The production process of wafers is a complex and delicate process involving multiple key steps.
The production process of wafers is a complex and delicate process involving multiple key steps. The following are the main steps of wafer manufacturing:
1. Raw material purification: Sand or quartz is used as raw material, and it is converted into silicon dioxide (SiO₂) with a silicon content of up to 25% through deoxidation purification, and then refined and distilled in an electric arc furnace to obtain high-purity polysilicon with a purity of up to 99.999999999%.
2. Manufacturing crystal rods: High-purity silicon is heated to a high temperature and a round crystal rod is formed by a rotation and stretching method.
3. Cutting wafers: The crystal rods are cut into thin slices of uniform thickness to form preliminary wafers.
4. Polishing: The cut wafers are ground and polished to remove surface defects and ensure smoothness.
5. Coating: A layer of silicon dioxide (SiO₂) is coated on the wafer to prepare for subsequent photolithography processes.
6. Photolithography: Coat the surface of the wafer with photoresist and transfer the designed circuit pattern to the photoresist by ultraviolet light irradiation.
7. Etching: Chemically or physically etch the wafer according to the photolithography pattern to form a circuit structure.
8. Doping: Doping is performed in specific areas to introduce impurities to change the conductive properties and form P-type and N-type semiconductor areas.
9. Metallization: Metal connections are formed between transistors and with external circuits, usually by metal evaporation or sputtering.
10. Packaging: The wafer with completed circuit design is packaged to protect the circuit from the external environment.
11. Testing: Functional and performance tests are performed on the packaged wafers to ensure that each chip meets the design specifications.
12. Sorting and packaging: Qualified chips are divided, packaged and packaged for subsequent distribution and application.
13. Shipping and distribution: Finally, the packaged and packaged chips are delivered to customers through logistics.
The above steps show the entire manufacturing process from raw materials to the final product, and each link is crucial to the quality and performance of the final product.