Silicon Oxide Wafer

Silicon oxide wafers are fabricated using a thermal oxidation process in atmospheric-pressure furnace systems at high temperatures ranging from 800°C to 1150°C. Oxygen or water vapor is introduced to grow a silicon dioxide (SiO₂) film directly on the silicon wafer surface. The achievable oxide thickness ranges from 50 nm to 2 μm, with process temperatures up to 1100°C. Thermal oxidation processes are generally classified into two types: dry oxidation and wet oxidation. Unlike CVD-deposited oxide films, thermal oxide layers are “grown” directly from the silicon substrate, resulting in superior uniformity, higher film density, and greater dielectric strength.

Dry Oxidation

In dry oxidation, silicon reacts with oxygen, and the oxide layer continuously grows into the substrate. Dry oxidation is typically performed at temperatures between 850°C and 1200°C. The growth rate is relatively slow, making it suitable for high-quality MOS gate oxide fabrication. When ultra-thin and high-quality silicon oxide layers are required, dry oxidation is preferred over wet oxidation. Dry Oxidation Capability: 15 nm – 300 nm.

Wet Oxidation

Wet oxidation introduces water vapor into the furnace tube at elevated temperatures to form the oxide layer. Compared with dry oxidation, wet oxidation produces oxide films with slightly lower density but significantly higher growth rates, making it suitable for thick oxide films above 500 nm.

Wet Oxidation Capability: 500 nm – 2 μm

AEMD’s atmospheric oxidation furnaces utilize SVCS horizontal furnace systems manufactured in the Czech Republic, featuring high process stability, excellent film uniformity, and superior particle control performance.

Each oxidation furnace tube can process up to 50 wafers simultaneously while maintaining excellent within-wafer and wafer-to-wafer uniformity.

Figure: AEMD Oxidation Furnace (SVCS Horizontal Oxidation/Diffusion Furnace)

Main Applications

Thermal oxide layers serve as excellent dielectric insulating materials. In various silicon-based devices, thermally grown oxide layers play critical roles as dopant blocking layers and surface dielectric layers.

1. Ion Implantation Blocking Layer. Silicon dioxide acts as a diffusion mask against impurities. In integrated circuit manufacturing, common dopants such as boron, phosphorus, and arsenic diffuse much more slowly in SiO₂ than in silicon. Therefore, during semiconductor fabrication, an oxide layer is first grown on the silicon wafer surface. After photolithography and development, oxide in selected regions is etched away to form doping windows, allowing selective impurity implantation into designated areas.

2. Gate Oxide Layer. In MOS/CMOS integrated circuit fabrication, SiO₂ is commonly used as the insulating gate dielectric layer of MOS transistors.

3. Dielectric Isolation. Integrated circuit isolation techniques include PN junction isolation and dielectric isolation. Silicon dioxide is widely used for dielectric isolation.

For example, field oxide layers in CMOS processes are used to isolate PMOS and NMOS transistors and their active regions.

4. Insulating Dielectric Layer. Silicon dioxide is an excellent electrical insulator. In multilayer metal interconnect structures, it serves as the insulating dielectric between upper and lower metal layers to prevent short circuits.

5. Metal Wire Bonding Testing. Thermal oxide layers are also used in metal wire bonding and related testing applications.

AEMD provides silicon oxide wafers fabricated using both dry and wet oxidation processes with various process parameters available.

The products feature competitive pricing and convenient procurement.

Product Parameters

类别	4寸二氧化硅	3寸二氧化硅
薄膜结构
拟合曲线
反射率曲线

Silicon Oxide Wafer