What Semiconductor Process Steps Can Electronic Fluorinated Liquids Be Used For?

Semiconductors are divided into two major sectors: front-end wafer fabrication and back-end packaging and testing. Electronic fluorinated liquids do not participate in the chemical reactions of photolithography or etching themselves; rather, they primarily serve five functions: precision cleaning and drying, equipment thermal management, device reliability testing, fixture and chamber leak detection, and specialty dilution, covering multiple critical process steps.

During wafer production, FOUP wafer transfer boxes, ceramic fixtures, clamps, and chamber accessories accumulate particles, fluorinated oils, and organic contaminants. Electronic fluorinated liquids are compatible with vapor degreasing and immersion/spray cleaning processes. Relying on their low surface tension, they penetrate fine gaps to remove microparticles and grease residues; they volatilize completely without leaving water stains or ionic contamination, meeting the cleanliness requirements of cleanrooms and protecting wafers from secondary contamination.

Note: Ordinary industrial-grade fluorinated liquids are not directly used in bare wafer wet processes. Scenarios involving direct wafer contact require semiconductor ultra-high purity grades with strictly controlled metal ion impurities.

Lithography machines, plasma etchers, and CVD thin film deposition equipment have extremely high requirements for temperature uniformity. Even minor temperature drift can cause etching linewidth deviations and uneven film thickness, directly reducing yield. Fluorinated liquids, as insulating heat transfer media, are used in equipment chiller circulation temperature control systems. Unlike water cooling, fluorinated liquids are insulating and non-conductive; even if leakage occurs, they will not damage high-precision components such as chambers and electrodes, ensuring stable and controllable process temperatures for etching and deposition.

For advanced packaging such as flip-chip, QFN, BGA, and SiP heterogeneous integration, flux, solder paste residues, and dicing dust remain after reflow soldering. Electronic fluorinated liquids can use vapor cleaning processes to dissolve and remove flux residues and ionic contaminants. They are compatible with copper, nickel plating, and most plastic encapsulation materials, avoiding pin corrosion and electrochemical migration, and reducing the risk of later device failure. For micro-pin devices with extremely small pitches, the low surface tension can penetrate pin gaps to achieve internal cleanliness. After cleaning, they volatilize and dry quickly without requiring an additional drying process.

When applying semiconductor nano-protective coatings and fluorinated lubricant coatings, fluorinated liquids serve as dilution carrier solvents to uniformly disperse the active coating components. The diluted coating forms a uniform film without damaging the molecular structure of fluorine-based coatings; after application, the solvent volatilizes completely, forming an ultra-thin protective film on chip and module surfaces. This is widely used in protective processing of power devices and MEMS devices.

In chip burn-in testing and temperature cycling reliability verification, fluorinated liquids, as insulating heat exchange media, enable wide-temperature-range immersion testing from -40°C to 125°C. By directly immersing the chips under test and probe cards, they can rapidly conduct heat and control temperature without causing short circuits, simulating the real extreme operating conditions of automotive chips and power devices to complete reliability screening.

For vacuum chambers, package housings, and pipeline seals, fluorinated liquids are used as tracer leak detection media. The liquid penetrates tiny leak points to quickly locate leakage positions; after detection, the solvent volatilizes on its own with no residue on the workpiece surface, eliminating the need for a secondary cleaning process. This is widely used in sealing testing of semiconductor equipment components.

Different process scenarios have completely different priorities for fluorinated liquid indicators:

Traditional HFC and HFE products with high GWP are increasingly restricted by global F-gas and REACH regulations. Represented by Electronic Fluorinated Liquid 39, the new generation of HCFO fluorinated solvents are non-flammable, with GWP < 1 and ODP ≈ 0, and have excellent material compatibility. They can be used in packaging/testing cleaning, fixture cleaning, coating dilution, and some heat transfer scenarios, serving as recyclable alternatives to HCFC-141b, HCFC-225, and traditional HFE solvents. They are compatible with production line vapor cleaning equipment, reducing corporate compliance pressure.

Electronic fluorinated liquids span multiple semiconductor process steps including fixture cleaning, equipment temperature control, advanced packaging cleaning, coating dilution, reliability testing, airtightness leak detection, and MEMS drying. They are not process chemicals that participate in chip chemical reactions, but are important auxiliary media for ensuring yield and stable equipment operation. Against the backdrop of tightening import material supply chains and stricter environmental regulations, low-GWP new-generation fluorinated liquid domestication solutions are becoming an important choice for process upgrading in semiconductor packaging/testing and component manufacturing enterprises.