Semiconductor cleaning is a critical step in semiconductor manufacturing, designed to remove impurities, organic contaminants, metal ions, and other residues from semiconductor surfaces, thereby ensuring the quality and performance of semiconductor devices. Cleaning processes are generally based on physical or chemical principles, and are classified into dry cleaning and wet cleaning.

Dry Cleaning

Dry cleaning removes surface contaminants from semiconductors using gases, plasma, laser, or other energy sources, without the use of liquid solvents. One major advantage of this method is its environmental friendliness, as it avoids solvent residues and reduces environmental pollution. In addition, dry cleaning typically achieves fast processing, improving production efficiency. Since no liquids are involved, it eliminates issues related to liquid handling, rinsing, and waste disposal. However, dry cleaning equipment generally requires high capital investment, which may increase overall production costs.

Common dry cleaning technologies are summarized below:

(1) Dry Ice Cleaning

Dry ice cleaning uses solid carbon dioxide (dry ice) pellets. Upon impact with the substrate surface, dry ice instantly undergoes sublimation from solid to gas, accompanied by rapid volume expansion and extreme temperature reduction. The resulting thermal shock causes surface contaminants to fracture and detach efficiently.

(2) Laser Cleaning

Laser cleaning employs a focused laser beam to directly irradiate the material surface, removing contaminants through laser-induced thermal effects and photolysis. This technique enables precise control, allowing targeted removal of fouling without damaging the base material. Its advantages include high efficiency and flexibility: laser parameters can be adjusted to accommodate different materials and contamination types. Furthermore, laser cleaning requires no chemical additives, making it a clean and environmentally friendly process.

(3) Plasma Cleaning

Plasma cleaning relies on high-energy particles and chemically reactive species within a plasma to clean material surfaces. Through high-energy physical bombardment and chemical reactions induced by active radicals, it effectively decomposes and removes organic contaminants, oxide layers, and other residual substances.

A key benefit of plasma cleaning is its ability to clean surfaces at the microscopic level, achieving extremely high cleanliness while remaining environmentally safe and free of secondary contamination. It is widely used in applications demanding ultra-high-purity surface treatment, such as semiconductors, photovoltaic panels, and precision machinery manufacturing. It is especially suitable for cleaning sensitive materials or removing ultrafine nano-scale contaminants.

Because plasma cleaning can be performed at room temperature, it causes minimal thermal damage to substrates, making it ideal for temperature-sensitive materials and delicate electronic components. In addition, the process is highly controllable: the chemical composition and operating parameters of the plasma can be tuned to meet specific cleaning requirements and achieve optimal performance.