventing breakdown.
• Feature: The thickness range of 100–500 μm provides the foundation for designing MOSFET devices with voltage ratings of 15 kV and beyond.

2. Exceptionally Precise Doping Control

• Reason: The doping concentration (typically using nitrogen) of the epitaxial layer directly affects the device's on-resistance (Rds(on)) and breakdown voltage. Excessive concentration reduces the breakdown voltage, while insufficient concentration increases the on-resistance.
• Feature: Extremely high doping uniformity (within-wafer, wafer-to-wafer, and batch-to-batch) must be maintained throughout the thick-film growth process to ensure consistent device parameters and high yield.

3. Extremely Low Defect Density

• Reason: Defects in the epitaxial layer (e.g., triangular defects, carrot defects, basal plane dislocations (BPDs)) can act as electric field concentration points or carrier recombination centers, leading to premature breakdown, increased leakage current, or reduced reliability under high voltage.
• Feature: Through optimized growth processes, the conversion of basal plane dislocations (BPDs) is effectively controlled, and fatal surface defects are minimized, ensuring the stability and longevity of ultra-high-voltage devices.

4. Excellent Surface Morphology

• Reason: A smooth surface is essential for subsequent high-quality gate oxide growth and photolithography processes. Any surface roughness or defects can compromise gate oxide integrity, leading to unstable threshold voltages and reliability issues.
• Feature: The surface is smooth, free of growth step bunching or macroscopic defects, providing an ideal starting point for critical process steps in ultra-high-voltage MOSFET fabrication.

6Inch SiC Epitaxial Wafer Main Applications

The sole objective of this epitaxial wafer is to manufacture ultra-high-voltage SiC power MOSFET devices, primarily for next-generation energy infrastructure applications that demand high efficiency, power density, and reliability:

① Smart Grid and Power Transmission

• High-Voltage Direct Current (HVDC) Transmission Systems: Used in solid-state transformers (SSTs) and circuit breakers within converter valves to achieve more efficient and flexible power distribution and fault isolation.
• Flexible AC Transmission Systems (FACTS): Used in devices such as static synchronous compensators (STATCOMs) to enhance grid stability and power quality.

② Industrial Drives and Large-Scale Energy Conversion

• Ultra-High-Voltage Frequency Converters and Motor Drives: Used in large motor drives for mining, metallurgy, and chemical industries, eliminating the need for bulky line-frequency transformers and enabling direct medium-voltage power supply, significantly improving system efficiency and power density.
• High-Power Industrial Supplies: Examples include induction heating and welding machines.

③ Rail Transportation

• Locomotive Traction Converters: Used in next-generation high-speed train traction systems, capable of withstanding higher DC bus voltages, thereby reducing transmission losses and improving system efficiency.

④ Renewable Energy Generation and Energy Storage

• Large-Scale Photovoltaic Inverter Stations and Wind Power Converters: Particularly in medium-voltage grid-connected scenarios, ultra-high-voltage SiC MOSFETs can simplify system architecture, reduce energy conversion stages, and enhance overall efficiency.
• Power Conversion Systems (PCS) for Energy Storage Systems (ESS): Used in large-scale grid-level energy storage systems.

Related SiC product recommendations

1. Q: What is the typical thickness range for 6-inch ultra-high voltage SiC epitaxial wafers used in MOSFETs?
A: The typical thickness ranges from 100 to 500 μm to support blocking voltages of 10 kV and above.

2. Q: Why are thick SiC epitaxial layers required for high-voltage MOSFET applications?
A: Thicker epitaxial layers are essential to sustain high electric fields and prevent avalanche breakdown under ultra-high voltage conditions.

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