Overview
Semiconductor processing is the complex sequence of chemical, physical, and thermal steps used to manufacture microchips. By manipulating materials at the atomic level, engineers create Integrated Circuits (ICs), microprocessors, and MEMS devices essential for modern electronics.
Essential Substrates
The foundation of every semiconductor device is the wafer substrate. The choice of material dictates the device's speed, power capability, and thermal performance.
Silicon (Si)
Primary Use: Logic chips, Memory, General electronics.
The standard substrate for 90% of semiconductors. Grown via Czochralski (CZ) or Float Zone (FZ) methods to achieve single-crystal purity.
Gallium Arsenide (GaAs)
Primary Use: RF Amplifiers, LEDs, High-speed logic.
Offers higher electron mobility than silicon, making it ideal for high-frequency telecommunications and optoelectronics.
Silicon Carbide (SiC) & GaN
Primary Use: EVs, Power inverters, High-voltage systems.
Wide-bandgap materials that operate at much higher temperatures and voltages than standard silicon.
Quartz & Glass
Primary Use: MEMS, Microfluidics, Photomasks.
Used where optical transparency or high thermal shock resistance is required.
Critical Fabrication Tools
Modern fabs utilize specialized equipment to achieve nanometer-scale precision.
Lithography Steppers & Scanners
Function: Pattern Transfer
Uses UV or EUV light to project circuit patterns from a photomask onto the photoresist-coated wafer. This is the most critical step for defining feature size.
Etching Systems (RIE/ICP)
Function: Material Removal
Reactive Ion Etching (RIE) uses plasma to remove specific areas of material (oxide, metal, silicon) to create trenches and contact holes.
Deposition Tools (CVD/PVD)
Function: Layer Creation
CVD (Chemical Vapor Deposition) and PVD (Sputtering) machines deposit insulating and conducting thin films onto the wafer.
Ion Implanters
Function: Doping
Accelerates ions (Boron, Phosphorus) into the silicon lattice to alter conductivity, creating n-type or p-type regions.
Step-by-Step Processing Guide
[Image of semiconductor manufacturing process flow chart]-
Wafer Preparation
Slicing, polishing, and cleaning single-crystal ingots to create atomic-flat surfaces.
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Oxidation
Growing a Silicon Dioxide (SiO₂) layer in a furnace to serve as an insulator.
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Photolithography
Coating with photoresist and exposing it to UV light through a mask to define circuit patterns.
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Etching (Wet & Dry)
Removing exposed oxide or metal layers using liquid chemicals or plasma.
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Doping
Introducing impurities via Ion Implantation or Diffusion to tune electrical properties.
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Metallization
Depositing Copper (Cu) or Aluminum (Al) interconnects to link transistors.
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Packaging
Dicing the wafer into individual dies, testing, and encapsulating them for final use.
Industry Applications
- Consumer Electronics: CPUs, GPUs, DRAM.
- Automotive: LiDAR sensors, Power management chips (SiC).
- Photonics: Lasers, Solar Cells, Photodetectors.