1. The core use of silicon wafers: the "foundation" of semiconductors and photovoltaics
Silicon wafers are thin round wafers made of high-purity silicon (more than 99.9999%) as raw materials. Their core uses can be divided into two categories:
1. Electronic device manufacturing: More than 90% of the world's integrated circuits rely on silicon wafers, including CPUs, GPUs, memory, etc. For example, a 12-inch silicon wafer can cut hundreds of chips, and TSMC's 5nm process silicon wafer monthly production capacity will exceed 150,000 pieces in 2023 (data source: TrendForce).
2. Solar cells: In the photovoltaic industry, the conversion efficiency of monocrystalline silicon wafers is more than 24% (Longi Green Energy 2023 Annual Report), and polycrystalline silicon wafers are lower in cost but slightly lower in efficiency (about 18%-20%).
2. Subdivided application areas and technology expansion
(I) Integrated circuits
- Logic chips: used in smartphones and computer processors, such as Apple's A16 chip uses 12-inch silicon wafers.
- Storage chips: DRAM and NAND flash memory require large-size silicon wafers, and Samsung has mass-produced 18-inch silicon wafer test lines.
(II) New energy and photovoltaics
- In 2023, the global demand for photovoltaic silicon wafers will exceed 300GW (data from the China Photovoltaic Industry Association), of which 182mm and 210mm large-size silicon wafers account for more than 70%.
- New technologies such as thin-film solar cells promote the thinning of silicon wafers, with the thickness reduced from 200μm to below 150μm.
(III) MEMS and sensors
- Silicon wafers are the substrates of accelerometers and pressure sensors. In automotive electronics, a single Tesla consumes about 50 8-inch silicon wafers (Yole Développement report).
(IV) Advanced technology exploration
- Quantum computing: Silicon-based spin quantum bit chips require ultra-high purity silicon-28 isotope materials.
- Biomedicine: Silicon wafers are used in microfluidic chips to achieve rapid DNA detection.
3. Future trends: large size, high purity and composite applications
1. Size upgrade: 12-inch silicon wafers have a market share of 80% (SEMI data), and 18-inch research and development is accelerating.
2. New material integration: Silicon carbide (SiC) silicon wafers are suitable for high-voltage devices in electric vehicles, and the market size is expected to exceed US$4 billion in 2025 (Wolfspeed forecast).
3. Recycling: The recycling rate of waste silicon wafers in wafer factories exceeds 95%, which helps green manufacturing.
The application boundaries of silicon wafers are constantly expanding with technological progress. From traditional electronics to space photovoltaic power stations, their importance will continue to increase.