SiC Substrate 4H/6H-P 3C-N 45.5mm~150.0mm Z Grade P Grade D Grade

4H/6H-P 3C-N SiC substrate's Abstract

This study explores the structural and electronic properties of 4H/6H polytype silicon carbide (SiC) substrates integrated with epitaxially grown 3C-N SiC films. The polytypic transition between 4H/6H-SiC and 3C-N-SiC offers unique opportunities to enhance the performance of SiC-based semiconductor devices. Through high-temperature chemical vapor deposition (CVD), 3C-SiC films are deposited on 4H/6H-SiC substrates, aiming to reduce lattice mismatch and dislocation densities. Detailed analysis using X-ray diffraction (XRD), atomic force microscopy (AFM), and transmission electron microscopy (TEM) reveals the epitaxial alignment and surface morphology of the films. Electrical measurements indicate improved carrier mobility and breakdown voltage, making this substrate configuration promising for next-generation high-power and high-frequency electronic applications. The study emphasizes the importance of optimizing growth conditions to minimize defects and enhance the structural coherence between the different SiC polytypes.

4H/6H-P 3C-N SiC substrate's properties

The 4H/6H polytype (P) silicon carbide (SiC) substrates with 3C-N (nitrogen-doped) SiC films exhibit a combination of properties that are beneficial for various high-power, high-frequency, and high-temperature applications. Here are the key properties of these materials:

1. Polytypes and Crystal Structure:

• 4H-SiC and 6H-SiC: These are hexagonal crystal structures with different stacking sequences of Si-C bilayers. The "H" denotes hexagonal symmetry, and the numbers refer to the number of layers in the stacking sequence.
  • 4H-SiC: Offers higher electron mobility and a wider bandgap (about 3.2 eV), making it suitable for high-frequency and high-power devices.
  • 6H-SiC: Has a slightly lower electron mobility and bandgap (about 3.0 eV) compared to 4H-SiC but is still used in power electronics.
• 3C-SiC (Cubic): The cubic form of SiC (3C-SiC) typically has a more isotropic crystal structure, leading to easier epitaxial growth on substrates with lower dislocation densities. It has a bandgap of about 2.36 eV and is favorable for integration with electronic devices.

2. Electronic Properties:

• Wide Bandgap: SiC has a wide bandgap that allows it to operate efficiently at high temperatures and voltages. The bandgap varies depending on the polytype:
  • 4H-SiC: 3.2 eV
  • 6H-SiC: 3.0 eV
  • 3C-SiC: 2.36 eV
• High Breakdown Electric Field: The high breakdown electric field (~3-4 MV/cm) makes these materials ideal for power devices that need to withstand high voltages without breaking down.
• Carrier Mobility:
  • 4H-SiC: High electron mobility (~800 cm²/Vs) compared to 6H-SiC.
  • 6H-SiC: Moderate electron mobility (~400 cm²/Vs).
  • 3C-SiC: Cubic form typically has higher electron mobility than the hexagonal forms, making it desirable for electronic devices.

3. Thermal Properties:

• High Thermal Conductivity: SiC has excellent thermal conductivity (~3-4 W/cm·K), enabling efficient heat dissipation, which is crucial for high-power electronics.
• Thermal Stability: SiC remains stable at temperatures exceeding 1000°C, making it suitable for high-temperature environments.

4. Mechanical Properties:

• High Hardness and Strength: SiC is an extremely hard material (Mohs hardness of 9.5), making it resistant to wear and mechanical damage.
• High Young’s Modulus: It has a high Young’s modulus (~410 GPa), contributing to its rigidity and durability in mechanical applications.

5. Chemical Properties:

• Chemical Stability: SiC is highly resistant to chemical corrosion and oxidation, which makes it suitable for harsh environments, including those with corrosive gases and chemicals.
• Low Chemical Reactivity: This property further enhances its stability and performance in demanding applications.

6. Optoelectronic Properties:

• Photoluminescence: 3C-SiC exhibits photoluminescence, making it useful in optoelectronic devices, particularly those operating in the ultraviolet range.
• High UV Sensitivity: The wide bandgap of SiC materials allows them to be used in UV detectors and other optoelectronic applications.

7. Doping Characteristics:

• Nitrogen Doping (N-Type): Nitrogen is often used as an n-type dopant in 3C-SiC, which enhances its conductivity and electron carrier concentration. The precise control of doping levels enables fine-tuning of the electrical properties of the substrate.

8. Applications:

• Power Electronics: The high breakdown voltage, wide bandgap, and thermal conductivity make these substrates ideal for power electronic devices such as MOSFETs, IGBTs, and Schottky diodes.
• High-Frequency Devices: The high electron mobility in 4H-SiC and 3C-SiC allows for efficient high-frequency operation, making them suitable for RF and microwave applications.
• Optoelectronics: 3C-SiC's optical properties make it a candidate for UV detectors and other photonic applications.

These properties make the combination of 4H/6H-P and 3C-N SiC a versatile substrate for a wide range of advanced electronic, optoelectronic, and high-temperature applications.

