A High Resistivity Float Zone (FZ) Silicon Wafer with a 2-inch diameter is a type of silicon wafer used primarily in high-performance applications, particularly where low electrical conductivity is required, such as in power devices, sensors, or research purposes. Here's an overview of this type of wafer:
Key Characteristics of High Resistivity Float Zone Silicon Wafers:
Float Zone Process:
The float zone process is a method used to produce high-purity silicon wafers. It involves passing a silicon rod through a high-temperature zone to melt and recrystallize it, which helps eliminate impurities and results in higher purity silicon.
This method produces a high-quality, low-defect silicon with uniform crystal structure, making it ideal for applications requiring precise electrical properties.
High Resistivity:
High resistivity wafers are made by controlling the level of dopants during the production process.
These wafers typically have a resistivity range of >1000 ohm-cm (up to several thousand ohm-cm), which makes them useful in applications where low current flow is desired, such as in power electronics, sensors, and high-voltage devices.
2-Inch Diameter:
The 2-inch diameter refers to the size of the silicon wafer. A 2-inch wafer is relatively small and may be used in applications like laboratory research, prototype development, or small-scale production. Smaller wafers are also common in specialized devices like diodes, photodetectors, and high-frequency devices.
Electrical Properties:
The high resistivity of these wafers means they have a low carrier concentration. This is useful for certain applications where you need the silicon material to resist current flow or function in environments with high voltages.
These wafers may also exhibit low leakage currents and minimal parasitic capacitance, making them suitable for high-precision and high-voltage electronic components.
Applications:
High-Power Devices: These wafers are often used in the fabrication of devices that operate at high voltages or require minimal electrical conductivity, such as power transistors and diodes.
Sensors and Detectors: Due to their high resistivity, they are also used in applications such as infrared detectors and capacitive sensors, where minimal conductivity is crucial.
Research and Development: Researchers use high resistivity FZ silicon wafers for testing new semiconductor designs or studying advanced material properties.
Crystal Orientation:
The wafers may be cut from a crystal with specific orientations, such as <100>, <111>, or <110>, depending on the requirements of the device being fabricated.
Thickness and Tolerance:
The thickness of a 2-inch high resistivity FZ silicon wafer can vary, but common thicknesses are in the range of 200 to 500 microns. The wafer's tolerance and flatness are also important for ensuring quality during device fabrication.
Advantages of High Resistivity Float Zone Silicon Wafers:
High Purity: The float zone process ensures a high level of purity, which is critical for sensitive devices.
Low Defects: The process also minimizes the introduction of defects, ensuring more reliable performance.
Customization: The resistivity and crystal orientation can be tailored to specific applications.
Conclusion:
A 2-inch high resistivity float zone silicon wafer is a specialized type of silicon wafer, often used in high-end electronic devices where low electrical conductivity is necessary. Its purity and electrical properties make it highly suitable for power electronics, sensor applications, and research.