4H/6H-P 3C-N SiC substrate's photo

4H/6H-P 3C-N SiC substrate's applications

The combination of 4H/6H-P and 3C-N SiC substrates has a range of applications across several industries, particularly in high-power, high-temperature, and high-frequency devices. Below are some of the key applications:

1. Power Electronics:

• High-Voltage Power Devices: The wide bandgap and high breakdown electric field of 4H-SiC and 6H-SiC make these substrates ideal for power devices such as MOSFETs, IGBTs, and Schottky diodes that need to operate at high voltages and currents. These devices are used in electric vehicles (EVs), industrial motor drives, and power grids.
• High-Efficiency Power Conversion: SiC-based devices enable efficient power conversion with lower energy losses, making them suitable for applications like inverters in solar power systems, wind turbines, and electric power transmission.

2. High-Frequency and RF Applications:

• RF and Microwave Devices: The high electron mobility and breakdown voltage of 4H-SiC make it suitable for radio frequency (RF) and microwave devices. These devices are critical in wireless communication systems, radar, and satellite communications, where high-frequency operation and thermal stability are essential.
• 5G Telecommunications: SiC substrates are used in power amplifiers and switches for 5G networks due to their ability to handle high-frequency signals with low power losses.

3. Aerospace and Defense:

• High-Temperature Sensors and Electronics: The thermal stability and radiation resistance of SiC make it suitable for aerospace and defense applications. SiC devices can operate in extreme temperatures, high-radiation environments, and harsh conditions found in space exploration, military equipment, and aviation systems.
• Power Supply Systems: SiC-based power electronics are used in aircraft and spacecraft power supply systems to improve energy efficiency and reduce weight and cooling requirements.

4. Automotive Industry:

• Electric Vehicles (EVs): SiC substrates are increasingly used in power electronics for EVs, such as inverters, on-board chargers, and DC-DC converters. SiC's high efficiency helps extend battery life and increase the driving range of electric vehicles.
• Fast Charging Stations: SiC devices enable faster and more efficient power conversion in EV fast charging stations, helping to reduce charging times and improve energy transfer efficiency.

5. Industrial Applications:

• Motor Drives and Controls: SiC-based power electronics are used in industrial motor drives for controlling and regulating large electric motors with high efficiency. These systems are widely used in manufacturing, robotics, and automation.
• Renewable Energy Systems: SiC substrates are crucial in renewable energy systems like solar inverters and wind turbine controllers, where efficient power conversion and thermal management are necessary for reliable operation.

6. Medical Devices:

• High-Precision Medical Equipment: The chemical stability and biocompatibility of SiC allow its use in medical devices such as implantable sensors, diagnostic equipment, and high-power medical lasers. Its ability to operate at high frequencies with low power losses is essential in precision medical applications.
• Radiation-Hardened Electronics: SiC's resistance to radiation makes it suitable for medical imaging devices and radiation therapy equipment, where reliability and precision are crucial.

7. Optoelectronics:

• UV Detectors and Photodetectors: 3C-SiC's bandgap makes it sensitive to ultraviolet (UV) light, making it useful for UV detectors in industrial, scientific, and environmental monitoring applications. These detectors are used in flame detection, space telescopes, and chemical analysis.
• LEDs and Lasers: SiC substrates are used in light-emitting diodes (LEDs) and laser diodes, particularly in applications requiring high brightness and durability, such as automotive lighting, displays, and solid-state lighting.

8. Energy Systems:

• Solid-State Transformers: SiC power devices are used in solid-state transformers, which are more efficient and compact than traditional transformers. These are critical in energy distribution and smart grid systems.
• Battery Management Systems: SiC devices in battery management systems improve the efficiency and safety of energy storage systems used in renewable energy installations and electric vehicles.

9. Semiconductor Manufacturing:

• Epitaxial Growth Substrates: The integration of 3C-SiC on 4H/6H-SiC substrates is important for reducing defects in epitaxial growth processes, leading to improved semiconductor device performance. This is particularly beneficial in the production of high-performance transistors and integrated circuits.
• GaN-on-SiC Devices: SiC substrates are used for gallium nitride (GaN) epitaxy in high-frequency and high-power semiconductor devices. GaN-on-SiC devices are common in RF power amplifiers, satellite communication systems, and radar systems.

10. Harsh Environment Electronics:

• Oil and Gas Exploration: SiC devices are used in electronics for downhole drilling and oil exploration, where they must withstand high temperatures, pressures, and corrosive environments.
• Industrial Automation: In harsh industrial environments with high temperatures and chemical exposure, SiC-based electronics provide reliability and durability for automation and control systems.

These applications highlight the versatility and importance of 4H/6H-P 3C-N SiC substrates in advancing modern technology across a range of industries.

Q&A

What is the difference between 4H-SiC and 6H-SiC?

In short, when choosing between 4H-SiC and 6H-SiC: Opt for 4H-SiC for high-power and high-frequency electronics where thermal management is critical. Choose 6H-SiC for applications prioritizing light emission and mechanical durability, including LEDs and mechanical components.

Key words: SiC Substrate SiC wafer silicon carbide wafer